Celestin Apprentice 7/Apprentice-Release7.iso/Source Code/C/Applications/Tcl-Tk 8.0/Pre-installed version/tk8.0/generic/tkBind.c

C/C++ Source or Header | 1997-08-15 | 129.4 KB | 4,534 lines | [TEXT/CWIE]

/*
 * tkBind.c --
 *
 *    This file provides procedures that associate Tcl commands
 *    with X events or sequences of X events.
 *
 * Copyright (c) 1989-1994 The Regents of the University of California.
 * Copyright (c) 1994-1996 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * SCCS: @(#) tkBind.c 1.133 97/07/01 17:59:53
 */

#include "tkPort.h"
#include "tkInt.h"

/*
 * File structure:
 *
 * Structure definitions and static variables.
 *
 * Init/Free this package.
 *
 * Tcl "bind" command (actually located in tkCmds.c).
 * "bind" command implementation.
 * "bind" implementation helpers.
 *
 * Tcl "event" command.
 * "event" command implementation.
 * "event" implementation helpers.
 *
 * Package-specific common helpers.
 *
 * Non-package-specific helpers.
 */


/*
 * The following union is used to hold the detail information from an
 * XEvent (including Tk's XVirtualEvent extension).
 */
typedef union {
    KeySym    keySym;        /* KeySym that corresponds to xkey.keycode. */
    int        button;        /* Button that was pressed (xbutton.button). */
    Tk_Uid    name;        /* Tk_Uid of virtual event. */
    ClientData    clientData; /* Used when type of Detail is unknown, and to
                 * ensure that all bytes of Detail are initialized
                 * when this structure is used in a hash key. */
} Detail;

/*
 * The structure below represents a binding table.  A binding table
 * represents a domain in which event bindings may occur.  It includes
 * a space of objects relative to which events occur (usually windows,
 * but not always), a history of recent events in the domain, and
 * a set of mappings that associate particular Tcl commands with sequences
 * of events in the domain.  Multiple binding tables may exist at once,
 * either because there are multiple applications open, or because there
 * are multiple domains within an application with separate event
 * bindings for each (for example, each canvas widget has a separate
 * binding table for associating events with the items in the canvas).
 *
 * Note: it is probably a bad idea to reduce EVENT_BUFFER_SIZE much
 * below 30.  To see this, consider a triple mouse button click while
 * the Shift key is down (and auto-repeating).  There may be as many
 * as 3 auto-repeat events after each mouse button press or release
 * (see the first large comment block within Tk_BindEvent for more on
 * this), for a total of 20 events to cover the three button presses
 * and two intervening releases.  If you reduce EVENT_BUFFER_SIZE too
 * much, shift multi-clicks will be lost.
 *
 */

#define EVENT_BUFFER_SIZE 30
typedef struct BindingTable {
    XEvent eventRing[EVENT_BUFFER_SIZE];/* Circular queue of recent events
                     * (higher indices are for more recent
                     * events). */
    Detail detailRing[EVENT_BUFFER_SIZE];/* "Detail" information (keySym,
                     * button, Tk_Uid, or 0) for each
                     * entry in eventRing. */
    int curEvent;            /* Index in eventRing of most recent
                     * event.  Newer events have higher
                     * indices. */
    Tcl_HashTable patternTable;        /* Used to map from an event to a
                     * list of patterns that may match that
                     * event.  Keys are PatternTableKey
                     * structs, values are (PatSeq *). */
    Tcl_HashTable objectTable;        /* Used to map from an object to a
                     * list of patterns associated with
                     * that object.  Keys are ClientData,
                     * values are (PatSeq *). */
    Tcl_Interp *interp;            /* Interpreter in which commands are
                     * executed. */
} BindingTable;

/*
 * The following structure represents virtual event table.  A virtual event
 * table provides a way to map from platform-specific physical events such
 * as button clicks or key presses to virtual events such as <<Paste>>,
 * <<Close>>, or <<ScrollWindow>>.
 *
 * A virtual event is usually never part of the event stream, but instead is
 * synthesized inline by matching low-level events.  However, a virtual
 * event may be generated by platform-specific code or by Tcl scripts.  In
 * that case, no lookup of the virtual event will need to be done using
 * this table, because the virtual event is actually in the event stream.
 */

typedef struct VirtualEventTable {
    Tcl_HashTable patternTable;     /* Used to map from a physical event to
                     * a list of patterns that may match that
                     * event.  Keys are PatternTableKey
                     * structs, values are (PatSeq *). */
    Tcl_HashTable nameTable;        /* Used to map a virtual event name to
                     * the array of physical events that can
                     * trigger it.  Keys are the Tk_Uid names
                     * of the virtual events, values are
                     * PhysicalsOwned structs. */
} VirtualEventTable;

/*
 * The following structure is used as a key in a patternTable for both
 * binding tables and a virtual event tables.
 *
 * In a binding table, the object field corresponds to the binding tag
 * for the widget whose bindings are being accessed.
 *
 * In a virtual event table, the object field is always NULL.  Virtual
 * events are a global definiton and are not tied to a particular
 * binding tag.
 *
 * The same key is used for both types of pattern tables so that the
 * helper functions that traverse and match patterns will work for both
 * binding tables and virtual event tables.
 */
typedef struct PatternTableKey {
    ClientData object;        /* For binding table, identifies the binding
                 * tag of the object (or class of objects)
                 * relative to which the event occurred.
                 * For virtual event table, always NULL. */
    int type;            /* Type of event (from X). */
    Detail detail;        /* Additional information, such as keysym,
                 * button, Tk_Uid, or 0 if nothing
                 * additional. */
} PatternTableKey;

/*
 * The following structure defines a pattern, which is matched against X
 * events as part of the process of converting X events into Tcl commands.
 */

typedef struct Pattern {
    int eventType;        /* Type of X event, e.g. ButtonPress. */
    int needMods;        /* Mask of modifiers that must be
                 * present (0 means no modifiers are
                 * required). */
    Detail detail;        /* Additional information that must
                 * match event.  Normally this is 0,
                 * meaning no additional information
                 * must match.  For KeyPress and
                 * KeyRelease events, a keySym may
                 * be specified to select a
                 * particular keystroke (0 means any
                 * keystrokes).  For button events,
                 * specifies a particular button (0
                 * means any buttons are OK).  For virtual
                 * events, specifies the Tk_Uid of the
                 * virtual event name (never 0). */
} Pattern;

/*
 * The following structure defines a pattern sequence, which consists of one
 * or more patterns.  In order to trigger, a pattern sequence must match
 * the most recent X events (first pattern to most recent event, next
 * pattern to next event, and so on).  It is used as the hash value in a
 * patternTable for both binding tables and virtual event tables.
 *
 * In a binding table, it is the sequence of physical events that make up
 * a binding for an object.
 *
 * In a virtual event table, it is the sequence of physical events that
 * define a virtual event.
 *
 * The same structure is used for both types of pattern tables so that the
 * helper functions that traverse and match patterns will work for both
 * binding tables and virtual event tables.
 */

typedef struct PatSeq {
    int numPats;        /* Number of patterns in sequence (usually
                 * 1). */
    TkBindEvalProc *eventProc;    /* The procedure that will be invoked on
                 * the clientData when this pattern sequence
                 * matches. */
    TkBindFreeProc *freeProc;    /* The procedure that will be invoked to
                 * release the clientData when this pattern
                 * sequence is freed. */
    ClientData clientData;    /* Arbitray data passed to eventProc and
                 * freeProc when sequence matches. */
    int flags;            /* Miscellaneous flag values; see below for
                 * definitions. */
    int refCount;        /* Number of times that this binding is in
                 * the midst of executing.  If greater than 1,
                 * then a recursive invocation is happening.
                 * Only when this is zero can the binding
                 * actually be freed. */
    struct PatSeq *nextSeqPtr;  /* Next in list of all pattern sequences
                 * that have the same initial pattern.  NULL
                 * means end of list. */
    Tcl_HashEntry *hPtr;    /* Pointer to hash table entry for the
                 * initial pattern.  This is the head of the
                 * list of which nextSeqPtr forms a part. */
    struct VirtualOwners *voPtr;/* In a binding table, always NULL.  In a
                 * virtual event table, identifies the array
                 * of virtual events that can be triggered by
                 * this event. */
    struct PatSeq *nextObjPtr;  /* In a binding table, next in list of all
                 * pattern sequences for the same object (NULL
                 * for end of list).  Needed to implement
                 * Tk_DeleteAllBindings.  In a virtual event
                 * table, always NULL. */
    Pattern pats[1];        /* Array of "numPats" patterns.  Only one
                 * element is declared here but in actuality
                 * enough space will be allocated for "numPats"
                 * patterns.  To match, pats[0] must match
                 * event n, pats[1] must match event n-1, etc.
                 */
} PatSeq;

/*
 * Flag values for PatSeq structures:
 *
 * PAT_NEARBY        1 means that all of the events matching
 *            this sequence must occur with nearby X
 *            and Y mouse coordinates and close in time.
 *            This is typically used to restrict multiple
 *            button presses.
 * MARKED_DELETED    1 means that this binding has been marked as deleted
 *            and removed from the binding table, but its memory
 *            could not be released because it was already queued for
 *            execution.  When the binding is actually about to be
 *            executed, this flag will be checked and the binding
 *            skipped if set.
 */

#define PAT_NEARBY        0x1
#define MARKED_DELETED        0x2

/*
 * Constants that define how close together two events must be
 * in milliseconds or pixels to meet the PAT_NEARBY constraint:
 */

#define NEARBY_PIXELS        5
#define NEARBY_MS        500


/*
 * The following structure keeps track of all the virtual events that are
 * associated with a particular physical event.  It is pointed to by the
 * voPtr field in a PatSeq in the patternTable of a  virtual event table.
 */

typedef struct VirtualOwners {
    int numOwners;            /* Number of virtual events to trigger. */
    Tcl_HashEntry *owners[1];        /* Array of pointers to entries in
                     * nameTable.  Enough space will
                     * actually be allocated for numOwners
                     * hash entries. */
} VirtualOwners;

/*
 * The following structure is used in the nameTable of a virtual event
 * table to associate a virtual event with all the physical events that can
 * trigger it.
 */
typedef struct PhysicalsOwned {
    int numOwned;            /* Number of physical events owned. */
    PatSeq *patSeqs[1];            /* Array of pointers to physical event
                     * patterns.  Enough space will actually
                     * be allocated to hold numOwned. */
} PhysicalsOwned;

/*
 * One of the following structures exists for each interpreter.  This
 * structure keeps track of the current display and screen in the
 * interpreter, so that a script can be invoked whenever the display/screen
 * changes (the script does things like point tkPriv at a display-specific
 * structure).
 */

typedef struct {
    TkDisplay *curDispPtr;    /* Display for last binding command invoked
                 * in this application. */
    int curScreenIndex;        /* Index of screen for last binding command. */
    int bindingDepth;        /* Number of active instances of Tk_BindEvent
                 * in this application. */
} ScreenInfo;

/*
 * The following structure is used to keep track of all the C bindings that
 * are awaiting invocation and whether the window they refer to has been
 * destroyed.  If the window is destroyed, then all pending callbacks for
 * that window will be cancelled.  The Tcl bindings will still all be
 * invoked, however.
 */

typedef struct PendingBinding {
    struct PendingBinding *nextPtr;
                /* Next in chain of pending bindings, in
                 * case a recursive binding evaluation is in
                 * progress. */
    Tk_Window tkwin;        /* The window that the following bindings
                 * depend upon. */
    int deleted;        /* Set to non-zero by window cleanup code
                 * if tkwin is deleted. */
    PatSeq *matchArray[5];    /* Array of pending C bindings.  The actual
                 * size of this depends on how many C bindings
                 * matched the event passed to Tk_BindEvent.
                 * THIS FIELD MUST BE THE LAST IN THE
                 * STRUCTURE. */
} PendingBinding;

/*
 * The following structure keeps track of all the information local to
 * the binding package on a per interpreter basis.
 */

typedef struct BindInfo {
    VirtualEventTable virtualEventTable;
                /* The virtual events that exist in this
                 * interpreter. */
    ScreenInfo screenInfo;    /* Keeps track of the current display and
                 * screen, so it can be restored after
                 * a binding has executed. */
    PendingBinding *pendingList;/* The list of pending C bindings, kept in
                 * case a C or Tcl binding causes the target
                 * window to be deleted. */
} BindInfo;

/*
 * In X11R4 and earlier versions, XStringToKeysym is ridiculously
 * slow.  The data structure and hash table below, along with the
 * code that uses them, implement a fast mapping from strings to
 * keysyms.  In X11R5 and later releases XStringToKeysym is plenty
 * fast so this stuff isn't needed.  The #define REDO_KEYSYM_LOOKUP
 * is normally undefined, so that XStringToKeysym gets used.  It
 * can be set in the Makefile to enable the use of the hash table
 * below.
 */

#ifdef REDO_KEYSYM_LOOKUP
typedef struct {
    char *name;                /* Name of keysym. */
    KeySym value;            /* Numeric identifier for keysym. */
} KeySymInfo;
static KeySymInfo keyArray[] = {
#ifndef lint
#include "ks_names.h"
#endif
    {(char *) NULL, 0}
};
static Tcl_HashTable keySymTable;    /* keyArray hashed by keysym value. */
static Tcl_HashTable nameTable;        /* keyArray hashed by keysym name. */
#endif /* REDO_KEYSYM_LOOKUP */

/*
 * Set to non-zero when the package-wide static variables have been
 * initialized.
 */

static int initialized = 0;

/*
 * A hash table is kept to map from the string names of event
 * modifiers to information about those modifiers.  The structure
 * for storing this information, and the hash table built at
 * initialization time, are defined below.
 */

typedef struct {
    char *name;            /* Name of modifier. */
    int mask;            /* Button/modifier mask value,                             * such as Button1Mask. */
    int flags;            /* Various flags;  see below for
                 * definitions. */
} ModInfo;

/*
 * Flags for ModInfo structures:
 *
 * DOUBLE -        Non-zero means duplicate this event,
 *            e.g. for double-clicks.
 * TRIPLE -        Non-zero means triplicate this event,
 *            e.g. for triple-clicks.
 */

#define DOUBLE        1
#define TRIPLE        2

/*
 * The following special modifier mask bits are defined, to indicate
 * logical modifiers such as Meta and Alt that may float among the
 * actual modifier bits.
 */

#define META_MASK    (AnyModifier<<1)
#define ALT_MASK    (AnyModifier<<2)

static ModInfo modArray[] = {
    {"Control",        ControlMask,    0},
    {"Shift",        ShiftMask,    0},
    {"Lock",        LockMask,    0},
    {"Meta",        META_MASK,    0},
    {"M",        META_MASK,    0},
    {"Alt",        ALT_MASK,    0},
    {"B1",        Button1Mask,    0},
    {"Button1",        Button1Mask,    0},
    {"B2",        Button2Mask,    0},
    {"Button2",        Button2Mask,    0},
    {"B3",        Button3Mask,    0},
    {"Button3",        Button3Mask,    0},
    {"B4",        Button4Mask,    0},
    {"Button4",        Button4Mask,    0},
    {"B5",        Button5Mask,    0},
    {"Button5",        Button5Mask,    0},
    {"Mod1",        Mod1Mask,    0},
    {"M1",        Mod1Mask,    0},
    {"Command",        Mod1Mask,    0},
    {"Mod2",        Mod2Mask,    0},
    {"M2",        Mod2Mask,    0},
    {"Option",        Mod2Mask,    0},
    {"Mod3",        Mod3Mask,    0},
    {"M3",        Mod3Mask,    0},
    {"Mod4",        Mod4Mask,    0},
    {"M4",        Mod4Mask,    0},
    {"Mod5",        Mod5Mask,    0},
    {"M5",        Mod5Mask,    0},
    {"Double",        0,        DOUBLE},
    {"Triple",        0,        TRIPLE},
    {"Any",        0,        0},    /* Ignored: historical relic. */
    {NULL,        0,        0}
};
static Tcl_HashTable modTable;

/*
 * This module also keeps a hash table mapping from event names
 * to information about those events.  The structure, an array
 * to use to initialize the hash table, and the hash table are
 * all defined below.
 */

typedef struct {
    char *name;            /* Name of event. */
    int type;            /* Event type for X, such as
                 * ButtonPress. */
    int eventMask;        /* Mask bits (for XSelectInput)
                 * for this event type. */
} EventInfo;

/*
 * Note:  some of the masks below are an OR-ed combination of
 * several masks.  This is necessary because X doesn't report
 * up events unless you also ask for down events.  Also, X
 * doesn't report button state in motion events unless you've
 * asked about button events.
 */

static EventInfo eventArray[] = {
    {"Key",        KeyPress,        KeyPressMask},
    {"KeyPress",    KeyPress,        KeyPressMask},
    {"KeyRelease",    KeyRelease,        KeyPressMask|KeyReleaseMask},
    {"Button",        ButtonPress,        ButtonPressMask},
    {"ButtonPress",    ButtonPress,        ButtonPressMask},
    {"ButtonRelease",    ButtonRelease,
        ButtonPressMask|ButtonReleaseMask},
    {"Motion",        MotionNotify,
        ButtonPressMask|PointerMotionMask},
    {"Enter",        EnterNotify,        EnterWindowMask},
    {"Leave",        LeaveNotify,        LeaveWindowMask},
    {"FocusIn",        FocusIn,        FocusChangeMask},
    {"FocusOut",    FocusOut,        FocusChangeMask},
    {"Expose",        Expose,            ExposureMask},
    {"Visibility",    VisibilityNotify,    VisibilityChangeMask},
    {"Destroy",        DestroyNotify,        StructureNotifyMask},
    {"Unmap",        UnmapNotify,        StructureNotifyMask},
    {"Map",        MapNotify,        StructureNotifyMask},
    {"Reparent",    ReparentNotify,        StructureNotifyMask},
    {"Configure",    ConfigureNotify,    StructureNotifyMask},
    {"Gravity",        GravityNotify,        StructureNotifyMask},
    {"Circulate",    CirculateNotify,    StructureNotifyMask},
    {"Property",    PropertyNotify,        PropertyChangeMask},
    {"Colormap",    ColormapNotify,        ColormapChangeMask},
    {"Activate",    ActivateNotify,        ActivateMask},
    {"Deactivate",    DeactivateNotify,    ActivateMask},
    {(char *) NULL,    0,            0}
};
static Tcl_HashTable eventTable;

