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Text File | 1993-01-04 | 41.1 KB | 527 lines

(***************************************************************************** * * * ADVCRT - Advanced Screen and Keyboard Manipulation Routines * * for Borland International's Turbo Pascal Version 5.5 * * * * Serial Number: 000000 - Released June 19, 1990 * * Licensed to: Author * * For: Normal use * * Current Version: 9.0 * * * ***************************************************************************** * * * Description of AdvCRT Routines: * * * ***************************************************************************** * * * Procedure FindScreenBase(var ScreenBase: Word); * * { * * DESCRIPTION: * * Returns type of display adaptor installed in the form of the * * Video Segment Address. * * PARAMETERS: * * ScreenBase (out) - Video Segment Address of display * * Hex B800 - SVGA/VGA/EGA/CGA/MCGA card * * Hex B000 - Monochrome card * * NOTE(S): * * Used primarily for DirectOut procedure. * * ----------------------------------------------------------------------} * * * * Function QuickScreenBase: Word; * * { * * DESCRIPTION: * * Returns the Video Segment Address of the current video * * display adaptor installed. Used instead of a global variable * * and the FindScreenBase procedure. * * ----------------------------------------------------------------------} * * * * Function MakeAttr(Fore, Back: Byte): Byte; * * { * * DESCRIPTION: * * Converts given Foreground and Background colors into a * * single Attribute byte for low level machine calls. * * PARAMETERS: * * Fore (in) - Foreground of Attribute to make * * Back (in) - Background of Attribute to make * * NOTE(S): * * Opposite of ExtractAttr procedure. * * ----------------------------------------------------------------------} * * * * Procedure ExtractAttr(Attr: Byte; var Fore, Back: Byte); * * { * * DESCRIPTION: * * Converts machine Attribute (single number) to Compiler * * specific Foreground and Background colors. * * PARAMETERS: * * Attr (in) - Attribute byte used in low level machine calls * * Fore (out) - Foreground color extracted from Attr * * Back (out) - Background color extracted from Attr * * NOTE(S): * * Opposite of MakeAttr function. * * ----------------------------------------------------------------------} * * * * Procedure TurnCursor(ONorOFF: Boolean); * * { * * DESCRIPTION: * * Turns the cursor ON or OFF. That is, makes it visible or * * invisble. Current cursor shape is retained in the global * * variable SaveCursor. * * PARAMETERS: * * ONorOFF (in) - Pass in ON to make cursor visible, OFF to hide * * cursor * * SYNTAX: * * 1. TurnCursor(OFF); - Hide Cursor * * 2. TurnCursor(ON); - Reveal Cursor * * ----------------------------------------------------------------------} * * * * Procedure SetCursor(StartScan, EndScan: Byte); * * { * * DESCRIPTION: * * Sets cursor to a specific size. * * PARAMETERS: * * StartScan (in) - Start cursor scan line (upper half) (0-13) * * EndScan (in) - Ending cursor scan line (bottom half) (0-13) * * NOTE(S): * * If StartScan>EndScan the cursor will become invisible. * * ----------------------------------------------------------------------} * * * * Procedure Scroll(X1,Y1,X2,Y2, LinesToScroll, BlankLineAttr, * * UPorDOWN: Byte); * * { * * DESCRIPTION: * * Scrolls a particular area of the screen up or down. * * PARAMETERS: * * X1, Y1 (in) - Coord. of upper-left area to be scrolled * * X2, