Amiga ISO Collection/AmigaUtilCD2.iso/Programming/Assembler/TFF-AOC.DMS/in.adf/Release3.1/AutoDocs3.1.lha/doc/commodities.doc

Text File | 1993-08-12 | 28.4 KB | 967 lines

TABLE OF CONTENTS

commodities.library/ActivateCxObj
commodities.library/AddIEvents
commodities.library/AttachCxObj
commodities.library/ClearCxObjError
commodities.library/CreateCxObj
commodities.library/CxBroker
commodities.library/CxMsgData
commodities.library/CxMsgID
commodities.library/CxMsgType
commodities.library/CxObjError
commodities.library/CxObjType
commodities.library/DeleteCxObj
commodities.library/DeleteCxObjAll
commodities.library/DisposeCxMsg
commodities.library/DivertCxMsg
commodities.library/EnqueueCxObj
commodities.library/InsertCxObj
commodities.library/InvertKeyMap
commodities.library/MatchIX
commodities.library/ParseIX
commodities.library/RemoveCxObj
commodities.library/RouteCxMsg
commodities.library/SetCxObjPri
commodities.library/SetFilter
commodities.library/SetFilterIX
commodities.library/SetTranslate
commodities.library/ActivateCxObj           commodities.library/ActivateCxObj

   NAME
    ActivateCxObj -- change the activation state of a commodity object.
             (V36)

   SYNOPSIS
    previous = ActivateCxObj(co,true);
    D0             A0 D0

    LONG ActivateCxObj(CxObj *,LONG);

   FUNCTION
    Commodity objects of all types maintain an activation state.
    If an object is "active", then it performs its particular action
    whenever a commodity message arrives. If the object is "inactive"
    no action is taken, and the message goes on to its next destination.

    All objects are created in the "active" state except brokers
    which are created "inactive". Thus, after you create your
    broker and hang a tree of objects off of it, you must remember
    to use this function to activate it. This causes it to divert all
    messages to your tree of objects.

    This function activates 'co' if 'true' is different than 0. and
    deactivates it otherwise. The previous activation state is
    returned.

   INPUTS
    co - the commodity object to affect (may be NULL)
    true - 0 to deactivate the object, anything else to activate it

   RESULTS
    previous - the previous activation state: 0 if the object was
           inactive or if 'co' was NULL, anything else if the object
           was active

   SEE ALSO
    CxBroker()

commodities.library/AddIEvents                 commodities.library/AddIEvents

   NAME
    AddIEvents -- add input events to commodities' input stream. (V36)

   SYNOPSIS
    AddIEvents(events)
           A0

    VOID AddIEvents(struct InputEvent *);

   FUNCTION
    This function adds a null-terminated linked list of input events to
    the input stream processed by commodities. It is a touch easier than
    using the input device directly.

    The contents of the input events are copied into commodity messages,
    so they may be disposed of as soon as this call returns.

    The messages are initially routed to the first broker in
    commodities' object list.

   INPUTS
    events - the list of input events to add (may be NULL)

   WARNING
    The cx_lib/InvertString() function creates lists of input events that
    are in reverse order. Thus, passing the result of InvertString()
    to this function will insert a series of input events that will
    generate a string that's a mirror image of the string passed to
    InvertString() originally.

    The solution to the above is to either flip the string before
    passing it to InvertString(), or flip the resulting list of input
    events.

   BUGS
    Prior to V40, this function did not copy the data pointed to by
    ie_EventAddress for any events of type IECLASS_NEWPOINTERPOS.

   SEE ALSO
    cx_lib/FreeIEvents()

commodities.library/AttachCxObj               commodities.library/AttachCxObj

   NAME
    AttachCxObj -- attach a commodity object to the end of an existing
               list of objects. (V36)

   SYNOPSIS
    AttachCxObj(headObj,co);
            A0      A1

    VOID AttachCxObj(CxObj *,CxObj *);

   FUNCTION
    Adds 'co' to the list of objects pointed to by 'headObj'. The
    new object is added at the end of the list.

   INPUTS
    headObj - pointer to a list of objects. If this value is NULL, then
          the entire tree of objects pointed to by 'co' is deleted
          and becomes invalid.
    co - the object to add to the list (may be NULL)

   RESULTS
    If 'co' is NULL, this function will record that fact in the
    internal accumulated error of 'headObj'. This error record
    can be retrieved using CxObjError() and cleared using
    ClearCxObjError().

   BUGS
    Until V38, passing a NULL 'headObj' parameter would cause low-memory
    access and unpredictable results.

   SEE ALSO
    CxObjError(), ClearCxObjError()

commodities.library/ClearCxObjError       commodities.library/ClearCxObjError

   NAME
    ClearCxObjError -- clear the accumulated error value of a commodity
               object. (V36)

   SYNOPSIS
    ClearCxObjError(co);
                      A0

    VOID ClearCxObjError(CxObj *);

   FUNCTION
    This function clears the accumulated error value of commodity object
    'co'.

    It is unwise to do this to a filter if COERR_BADFILTER is set.
    This will fool commodities into thinking the filter is OK. Set
    another valid filter, or leave the error value alone.

   INPUTS
    co - the object to affect (may be NULL)

   SEE ALSO
    CxObjError()

commodities.library/CreateCxObj               commodities.library/CreateCxObj

   NAME
    CreateCxObj -- create a new commodity object. (V36)

   SYNOPSIS
    co = CreateCxObj(type,arg1,arg2);
    D0         D0   A0   A1

    CxObj *CreateCxObj(ULONG,LONG,LONG);

   FUNCTION
    This function creates a commodity object of type 'type'. It is not
    proper to call this function directly. Each object creation routine
    except CxBroker() is defined as a macro in <libraries/commodities.h>
    These are independently documented.

    All functions which operate on a commodity object are made with
    a reference to the thirty-two bit value returned by this function
    (or by CxBroker()).

   INPUTS
    type - the type of object to create as defined in
           <libraries/commodities.h>
    arg1 - first argument, meaning depends on 'type'
    arg2 - second argument, meaning depends on 'type'

   RESULTS
    co - a pointer to the new object or NULL if it could not be created.
         A NULL return indicates typically a lack of system memory. Minor
         problems in creating an object, such as providing a bad filter
         description to cx_lib/CxFilter(), typically don't cause failure,
         but are recorded in an internal error field in the new object
         which can be accessed via CxObjError().

   SEE ALSO
    CxObjError(), cx_lib/CxFilter(), cx_lib/CxSender(),
    cx_lib/CxSignal(), cx_lib/CxTranslate(), cx_lib/CxDebug(),
    cx_lib/CxCustom(), CxBroker()

commodities.library/CxBroker                     commodities.library/CxBroker

   NAME
    CxBroker -- create a commodity broker. (V36)

   SYNOPSIS
    broker = CxBroker(nb,error);
    D0          A0 D0

    CxObj *CxBroker(struct NewBroker *,LONG *);

   FUNCTION
    This function creates a broker from the specification found in the
    NewBroker structure pointed to by 'nb'. The purpose and meaning of the
    fields of the NewBroker structure are described below. Also see
    <libraries/commodities.h> for more info.

    struct NewBroker
    {
        BYTE            nb_Version;
        STRPTR          nb_Name;
        STRPTR          nb_Title;
        STRPTR          nb_Descr;
        WORD            nb_Unique;
        WORD        nb_Flags;
        BYTE            nb_Pri;
        struct MsgPort *nb_Port;
        WORD            nb_ReservedChannel;
    };

    nb_Version
    This is the way that future versions of commodities can identify
    which version of the NewBroker structure you are using. This should be
    set to NB_VERSION as defined in <libraries/commodities.h>

    nb_Name
    This is the name of the broker. This name is used to find the broker
    in commodities' object list and is the name shown in the listview
    gadget of the Exchange program. The name string is copied in the
    broker object upon creation so it can be discarded right after
    CxBroker() returns. The maximum length of the name string is defined
    by a constant in <libraries/commodities.h>.

    nb_Title, nb_Descr
    These are two strings which appear to the user in the Exchange
    program and describe the application the broker is representing.
    Note that these strings are copied into the broker object so they
    can be discarded right after CxBroker() returns. The maximum length
    of these strings that will be recognized are defined by constants in
    <libraries/commodities.h>.

    nb_Unique
    This field indicates what should happen if a broker of the same name
    (nb_Name) already exists in commodities' object list. Constants
    in <libraries/commodities.h> allow the caller to specify whether
    another broker is to be created, and whether any existing broker of
    the same name should be notified that an attempt at creating a
    duplicate has been made.

    nb_Pri
    This specifies with what priority the new broker is to be inserted
    within commodities' object list. Higher priority nodes appear
    earlier in a list. It is strongly recommended that the ToolTypes
    environment of an application be used to allow the end-user to set
    the priority of the broker.

   INPUTS
    nb - an initialized NewBroker structure
    error - a pointer to a longword where to store a failure code (may be
        NULL)

   RESULTS
    broker - a pointer to the broker object or NULL upon failure. If the
         'error' pointer is not NULL, a further diagnostic code is
         placed at that address. Error codes are defined in
         <libraries/commodities.h> and include:

            CBERR_OK
            No problems; broker created OK.

             CBERR_SYSERR
            System problems, not your fault, sign of low memory.

            CBERR_DUP
            The nb_Unique field specified that only one broker of
            'nb_Name' should be allowed, and one already exists.

            CBERR_VERSION
            The version specified in 'nb_Version' is unknown to the
            library.

   SEE ALSO
    SetCxObjPri(), <libraries/commodities.h>

commodities.library/CxMsgData                   commodities.library/CxMsgData

   NAME
    CxMsgData -- obtain a pointer to a commodity message's data area. (V36)

   SYNOPSIS
    data = CxMsgData(cxm);
    D0         A0

    APTR CxMsgData(struct CxMsg *);

   FUNCTION
    Most commodity messages contain meaningful data such as an InputEvent
    structure. This function returns a pointer to this data.

    You may get a commodity message from a synchronous (custom object) or
    asynchronous (sender object) source. In the second case, 'data' is
    not valid after you have replied to the message.

   INPUTS
    cxm - the commodity message to get the data pointer from (may be NULL)

   RESULTS
    data - a pointer to the message's data, or NULL if 'cxm' is NULL.
           The meaning of the data varies depending on which kind of
           object is being inspected.

   BUGS
    Until V38, passing a NULL 'cxm' parameter would cause low-memory
    access and unpredictable results.

    Until V40, whenever the data pointer is a (struct InputEvent), the
    ie_EventAddress field of these structures was not reliable whenever
    the message was generated by a sender object.

   SEE ALSO
    cx_lib/CxSender(), cx_lib/CxCustom()

commodities.library/CxMsgID                       commodities.library/CxMsgID

   NAME
    CxMsgID -- obtain the ID of a commodity message. (V36)

   SYNOPSIS
    id = CxMsgID(cxm);
    D0         A0

    LONG CxMsgID(struct CxMsg *);

   FUNCTION
    This function returns the value associated with the cause or source
    of the commodity message 'cxm'. Values are provided by the application
    when a sender or custom object is created.

   INPUTS
    cxm - the commodity message to inquire about (must NOT be NULL)

   RESULTS
    id - if not specified by the application, the ID value of a
         commodity message will be 0. It is suggested that using
         non-zero values in your program as a rule may identify some
         possible errors.

   SEE ALSO
    cx_lib/CxSender(), cx_lib/CxCustom()

commodities.library/CxMsgType                   commodities.library/CxMsgType

   NAME
    CxMsgType -- obtain the type of a commodity message. (V36)

   SYNOPSIS
    type = CxMsgType(cxm);
    D0         A0

    ULONG CxMsgType(struct CxMsg *);

   FUNCTION
    This function returns the type of a commodity message. Possible values
    of 'type' are defined in <libraries/commodities.h>. Most commodity
    messages are of type CXM_IEVENT.

   INPUTS
    cxm - the commodity message to inquire about (must NOT be NULL)

   RESULTS
       type - the type of the commodity message, possible values are defined
           in <libraries/commodities.h>

commodities.library/CxObjError                 commodities.library/CxObjError

   NAME
    CxObjError -- obtain a commodity object's accumulated error. (V36)

   SYNOPSIS
    error = CxObjError(co);
    D0           A0

    LONG CxObjError(CxObj *);

   FUNCTION
    When a function acting on an object fails, it records the failure
    in the object. This function returns the accumulated error value.
    The values are represented by flag bits defined in
    <libraries/commodities.h>. Several errors may be recorded by multiple
    bits in 'error'.

    The currently defined errors are:

    COERR_ISNULL
      The value of parameter 'co' was in fact NULL. This error
      means "the problem with the object you inquire about is
      that it failed to be created."

      COERR_NULLATTACH
      Using the commodities' list manipulation functions, an attempt was
      made to add a NULL object to the list belonging to 'co'. This allows
      a line of code as follows to exist in an error-tolerant program:

        AttachCxObj(filter,CxSender(myport,MY_ID));

      COERR_BADFILTER
      The most recent filter specification for a filter object
      was faulty. This happens if no sense can be made out of a
      description string, or if an input expression (IX) has an
      invalid format or version byte. When this bit is set in a
      filter's error field, the filter will match nothing, but this
      is not the proper way to "turn off" a filter, use ActivateCxObj().

      COERR_BADTYPE
      A type specific operation, such as SetFilterIX(), was called
      for object 'co', but 'co' isn't of the proper type.

   INPUTS
    co - the commodity object to get the accumulated error from (may be
         NULL)

   RESULTS
    error - the accumulated error, or 0 if 'co' is NULL

   SEE ALSO
    SetFilter(), SetFilterIX(), AttachCxObj(), ActivateCxObj(),
    ClearCxObjError()

commodities.library/CxObjType                   commodities.library/CxObjType

   NAME
    CxObjType -- obtain the type of a commodity object. (V36)

   SYNOPSIS
    type = CxObjType(co);
    D0         A0

    ULONG CxObjType(CxObj *);

   FUNCTION
    This function should not really be necessary. It returns
    the type of a commodity object, which you should already
    know, since you created it in the first place.

   INPUTS
    co - the commodity object to inquire about (may be NULL)

   RESULTS
    type - the type of the commodity object, possible values are
           defined in <libraries/commodities.h>. Returns CX_INVALID
           if 'co' is NULL.

   SEE ALSO
    CreateCxObj()

commodities.library/DeleteCxObj               commodities.library/DeleteCxObj

   NAME
    DeleteCxObj -- delete a commmodity object. (V36)

   SYNOPSIS
    DeleteCxObj(co);
                A0

    VOID DeleteCxObj(CxObj *);

   FUNCTION
    Deletes a commodity object of any type. If the object
    is linked into a list, it is first removed. Note that
    the handle 'co' is invalid after this function is called.

    Also note that deleting an object which has other objects attached
    to it may be undesirable. Use the function DeleteCxObjAll()
    to delete an entire sub-tree of objects.

   INPUTS
    co - the commodity object to delete (may be NULL)

   SEE ALSO
    DeleteCxObjAll()

commodities.library/DeleteCxObjAll         commodities.library/DeleteCxObjAll

   NAME
    DeleteCxObjAll -- recursively delete a tree of commodity objects.
              (V36)

   SYNOPSIS
    DeleteCxObjAll(co);
               A0

    VOID DeleteCxObjAll(CxObj *);

   FUNCTION
    This function deletes the commodity object 'co', and
    recursively deletes all objects attached to it, and the
    objects attached to them, etc.

    If 'co' is linked into a list, it is first removed. Note
    that the handle 'co' is invalid after this function is called.

    This function is useful when an application exits: most
    applications can clean up completely by deleting the
    entire sub-tree of objects starting at their broker.

   INPUTS
    co - the first commodity object to delete (may be NULL)

   SEE ALSO
    DeleteCxObj()

commodities.library/DisposeCxMsg             commodities.library/DisposeCxMsg

   NAME
    DisposeCxMsg -- delete a commodity message. (V36)

   SYNOPSIS
    DisposeCxMsg(cxm);
             A0

    VOID DisposeCxMsg(struct CxMsg *);

   FUNCTION
    This function eliminates the commodity message pointed to by 'cxm'.
    Can be used to 'swallow' input events by disposing of every commodity
    message of type CXM_IEVENT.