/*
 * The defines and table below are used to classify events into
 * various groups.  The reason for this is that logically identical
 * fields (e.g. "state") appear at different places in different
 * types of events.  The classification masks can be used to figure
 * out quickly where to extract information from events.
 */

#define KEY            0x1
#define BUTTON            0x2
#define MOTION            0x4
#define CROSSING        0x8
#define FOCUS            0x10
#define EXPOSE            0x20
#define VISIBILITY        0x40
#define CREATE            0x80
#define DESTROY            0x100
#define UNMAP            0x200
#define MAP            0x400
#define REPARENT        0x800
#define CONFIG            0x1000
#define GRAVITY            0x2000
#define CIRC            0x4000
#define PROP            0x8000
#define COLORMAP        0x10000
#define VIRTUAL            0x20000
#define ACTIVATE        0x40000

#define KEY_BUTTON_MOTION_VIRTUAL    (KEY|BUTTON|MOTION|VIRTUAL)

static int flagArray[TK_LASTEVENT] = {
   /* Not used */        0,
   /* Not used */        0,
   /* KeyPress */        KEY,
   /* KeyRelease */        KEY,
   /* ButtonPress */        BUTTON,
   /* ButtonRelease */        BUTTON,
   /* MotionNotify */        MOTION,
   /* EnterNotify */        CROSSING,
   /* LeaveNotify */        CROSSING,
   /* FocusIn */        FOCUS,
   /* FocusOut */        FOCUS,
   /* KeymapNotify */        0,
   /* Expose */            EXPOSE,
   /* GraphicsExpose */        EXPOSE,
   /* NoExpose */        0,
   /* VisibilityNotify */    VISIBILITY,
   /* CreateNotify */        CREATE,
   /* DestroyNotify */        DESTROY,
   /* UnmapNotify */        UNMAP,
   /* MapNotify */        MAP,
   /* MapRequest */        0,
   /* ReparentNotify */        REPARENT,
   /* ConfigureNotify */    CONFIG,
   /* ConfigureRequest */    0,
   /* GravityNotify */        GRAVITY,
   /* ResizeRequest */        0,
   /* CirculateNotify */    CIRC,
   /* CirculateRequest */    0,
   /* PropertyNotify */        PROP,
   /* SelectionClear */        0,
   /* SelectionRequest */    0,
   /* SelectionNotify */    0,
   /* ColormapNotify */        COLORMAP,
   /* ClientMessage */        0,
   /* MappingNotify */        0,
   /* VirtualEvent */        VIRTUAL,
   /* Activate */        ACTIVATE,
   /* Deactivate */        ACTIVATE
};

/*
 * The following tables are used as a two-way map between X's internal
 * numeric values for fields in an XEvent and the strings used in Tcl.  The
 * tables are used both when constructing an XEvent from user input and
 * when providing data from an XEvent to the user.
 */

static TkStateMap notifyMode[] = {
    {NotifyNormal,        "NotifyNormal"},
    {NotifyGrab,        "NotifyGrab"},
    {NotifyUngrab,        "NotifyUngrab"},
    {NotifyWhileGrabbed,    "NotifyWhileGrabbed"},
    {-1, NULL}
};

static TkStateMap notifyDetail[] = {
    {NotifyAncestor,        "NotifyAncestor"},
    {NotifyVirtual,        "NotifyVirtual"},
    {NotifyInferior,        "NotifyInferior"},
    {NotifyNonlinear,        "NotifyNonlinear"},
    {NotifyNonlinearVirtual,    "NotifyNonlinearVirtual"},
    {NotifyPointer,        "NotifyPointer"},
    {NotifyPointerRoot,        "NotifyPointerRoot"},
    {NotifyDetailNone,        "NotifyDetailNone"},
    {-1, NULL}
};

static TkStateMap circPlace[] = {
    {PlaceOnTop,        "PlaceOnTop"},
    {PlaceOnBottom,        "PlaceOnBottom"},
    {-1, NULL}
};

static TkStateMap visNotify[] = {
    {VisibilityUnobscured,        "VisibilityUnobscured"},
    {VisibilityPartiallyObscured,   "VisibilityPartiallyObscured"},
    {VisibilityFullyObscured,        "VisibilityFullyObscured"},
    {-1, NULL}
};

/*
 * Prototypes for local procedures defined in this file:
 */

static void        ChangeScreen _ANSI_ARGS_((Tcl_Interp *interp,
                char *dispName, int screenIndex));
static int        CreateVirtualEvent _ANSI_ARGS_((Tcl_Interp *interp,
                VirtualEventTable *vetPtr, char *virtString,
                char *eventString));
static int        DeleteVirtualEvent _ANSI_ARGS_((Tcl_Interp *interp,
                VirtualEventTable *vetPtr, char *virtString,
                char *eventString));
static void        DeleteVirtualEventTable _ANSI_ARGS_((
                VirtualEventTable *vetPtr));
static void        ExpandPercents _ANSI_ARGS_((TkWindow *winPtr,
                char *before, XEvent *eventPtr, KeySym keySym,
                Tcl_DString *dsPtr));
static void        FreeTclBinding _ANSI_ARGS_((ClientData clientData));
static PatSeq *        FindSequence _ANSI_ARGS_((Tcl_Interp *interp,
                Tcl_HashTable *patternTablePtr, ClientData object,
                char *eventString, int create, int allowVirtual,
                unsigned long *maskPtr));
static void        GetAllVirtualEvents _ANSI_ARGS_((Tcl_Interp *interp,
                VirtualEventTable *vetPtr));
static char *        GetField _ANSI_ARGS_((char *p, char *copy, int size));
static KeySym        GetKeySym _ANSI_ARGS_((TkDisplay *dispPtr,
                XEvent *eventPtr));
static void        GetPatternString _ANSI_ARGS_((PatSeq *psPtr,
                Tcl_DString *dsPtr));
static int        GetVirtualEvent _ANSI_ARGS_((Tcl_Interp *interp,
                VirtualEventTable *vetPtr, char *virtString));
static Tk_Uid        GetVirtualEventUid _ANSI_ARGS_((Tcl_Interp *interp,
                char *virtString));
static int        HandleEventGenerate _ANSI_ARGS_((Tcl_Interp *interp,
                Tk_Window main, int argc, char **argv));
static void        InitKeymapInfo _ANSI_ARGS_((TkDisplay *dispPtr));
static void        InitVirtualEventTable _ANSI_ARGS_((
                VirtualEventTable *vetPtr));
static PatSeq *        MatchPatterns _ANSI_ARGS_((TkDisplay *dispPtr,
                BindingTable *bindPtr, PatSeq *psPtr,
                PatSeq *bestPtr, ClientData *objectPtr,
                PatSeq **sourcePtrPtr));
static int        ParseEventDescription _ANSI_ARGS_((Tcl_Interp *interp,
                char **eventStringPtr, Pattern *patPtr,
                unsigned long *eventMaskPtr));

/*
 * The following define is used as a short circuit for the callback
 * procedure to evaluate a TclBinding.  The actual evaluation of the
 * binding is handled inline, because special things have to be done
 * with a Tcl binding before evaluation time.
 */

#define EvalTclBinding    ((TkBindEvalProc *) 1)


/*
 *---------------------------------------------------------------------------
 *
 * TkBindInit --
 *
 *    This procedure is called when an application is created.  It
 *    initializes all the structures used by bindings and virtual
 *    events.  It must be called before any other functions in this
 *    file are called.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Memory allocated.
 *
 *---------------------------------------------------------------------------
 */

void
TkBindInit(mainPtr)
    TkMainInfo *mainPtr;    /* The newly created application. */
{
    BindInfo *bindInfoPtr;

    if (sizeof(XEvent) < sizeof(XVirtualEvent)) {
    panic("TkBindInit: virtual events can't be supported");
    }

    /*
     * Initialize the static data structures used by the binding package.
     * They are only initialized once, no matter how many interps are
     * created.
     */

    if (!initialized) {
    Tcl_HashEntry *hPtr;
    ModInfo *modPtr;
    EventInfo *eiPtr;
    int dummy;

#ifdef REDO_KEYSYM_LOOKUP
    KeySymInfo *kPtr;

    Tcl_InitHashTable(&keySymTable, TCL_STRING_KEYS);
    Tcl_InitHashTable(&nameTable, TCL_ONE_WORD_KEYS);
    for (kPtr = keyArray; kPtr->name != NULL; kPtr++) {
        hPtr = Tcl_CreateHashEntry(&keySymTable, kPtr->name, &dummy);
        Tcl_SetHashValue(hPtr, kPtr->value);
        hPtr = Tcl_CreateHashEntry(&nameTable, (char *) kPtr->value,
            &dummy);
        Tcl_SetHashValue(hPtr, kPtr->name);
    }
#endif /* REDO_KEYSYM_LOOKUP */

    Tcl_InitHashTable(&modTable, TCL_STRING_KEYS);
    for (modPtr = modArray; modPtr->name != NULL; modPtr++) {
        hPtr = Tcl_CreateHashEntry(&modTable, modPtr->name, &dummy);
        Tcl_SetHashValue(hPtr, modPtr);
    }

    Tcl_InitHashTable(&eventTable, TCL_STRING_KEYS);
    for (eiPtr = eventArray; eiPtr->name != NULL; eiPtr++) {
        hPtr = Tcl_CreateHashEntry(&eventTable, eiPtr->name, &dummy);
        Tcl_SetHashValue(hPtr, eiPtr);
    }
    initialized = 1;
    }

    mainPtr->bindingTable = Tk_CreateBindingTable(mainPtr->interp);

    bindInfoPtr = (BindInfo *) ckalloc(sizeof(BindInfo));
    InitVirtualEventTable(&bindInfoPtr->virtualEventTable);
    bindInfoPtr->screenInfo.curDispPtr = NULL;
    bindInfoPtr->screenInfo.curScreenIndex = -1;
    bindInfoPtr->screenInfo.bindingDepth = 0;
    bindInfoPtr->pendingList = NULL;
    mainPtr->bindInfo = (TkBindInfo) bindInfoPtr;

    TkpInitializeMenuBindings(mainPtr->interp, mainPtr->bindingTable);
}

/*
 *---------------------------------------------------------------------------
 *
 * TkBindFree --
 *
 *    This procedure is called when an application is deleted.  It
 *    deletes all the structures used by bindings and virtual events.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Memory freed.
 *
 *---------------------------------------------------------------------------
 */

void
TkBindFree(mainPtr)
    TkMainInfo *mainPtr;    /* The newly created application. */
{
    BindInfo *bindInfoPtr;

    Tk_DeleteBindingTable(mainPtr->bindingTable);
    mainPtr->bindingTable = NULL;

    bindInfoPtr = (BindInfo *) mainPtr->bindInfo;
    DeleteVirtualEventTable(&bindInfoPtr->virtualEventTable);
    mainPtr->bindInfo = NULL;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_CreateBindingTable --
 *
 *    Set up a new domain in which event bindings may be created.
 *
 * Results:
 *    The return value is a token for the new table, which must
 *    be passed to procedures like Tk_CreatBinding.
 *
 * Side effects:
 *    Memory is allocated for the new table.
 *
 *--------------------------------------------------------------
 */

Tk_BindingTable
Tk_CreateBindingTable(interp)
    Tcl_Interp *interp;        /* Interpreter to associate with the binding
                 * table:  commands are executed in this
                 * interpreter. */
{
    BindingTable *bindPtr;
    int i;

    /*
     * Create and initialize a new binding table.
     */

    bindPtr = (BindingTable *) ckalloc(sizeof(BindingTable));
    for (i = 0; i < EVENT_BUFFER_SIZE; i++) {
    bindPtr->eventRing[i].type = -1;
    }
    bindPtr->curEvent = 0;
    Tcl_InitHashTable(&bindPtr->patternTable,
        sizeof(PatternTableKey)/sizeof(int));
    Tcl_InitHashTable(&bindPtr->objectTable, TCL_ONE_WORD_KEYS);
    bindPtr->interp = interp;
    return (Tk_BindingTable) bindPtr;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_DeleteBindingTable --
 *
 *    Destroy a binding table and free up all its memory.
 *    The caller should not use bindingTable again after
 *    this procedure returns.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Memory is freed.
 *
 *--------------------------------------------------------------
 */

void
Tk_DeleteBindingTable(bindingTable)
    Tk_BindingTable bindingTable;    /* Token for the binding table to
                     * destroy. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr, *nextPtr;
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;

    /*
     * Find and delete all of the patterns associated with the binding
     * table.
     */

    for (hPtr = Tcl_FirstHashEntry(&bindPtr->patternTable, &search);
        hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
    for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
        psPtr != NULL; psPtr = nextPtr) {
        nextPtr = psPtr->nextSeqPtr;
        psPtr->flags |= MARKED_DELETED;
        if (psPtr->refCount == 0) {
        if (psPtr->freeProc != NULL) {
            (*psPtr->freeProc)(psPtr->clientData);
        }
        ckfree((char *) psPtr);
        }
    }
    }

    /*
     * Clean up the rest of the information associated with the
     * binding table.
     */

    Tcl_DeleteHashTable(&bindPtr->patternTable);
    Tcl_DeleteHashTable(&bindPtr->objectTable);
    ckfree((char *) bindPtr);
}

/*
 *--------------------------------------------------------------
 *
 * Tk_CreateBinding --
 *
 *    Add a binding to a binding table, so that future calls to
 *    Tk_BindEvent may execute the command in the binding.
 *
 * Results:
 *    The return value is 0 if an error occurred while setting
 *    up the binding.  In this case, an error message will be
 *    left in interp->result.  If all went well then the return
 *    value is a mask of the event types that must be made
 *    available to Tk_BindEvent in order to properly detect when
 *    this binding triggers.  This value can be used to determine
 *    what events to select for in a window, for example.
 *
 * Side effects:
 *    An existing binding on the same event sequence may be
 *    replaced.
 *    The new binding may cause future calls to Tk_BindEvent to
 *    behave differently than they did previously.
 *
 *--------------------------------------------------------------
 */

unsigned long
Tk_CreateBinding(interp, bindingTable, object, eventString, command, append)
    Tcl_Interp *interp;        /* Used for error reporting. */
    Tk_BindingTable bindingTable;
                /* Table in which to create binding. */
    ClientData object;        /* Token for object with which binding is
                 * associated. */
    char *eventString;        /* String describing event sequence that
                 * triggers binding. */
    char *command;        /* Contains Tcl command to execute when
                 * binding triggers. */
    int append;            /* 0 means replace any existing binding for
                 * eventString; 1 means append to that
                 * binding.  If the existing binding is for a
                 * callback function and not a Tcl command
                 * string, the existing binding will always be
                 * replaced. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    unsigned long eventMask;
    char *new, *old;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
        1, 1, &eventMask);
    if (psPtr == NULL) {
    return 0;
    }
    if (psPtr->eventProc == NULL) {
    int new;
    Tcl_HashEntry *hPtr;

    /*
     * This pattern sequence was just created.
     * Link the pattern into the list associated with the object, so
     * that if the object goes away, these bindings will all
     * automatically be deleted.
     */

    hPtr = Tcl_CreateHashEntry(&bindPtr->objectTable, (char *) object,
        &new);
    if (new) {
        psPtr->nextObjPtr = NULL;
    } else {
        psPtr->nextObjPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
    }
    Tcl_SetHashValue(hPtr, psPtr);
    } else if (psPtr->eventProc != EvalTclBinding) {
    /*
     * Free existing procedural binding.
     */

    if (psPtr->freeProc != NULL) {
        (*psPtr->freeProc)(psPtr->clientData);
    }
    psPtr->clientData = NULL;
    append = 0;
    }

    old = (char *) psPtr->clientData;
    if ((append != 0) && (old != NULL)) {
    int length;

    length = strlen(old) + strlen(command) + 2;
    new = (char *) ckalloc((unsigned) length);
    sprintf(new, "%s\n%s", old, command);
    } else {
    new = (char *) ckalloc((unsigned) strlen(command) + 1);
    strcpy(new, command);
    }
    if (old != NULL) {
    ckfree(old);
    }
    psPtr->eventProc = EvalTclBinding;
    psPtr->freeProc = FreeTclBinding;
    psPtr->clientData = (ClientData) new;
    return eventMask;
}

/*
 *---------------------------------------------------------------------------
 *
 * TkCreateBindingProcedure --
 *
 *    Add a C binding to a binding table, so that future calls to
 *    Tk_BindEvent may callback the procedure in the binding.
 *
 * Results:
 *    The return value is 0 if an error occurred while setting
 *    up the binding.  In this case, an error message will be
 *    left in interp->result.  If all went well then the return
 *    value is a mask of the event types that must be made
 *    available to Tk_BindEvent in order to properly detect when
 *    this binding triggers.  This value can be used to determine
 *    what events to select for in a window, for example.
 *
 * Side effects:
 *    Any existing binding on the same event sequence will be
 *    replaced.
 *
 *---------------------------------------------------------------------------
 */

unsigned long
TkCreateBindingProcedure(interp, bindingTable, object, eventString,
    eventProc, freeProc, clientData)
    Tcl_Interp *interp;        /* Used for error reporting. */
    Tk_BindingTable bindingTable;
                /* Table in which to create binding. */
    ClientData object;        /* Token for object with which binding is
                 * associated. */
    char *eventString;        /* String describing event sequence that
                 * triggers binding. */
    TkBindEvalProc *eventProc;    /* Procedure to invoke when binding
                 * triggers.  Must not be NULL. */
    TkBindFreeProc *freeProc;    /* Procedure to invoke when binding is
                 * freed.  May be NULL for no procedure. */
    ClientData clientData;    /* Arbitrary ClientData to pass to eventProc
                 * and freeProc. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    unsigned long eventMask;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
        1, 1, &eventMask);
    if (psPtr == NULL) {
    return 0;
    }
    if (psPtr->eventProc == NULL) {
    int new;
    Tcl_HashEntry *hPtr;

    /*
     * This pattern sequence was just created.
     * Link the pattern into the list associated with the object, so
     * that if the object goes away, these bindings will all
     * automatically be deleted.
     */

    hPtr = Tcl_CreateHashEntry(&bindPtr->objectTable, (char *) object,
        &new);
    if (new) {
        psPtr->nextObjPtr = NULL;
    } else {
        psPtr->nextObjPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
    }
    Tcl_SetHashValue(hPtr, psPtr);
    } else {

    /*
     * Free existing callback.
     */

    if (psPtr->freeProc != NULL) {
        (*psPtr->freeProc)(psPtr->clientData);
    }
    }

    psPtr->eventProc = eventProc;
    psPtr->freeProc = freeProc;
    psPtr->clientData = clientData;
    return eventMask;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_DeleteBinding --
 *
 *    Remove an event binding from a binding table.
 *
 * Results:
 *    The result is a standard Tcl return value.  If an error
 *    occurs then interp->result will contain an error message.
 *
 * Side effects:
 *    The binding given by object and eventString is removed
 *    from bindingTable.
 *
 *--------------------------------------------------------------
 */

int
Tk_DeleteBinding(interp, bindingTable, object, eventString)
    Tcl_Interp *interp;            /* Used for error reporting. */
    Tk_BindingTable bindingTable;    /* Table in which to delete binding. */
    ClientData object;            /* Token for object with which binding
                     * is associated. */
    char *eventString;            /* String describing event sequence
                     * that triggers binding. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr, *prevPtr;
    unsigned long eventMask;
    Tcl_HashEntry *hPtr;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
        0, 1, &eventMask);
    if (psPtr == NULL) {
    Tcl_ResetResult(interp);
    return TCL_OK;
    }

    /*
     * Unlink the binding from the list for its object, then from the
     * list for its pattern.
     */

    hPtr = Tcl_FindHashEntry(&bindPtr->objectTable, (char *) object);
    if (hPtr == NULL) {
    panic("Tk_DeleteBinding couldn't find object table entry");
    }
    prevPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
    if (prevPtr == psPtr) {
    Tcl_SetHashValue(hPtr, psPtr->nextObjPtr);
    } else {
    for ( ; ; prevPtr = prevPtr->nextObjPtr) {
        if (prevPtr == NULL) {
        panic("Tk_DeleteBinding couldn't find on object list");
        }
        if (prevPtr->nextObjPtr == psPtr) {
        prevPtr->nextObjPtr = psPtr->nextObjPtr;
        break;
        }
    }
    }
    prevPtr = (PatSeq *) Tcl_GetHashValue(psPtr->hPtr);
    if (prevPtr == psPtr) {
    if (psPtr->nextSeqPtr == NULL) {
        Tcl_DeleteHashEntry(psPtr->hPtr);
    } else {
        Tcl_SetHashValue(psPtr->hPtr, psPtr->nextSeqPtr);
    }
    } else {
    for ( ; ; prevPtr = prevPtr->nextSeqPtr) {
        if (prevPtr == NULL) {
        panic("Tk_DeleteBinding couldn't find on hash chain");
        }
        if (prevPtr->nextSeqPtr == psPtr) {
        prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
        break;
        }
    }
    }

    psPtr->flags |= MARKED_DELETED;
    if (psPtr->refCount == 0) {
    if (psPtr->freeProc != NULL) {
        (*psPtr->freeProc)(psPtr->clientData);
    }
    ckfree((char *) psPtr);
    }
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * Tk_GetBinding --
 *
 *    Return the command associated with a given event string.
 *
 * Results:
 *    The return value is a pointer to the command string
 *    associated with eventString for object in the domain
 *    given by bindingTable.  If there is no binding for
 *    eventString, or if eventString is improperly formed,
 *    then NULL is returned and an error message is left in
 *    interp->result.  The return value is semi-static:  it
 *    will persist until the binding is changed or deleted.
 *
 * Side effects:
 *    None.
 *
 *--------------------------------------------------------------
 */

char *
Tk_GetBinding(interp, bindingTable, object, eventString)
    Tcl_Interp *interp;            /* Interpreter for error reporting. */
    Tk_BindingTable bindingTable;    /* Table in which to look for
                     * binding. */
    ClientData object;            /* Token for object with which binding
                     * is associated. */
    char *eventString;            /* String describing event sequence
                     * that triggers binding. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    unsigned long eventMask;

    psPtr = FindSequence(interp, &bindPtr->patternTable, object, eventString,
        0, 1, &eventMask);
    if (psPtr == NULL) {
    return NULL;
    }
    if (psPtr->eventProc == EvalTclBinding) {
    return (char *) psPtr->clientData;
    }
    return "";
}

/*
 *--------------------------------------------------------------
 *
 * Tk_GetAllBindings --
 *
 *    Return a list of event strings for all the bindings
 *    associated with a given object.
 *
 * Results:
 *    There is no return value.  Interp->result is modified to
 *    hold a Tcl list with one entry for each binding associated
 *    with object in bindingTable.  Each entry in the list
 *    contains the event string associated with one binding.
 *
 * Side effects:
 *    None.
 *
 *--------------------------------------------------------------
 */

void
Tk_GetAllBindings(interp, bindingTable, object)
    Tcl_Interp *interp;            /* Interpreter returning result or
                     * error. */
    Tk_BindingTable bindingTable;    /* Table in which to look for
                     * bindings. */
    ClientData object;            /* Token for object. */

{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr;
    Tcl_HashEntry *hPtr;
    Tcl_DString ds;

    hPtr = Tcl_FindHashEntry(&bindPtr->objectTable, (char *) object);
    if (hPtr == NULL) {
    return;
    }
    Tcl_DStringInit(&ds);
    for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr); psPtr != NULL;
        psPtr = psPtr->nextObjPtr) {
    /*
     * For each binding, output information about each of the
     * patterns in its sequence.
     */

    Tcl_DStringSetLength(&ds, 0);
    GetPatternString(psPtr, &ds);
    Tcl_AppendElement(interp, Tcl_DStringValue(&ds));
    }
    Tcl_DStringFree(&ds);
}

/*
 *--------------------------------------------------------------
 *
 * Tk_DeleteAllBindings --
 *
 *    Remove all bindings associated with a given object in a
 *    given binding table.
 *
 * Results:
 *    All bindings associated with object are removed from
 *    bindingTable.
 *
 * Side effects:
 *    None.
 *
 *--------------------------------------------------------------
 */

void
Tk_DeleteAllBindings(bindingTable, object)
    Tk_BindingTable bindingTable;    /* Table in which to delete
                     * bindings. */
    ClientData object;            /* Token for object. */
{
    BindingTable *bindPtr = (BindingTable *) bindingTable;
    PatSeq *psPtr, *prevPtr;
    PatSeq *nextPtr;
    Tcl_HashEntry *hPtr;

    hPtr = Tcl_FindHashEntry(&bindPtr->objectTable, (char *) object);
    if (hPtr == NULL) {
    return;
    }
    for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr); psPtr != NULL;
        psPtr = nextPtr) {
    nextPtr  = psPtr->nextObjPtr;

    /*
     * Be sure to remove each binding from its hash chain in the
     * pattern table.  If this is the last pattern in the chain,
     * then delete the hash entry too.
     */

    prevPtr = (PatSeq *) Tcl_GetHashValue(psPtr->hPtr);
    if (prevPtr == psPtr) {
        if (psPtr->nextSeqPtr == NULL) {
        Tcl_DeleteHashEntry(psPtr->hPtr);
        } else {
        Tcl_SetHashValue(psPtr->hPtr, psPtr->nextSeqPtr);
        }
    } else {
        for ( ; ; prevPtr = prevPtr->nextSeqPtr) {
        if (prevPtr == NULL) {
            panic("Tk_DeleteAllBindings couldn't find on hash chain");
        }
        if (prevPtr->nextSeqPtr == psPtr) {
            prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
            break;
        }
        }
    }
    psPtr->flags |= MARKED_DELETED;

    if (psPtr->refCount == 0) {
        if (psPtr->freeProc != NULL) {
        (*psPtr->freeProc)(psPtr->clientData);
        }
        ckfree((char *) psPtr);
    }
    }
    Tcl_DeleteHashEntry(hPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * Tk_BindEvent --
 *
 *    This procedure is invoked to process an X event.  The
 *    event is added to those recorded for the binding table.
 *    Then each of the objects at *objectPtr is checked in
 *    order to see if it has a binding that matches the recent
 *    events.  If so, the most specific binding is invoked for
 *    each object.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Depends on the command associated with the matching binding.
 *
 *    All Tcl bindings scripts for each object are accumulated before
 *    the first binding is evaluated.  If the action of a Tcl binding
 *    is to change or delete a binding, or delete the window associated
 *    with the binding, all the original Tcl binding scripts will still
 *    fire.  Contrast this with C binding procedures.  If a pending C
 *    binding (one that hasn't fired yet, but is queued to be fired for
 *    this window) is deleted, it will not be called, and if it is
 *    changed, then the new binding procedure will be called.  If the
 *    window itself is deleted, no further C binding procedures will be
 *    called for this window.  When both Tcl binding scripts and C binding
 *    procedures are interleaved, the above rules still apply.
 *
 *---------------------------------------------------------------------------
 */

void
Tk_BindEvent(bindingTable, eventPtr, tkwin, numObjects, objectPtr)
    Tk_BindingTable bindingTable;    /* Table in which to look for
                     * bindings. */
    XEvent *eventPtr;            /* What actually happened. */
    Tk_Window tkwin;            /* Window on display where event
                     * occurred (needed in order to
                     * locate display information). */
    int numObjects;            /* Number of objects at *objectPtr. */
    ClientData *objectPtr;        /* Array of one or more objects
                     * to check for a matching binding. */
{
    BindingTable *bindPtr;
    TkDisplay *dispPtr;
    BindInfo *bindInfoPtr;
    TkDisplay *oldDispPtr;
    ScreenInfo *screenPtr;
    XEvent *ringPtr;
    PatSeq *vMatchDetailList, *vMatchNoDetailList;
    int flags, oldScreen, i, deferModal;
    unsigned int matchCount, matchSpace;
    Tcl_Interp *interp;
    Tcl_DString scripts, savedResult;
    Detail detail;
    char *p, *end;
    PendingBinding *pendingPtr;
    PendingBinding staticPending;
    TkWindow *winPtr = (TkWindow *)tkwin;
    PatternTableKey key;

    /*
     * Ignore events on windows that don't have names: these are windows
     * like wrapper windows that shouldn't be visible to the
     * application.
     */

    if (winPtr->pathName == NULL) {
    return;
    }

    /*
     * Ignore the event completely if it is an Enter, Leave, FocusIn,
     * or FocusOut event with detail NotifyInferior.  The reason for
     * ignoring these events is that we don't want transitions between
     * a window and its children to visible to bindings on the parent:
     * this would cause problems for mega-widgets, since the internal
     * structure of a mega-widget isn't supposed to be visible to
     * people watching the parent.
     */

    if ((eventPtr->type == EnterNotify)  || (eventPtr->type == LeaveNotify)) {
    if (eventPtr->xcrossing.detail == NotifyInferior) {
        return;
    }
    }
    if ((eventPtr->type == FocusIn)  || (eventPtr->type == FocusOut)) {
    if (eventPtr->xfocus.detail == NotifyInferior) {
        return;
    }
    }

    bindPtr = (BindingTable *) bindingTable;
    dispPtr = ((TkWindow *) tkwin)->dispPtr;
    bindInfoPtr = (BindInfo *) winPtr->mainPtr->bindInfo;

    /*
     * Add the new event to the ring of saved events for the
     * binding table.  Two tricky points:
     *
     * 1. Combine consecutive MotionNotify events.  Do this by putting
     *    the new event *on top* of the previous event.
     * 2. If a modifier key is held down, it auto-repeats to generate
     *    continuous KeyPress and KeyRelease events.  These can flush
     *    the event ring so that valuable information is lost (such
     *    as repeated button clicks).  To handle this, check for the
     *    special case of a modifier KeyPress arriving when the previous
     *    two events are a KeyRelease and KeyPress of the same key.
     *    If this happens, mark the most recent event (the KeyRelease)
     *    invalid and put the new event on top of the event before that
     *    (the KeyPress).
     */

    if ((eventPtr->type == MotionNotify)
        && (bindPtr->eventRing[bindPtr->curEvent].type == MotionNotify)) {
    /*
     * Don't advance the ring pointer.
     */
    } else if (eventPtr->type == KeyPress) {
    int i;
    for (i = 0; ; i++) {
        if (i >= dispPtr->numModKeyCodes) {
        goto advanceRingPointer;
        }
        if (dispPtr->modKeyCodes[i] == eventPtr->xkey.keycode) {
        break;
        }
    }
    ringPtr = &bindPtr->eventRing[bindPtr->curEvent];
    if ((ringPtr->type != KeyRelease)
        || (ringPtr->xkey.keycode != eventPtr->xkey.keycode)) {
        goto advanceRingPointer;
    }
    if (bindPtr->curEvent <= 0) {
        i = EVENT_BUFFER_SIZE - 1;
    } else {
        i = bindPtr->curEvent - 1;
    }
    ringPtr = &bindPtr->eventRing[i];
    if ((ringPtr->type != KeyPress)
        || (ringPtr->xkey.keycode != eventPtr->xkey.keycode)) {
        goto advanceRingPointer;
    }
    bindPtr->eventRing[bindPtr->curEvent].type = -1;
    bindPtr->curEvent = i;
    } else {
    advanceRingPointer:
    bindPtr->curEvent++;
    if (bindPtr->curEvent >= EVENT_BUFFER_SIZE) {
        bindPtr->curEvent = 0;
    }
    }
    ringPtr = &bindPtr->eventRing[bindPtr->curEvent];
    memcpy((VOID *) ringPtr, (VOID *) eventPtr, sizeof(XEvent));
    detail.clientData = 0;
    flags = flagArray[ringPtr->type];
    if (flags & KEY) {
    detail.keySym = GetKeySym(dispPtr, ringPtr);
    if (detail.keySym == NoSymbol) {
        detail.keySym = 0;
    }
    } else if (flags & BUTTON) {
    detail.button = ringPtr->xbutton.button;
    } else if (flags & VIRTUAL) {
    detail.name = ((XVirtualEvent *) ringPtr)->name;
    }
    bindPtr->detailRing[bindPtr->curEvent] = detail;

    /*
     * Find out if there are any virtual events that correspond to this
     * physical event (or sequence of physical events).
     */

    vMatchDetailList = NULL;
    vMatchNoDetailList = NULL;
    memset(&key, 0, sizeof(key));

    if (ringPtr->type != VirtualEvent) {
    Tcl_HashTable *veptPtr;
    Tcl_HashEntry *hPtr;

    veptPtr = &bindInfoPtr->virtualEventTable.patternTable;

        key.object  = NULL;
    key.type    = ringPtr->type;
    key.detail  = detail;

    hPtr = Tcl_FindHashEntry(veptPtr, (char *) &key);
    if (hPtr != NULL) {
        vMatchDetailList = (PatSeq *) Tcl_GetHashValue(hPtr);
    }

    if (key.detail.clientData != 0) {
        key.detail.clientData = 0;
        hPtr = Tcl_FindHashEntry(veptPtr, (char *) &key);
        if (hPtr != NULL) {
            vMatchNoDetailList = (PatSeq *) Tcl_GetHashValue(hPtr);
        }
    }
    }

    /*
     * Loop over all the binding tags, finding the binding script or
     * callback for each one.  Append all of the binding scripts, with
     * %-sequences expanded, to "scripts", with null characters separating
     * the scripts for each object.  Append all the callbacks to the array
     * of pending callbacks.
     */

    pendingPtr = &staticPending;
    matchCount = 0;
    matchSpace = sizeof(staticPending.matchArray) / sizeof(PatSeq *);
    Tcl_DStringInit(&scripts);

    for ( ; numObjects > 0; numObjects--, objectPtr++) {
    PatSeq *matchPtr, *sourcePtr;
    Tcl_HashEntry *hPtr;

    matchPtr = NULL;
    sourcePtr = NULL;