    This function can only be called from within a custom object running
    on the input handler's context. It cannot be called from code running
    on a commodities' context, such as when receiving a CXM_IEVENT message
    from a sender object. CxMsg sent to a commodity program from a sender
    object must be sent back using ReplyMsg().

   INPUTS
    cxm - the commodity message to delete (must NOT be NULL)

commodities.library/DivertCxMsg               commodities.library/DivertCxMsg

   NAME
    DivertCxMsg -- send a commodity message down an object list. (V36)

   SYNOPSIS
    DivertCxMsg(cxm,headObj,returnObj);
            A0  A1      A2

    VOID DivertCxMsg(struct CxMsg *,CxObj *,CxObj *);

   FUNCTION
    This function sends the commodity message 'cxm' down the list of
    objects attached to 'headObj'. The pointer 'returnObj' is first
    pushed onto the routing stack of 'cxm' so that when the end of the
    list of 'headObj' is reached the SUCCESSOR of 'returnObj' is the
    next destination.

    For example, when a filter finds a match with a message, the
    message is diverted down the filter's list like this:

      DivertCxMsg(cxm,filter,filter);

   INPUTS
    cxm - the commodity message to divert (must NOT be NULL)
    headObj - the list of objects to divert the message to
    returnObj - the object to use as a place holder

   SEE ALSO
    RouteCxMsg()

commodities.library/EnqueueCxObj             commodities.library/EnqueueCxObj

   NAME
    EnqueueCxObj -- insert a commodity object within a list of objects
                based on object priority. (V36)

   SYNOPSIS
    EnqueueCxObj(headObj,co);
             A0      A1

    VOID EnqueueCxObj(CxObj *,CxObj *);

   FUNCTION
    This function puts object 'co' into the list of object 'headObj'.
    The insertion point is determined by the object's priority. The
    objects are kept in the list from the highest priority to the
    lowest. New nodes are inserted in front of the first node with a
    lower priority. Hence a FIFO queue for nodes of equal priority.

    The priority of the commodity object can be set using SetCxObjPri().

   INPUTS
    headObj - pointer to a list of objects. If this value is NULL, then
          the entire tree of objects pointed to by 'co' is deleted
          and becomes invalid.
    co - the object to add to the list (may be NULL)

   RESULTS
    If 'co' is NULL, this function will record that fact in the
    internal accumulated error of 'headObj'. This error record
    can be retrieved using CxObjError() and cleared using
    ClearCxObjError().

   BUGS
    Until V38, passing a NULL 'headObj' parameter would cause low-memory
    access and unpredictable results.

   SEE ALSO
    SetCxObjPri(), CxObjError(), ClearCxObjError()

commodities.library/InsertCxObj               commodities.library/InsertCxObj

   NAME
    InsertCxObj -- insert a commodity object in a list after a given
               object. (V36)

   SYNOPSIS
    InsertCxObj(headObj,co,pred);
            A0      A1 A2

    VOID InsertCxObj(CxObj *,CxObj *,CxObj *);

   FUNCTION
    Adds 'co' to the list of objects pointed to by 'headObj' after
    object 'pred'.

   INPUTS
    headObj - pointer to a list of objects. If this value is NULL, then
          the entire tree of objects pointed to by 'co' is deleted
          and becomes invalid.
    co - the object to add to the list (may be NULL)
    pred - the object after which 'co' should be inserted. If this is NULL
           then 'co' is added to the head of the list.

   RESULTS
    If 'co' is NULL, this function will record that fact in the
    internal accumulated error of 'headObj'. This error record
    can be retrieved using CxObjError() and cleared using
    ClearCxObjError().

   BUGS
    Until V38, passing a NULL 'headObj' parameter would cause low-memory
    access and unpredictable results.

   SEE ALSO
    CxObjError(), ClearCxObjError()

commodities.library/InvertKeyMap             commodities.library/InvertKeyMap

   NAME
    InvertKeyMap -- generate an input event from an ANSI code. (V36)

   SYNOPSIS
    success = InvertKeyMap(ansiCode,event,km)
    D0                D0       A0    A1

    BOOL InvertKeyMap(ULONG,struct InputEvent *,struct KeyMap *);

   FUNCTION
    This function uses the system call MapANSI() to figure out what
    InputEvent translates to an ANSI character code 'ansiCode'. The
    InputEvent pointed to by 'event' is filled in with that information.
    The KeyMap 'km' is used for the translation, unless it is NULL, in
    which case the current system default keymap is used.