    /*
     * Match the new event against those recorded in the pattern table,
     * saving the longest matching pattern.  For events with details
     * (button and key events), look for a binding for the specific
     * key or button.  First see if the event matches a physical event
     * that the object is interested in, then look for a virtual event.
     */

    key.object = *objectPtr;
    key.type = ringPtr->type;
    key.detail = detail;
    hPtr = Tcl_FindHashEntry(&bindPtr->patternTable, (char *) &key);
    if (hPtr != NULL) {
        matchPtr = MatchPatterns(dispPtr, bindPtr,
            (PatSeq *) Tcl_GetHashValue(hPtr), matchPtr, NULL,
            &sourcePtr);
    }

    if (vMatchDetailList != NULL) {
        matchPtr = MatchPatterns(dispPtr, bindPtr, vMatchDetailList,
            matchPtr, objectPtr, &sourcePtr);
    }

    /*
     * If no match was found, look for a binding for all keys or buttons
     * (detail of 0).  Again, first match on a virtual event.
     */

    if ((detail.clientData != 0) && (matchPtr == NULL)) {
        key.detail.clientData = 0;
        hPtr = Tcl_FindHashEntry(&bindPtr->patternTable, (char *) &key);
        if (hPtr != NULL) {
        matchPtr = MatchPatterns(dispPtr, bindPtr,
            (PatSeq *) Tcl_GetHashValue(hPtr), matchPtr, NULL,
            &sourcePtr);
        }

        if (vMatchNoDetailList != NULL) {
            matchPtr = MatchPatterns(dispPtr, bindPtr, vMatchNoDetailList,
            matchPtr, objectPtr, &sourcePtr);
        }

    }

    if (matchPtr != NULL) {
        if (sourcePtr->eventProc == NULL) {
        panic("Tk_BindEvent: missing command");
        }
        if (sourcePtr->eventProc == EvalTclBinding) {
        ExpandPercents(winPtr, (char *) sourcePtr->clientData,
            eventPtr, detail.keySym, &scripts);
        } else {
        if (matchCount >= matchSpace) {
            PendingBinding *new;
            unsigned int oldSize, newSize;

            oldSize = sizeof(staticPending)
            - sizeof(staticPending.matchArray)
            + matchSpace * sizeof(PatSeq*);
            matchSpace *= 2;
            newSize = sizeof(staticPending)
            - sizeof(staticPending.matchArray)
            + matchSpace * sizeof(PatSeq*);
            new = (PendingBinding *) ckalloc(newSize);
            memcpy((VOID *) new, (VOID *) pendingPtr, oldSize);
            if (pendingPtr != &staticPending) {
            ckfree((char *) pendingPtr);
            }
            pendingPtr = new;
        }
        sourcePtr->refCount++;
        pendingPtr->matchArray[matchCount] = sourcePtr;
        matchCount++;
        }
        /*
         * A "" is added to the scripts string to separate the
         * various scripts that should be invoked.
         */

        Tcl_DStringAppend(&scripts, "", 1);
    }
    }
    if (Tcl_DStringLength(&scripts) == 0) {
    return;
    }

    /*
     * Now go back through and evaluate the binding for each object,
     * in order, dealing with "break" and "continue" exceptions
     * appropriately.
     *
     * There are two tricks here:
     * 1. Bindings can be invoked from in the middle of Tcl commands,
     *    where interp->result is significant (for example, a widget
     *    might be deleted because of an error in creating it, so the
     *    result contains an error message that is eventually going to
     *    be returned by the creating command).  To preserve the result,
     *    we save it in a dynamic string.
     * 2. The binding's action can potentially delete the binding,
     *    so bindPtr may not point to anything valid once the action
     *    completes.  Thus we have to save bindPtr->interp in a
     *    local variable in order to restore the result.
     */

    interp = bindPtr->interp;
    Tcl_DStringInit(&savedResult);

    /*
     * Save information about the current screen, then invoke a script
     * if the screen has changed.
     */

    Tcl_DStringGetResult(interp, &savedResult);
    screenPtr = &bindInfoPtr->screenInfo;
    oldDispPtr = screenPtr->curDispPtr;
    oldScreen = screenPtr->curScreenIndex;
    if ((dispPtr != screenPtr->curDispPtr)
        || (Tk_ScreenNumber(tkwin) != screenPtr->curScreenIndex)) {
    screenPtr->curDispPtr = dispPtr;
    screenPtr->curScreenIndex = Tk_ScreenNumber(tkwin);
    ChangeScreen(interp, dispPtr->name, screenPtr->curScreenIndex);
    }

    if (matchCount > 0) {
    pendingPtr->nextPtr = bindInfoPtr->pendingList;
    pendingPtr->tkwin = tkwin;
    pendingPtr->deleted = 0;
    bindInfoPtr->pendingList = pendingPtr;
    }

    /*
     * Save the current value of the TK_DEFER_MODAL flag so we can
     * restore it at the end of the loop.  Clear the flag so we can
     * detect any recursive requests for a modal loop.
     */

    flags = winPtr->flags;
    winPtr->flags &= ~TK_DEFER_MODAL;

    p = Tcl_DStringValue(&scripts);
    end = p + Tcl_DStringLength(&scripts);
    i = 0;

    while (p < end) {
    int code;

    screenPtr->bindingDepth++;
    Tcl_AllowExceptions(interp);

    if (*p == '\0') {
        PatSeq *psPtr;

        psPtr = pendingPtr->matchArray[i];
        i++;
        code = TCL_OK;
        if ((pendingPtr->deleted == 0)
            && ((psPtr->flags & MARKED_DELETED) == 0)) {
        code = (*psPtr->eventProc)(psPtr->clientData, interp, eventPtr,
            tkwin, detail.keySym);
        }
        psPtr->refCount--;
        if ((psPtr->refCount == 0) && (psPtr->flags & MARKED_DELETED)) {
        if (psPtr->freeProc != NULL) {
            (*psPtr->freeProc)(psPtr->clientData);
        }
        ckfree((char *) psPtr);
        }
    } else {
        code = Tcl_GlobalEval(interp, p);
        p += strlen(p);
    }
    p++;
    screenPtr->bindingDepth--;
    if (code != TCL_OK) {
        if (code == TCL_CONTINUE) {
        /*
         * Do nothing:  just go on to the next command.
         */
        } else if (code == TCL_BREAK) {
        break;
        } else {
        Tcl_AddErrorInfo(interp, "\n    (command bound to event)");
        Tcl_BackgroundError(interp);
        break;
        }
    }
    }

    if (matchCount > 0 && !pendingPtr->deleted) {
    /*
     * Restore the original modal flag value and invoke the modal loop
     * if needed.
     */

    deferModal = winPtr->flags & TK_DEFER_MODAL;
    winPtr->flags = (winPtr->flags & (unsigned int) ~TK_DEFER_MODAL)
        | (flags & TK_DEFER_MODAL);
    if (deferModal) {
        (*winPtr->classProcsPtr->modalProc)(tkwin, eventPtr);
    }
    }

    if ((screenPtr->bindingDepth != 0) &&
            ((oldDispPtr != screenPtr->curDispPtr)
                    || (oldScreen != screenPtr->curScreenIndex))) {

    /*
     * Some other binding script is currently executing, but its
     * screen is no longer current.  Change the current display
     * back again.
     */

    screenPtr->curDispPtr = oldDispPtr;
    screenPtr->curScreenIndex = oldScreen;
    ChangeScreen(interp, oldDispPtr->name, oldScreen);
    }
    Tcl_DStringResult(interp, &savedResult);
    Tcl_DStringFree(&scripts);

    if (matchCount > 0) {
    PendingBinding **curPtrPtr;

    for (curPtrPtr = &bindInfoPtr->pendingList; ; ) {
        if (*curPtrPtr == pendingPtr) {
        *curPtrPtr = pendingPtr->nextPtr;
        break;
        }
        curPtrPtr = &(*curPtrPtr)->nextPtr;
    }
    if (pendingPtr != &staticPending) {
        ckfree((char *) pendingPtr);
    }
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * TkBindDeadWindow --
 *
 *    This procedure is invoked when it is determined that a window is
 *    dead.  It cleans up bind-related information about the window
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Any pending C bindings for this window are cancelled.
 *
 *---------------------------------------------------------------------------
 */

void
TkBindDeadWindow(winPtr)
    TkWindow *winPtr;        /* The window that is being deleted. */
{
    BindInfo *bindInfoPtr;
    PendingBinding *curPtr;

    bindInfoPtr = (BindInfo *) winPtr->mainPtr->bindInfo;
    curPtr = bindInfoPtr->pendingList;
    while (curPtr != NULL) {
    if (curPtr->tkwin == (Tk_Window) winPtr) {
        curPtr->deleted = 1;
    }
    curPtr = curPtr->nextPtr;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * MatchPatterns --
 *
 *      Given a list of pattern sequences and a list of recent events,
 *      return the pattern sequence that best matches the event list,
 *    if there is one.
 *
 *    This procedure is used in two different ways.  In the simplest
 *    use, "object" is NULL and psPtr is a list of pattern sequences,
 *    each of which corresponds to a binding.  In this case, the
 *    procedure finds the pattern sequences that match the event list
 *    and returns the most specific of those, if there is more than one.
 *
 *    In the second case, psPtr is a list of pattern sequences, each
 *    of which corresponds to a definition for a virtual binding.
 *    In order for one of these sequences to "match", it must match
 *    the events (as above) but in addition there must be a binding
 *    for its associated virtual event on the current object.  The
 *    "object" argument indicates which object the binding must be for.
 *
 * Results:
 *      The return value is NULL if bestPtr is NULL and no pattern matches
 *    the recent events from bindPtr.  Otherwise the return value is
 *    the most specific pattern sequence among bestPtr and all those
 *    at psPtr that match the event list and object.  If a pattern
 *    sequence other than bestPtr is returned, then *bestCommandPtr
 *    is filled in with a pointer to the command from the best sequence.
 *
 * Side effects:
 *      None.
 *
 *----------------------------------------------------------------------
 */
static PatSeq *
MatchPatterns(dispPtr, bindPtr, psPtr, bestPtr, objectPtr, sourcePtrPtr)
    TkDisplay *dispPtr;        /* Display from which the event came. */
    BindingTable *bindPtr;    /* Information about binding table, such as
                 * ring of recent events. */
    PatSeq *psPtr;        /* List of pattern sequences. */
    PatSeq *bestPtr;         /* The best match seen so far, from a
                 * previous call to this procedure.  NULL
                 * means no prior best match. */
    ClientData *objectPtr;    /* If NULL, the sequences at psPtr
                 * correspond to "normal" bindings.  If
                 * non-NULL, the sequences at psPtr correspond
                 * to virtual bindings; in order to match each
                 * sequence must correspond to a virtual
                 * binding for which a binding exists for
                 * object in bindPtr. */
    PatSeq **sourcePtrPtr;    /* Filled with the pattern sequence that
                 * contains the eventProc and clientData
                 * associated with the best match.  If this
                 * differs from the return value, it is the
                 * virtual event that most closely matched the
                 * return value (a physical event).  Not
                 * modified unless a result other than bestPtr
                 * is returned. */
{
    PatSeq *matchPtr, *bestSourcePtr, *sourcePtr;

    bestSourcePtr = *sourcePtrPtr;

    /*
     * Iterate over all the pattern sequences.
     */

    for ( ; psPtr != NULL; psPtr = psPtr->nextSeqPtr) {
    XEvent *eventPtr;
    Pattern *patPtr;
    Window window;
    Detail *detailPtr;
    int patCount, ringCount, flags, state;
    int modMask;

    /*
     * Iterate over all the patterns in a sequence to be
     * sure that they all match.
     */

    eventPtr = &bindPtr->eventRing[bindPtr->curEvent];
    detailPtr = &bindPtr->detailRing[bindPtr->curEvent];
    window = eventPtr->xany.window;
    patPtr = psPtr->pats;
    patCount = psPtr->numPats;
    ringCount = EVENT_BUFFER_SIZE;
    while (patCount > 0) {
        if (ringCount <= 0) {
        goto nextSequence;
        }
        if (eventPtr->xany.type != patPtr->eventType) {
        /*
         * Most of the event types are considered superfluous
         * in that they are ignored if they occur in the middle
         * of a pattern sequence and have mismatching types.  The
         * only ones that cannot be ignored are ButtonPress and
         * ButtonRelease events (if the next event in the pattern
         * is a KeyPress or KeyRelease) and KeyPress and KeyRelease
         * events (if the next pattern event is a ButtonPress or
         * ButtonRelease).  Here are some tricky cases to consider:
         * 1. Double-Button or Double-Key events.
         * 2. Double-ButtonRelease or Double-KeyRelease events.
         * 3. The arrival of various events like Enter and Leave
         *    and FocusIn and GraphicsExpose between two button
         *    presses or key presses.
         * 4. Modifier keys like Shift and Control shouldn't
         *    generate conflicts with button events.
         */

        if ((patPtr->eventType == KeyPress)
            || (patPtr->eventType == KeyRelease)) {
            if ((eventPtr->xany.type == ButtonPress)
                || (eventPtr->xany.type == ButtonRelease)) {
            goto nextSequence;
            }
        } else if ((patPtr->eventType == ButtonPress)
            || (patPtr->eventType == ButtonRelease)) {
            if ((eventPtr->xany.type == KeyPress)
                || (eventPtr->xany.type == KeyRelease)) {
            int i;

            /*
             * Ignore key events if they are modifier keys.
             */

            for (i = 0; i < dispPtr->numModKeyCodes; i++) {
                if (dispPtr->modKeyCodes[i]
                    == eventPtr->xkey.keycode) {
                /*
                 * This key is a modifier key, so ignore it.
                 */
                goto nextEvent;
                }
            }
            goto nextSequence;
            }
        }
        goto nextEvent;
        }
        if (eventPtr->xany.window != window) {
        goto nextSequence;
        }

        /*
         * Note: it's important for the keysym check to go before
         * the modifier check, so we can ignore unwanted modifier
         * keys before choking on the modifier check.
         */

        if ((patPtr->detail.clientData != 0)
            && (patPtr->detail.clientData != detailPtr->clientData)) {
        /*
         * The detail appears not to match.  However, if the event
         * is a KeyPress for a modifier key then just ignore the
         * event.  Otherwise event sequences like "aD" never match
         * because the shift key goes down between the "a" and the
         * "D".
         */

        if (eventPtr->xany.type == KeyPress) {
            int i;

            for (i = 0; i < dispPtr->numModKeyCodes; i++) {
            if (dispPtr->modKeyCodes[i] == eventPtr->xkey.keycode) {
                goto nextEvent;
            }
            }
        }
        goto nextSequence;
        }
        flags = flagArray[eventPtr->type];
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
        state = eventPtr->xkey.state;
        } else if (flags & CROSSING) {
        state = eventPtr->xcrossing.state;
        } else {
        state = 0;
        }
        if (patPtr->needMods != 0) {
        modMask = patPtr->needMods;
        if ((modMask & META_MASK) && (dispPtr->metaModMask != 0)) {
            modMask = (modMask & ~META_MASK) | dispPtr->metaModMask;
        }
        if ((modMask & ALT_MASK) && (dispPtr->altModMask != 0)) {
            modMask = (modMask & ~ALT_MASK) | dispPtr->altModMask;
        }
        if ((state & modMask) != modMask) {
            goto nextSequence;
        }
        }
        if (psPtr->flags & PAT_NEARBY) {
        XEvent *firstPtr;
        int timeDiff;

        firstPtr = &bindPtr->eventRing[bindPtr->curEvent];
        timeDiff = (Time) firstPtr->xkey.time - eventPtr->xkey.time;
        if ((firstPtr->xkey.x_root
                < (eventPtr->xkey.x_root - NEARBY_PIXELS))
            || (firstPtr->xkey.x_root
                > (eventPtr->xkey.x_root + NEARBY_PIXELS))
            || (firstPtr->xkey.y_root
                < (eventPtr->xkey.y_root - NEARBY_PIXELS))
            || (firstPtr->xkey.y_root
                > (eventPtr->xkey.y_root + NEARBY_PIXELS))
            || (timeDiff > NEARBY_MS)) {
            goto nextSequence;
        }
        }
        patPtr++;
        patCount--;
        nextEvent:
        if (eventPtr == bindPtr->eventRing) {
        eventPtr = &bindPtr->eventRing[EVENT_BUFFER_SIZE-1];
        detailPtr = &bindPtr->detailRing[EVENT_BUFFER_SIZE-1];
        } else {
        eventPtr--;
        detailPtr--;
        }
        ringCount--;
    }

    matchPtr = psPtr;
    sourcePtr = psPtr;

    if (objectPtr != NULL) {
        int iVirt;
        VirtualOwners *voPtr;
        PatternTableKey key;

        /*
         * The sequence matches the physical constraints.
         * Is this object interested in any of the virtual events
         * that correspond to this sequence?
         */

        voPtr = psPtr->voPtr;

        memset(&key, 0, sizeof(key));
        key.object = *objectPtr;
        key.type = VirtualEvent;
        key.detail.clientData = 0;

        for (iVirt = 0; iVirt < voPtr->numOwners; iVirt++) {
            Tcl_HashEntry *hPtr = voPtr->owners[iVirt];

            key.detail.name = (Tk_Uid) Tcl_GetHashKey(hPtr->tablePtr,
            hPtr);
        hPtr = Tcl_FindHashEntry(&bindPtr->patternTable,
            (char *) &key);
        if (hPtr != NULL) {

            /*
             * This tag is interested in this virtual event and its
             * corresponding physical event is a good match with the
             * virtual event's definition.
             */

            PatSeq *virtMatchPtr;

            virtMatchPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
            if ((virtMatchPtr->numPats != 1)
                || (virtMatchPtr->nextSeqPtr != NULL)) {
            panic("MatchPattern: badly constructed virtual event");
            }
            sourcePtr = virtMatchPtr;
            goto match;
        }
        }

        /*
         * The physical event matches a virtual event's definition, but
         * the tag isn't interested in it.
         */
        goto nextSequence;
    }
    match:

    /*
     * This sequence matches.  If we've already got another match,
     * pick whichever is most specific.  Detail is most important,
     * then needMods.
     */

    if (bestPtr != NULL) {
        Pattern *patPtr2;
        int i;

        if (matchPtr->numPats != bestPtr->numPats) {
        if (bestPtr->numPats > matchPtr->numPats) {
            goto nextSequence;
        } else {
            goto newBest;
        }
        }
        for (i = 0, patPtr = matchPtr->pats, patPtr2 = bestPtr->pats;
            i < matchPtr->numPats; i++, patPtr++, patPtr2++) {
        if (patPtr->detail.clientData != patPtr2->detail.clientData) {
            if (patPtr->detail.clientData == 0) {
            goto nextSequence;
            } else {
            goto newBest;
            }
        }
        if (patPtr->needMods != patPtr2->needMods) {
            if ((patPtr->needMods & patPtr2->needMods)
                == patPtr->needMods) {
            goto nextSequence;
            } else if ((patPtr->needMods & patPtr2->needMods)
                == patPtr2->needMods) {
            goto newBest;
            }
        }
        }
        /*
         * Tie goes to current best pattern.
         *
         * (1) For virtual vs. virtual, the least recently defined
         * virtual wins, because virtuals are examined in order of
         * definition.  This order is _not_ guaranteed in the
         * documentation.
         *
         * (2) For virtual vs. physical, the physical wins because all
         * the physicals are examined before the virtuals.  This order
         * is guaranteed in the documentation.
         *
         * (3) For physical vs. physical pattern, the most recently
         * defined physical wins, because physicals are examined in
         * reverse order of definition.  This order is guaranteed in
         * the documentation.
         */

        goto nextSequence;
    }
    newBest:
    bestPtr = matchPtr;
    bestSourcePtr = sourcePtr;

    nextSequence: continue;
    }

    *sourcePtrPtr = bestSourcePtr;
    return bestPtr;
}

/*
 *--------------------------------------------------------------
 *
 * ExpandPercents --
 *
 *    Given a command and an event, produce a new command
 *    by replacing % constructs in the original command
 *    with information from the X event.
 *
 * Results:
 *    The new expanded command is appended to the dynamic string
 *    given by dsPtr.
 *
 * Side effects:
 *    None.
 *
 *--------------------------------------------------------------
 */

static void
ExpandPercents(winPtr, before, eventPtr, keySym, dsPtr)
    TkWindow *winPtr;        /* Window where event occurred:  needed to
                 * get input context. */
    char *before;        /* Command containing percent expressions
                 * to be replaced. */
    XEvent *eventPtr;        /* X event containing information to be
                 * used in % replacements. */
    KeySym keySym;        /* KeySym: only relevant for KeyPress and
                 * KeyRelease events). */
    Tcl_DString *dsPtr;        /* Dynamic string in which to append new
                 * command. */
{
    int spaceNeeded, cvtFlags;    /* Used to substitute string as proper Tcl
                 * list element. */
    int number, flags, length;
#define NUM_SIZE 40
    char *string;
    char numStorage[NUM_SIZE+1];

    if (eventPtr->type < TK_LASTEVENT) {
    flags = flagArray[eventPtr->type];
    } else {
    flags = 0;
    }
    while (1) {
    /*
     * Find everything up to the next % character and append it
     * to the result string.
     */

    for (string = before; (*string != 0) && (*string != '%'); string++) {
        /* Empty loop body. */
    }
    if (string != before) {
        Tcl_DStringAppend(dsPtr, before, string-before);
        before = string;
    }
    if (*before == 0) {
        break;
    }

    /*
     * There's a percent sequence here.  Process it.
     */

    number = 0;
    string = "??";
    switch (before[1]) {
        case '#':
        number = eventPtr->xany.serial;
        goto doNumber;
        case 'a':
        TkpPrintWindowId(numStorage, eventPtr->xconfigure.above);
        string = numStorage;
        goto doString;
        case 'b':
        number = eventPtr->xbutton.button;
        goto doNumber;
        case 'c':
        if (flags & EXPOSE) {
            number = eventPtr->xexpose.count;
        }
        goto doNumber;
        case 'd':
        if (flags & (CROSSING|FOCUS)) {
            if (flags & FOCUS) {
            number = eventPtr->xfocus.detail;
            } else {
            number = eventPtr->xcrossing.detail;
            }
            string = TkFindStateString(notifyDetail, number);
        }
        goto doString;
        case 'f':
        number = eventPtr->xcrossing.focus;
        goto doNumber;
        case 'h':
        if (flags & EXPOSE) {
            number = eventPtr->xexpose.height;
        } else if (flags & (CONFIG)) {
            number = eventPtr->xconfigure.height;
        }
        goto doNumber;
        case 'k':
        number = eventPtr->xkey.keycode;
        goto doNumber;
        case 'm':
        if (flags & CROSSING) {
            number = eventPtr->xcrossing.mode;
        } else if (flags & FOCUS) {
            number = eventPtr->xfocus.mode;
        }
        string = TkFindStateString(notifyMode, number);
        goto doString;
        case 'o':
        if (flags & CREATE) {
            number = eventPtr->xcreatewindow.override_redirect;
        } else if (flags & MAP) {
            number = eventPtr->xmap.override_redirect;
        } else if (flags & REPARENT) {
            number = eventPtr->xreparent.override_redirect;
        } else if (flags & CONFIG) {
            number = eventPtr->xconfigure.override_redirect;
        }
        goto doNumber;
        case 'p':
        string = TkFindStateString(circPlace, eventPtr->xcirculate.place);
        goto doString;
        case 's':
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
            number = eventPtr->xkey.state;
        } else if (flags & CROSSING) {
            number = eventPtr->xcrossing.state;
        } else if (flags & VISIBILITY) {
            string = TkFindStateString(visNotify,
                eventPtr->xvisibility.state);
            goto doString;
        }
        goto doNumber;
        case 't':
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
            number = (int) eventPtr->xkey.time;
        } else if (flags & CROSSING) {
            number = (int) eventPtr->xcrossing.time;
        } else if (flags & PROP) {
            number = (int) eventPtr->xproperty.time;
        }
        goto doNumber;
        case 'v':
        number = eventPtr->xconfigurerequest.value_mask;
        goto doNumber;
        case 'w':
        if (flags & EXPOSE) {
            number = eventPtr->xexpose.width;
        } else if (flags & CONFIG) {
            number = eventPtr->xconfigure.width;
        }
        goto doNumber;
        case 'x':
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
            number = eventPtr->xkey.x;
        } else if (flags & CROSSING) {
            number = eventPtr->xcrossing.x;
        } else if (flags & EXPOSE) {
            number = eventPtr->xexpose.x;
        } else if (flags & (CREATE|CONFIG|GRAVITY)) {
            number = eventPtr->xcreatewindow.x;
        } else if (flags & REPARENT) {
            number = eventPtr->xreparent.x;
        }
        goto doNumber;
        case 'y':
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
            number = eventPtr->xkey.y;
        } else if (flags & EXPOSE) {
            number = eventPtr->xexpose.y;
        } else if (flags & (CREATE|CONFIG|GRAVITY)) {
            number = eventPtr->xcreatewindow.y;
        } else if (flags & REPARENT) {
            number = eventPtr->xreparent.y;
        } else if (flags & CROSSING) {
            number = eventPtr->xcrossing.y;

        }
        goto doNumber;
        case 'A':
        if (flags & KEY) {
            int numChars;

            /*
             * If we're using input methods and this is a keypress
             * event, invoke XmbTkFindStateString.  Otherwise just use
             * the older XTkFindStateString.
             */

#ifdef TK_USE_INPUT_METHODS
            Status status;
            if ((winPtr->inputContext != NULL)
                && (eventPtr->type == KeyPress)) {
                        numChars = XmbLookupString(winPtr->inputContext,
                                &eventPtr->xkey, numStorage, NUM_SIZE,
                                (KeySym *) NULL, &status);
            if ((status != XLookupChars)
                && (status != XLookupBoth)) {
                numChars = 0;
            }
                    } else {
                        numChars = XLookupString(&eventPtr->xkey, numStorage,
                                NUM_SIZE, (KeySym *) NULL,
                                (XComposeStatus *) NULL);
            }
#else /* TK_USE_INPUT_METHODS */
            numChars = XLookupString(&eventPtr->xkey, numStorage,
                NUM_SIZE, (KeySym *) NULL,
                (XComposeStatus *) NULL);
#endif /* TK_USE_INPUT_METHODS */
            numStorage[numChars] = '\0';
            string = numStorage;
        }
        goto doString;
        case 'B':
        number = eventPtr->xcreatewindow.border_width;
        goto doNumber;
        case 'E':
        number = (int) eventPtr->xany.send_event;
        goto doNumber;
        case 'K':
        if (flags & KEY) {
            char *name;

            name = TkKeysymToString(keySym);
            if (name != NULL) {
            string = name;
            }
        }
        goto doString;
        case 'N':
        number = (int) keySym;
        goto doNumber;
        case 'R':
        TkpPrintWindowId(numStorage, eventPtr->xkey.root);
        string = numStorage;
        goto doString;
            case 'S':
        TkpPrintWindowId(numStorage, eventPtr->xkey.subwindow);
        string = numStorage;
        goto doString;
        case 'T':
        number = eventPtr->type;
        goto doNumber;
        case 'W': {
        Tk_Window tkwin;

        tkwin = Tk_IdToWindow(eventPtr->xany.display,
            eventPtr->xany.window);
        if (tkwin != NULL) {
            string = Tk_PathName(tkwin);
        } else {
            string = "??";
        }
        goto doString;
        }
        case 'X': {
        Tk_Window tkwin;
        int x, y;
        int width, height;

        number = eventPtr->xkey.x_root;
        tkwin = Tk_IdToWindow(eventPtr->xany.display,
            eventPtr->xany.window);
        if (tkwin != NULL) {
            Tk_GetVRootGeometry(tkwin, &x, &y, &width, &height);
            number -= x;
        }
        goto doNumber;
        }
        case 'Y': {
        Tk_Window tkwin;
        int x, y;
        int width, height;

        number = eventPtr->xkey.y_root;
        tkwin = Tk_IdToWindow(eventPtr->xany.display,
            eventPtr->xany.window);
        if (tkwin != NULL) {
            Tk_GetVRootGeometry(tkwin, &x, &y, &width, &height);
            number -= y;
        }
        goto doNumber;
        }
        default:
        numStorage[0] = before[1];
        numStorage[1] = '\0';
        string = numStorage;
        goto doString;
    }

    doNumber:
    sprintf(numStorage, "%d", number);
    string = numStorage;

    doString:
    spaceNeeded = Tcl_ScanElement(string, &cvtFlags);
    length = Tcl_DStringLength(dsPtr);
    Tcl_DStringSetLength(dsPtr, length + spaceNeeded);
    spaceNeeded = Tcl_ConvertElement(string,
        Tcl_DStringValue(dsPtr) + length,
        cvtFlags | TCL_DONT_USE_BRACES);
    Tcl_DStringSetLength(dsPtr, length + spaceNeeded);
    before += 2;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * ChangeScreen --
 *
 *    This procedure is invoked whenever the current screen changes
 *    in an application.  It invokes a Tcl procedure named
 *    "tkScreenChanged", passing it the screen name as argument.
 *    tkScreenChanged does things like making the tkPriv variable
 *    point to an array for the current display.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Depends on what tkScreenChanged does.  If an error occurs
 *    them tkError will be invoked.
 *
 *----------------------------------------------------------------------
 */

static void
ChangeScreen(interp, dispName, screenIndex)
    Tcl_Interp *interp;            /* Interpreter in which to invoke
                     * command. */
    char *dispName;            /* Name of new display. */
    int screenIndex;            /* Index of new screen. */
{
    Tcl_DString cmd;
    int code;
    char screen[30];

    Tcl_DStringInit(&cmd);
    Tcl_DStringAppend(&cmd, "tkScreenChanged ", 16);
    Tcl_DStringAppend(&cmd, dispName, -1);
    sprintf(screen, ".%d", screenIndex);
    Tcl_DStringAppend(&cmd, screen, -1);
    code = Tcl_GlobalEval(interp, Tcl_DStringValue(&cmd));
    if (code != TCL_OK) {
    Tcl_AddErrorInfo(interp,
        "\n    (changing screen in event binding)");
    Tcl_BackgroundError(interp);
    }
}


/*
 *----------------------------------------------------------------------
 *
 * Tk_EventCmd --
 *
 *    This procedure is invoked to process the "event" Tcl command.
 *    It is used to define and generate events.
 *
 * Results:
 *    A standard Tcl result.
 *
 * Side effects:
 *    See the user documentation.
 *
 *----------------------------------------------------------------------
 */

int
Tk_EventCmd(clientData, interp, argc, argv)
    ClientData clientData;    /* Main window associated with
                 * interpreter. */
    Tcl_Interp *interp;        /* Current interpreter. */
    int argc;            /* Number of arguments. */
    char **argv;        /* Argument strings. */
{
    int i;
    size_t length;
    char *option;
    Tk_Window tkwin;
    VirtualEventTable *vetPtr;
    TkBindInfo bindInfo;

    if (argc < 2) {
    Tcl_AppendResult(interp, "wrong # args: should be \"",
        argv[0], " option ?arg1?\"", (char *) NULL);
    return TCL_ERROR;
    }

    option = argv[1];
    length = strlen(option);
    if (length == 0) {
    goto badopt;
    }

    tkwin = (Tk_Window) clientData;
    bindInfo = ((TkWindow *) tkwin)->mainPtr->bindInfo;
    vetPtr = &((BindInfo *) bindInfo)->virtualEventTable;

    if (strncmp(option, "add", length) == 0) {
    if (argc < 4) {
        Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
            " add virtual sequence ?sequence ...?\"", (char *) NULL);
        return TCL_ERROR;
    }
    for (i = 3; i < argc; i++) {
        if (CreateVirtualEvent(interp, vetPtr, argv[2], argv[i])
            != TCL_OK) {
        return TCL_ERROR;
        }
    }
    } else if (strncmp(option, "delete", length) == 0) {
    if (argc < 3) {
        Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
            " delete virtual ?sequence sequence ...?\"",
            (char *) NULL);
        return TCL_ERROR;
    }
    if (argc == 3) {
        return DeleteVirtualEvent(interp, vetPtr, argv[2], NULL);
    }
    for (i = 3; i < argc; i++) {
        if (DeleteVirtualEvent(interp, vetPtr, argv[2], argv[i])
            != TCL_OK) {
        return TCL_ERROR;
        }
    }
    } else if (strncmp(option, "generate", length) == 0) {
    if (argc < 4) {
        Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
            " generate window event ?options?\"", (char *) NULL);
        return TCL_ERROR;
    }
    return HandleEventGenerate(interp, tkwin, argc - 2, argv + 2);
    } else if (strncmp(option, "info", length) == 0) {
    if (argc == 2) {
        GetAllVirtualEvents(interp, vetPtr);
        return TCL_OK;
    } else if (argc == 3) {
        return GetVirtualEvent(interp, vetPtr, argv[2]);
    } else {
        Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
            " info ?virtual?\"", (char *) NULL);
        return TCL_ERROR;
    }
    } else {
    badopt:
    Tcl_AppendResult(interp, "bad option \"", argv[1],
        "\": should be add, delete, generate, info", (char *) NULL);
    return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * InitVirtualEventTable --
 *
 *    Given storage for a virtual event table, set up the fields to
 *    prepare a new domain in which virtual events may be defined.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    *vetPtr is now initialized.
 *
 *---------------------------------------------------------------------------
 */

static void
InitVirtualEventTable(vetPtr)
    VirtualEventTable *vetPtr;    /* Pointer to virtual event table.  Memory
                 * is supplied by the caller. */
{
    Tcl_InitHashTable(&vetPtr->patternTable,
        sizeof(PatternTableKey) / sizeof(int));
    Tcl_InitHashTable(&vetPtr->nameTable, TCL_ONE_WORD_KEYS);
}

/*
 *---------------------------------------------------------------------------
 *
 * DeleteVirtualEventTable --
 *
 *    Delete the contents of a virtual event table.  The caller is
 *    responsible for freeing any memory used by the table itself.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Memory is freed.
 *
 *---------------------------------------------------------------------------
 */

static void
DeleteVirtualEventTable(vetPtr)
    VirtualEventTable *vetPtr;    /* The virtual event table to delete. */
{
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;
    PatSeq *psPtr, *nextPtr;

    hPtr = Tcl_FirstHashEntry(&vetPtr->patternTable, &search);
    for ( ; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
    psPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
    for ( ; psPtr != NULL; psPtr = nextPtr) {
        nextPtr = psPtr->nextSeqPtr;
        ckfree((char *) psPtr->voPtr);
        ckfree((char *) psPtr);
    }
    }
    Tcl_DeleteHashTable(&vetPtr->patternTable);

    hPtr = Tcl_FirstHashEntry(&vetPtr->nameTable, &search);
    for ( ; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
        ckfree((char *) Tcl_GetHashValue(hPtr));
    }
    Tcl_DeleteHashTable(&vetPtr->nameTable);
}