   INPUTS
    ansiCode - the ANSI code to convert to an input event
    event - the InputEvent to fill-in
    km - the keymap to use for the translation, or NULL to use the
         current system default keymap.

   RESULTS
    success - TRUE if the translation worked, FALSE otherwise.

   BUGS
    This function currently handles one-deep dead keys (such as
    <alt f>o ). It does not look up the high key map (keystrokes
    with scan codes greater than 0x40).

    Prior to V40, this function was not initializing the ie_SubClass
    and ie_TimeStamp fields of the InputEvent structure. A simple work
    around to the problem is to clear these values to 0 before making
    a call to this function:

        struct InputEvent ie;

            ie.ie_SubClass           = 0;
            ie.ie_TimeStamp.tv_secs  = 0;
            ie.ie_TimeStamp.tv_micro = 0;
            if (InvertKeyMap(ansiCode,&ie,NULL))
            ...

   SEE ALSO
    cx_lib/InvertString()

commodities.library/MatchIX                       commodities.library/MatchIX

   NAME
    MatchIX -- see if an input event matches an initialized input
           expression. (V38)

   SYNOPSIS
    match = MatchIX(event,ix);
    D0        A0    A1

    BOOL MatchIX(struct InputEvent *,IX *);

   FUNCTION
    This function determines whether an input event matches an
    initialized input expression. Applications generally do not
    need to call this function as filter objects will normally provide
    all the event filtering needed. Nevertheless, MatchIX()
    can come in handy as it is the same function used to match an
    event to the various filter objects when an event makes its way
    through the input network.

   INPUTS
    event - the input event to match against the input expression
    ix - the input expression for the comparison

   RESULTS
    match - TRUE if the input event matches the input expression, or
        FALSE if not

   SEE ALSO
    <libraries/commodities.h>, ParseIX()

commodities.library/ParseIX                       commodities.library/ParseIX

   NAME
    ParseIX -- initialize an input expression given a description string.
           (V36)

   SYNOPSIS
    failureCode = ParseIX(description,ix);
    D0              A0          A1

    LONG ParseIX(STRPTR,IX *);

   FUNCTION
    Given an input description string and an allocated input
    expression, sets the fields of the input expression to
    correspond to the description string.

   INPUTS
    description - the string to parse
    ix - the input expression to hold the result of the parse

   RESULTS
    failureCode -  0 if all went well,
              -1 if tokens after end (code spec)
                  -2 if 'description' was NULL

   SEE ALSO
    <libraries/commodities.h>, MatchIX()

commodities.library/RemoveCxObj               commodities.library/RemoveCxObj

   NAME
    RemoveCxObj -- remove a commodity object from a list. (V36)

   SYNOPSIS
    RemoveCxObj(co);
            A0

    VOID RemoveCxObj(CxObj *);

   FUNCTION
    This function removes 'co' from any list it may be a part of.
    Will not crash if 'co' is NULL, or if it has not been inserted
    in a list.

   INPUTS
    co - the object to remove (may be NULL)

   SEE ALSO
    AttachCxObj(), EnqueueCxObj(), InsertCxObj()

commodities.library/RouteCxMsg                 commodities.library/RouteCxMsg

   NAME
    RouteCxMsg -- set the next destination of a commodity message. (V36)

   SYNOPSIS
    RouteCxMsg(cxm,co);
           A0  A1

    VOID RouteCxMsg(struct CxMsg *,CxObj *);

   FUNCTION
    Establishes the next destination of a commodity message
    to be 'co', which must be a valid commodity object, and
    must be linked in ultimately to commodities' object list.

    Routing of an object is analogous to a 'goto' in a program.
    There is no effect on the message's routing stack.