/*
 *----------------------------------------------------------------------
 *
 * CreateVirtualEvent --
 *
 *    Add a new definition for a virtual event.  If the virtual event
 *    is already defined, the new definition augments those that
 *    already exist.
 *
 * Results:
 *    The return value is TCL_ERROR if an error occured while
 *    creating the virtual binding.  In this case, an error message
 *    will be left in interp->result.  If all went well then the return
 *    value is TCL_OK.
 *
 * Side effects:
 *    The virtual event may cause future calls to Tk_BindEvent to
 *    behave differently than they did previously.
 *
 *----------------------------------------------------------------------
 */

static int
CreateVirtualEvent(interp, vetPtr, virtString, eventString)
    Tcl_Interp *interp;        /* Used for error reporting. */
    VirtualEventTable *vetPtr;/* Table in which to augment virtual event. */
    char *virtString;        /* Name of new virtual event. */
    char *eventString;        /* String describing physical event that
                 * triggers virtual event. */
{
    PatSeq *psPtr;
    int dummy;
    Tcl_HashEntry *vhPtr;
    unsigned long eventMask;
    PhysicalsOwned *poPtr;
    VirtualOwners *voPtr;
    Tk_Uid virtUid;

    virtUid = GetVirtualEventUid(interp, virtString);
    if (virtUid == NULL) {
        return TCL_ERROR;
    }

    /*
     * Find/create physical event
     */

    psPtr = FindSequence(interp, &vetPtr->patternTable, NULL, eventString,
        1, 0, &eventMask);
    if (psPtr == NULL) {
        return TCL_ERROR;
    }

    /*
     * Find/create virtual event.
     */

    vhPtr = Tcl_CreateHashEntry(&vetPtr->nameTable, virtUid, &dummy);

    /*
     * Make virtual event own the physical event.
     */

    poPtr = (PhysicalsOwned *) Tcl_GetHashValue(vhPtr);
    if (poPtr == NULL) {
    poPtr = (PhysicalsOwned *) ckalloc(sizeof(PhysicalsOwned));
    poPtr->numOwned = 0;
    } else {
        /*
     * See if this virtual event is already defined for this physical
     * event and just return if it is.
     */

    int i;
    for (i = 0; i < poPtr->numOwned; i++) {
        if (poPtr->patSeqs[i] == psPtr) {
            return TCL_OK;
        }
    }
    poPtr = (PhysicalsOwned *) ckrealloc((char *) poPtr,
        sizeof(PhysicalsOwned) + poPtr->numOwned * sizeof(PatSeq *));
    }
    Tcl_SetHashValue(vhPtr, (ClientData) poPtr);
    poPtr->patSeqs[poPtr->numOwned] = psPtr;
    poPtr->numOwned++;

    /*
     * Make physical event so it can trigger the virtual event.
     */

    voPtr = psPtr->voPtr;
    if (voPtr == NULL) {
        voPtr = (VirtualOwners *) ckalloc(sizeof(VirtualOwners));
    voPtr->numOwners = 0;
    } else {
        voPtr = (VirtualOwners *) ckrealloc((char *) voPtr,
        sizeof(VirtualOwners)
        + voPtr->numOwners * sizeof(Tcl_HashEntry *));
    }
    psPtr->voPtr = voPtr;
    voPtr->owners[voPtr->numOwners] = vhPtr;
    voPtr->numOwners++;

    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * DeleteVirtualEvent --
 *
 *    Remove the definition of a given virtual event.  If the
 *    event string is NULL, all definitions of the virtual event
 *    will be removed.  Otherwise, just the specified definition
 *    of the virtual event will be removed.
 *
 * Results:
 *    The result is a standard Tcl return value.  If an error
 *    occurs then interp->result will contain an error message.
 *    It is not an error to attempt to delete a virtual event that
 *    does not exist or a definition that does not exist.
 *
 * Side effects:
 *    The virtual event given by virtString may be removed from the
 *    virtual event table.
 *
 *--------------------------------------------------------------
 */

static int
DeleteVirtualEvent(interp, vetPtr, virtString, eventString)
    Tcl_Interp *interp;        /* Used for error reporting. */
    VirtualEventTable *vetPtr;/* Table in which to delete event. */
    char *virtString;        /* String describing event sequence that
                 * triggers binding. */
    char *eventString;        /* The event sequence that should be deleted,
                 * or NULL to delete all event sequences for
                 * the entire virtual event. */
{
    int iPhys;
    Tk_Uid virtUid;
    Tcl_HashEntry *vhPtr;
    PhysicalsOwned *poPtr;
    PatSeq *eventPSPtr;

    virtUid = GetVirtualEventUid(interp, virtString);
    if (virtUid == NULL) {
        return TCL_ERROR;
    }

    vhPtr = Tcl_FindHashEntry(&vetPtr->nameTable, virtUid);
    if (vhPtr == NULL) {
        return TCL_OK;
    }
    poPtr = (PhysicalsOwned *) Tcl_GetHashValue(vhPtr);

    eventPSPtr = NULL;
    if (eventString != NULL) {
    unsigned long eventMask;

    /*
     * Delete only the specific physical event associated with the
     * virtual event.  If the physical event doesn't already exist, or
     * the virtual event doesn't own that physical event, return w/o
     * doing anything.
     */

    eventPSPtr = FindSequence(interp, &vetPtr->patternTable, NULL,
        eventString, 0, 0, &eventMask);
    if (eventPSPtr == NULL) {
        return (interp->result[0] != '\0') ? TCL_ERROR : TCL_OK;
    }
    }

    for (iPhys = poPtr->numOwned; --iPhys >= 0; ) {
    PatSeq *psPtr = poPtr->patSeqs[iPhys];
    if ((eventPSPtr == NULL) || (psPtr == eventPSPtr)) {
        int iVirt;
        VirtualOwners *voPtr;

        /*
         * Remove association between this physical event and the given
         * virtual event that it triggers.
         */

        voPtr = psPtr->voPtr;
        for (iVirt = 0; iVirt < voPtr->numOwners; iVirt++) {
        if (voPtr->owners[iVirt] == vhPtr) {
            break;
        }
        }
        if (iVirt == voPtr->numOwners) {
        panic("DeleteVirtualEvent: couldn't find owner");
        }
        voPtr->numOwners--;
        if (voPtr->numOwners == 0) {
        /*
         * Removed last reference to this physical event, so
         * remove it from physical->virtual map.
         */
        PatSeq *prevPtr = (PatSeq *) Tcl_GetHashValue(psPtr->hPtr);
        if (prevPtr == psPtr) {
            if (psPtr->nextSeqPtr == NULL) {
            Tcl_DeleteHashEntry(psPtr->hPtr);
            } else {
            Tcl_SetHashValue(psPtr->hPtr,
                psPtr->nextSeqPtr);
            }
        } else {
            for ( ; ; prevPtr = prevPtr->nextSeqPtr) {
            if (prevPtr == NULL) {
                panic("Tk_DeleteVirtualEvent couldn't find on hash chain");
            }
            if (prevPtr->nextSeqPtr == psPtr) {
                prevPtr->nextSeqPtr = psPtr->nextSeqPtr;
                break;
            }
            }
        }
        ckfree((char *) psPtr->voPtr);
        ckfree((char *) psPtr);
        } else {
        /*
         * This physical event still triggers some other virtual
         * event(s).  Consolidate the list of virtual owners for
         * this physical event so it no longer triggers the
         * given virtual event.
         */
        voPtr->owners[iVirt] = voPtr->owners[voPtr->numOwners];
        }

        /*
         * Now delete the virtual event's reference to the physical
         * event.
         */

        poPtr->numOwned--;
        if (eventPSPtr != NULL && poPtr->numOwned != 0) {
            /*
         * Just deleting this one physical event.  Consolidate list
         * of owned physical events and return.
         */

        poPtr->patSeqs[iPhys] = poPtr->patSeqs[poPtr->numOwned];
        return TCL_OK;
        }
    }
    }

    if (poPtr->numOwned == 0) {
    /*
     * All the physical events for this virtual event were deleted,
     * either because there was only one associated physical event or
     * because the caller was deleting the entire virtual event.  Now
     * the virtual event itself should be deleted.
     */

    ckfree((char *) poPtr);
    Tcl_DeleteHashEntry(vhPtr);
    }
    return TCL_OK;
}

/*
 *---------------------------------------------------------------------------
 *
 * GetVirtualEvent --
 *
 *    Return the list of physical events that can invoke the
 *    given virtual event.
 *
 * Results:
 *    The return value is TCL_OK and interp->result is filled with the
 *    string representation of the physical events associated with the
 *    virtual event; if there are no physical events for the given virtual
 *    event, interp->result is filled with and empty string.  If the
 *    virtual event string is improperly formed, then TCL_ERROR is
 *    returned and an error message is left in interp->result.
 *
 * Side effects:
 *    None.
 *
 *---------------------------------------------------------------------------
 */

static int
GetVirtualEvent(interp, vetPtr, virtString)
    Tcl_Interp *interp;        /* Interpreter for reporting. */
    VirtualEventTable *vetPtr;/* Table in which to look for event. */
    char *virtString;        /* String describing virtual event. */
{
    Tcl_HashEntry *vhPtr;
    Tcl_DString ds;
    int iPhys;
    PhysicalsOwned *poPtr;
    Tk_Uid virtUid;

    virtUid = GetVirtualEventUid(interp, virtString);
    if (virtUid == NULL) {
        return TCL_ERROR;
    }

    vhPtr = Tcl_FindHashEntry(&vetPtr->nameTable, virtUid);
    if (vhPtr == NULL) {
        return TCL_OK;
    }

    Tcl_DStringInit(&ds);

    poPtr = (PhysicalsOwned *) Tcl_GetHashValue(vhPtr);
    for (iPhys = 0; iPhys < poPtr->numOwned; iPhys++) {
    Tcl_DStringSetLength(&ds, 0);
    GetPatternString(poPtr->patSeqs[iPhys], &ds);
    Tcl_AppendElement(interp, Tcl_DStringValue(&ds));
    }
    Tcl_DStringFree(&ds);

    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * GetAllVirtualEvents --
 *
 *    Return a list that contains the names of all the virtual
 *    event defined.
 *
 * Results:
 *    There is no return value.  Interp->result is modified to
 *    hold a Tcl list with one entry for each virtual event in
 *    nameTable.
 *
 * Side effects:
 *    None.
 *
 *--------------------------------------------------------------
 */

static void
GetAllVirtualEvents(interp, vetPtr)
    Tcl_Interp *interp;        /* Interpreter returning result. */
    VirtualEventTable *vetPtr;/* Table containing events. */
{
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;
    Tcl_DString ds;

    Tcl_DStringInit(&ds);

    hPtr = Tcl_FirstHashEntry(&vetPtr->nameTable, &search);
    for ( ; hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
    Tcl_DStringSetLength(&ds, 0);
    Tcl_DStringAppend(&ds, "<<", 2);
    Tcl_DStringAppend(&ds, Tcl_GetHashKey(hPtr->tablePtr, hPtr), -1);
    Tcl_DStringAppend(&ds, ">>", 2);
        Tcl_AppendElement(interp, Tcl_DStringValue(&ds));
    }

    Tcl_DStringFree(&ds);
}

/*
 *---------------------------------------------------------------------------
 *
 * HandleEventGenerate --
 *
 *    Helper function for the "event generate" command.  Generate and
 *    process an XEvent, constructed from information parsed from the
 *    event description string and its optional arguments.
 *
 *    argv[0] contains name of the target window.
 *    argv[1] contains pattern string for one event (e.g, <Control-v>).
 *    argv[2..argc-1] contains -field/option pairs for specifying
 *                additional detail in the generated event.
 *
 *    Either virtual or physical events can be generated this way.
 *    The event description string must contain the specification
 *    for only one event.
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    When constructing the event,
 *     event.xany.serial is filled with the current X serial number.
 *     event.xany.window is filled with the target window.
 *     event.xany.display is filled with the target window's display.
 *    Any other fields in eventPtr which are not specified by the pattern
 *    string or the optional arguments, are set to 0.
 *
 *    The event may be handled sychronously or asynchronously, depending
 *    on the value specified by the optional "-when" option.  The
 *    default setting is synchronous.
 *
 *---------------------------------------------------------------------------
 */
static int
HandleEventGenerate(interp, main, argc, argv)
    Tcl_Interp *interp;        /* Interp for error messages and name lookup. */
    Tk_Window main;        /* Main window associated with interp. */
    int argc;            /* Number of arguments. */
    char **argv;        /* Argument strings. */
{
    Pattern pat;
    Tk_Window tkwin;
    char *p;
    unsigned long eventMask;
    int count, i, state, flags, synch;
    Tcl_QueuePosition pos;
    XEvent event;

    if (argv[0][0] == '.') {
    tkwin = Tk_NameToWindow(interp, argv[0], main);
    if (tkwin == NULL) {
        return TCL_ERROR;
    }
    } else {
    if (TkpScanWindowId(NULL, argv[0], &i) != TCL_OK) {
        Tcl_AppendResult(interp, "bad window name/identifier \"",
            argv[0], "\"", (char *) NULL);
        return TCL_ERROR;
    }
    tkwin = Tk_IdToWindow(Tk_Display(main), (Window) i);
    if ((tkwin == NULL) || (((TkWindow *) main)->mainPtr
        != ((TkWindow *) tkwin)->mainPtr)) {
        Tcl_AppendResult(interp, "window id \"", argv[0],
            "\" doesn't exist in this application", (char *) NULL);
        return TCL_ERROR;
    }
    }

    p = argv[1];
    count = ParseEventDescription(interp, &p, &pat, &eventMask);
    if (count == 0) {
    return TCL_ERROR;
    }
    if (count != 1) {
    interp->result = "Double or Triple modifier not allowed";
    return TCL_ERROR;
    }
    if (*p != '\0') {
    interp->result = "only one event specification allowed";
    return TCL_ERROR;
    }
    if (argc & 1) {
        Tcl_AppendResult(interp, "value for \"", argv[argc - 1],
        "\" missing", (char *) NULL);
    return TCL_ERROR;
    }

    memset((VOID *) &event, 0, sizeof(event));
    event.xany.type = pat.eventType;
    event.xany.serial = NextRequest(Tk_Display(tkwin));
    event.xany.send_event = False;
    event.xany.window = Tk_WindowId(tkwin);
    event.xany.display = Tk_Display(tkwin);

    flags = flagArray[event.xany.type];
    if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
    event.xkey.state = pat.needMods;
    if (flags & KEY) {
        /*
         * When mapping from a keysym to a keycode, need information about
         * the modifier state that should be used so that when they call
         * XKeycodeToKeysym    taking into account the xkey.state, they will
         * get back the original keysym.
         */

        if (pat.detail.keySym == NoSymbol) {
            event.xkey.keycode = 0;
        } else {
        event.xkey.keycode = XKeysymToKeycode(event.xany.display,
            pat.detail.keySym);
        }
        if (event.xkey.keycode != 0) {
        for (state = 0; state < 4; state++) {
            if (XKeycodeToKeysym(event.xany.display,
                event.xkey.keycode, state) == pat.detail.keySym) {
            if (state & 1) {
                event.xkey.state |= ShiftMask;
            }
            if (state & 2) {
                TkDisplay *dispPtr = ((TkWindow *) tkwin)->dispPtr;
                event.xkey.state |= dispPtr->modeModMask;
            }
            break;
            }
        }
        }
    } else if (flags & BUTTON) {
        event.xbutton.button = pat.detail.button;
    } else if (flags & VIRTUAL) {
        ((XVirtualEvent *) &event)->name = pat.detail.name;
    }
    }
    if (flags & (CREATE|DESTROY|UNMAP|MAP|REPARENT|CONFIG|GRAVITY|CIRC)) {
    event.xcreatewindow.window = event.xany.window;
    }

    /*
     * Process the remaining arguments to fill in additional fields
     * of the event.
     */

    synch = 1;
    pos = TCL_QUEUE_TAIL;
    for (i = 2; i < argc; i += 2) {
    char *field, *value;
    Tk_Window tkwin2;
    int number;
    KeySym keysym;

    field = argv[i];
    value = argv[i+1];

    if (strcmp(field, "-when") == 0) {
        if (strcmp(value, "now") == 0) {
        synch = 1;
        } else if (strcmp(value, "head") == 0) {
        pos = TCL_QUEUE_HEAD;
        synch = 0;
        } else if (strcmp(value, "mark") == 0) {
        pos = TCL_QUEUE_MARK;
        synch = 0;
        } else if (strcmp(value, "tail") == 0) {
        pos = TCL_QUEUE_TAIL;
        synch = 0;
        } else {
        Tcl_AppendResult(interp, "bad position \"", value,
            "\": should be now, head, mark, tail", (char *) NULL);
        return TCL_ERROR;
        }
    } else if (strcmp(field, "-above") == 0) {
        if (value[0] == '.') {
        tkwin2 = Tk_NameToWindow(interp, value, main);
        if (tkwin2 == NULL) {
            return TCL_ERROR;
        }
        number = Tk_WindowId(tkwin2);
        } else if (TkpScanWindowId(interp, value, &number)
            != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & CONFIG) {
        event.xconfigure.above = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-borderwidth") == 0) {
        if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & (CREATE|CONFIG)) {
        event.xcreatewindow.border_width = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-button") == 0) {
        if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & BUTTON) {
            event.xbutton.button = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-count") == 0) {
        if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & EXPOSE) {
        event.xexpose.count = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-detail") == 0) {
        number = TkFindStateNum(interp, field, notifyDetail, value);
        if (number < 0) {
        return TCL_ERROR;
        }
        if (flags & FOCUS) {
        event.xfocus.detail = number;
        } else if (flags & CROSSING) {
        event.xcrossing.detail = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-focus") == 0) {
        if (Tcl_GetBoolean(interp, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & CROSSING) {
        event.xcrossing.focus = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-height") == 0) {
        if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & EXPOSE) {
         event.xexpose.height = number;
        } else if (flags & CONFIG) {
        event.xconfigure.height = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-keycode") == 0) {
        if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & KEY) {
            event.xkey.keycode = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-keysym") == 0) {
        keysym = TkStringToKeysym(value);
        if (keysym == NoSymbol) {
        Tcl_AppendResult(interp, "unknown keysym \"", value,
            "\"", (char *) NULL);
        return TCL_ERROR;
        }
        /*
         * When mapping from a keysym to a keycode, need information about
         * the modifier state that should be used so that when they call
         * XKeycodeToKeysym    taking into account the xkey.state, they will
         * get back the original keysym.
         */

        number = XKeysymToKeycode(event.xany.display, keysym);
        if (number == 0) {
        Tcl_AppendResult(interp, "no keycode for keysym \"", value,
            "\"", (char *) NULL);
        return TCL_ERROR;
        }
        for (state = 0; state < 4; state++) {
        if (XKeycodeToKeysym(event.xany.display, (unsigned) number,
            state) == keysym) {
            if (state & 1) {
            event.xkey.state |= ShiftMask;
            }
            if (state & 2) {
            TkDisplay *dispPtr = ((TkWindow *) tkwin)->dispPtr;
            event.xkey.state |= dispPtr->modeModMask;
            }
            break;
        }
        }
        if (flags & KEY) {
        event.xkey.keycode = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-mode") == 0) {
        number = TkFindStateNum(interp, field, notifyMode, value);
        if (number < 0) {
        return TCL_ERROR;
        }
        if (flags & CROSSING) {
        event.xcrossing.mode = number;
        } else if (flags & FOCUS) {
        event.xfocus.mode = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-override") == 0) {
        if (Tcl_GetBoolean(interp, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & CREATE) {
        event.xcreatewindow.override_redirect = number;
        } else if (flags & MAP) {
        event.xmap.override_redirect = number;
        } else if (flags & REPARENT) {
        event.xreparent.override_redirect = number;
        } else if (flags & CONFIG) {
        event.xconfigure.override_redirect = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-place") == 0) {
        number = TkFindStateNum(interp, field, circPlace, value);
        if (number < 0) {
        return TCL_ERROR;
        }
        if (flags & CIRC) {
        event.xcirculate.place = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-root") == 0) {
        if (value[0] == '.') {
        tkwin2 = Tk_NameToWindow(interp, value, main);
        if (tkwin2 == NULL) {
            return TCL_ERROR;
        }
        number = Tk_WindowId(tkwin2);
        } else if (TkpScanWindowId(interp, value, &number)
            != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
        event.xkey.root = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-rootx") == 0) {
        if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
        event.xkey.x_root = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-rooty") == 0) {
        if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
        event.xkey.y_root = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-sendevent") == 0) {
        if (isdigit(UCHAR(value[0]))) {
        /*
         * Allow arbitrary integer values for the field; they
         * are needed by a few of the tests in the Tk test suite.
         */

        if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
            return TCL_ERROR;
        }
        } else {
        if (Tcl_GetBoolean(interp, value, &number) != TCL_OK) {
            return TCL_ERROR;
        }
        }
        event.xany.send_event = number;
    } else if (strcmp(field, "-serial") == 0) {
        if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        event.xany.serial = number;
    } else if (strcmp(field, "-state") == 0) {
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
        if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
            return TCL_ERROR;
        }
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL)) {
            event.xkey.state = number;
        } else {
            event.xcrossing.state = number;
        }
        } else if (flags & VISIBILITY) {
        number = TkFindStateNum(interp, field, visNotify, value);
        if (number < 0) {
            return TCL_ERROR;
        }
        event.xvisibility.state = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-subwindow") == 0) {
        if (value[0] == '.') {
        tkwin2 = Tk_NameToWindow(interp, value, main);
        if (tkwin2 == NULL) {
            return TCL_ERROR;
        }
        number = Tk_WindowId(tkwin2);
        } else if (TkpScanWindowId(interp, value, &number)
            != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
        event.xkey.subwindow = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-time") == 0) {
        if (Tcl_GetInt(interp, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
        event.xkey.time = (Time) number;
        } else if (flags & PROP) {
        event.xproperty.time = (Time) number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-width") == 0) {
        if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & EXPOSE) {
        event.xexpose.width = number;
        } else if (flags & (CREATE|CONFIG)) {
        event.xcreatewindow.width = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-window") == 0) {
        if (value[0] == '.') {
        tkwin2 = Tk_NameToWindow(interp, value, main);
        if (tkwin2 == NULL) {
            return TCL_ERROR;
        }
        number = Tk_WindowId(tkwin2);
        } else if (TkpScanWindowId(interp, value, &number)
            != TCL_OK) {
        return TCL_ERROR;
        }
        if (flags & (CREATE|DESTROY|UNMAP|MAP|REPARENT|CONFIG
            |GRAVITY|CIRC)) {
        event.xcreatewindow.window = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-x") == 0) {
        int rootX, rootY;
        if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        Tk_GetRootCoords(tkwin, &rootX, &rootY);
        rootX += number;
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
        event.xkey.x = number;
        event.xkey.x_root = rootX;
        } else if (flags & EXPOSE) {
        event.xexpose.x = number;
        } else if (flags & (CREATE|CONFIG|GRAVITY)) {
        event.xcreatewindow.x = number;
        } else if (flags & REPARENT) {
        event.xreparent.x = number;
        } else {
        goto badopt;
        }
    } else if (strcmp(field, "-y") == 0) {
        int rootX, rootY;
        if (Tk_GetPixels(interp, tkwin, value, &number) != TCL_OK) {
        return TCL_ERROR;
        }
        Tk_GetRootCoords(tkwin, &rootX, &rootY);
        rootY += number;
        if (flags & (KEY_BUTTON_MOTION_VIRTUAL|CROSSING)) {
        event.xkey.y = number;
        event.xkey.y_root = rootY;
        } else if (flags & EXPOSE) {
        event.xexpose.y = number;
        } else if (flags & (CREATE|CONFIG|GRAVITY)) {
        event.xcreatewindow.y = number;
        } else if (flags & REPARENT) {
        event.xreparent.y = number;
        } else {
        goto badopt;
        }
    } else {
        badopt:
        Tcl_AppendResult(interp, "bad option to ", argv[1],
            " event: \"", field, "\"", (char *) NULL);
        return TCL_ERROR;
    }
    }

    if (synch != 0) {
    Tk_HandleEvent(&event);
    } else {
    Tk_QueueWindowEvent(&event, pos);
    }
    Tcl_ResetResult(interp);
    return TCL_OK;
}

/*
 *-------------------------------------------------------------------------
 *
 * GetVirtualEventUid --
 *
 *    Determine if the given string is in the proper format for a
 *    virtual event.
 *
 * Results:
 *    The return value is NULL if the virtual event string was
 *    not in the proper format.  In this case, an error message
 *    will be left in interp->result.  Otherwise the return
 *    value is a Tk_Uid that represents the virtual event.
 *
 * Side effects:
 *    None.
 *
 *-------------------------------------------------------------------------
 */
static Tk_Uid
GetVirtualEventUid(interp, virtString)
    Tcl_Interp *interp;
    char *virtString;
{
    Tk_Uid uid;
    int length;

    length = strlen(virtString);

    if (length < 5 || virtString[0] != '<' || virtString[1] != '<' ||
        virtString[length - 2] != '>' || virtString[length - 1] != '>') {
        Tcl_AppendResult(interp, "virtual event \"", virtString,
        "\" is badly formed", (char *) NULL);
        return NULL;
    }
    virtString[length - 2] = '\0';
    uid = Tk_GetUid(virtString + 2);
    virtString[length - 2] = '>';

    return uid;
}


/*
 *----------------------------------------------------------------------
 *
 * FindSequence --
 *
 *    Find the entry in the pattern table that corresponds to a
 *    particular pattern string, and return a pointer to that
 *    entry.
 *
 * Results:
 *    The return value is normally a pointer to the PatSeq
 *    in patternTable that corresponds to eventString.  If an error
 *    was found while parsing eventString, or if "create" is 0 and
 *    no pattern sequence previously existed, then NULL is returned
 *    and interp->result contains a message describing the problem.
 *    If no pattern sequence previously existed for eventString, then
 *    a new one is created with a NULL command field.  In a successful
 *    return, *maskPtr is filled in with a mask of the event types
 *    on which the pattern sequence depends.
 *
 * Side effects:
 *    A new pattern sequence may be allocated.
 *
 *----------------------------------------------------------------------
 */

static PatSeq *
FindSequence(interp, patternTablePtr, object, eventString, create,
    allowVirtual, maskPtr)
    Tcl_Interp *interp;        /* Interpreter to use for error
                 * reporting. */
    Tcl_HashTable *patternTablePtr; /* Table to use for lookup. */
    ClientData object;        /* For binding table, token for object with
                 * which binding is associated.
                 * For virtual event table, NULL. */
    char *eventString;        /* String description of pattern to
                 * match on.  See user documentation
                 * for details. */
    int create;            /* 0 means don't create the entry if
                 * it doesn't already exist.   Non-zero
                 * means create. */
    int allowVirtual;        /* 0 means that virtual events are not
                 * allowed in the sequence.  Non-zero
                 * otherwise. */
    unsigned long *maskPtr;    /* *maskPtr is filled in with the event
                 * types on which this pattern sequence
                 * depends. */
{

    Pattern pats[EVENT_BUFFER_SIZE];
    int numPats, virtualFound;
    char *p;
    Pattern *patPtr;
    PatSeq *psPtr;
    Tcl_HashEntry *hPtr;
    int flags, count, new;
    size_t sequenceSize;
    unsigned long eventMask;
    PatternTableKey key;

    /*
     *-------------------------------------------------------------
     * Step 1: parse the pattern string to produce an array
     * of Patterns.  The array is generated backwards, so
     * that the lowest-indexed pattern corresponds to the last
     * event that must occur.
     *-------------------------------------------------------------
     */

    p = eventString;
    flags = 0;
    eventMask = 0;
    virtualFound = 0;

    patPtr = &pats[EVENT_BUFFER_SIZE-1];
    for (numPats = 0; numPats < EVENT_BUFFER_SIZE; numPats++, patPtr--) {
    while (isspace(UCHAR(*p))) {
        p++;
    }
    if (*p == '\0') {
        break;
    }

    count = ParseEventDescription(interp, &p, patPtr, &eventMask);
    if (count == 0) {
        return NULL;
    }

    if (eventMask & VirtualEventMask) {
        if (allowVirtual == 0) {
        interp->result =
            "virtual event not allowed in definition of another virtual event";
        return NULL;
        }
        virtualFound = 1;
    }

    /*
     * Replicate events for DOUBLE and TRIPLE.
     */

    if ((count > 1) && (numPats < EVENT_BUFFER_SIZE-1)) {
        flags |= PAT_NEARBY;
        patPtr[-1] = patPtr[0];
        patPtr--;
        numPats++;
        if ((count == 3) && (numPats < EVENT_BUFFER_SIZE-1)) {
        patPtr[-1] = patPtr[0];
        patPtr--;
        numPats++;
        }
    }
    }

    /*
     *-------------------------------------------------------------
     * Step 2: find the sequence in the binding table if it exists,
     * and add a new sequence to the table if it doesn't.
     *-------------------------------------------------------------
     */

    if (numPats == 0) {
    interp->result = "no events specified in binding";
    return NULL;
    }
    if ((numPats > 1) && (virtualFound != 0)) {
        interp->result = "virtual events may not be composed";
    return NULL;
    }

    patPtr = &pats[EVENT_BUFFER_SIZE-numPats];
    memset(&key, 0, sizeof(key));
    key.object = object;
    key.type = patPtr->eventType;
    key.detail = patPtr->detail;
    hPtr = Tcl_CreateHashEntry(patternTablePtr, (char *) &key, &new);
    sequenceSize = numPats*sizeof(Pattern);
    if (!new) {
    for (psPtr = (PatSeq *) Tcl_GetHashValue(hPtr); psPtr != NULL;
        psPtr = psPtr->nextSeqPtr) {
        if ((numPats == psPtr->numPats)
            && ((flags & PAT_NEARBY) == (psPtr->flags & PAT_NEARBY))
            && (memcmp((char *) patPtr, (char *) psPtr->pats,
            sequenceSize) == 0)) {
        goto done;
        }
    }
    }
    if (!create) {
    if (new) {
        Tcl_DeleteHashEntry(hPtr);
    }
    return NULL;
    }
    psPtr = (PatSeq *) ckalloc((unsigned) (sizeof(PatSeq)
        + (numPats-1)*sizeof(Pattern)));
    psPtr->numPats = numPats;
    psPtr->eventProc = NULL;
    psPtr->freeProc = NULL;
    psPtr->clientData = NULL;
    psPtr->flags = flags;
    psPtr->refCount = 0;
    psPtr->nextSeqPtr = (PatSeq *) Tcl_GetHashValue(hPtr);
    psPtr->hPtr = hPtr;
    psPtr->voPtr = NULL;
    psPtr->nextObjPtr = NULL;
    Tcl_SetHashValue(hPtr, psPtr);

    memcpy((VOID *) psPtr->pats, (VOID *) patPtr, sequenceSize);

    done:
    *maskPtr = eventMask;
    return psPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * ParseEventDescription --
 *
 *    Fill Pattern buffer with information about event from
 *    event string.
 *
 * Results:
 *    Leaves error message in interp and returns 0 if there was an
 *    error due to a badly formed event string.  Returns 1 if proper
 *    event was specified, 2 if Double modifier was used in event
 *    string, or 3 if Triple was used.
 *
 * Side effects:
 *    On exit, eventStringPtr points to rest of event string (after the
 *    closing '>', so that this procedure can be called repeatedly to
 *    parse all the events in the entire sequence.
 *
 *---------------------------------------------------------------------------
 */

static int
ParseEventDescription(interp, eventStringPtr, patPtr,
    eventMaskPtr)
    Tcl_Interp *interp;        /* For error messages. */
    char **eventStringPtr;    /* On input, holds a pointer to start of
                 * event string.  On exit, gets pointer to
                 * rest of string after parsed event. */
    Pattern *patPtr;        /* Filled with the pattern parsed from the
                 * event string. */
    unsigned long *eventMaskPtr;/* Filled with event mask of matched event. */

{
    char *p;
    unsigned long eventMask;
    int count, eventFlags;
#define FIELD_SIZE 48
    char field[FIELD_SIZE];
    Tcl_HashEntry *hPtr;

    p = *eventStringPtr;

    patPtr->eventType = -1;
    patPtr->needMods = 0;
    patPtr->detail.clientData = 0;

    eventMask = 0;
    count = 1;

    /*
     * Handle simple ASCII characters.
     */

    if (*p != '<') {
    char string[2];

    patPtr->eventType = KeyPress;
    eventMask = KeyPressMask;
    string[0] = *p;
    string[1] = 0;
    patPtr->detail.keySym = TkStringToKeysym(string);
    if (patPtr->detail.keySym == NoSymbol) {
        if (isprint(UCHAR(*p))) {
        patPtr->detail.keySym = *p;
        } else {
        sprintf(interp->result,
            "bad ASCII character 0x%x", (unsigned char) *p);
        return 0;
        }
    }
    p++;
    goto end;
    }