   INPUTS
    cxm - the commodity message to route (must NOT be NULL)
    co - the commodity object to route the message to (must NOT be NULL)

   SEE ALSO
    DivertCxMsg()

commodities.library/SetCxObjPri               commodities.library/SetCxObjPri

   NAME
    SetCxObjPri -- set the priority of a commodity object. (V36)

   SYNOPSIS
    oldPri = SetCxObjPri(co,pri)
    D0                   A0 D0

    LONG SetCxObjPri(CxObj *,LONG);

   FUNCTION
    This function sets the priority of a commodity object for the
    purposes of EnqueueCxObj().

    It is strongly recommended that the ToolTypes environment be
    utilized to provide end-user control over the priority of
     brokers, but application specific ordering of other objects
    within their lists is not dictated.

   INPUTS
    co - the commodity object to affect (may be NULL)
    pri - the object's new priority in the range -128 to +127. A value
          of 0 is normal.

   RESULTS
    oldPri - the previous priority of the object or 0 if 'co' was NULL.
         This value is only returned in V38 and beyond.

   BUGS
    This function will not reposition an object within its list when
    its priority changes. To attain the same effect, first remove the
    object from its list using RemoveCxObj(), set its priority using
    SetCxObjPri(), and reinsert it in the list using EnqueueCxObj().

   SEE ALSO
    EnqueueCxObj()

commodities.library/SetFilter                   commodities.library/SetFilter

   NAME
    SetFilter -- change the matching condition of a commodity filter.
             (V36)

   SYNOPSIS
    SetFilter(filter,text);
          A0     A1

    VOID SetFilter(CxObj *,STRPTR);

   FUNCTION
    This function changes the matching condition of a commodity input
    filter to that described by the input description string 'text'.

   INPUTS
    filter - the filter object to affect (may be NULL)
    text - the new matching conditions for the filter

   RESULTS
    The internal error of 'filter' will have the COERR_BADFILTER
    bit set or cleared depending on the failure or success of this
    function.

   SEE ALSO
    SetFilterIX(), CxObjError()

commodities.library/SetFilterIX               commodities.library/SetFilterIX

   NAME
    SetFilterIX -- change the matching condition of a commodity filter.
               (V36)

   SYNOPSIS
    SetFilterIX(filter,ix);
            A0     A1

    VOID SetFilterIX(CxObj *,IX *);

   FUNCTION
    This function changes the matching condition of a commodity input
    filter to that described by the binary input expression pointed by
    'ix'.

    Input expressions are defined in <libraries/commodities.h>.
    It is important to remember that the first field of the input
    expression structure must indicate which version of the
    input expression structure is being used.

   INPUTS
    filter - the filter object to affect (may be NULL)
    ix - the new matching conditions for the filter

   RESULTS
    The internal error of 'filter' will have the COERR_BADFILTER
    bit set or cleared depending on the failure or success of this
    function.

   SEE ALSO
    SetFilter(), CxObjError()

commodities.library/SetTranslate             commodities.library/SetTranslate

   NAME
    SetTranslate -- replace a translator object's translation list. (V36)

   SYNOPSIS
    SetTranslate(translator,events);
             A0         A1

    VOID SetTranslate(CxObj *,struct InputEvent *);

   FUNCTION
    This function replaces the translation list of a commodity
    translator object with the linked list starting at 'events'.

    A NULL value for 'events' indicates that the object 'translator'
    should swallow all commodity messages that are sent its way.

    Note that the input events are not copied into commodities' private
    memory, but the value of 'events' is used -- asynchronously to the
    application program -- to find a chain of InputEvents in the
    application's data space. At the time of translation, each input event
    is copied into its own new commodity message.

    The above means that no other commodities' user, nor
    commodities.library itself will be modifying your list of InputEvents.
    On the other hand, your program must not corrupt the input event
    chain that has been presented to a translator.

   INPUTS
    translator - the translator object to affect (may be NULL)
    events - the new input event translation list

   BUGS
    The list of input events manipulated by a translator object is
    inserted in reverse order in the commodities network, and come out
    of the network in reverse order as well. The cx_lib/InvertString()
    function creates lists of input events that are in reverse order so
    they can be used directly with translator objects.

   SEE ALSO
    <devices/inputevent.h>, cx_lib/CxTranslate()