    /*
     * A fancier event description.  This can be either a virtual event
     * or a physical event.
     *
     * A virtual event description consists of:
     *
     * 1. double open angle brackets.
     * 2. virtual event name.
     * 3. double close angle brackets.
     *
     * A physical event description consists of:
     *
     * 1. open angle bracket.
     * 2. any number of modifiers, each followed by spaces
     *    or dashes.
     * 3. an optional event name.
     * 4. an option button or keysym name.  Either this or
     *    item 3 *must* be present;  if both are present
     *    then they are separated by spaces or dashes.
     * 5. a close angle bracket.
     */

    p++;
    if (*p == '<') {
    /*
     * This is a virtual event: soak up all the characters up to
     * the next '>'.
     */

    char *field = p + 1;
    p = strchr(field, '>');
    if (p == field) {
        interp->result = "virtual event \"<<>>\" is badly formed";
        return 0;
    }
    if ((p == NULL) || (p[1] != '>')) {
        interp->result = "missing \">\" in virtual binding";
        return 0;
    }
    *p = '\0';
    patPtr->eventType = VirtualEvent;
    eventMask = VirtualEventMask;
    patPtr->detail.name = Tk_GetUid(field);
    *p = '>';

    p += 2;
    goto end;
    }

    while (1) {
    ModInfo *modPtr;
    p = GetField(p, field, FIELD_SIZE);
    if (*p == '>') {
        /*
         * This solves the problem of, e.g., <Control-M> being
         * misinterpreted as Control + Meta + missing keysym
         * instead of Control + KeyPress + M.
         */
         break;
    }
    hPtr = Tcl_FindHashEntry(&modTable, field);
    if (hPtr == NULL) {
        break;
    }
    modPtr = (ModInfo *) Tcl_GetHashValue(hPtr);
    patPtr->needMods |= modPtr->mask;
    if (modPtr->flags & (DOUBLE|TRIPLE)) {
        if (modPtr->flags & DOUBLE) {
        count = 2;
        } else {
        count = 3;
        }
    }
    while ((*p == '-') || isspace(UCHAR(*p))) {
        p++;
    }
    }

    eventFlags = 0;
    hPtr = Tcl_FindHashEntry(&eventTable, field);
    if (hPtr != NULL) {
    EventInfo *eiPtr;
    eiPtr = (EventInfo *) Tcl_GetHashValue(hPtr);

    patPtr->eventType = eiPtr->type;
    eventFlags = flagArray[eiPtr->type];
    eventMask = eiPtr->eventMask;
    while ((*p == '-') || isspace(UCHAR(*p))) {
        p++;
    }
    p = GetField(p, field, FIELD_SIZE);
    }
    if (*field != '\0') {
    if ((*field >= '1') && (*field <= '5') && (field[1] == '\0')) {
        if (eventFlags == 0) {
        patPtr->eventType = ButtonPress;
        eventMask = ButtonPressMask;
        } else if (eventFlags & KEY) {
        goto getKeysym;
        } else if ((eventFlags & BUTTON) == 0) {
        Tcl_AppendResult(interp, "specified button \"", field,
            "\" for non-button event", (char *) NULL);
        return 0;
        }
        patPtr->detail.button = (*field - '0');
    } else {
        getKeysym:
        patPtr->detail.keySym = TkStringToKeysym(field);
        if (patPtr->detail.keySym == NoSymbol) {
        Tcl_AppendResult(interp, "bad event type or keysym \"",
            field, "\"", (char *) NULL);
        return 0;
        }
        if (eventFlags == 0) {
        patPtr->eventType = KeyPress;
        eventMask = KeyPressMask;
        } else if ((eventFlags & KEY) == 0) {
        Tcl_AppendResult(interp, "specified keysym \"", field,
            "\" for non-key event", (char *) NULL);
        return 0;
        }
    }
    } else if (eventFlags == 0) {
    interp->result = "no event type or button # or keysym";
    return 0;
    }

    while ((*p == '-') || isspace(UCHAR(*p))) {
    p++;
    }
    if (*p != '>') {
    while (*p != '\0') {
        p++;
        if (*p == '>') {
        interp->result = "extra characters after detail in binding";
        return 0;
        }
    }
    interp->result = "missing \">\" in binding";
    return 0;
    }
    p++;

end:
    *eventStringPtr = p;
    *eventMaskPtr |= eventMask;
    return count;
}

/*
 *----------------------------------------------------------------------
 *
 * GetField --
 *
 *    Used to parse pattern descriptions.  Copies up to
 *    size characters from p to copy, stopping at end of
 *    string, space, "-", ">", or whenever size is
 *    exceeded.
 *
 * Results:
 *    The return value is a pointer to the character just
 *    after the last one copied (usually "-" or space or
 *    ">", but could be anything if size was exceeded).
 *    Also places NULL-terminated string (up to size
 *    character, including NULL), at copy.
 *
 * Side effects:
 *    None.
 *
 *----------------------------------------------------------------------
 */

static char *
GetField(p, copy, size)
    char *p;        /* Pointer to part of pattern. */
    char *copy;    /* Place to copy field. */
    int size;            /* Maximum number of characters to
                 * copy. */
{
    while ((*p != '\0') && !isspace(UCHAR(*p)) && (*p != '>')
        && (*p != '-') && (size > 1)) {
    *copy = *p;
    p++;
    copy++;
    size--;
    }
    *copy = '\0';
    return p;
}

/*
 *---------------------------------------------------------------------------
 *
 * GetPatternString --
 *
 *    Produce a string version of the given event, for displaying to
 *    the user.
 *
 * Results:
 *    The string is left in dsPtr.
 *
 * Side effects:
 *    It is the caller's responsibility to initialize the DString before
 *    and to free it after calling this procedure.
 *
 *---------------------------------------------------------------------------
 */
static void
GetPatternString(psPtr, dsPtr)
    PatSeq *psPtr;
    Tcl_DString *dsPtr;
{
    Pattern *patPtr;
    char c, buffer[10];
    int patsLeft, needMods;
    ModInfo *modPtr;
    EventInfo *eiPtr;

    /*
     * The order of the patterns in the sequence is backwards from the order
     * in which they must be output.
     */

    for (patsLeft = psPtr->numPats, patPtr = &psPtr->pats[psPtr->numPats - 1];
        patsLeft > 0; patsLeft--, patPtr--) {

    /*
     * Check for simple case of an ASCII character.
     */

    if ((patPtr->eventType == KeyPress)
        && ((psPtr->flags & PAT_NEARBY) == 0)
        && (patPtr->needMods == 0)
        && (patPtr->detail.keySym < 128)
        && isprint(UCHAR(patPtr->detail.keySym))
        && (patPtr->detail.keySym != '<')
        && (patPtr->detail.keySym != ' ')) {

        c = (char) patPtr->detail.keySym;
        Tcl_DStringAppend(dsPtr, &c, 1);
        continue;
    }

    /*
     * Check for virtual event.
     */

    if (patPtr->eventType == VirtualEvent) {
        Tcl_DStringAppend(dsPtr, "<<", 2);
        Tcl_DStringAppend(dsPtr, patPtr->detail.name, -1);
        Tcl_DStringAppend(dsPtr, ">>", 2);
        continue;
    }

    /*
     * It's a more general event specification.  First check
     * for "Double" or "Triple", then modifiers, then event type,
     * then keysym or button detail.
     */

    Tcl_DStringAppend(dsPtr, "<", 1);
    if ((psPtr->flags & PAT_NEARBY) && (patsLeft > 1)
        && (memcmp((char *) patPtr, (char *) (patPtr-1),
            sizeof(Pattern)) == 0)) {
        patsLeft--;
        patPtr--;
        if ((patsLeft > 1) && (memcmp((char *) patPtr,
            (char *) (patPtr-1), sizeof(Pattern)) == 0)) {
        patsLeft--;
        patPtr--;
        Tcl_DStringAppend(dsPtr, "Triple-", 7);
        } else {
        Tcl_DStringAppend(dsPtr, "Double-", 7);
        }
    }
    for (needMods = patPtr->needMods, modPtr = modArray;
        needMods != 0; modPtr++) {
        if (modPtr->mask & needMods) {
        needMods &= ~modPtr->mask;
        Tcl_DStringAppend(dsPtr, modPtr->name, -1);
        Tcl_DStringAppend(dsPtr, "-", 1);
        }
    }
    for (eiPtr = eventArray; eiPtr->name != NULL; eiPtr++) {
        if (eiPtr->type == patPtr->eventType) {
        Tcl_DStringAppend(dsPtr, eiPtr->name, -1);
        if (patPtr->detail.clientData != 0) {
            Tcl_DStringAppend(dsPtr, "-", 1);
        }
        break;
        }
    }

    if (patPtr->detail.clientData != 0) {
        if ((patPtr->eventType == KeyPress)
            || (patPtr->eventType == KeyRelease)) {
        char *string;

        string = TkKeysymToString(patPtr->detail.keySym);
        if (string != NULL) {
            Tcl_DStringAppend(dsPtr, string, -1);
        }
        } else {
        sprintf(buffer, "%d", patPtr->detail.button);
        Tcl_DStringAppend(dsPtr, buffer, -1);
        }
    }
    Tcl_DStringAppend(dsPtr, ">", 1);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * GetKeySym --
 *
 *    Given an X KeyPress or KeyRelease event, map the
 *    keycode in the event into a KeySym.
 *
 * Results:
 *    The return value is the KeySym corresponding to
 *    eventPtr, or NoSymbol if no matching Keysym could be
 *    found.
 *
 * Side effects:
 *    In the first call for a given display, keycode-to-
 *    KeySym maps get loaded.
 *
 *----------------------------------------------------------------------
 */

static KeySym
GetKeySym(dispPtr, eventPtr)
    TkDisplay *dispPtr;    /* Display in which to
                     * map keycode. */
    XEvent *eventPtr;        /* Description of X event. */
{
    KeySym sym;
    int index;

    /*
     * Refresh the mapping information if it's stale
     */

    if (dispPtr->bindInfoStale) {
    InitKeymapInfo(dispPtr);
    }

    /*
     * Figure out which of the four slots in the keymap vector to
     * use for this key.  Refer to Xlib documentation for more info
     * on how this computation works.
     */

    index = 0;
    if (eventPtr->xkey.state & dispPtr->modeModMask) {
    index = 2;
    }
    if ((eventPtr->xkey.state & ShiftMask)
        || ((dispPtr->lockUsage != LU_IGNORE)
        && (eventPtr->xkey.state & LockMask))) {
    index += 1;
    }
    sym = XKeycodeToKeysym(dispPtr->display, eventPtr->xkey.keycode, index);

    /*
     * Special handling:  if the key was shifted because of Lock, but
     * lock is only caps lock, not shift lock, and the shifted keysym
     * isn't upper-case alphabetic, then switch back to the unshifted
     * keysym.
     */

    if ((index & 1) && !(eventPtr->xkey.state & ShiftMask)
        && (dispPtr->lockUsage == LU_CAPS)) {
    if (!(((sym >= XK_A) && (sym <= XK_Z))
        || ((sym >= XK_Agrave) && (sym <= XK_Odiaeresis))
        || ((sym >= XK_Ooblique) && (sym <= XK_Thorn)))) {
        index &= ~1;
        sym = XKeycodeToKeysym(dispPtr->display, eventPtr->xkey.keycode,
            index);
    }
    }

    /*
     * Another bit of special handling:  if this is a shifted key and there
     * is no keysym defined, then use the keysym for the unshifted key.
     */

    if ((index & 1) && (sym == NoSymbol)) {
    sym = XKeycodeToKeysym(dispPtr->display, eventPtr->xkey.keycode,
            index & ~1);
    }
    return sym;
}

/*
 *--------------------------------------------------------------
 *
 * InitKeymapInfo --
 *
 *    This procedure is invoked to scan keymap information
 *    to recompute stuff that's important for binding, such
 *    as the modifier key (if any) that corresponds to "mode
 *    switch".
 *
 * Results:
 *    None.
 *
 * Side effects:
 *    Keymap-related information in dispPtr is updated.
 *
 *--------------------------------------------------------------
 */

static void
InitKeymapInfo(dispPtr)
    TkDisplay *dispPtr;        /* Display for which to recompute keymap
                 * information. */
{
    XModifierKeymap *modMapPtr;
    KeyCode *codePtr;
    KeySym keysym;
    int count, i, j, max, arraySize;
#define KEYCODE_ARRAY_SIZE 20

    dispPtr->bindInfoStale = 0;
    modMapPtr = XGetModifierMapping(dispPtr->display);

    /*
     * Check the keycodes associated with the Lock modifier.  If
     * any of them is associated with the XK_Shift_Lock modifier,
     * then Lock has to be interpreted as Shift Lock, not Caps Lock.
     */

    dispPtr->lockUsage = LU_IGNORE;
    codePtr = modMapPtr->modifiermap + modMapPtr->max_keypermod*LockMapIndex;
    for (count = modMapPtr->max_keypermod; count > 0; count--, codePtr++) {
    if (*codePtr == 0) {
        continue;
    }
    keysym = XKeycodeToKeysym(dispPtr->display, *codePtr, 0);
    if (keysym == XK_Shift_Lock) {
        dispPtr->lockUsage = LU_SHIFT;
        break;
    }
    if (keysym == XK_Caps_Lock) {
        dispPtr->lockUsage = LU_CAPS;
        break;
    }
    }

    /*
     * Look through the keycodes associated with modifiers to see if
     * the the "mode switch", "meta", or "alt" keysyms are associated
     * with any modifiers.  If so, remember their modifier mask bits.
     */

    dispPtr->modeModMask = 0;
    dispPtr->metaModMask = 0;
    dispPtr->altModMask = 0;
    codePtr = modMapPtr->modifiermap;
    max = 8*modMapPtr->max_keypermod;
    for (i = 0; i < max; i++, codePtr++) {
    if (*codePtr == 0) {
        continue;
    }
    keysym = XKeycodeToKeysym(dispPtr->display, *codePtr, 0);
    if (keysym == XK_Mode_switch) {
        dispPtr->modeModMask |= ShiftMask << (i/modMapPtr->max_keypermod);
    }
    if ((keysym == XK_Meta_L) || (keysym == XK_Meta_R)) {
        dispPtr->metaModMask |= ShiftMask << (i/modMapPtr->max_keypermod);
    }
    if ((keysym == XK_Alt_L) || (keysym == XK_Alt_R)) {
        dispPtr->altModMask |= ShiftMask << (i/modMapPtr->max_keypermod);
    }
    }

    /*
     * Create an array of the keycodes for all modifier keys.
     */

    if (dispPtr->modKeyCodes != NULL) {
    ckfree((char *) dispPtr->modKeyCodes);
    }
    dispPtr->numModKeyCodes = 0;
    arraySize = KEYCODE_ARRAY_SIZE;
    dispPtr->modKeyCodes = (KeyCode *) ckalloc((unsigned)
        (KEYCODE_ARRAY_SIZE * sizeof(KeyCode)));
    for (i = 0, codePtr = modMapPtr->modifiermap; i < max; i++, codePtr++) {
    if (*codePtr == 0) {
        continue;
    }

    /*
     * Make sure that the keycode isn't already in the array.
     */

    for (j = 0; j < dispPtr->numModKeyCodes; j++) {
        if (dispPtr->modKeyCodes[j] == *codePtr) {
        goto nextModCode;
        }
    }
    if (dispPtr->numModKeyCodes >= arraySize) {
        KeyCode *new;

        /*
         * Ran out of space in the array;  grow it.
         */

        arraySize *= 2;
        new = (KeyCode *) ckalloc((unsigned)
            (arraySize * sizeof(KeyCode)));
        memcpy((VOID *) new, (VOID *) dispPtr->modKeyCodes,
            (dispPtr->numModKeyCodes * sizeof(KeyCode)));
        ckfree((char *) dispPtr->modKeyCodes);
        dispPtr->modKeyCodes = new;
    }
    dispPtr->modKeyCodes[dispPtr->numModKeyCodes] = *codePtr;
    dispPtr->numModKeyCodes++;
    nextModCode: continue;
    }
    XFreeModifiermap(modMapPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * EvalTclBinding --
 *
 *    The procedure that is invoked by Tk_BindEvent when a Tcl binding
 *    is fired.
 *
 * Results:
 *    A standard Tcl result code, the result of globally evaluating the
 *    percent-substitued binding string.
 *
 * Side effects:
 *    Normal side effects due to eval.
 *
 *---------------------------------------------------------------------------
 */

static void
FreeTclBinding(clientData)
    ClientData clientData;
{
    ckfree((char *) clientData);
}

/*
 *----------------------------------------------------------------------
 *
 * TkStringToKeysym --
 *
 *    This procedure finds the keysym associated with a given keysym
 *    name.
 *
 * Results:
 *    The return value is the keysym that corresponds to name, or
 *    NoSymbol if there is no such keysym.
 *
 * Side effects:
 *    None.
 *
 *----------------------------------------------------------------------
 */

KeySym
TkStringToKeysym(name)
    char *name;            /* Name of a keysym. */
{
#ifdef REDO_KEYSYM_LOOKUP
    Tcl_HashEntry *hPtr;
    KeySym keysym;

    hPtr = Tcl_FindHashEntry(&keySymTable, name);
    if (hPtr != NULL) {
    return (KeySym) Tcl_GetHashValue(hPtr);
    }
    if (strlen(name) == 1) {
    keysym = (KeySym) (unsigned char) name[0];
    if (TkKeysymToString(keysym) != NULL) {
        return keysym;
    }
    }
#endif /* REDO_KEYSYM_LOOKUP */
    return XStringToKeysym(name);
}

/*
 *----------------------------------------------------------------------
 *
 * TkKeysymToString --
 *
 *    This procedure finds the keysym name associated with a given
 *    keysym.
 *
 * Results:
 *    The return value is a pointer to a static string containing
 *    the name of the given keysym, or NULL if there is no known name.
 *
 * Side effects:
 *    None.
 *
 *----------------------------------------------------------------------
 */

char *
TkKeysymToString(keysym)
    KeySym keysym;
{
#ifdef REDO_KEYSYM_LOOKUP
    Tcl_HashEntry *hPtr;

    hPtr = Tcl_FindHashEntry(&nameTable, (char *)keysym);
    if (hPtr != NULL) {
    return (char *) Tcl_GetHashValue(hPtr);
    }
#endif /* REDO_KEYSYM_LOOKUP */
    return XKeysymToString(keysym);
}

/*
 *----------------------------------------------------------------------
 *
 * TkCopyAndGlobalEval --
 *
 *    This procedure makes a copy of a script then calls Tcl_GlobalEval
 *    to evaluate it.  It's used in situations where the execution of
 *    a command may cause the original command string to be reallocated.
 *
 * Results:
 *    Returns the result of evaluating script, including both a standard
 *    Tcl completion code and a string in interp->result.
 *
 * Side effects:
 *    None.
 *
 *----------------------------------------------------------------------
 */

int
TkCopyAndGlobalEval(interp, script)
    Tcl_Interp *interp;            /* Interpreter in which to evaluate
                     * script. */
    char *script;            /* Script to evaluate. */
{
    Tcl_DString buffer;
    int code;

    Tcl_DStringInit(&buffer);
    Tcl_DStringAppend(&buffer, script, -1);
    code = Tcl_GlobalEval(interp, Tcl_DStringValue(&buffer));
    Tcl_DStringFree(&buffer);
    return code;
}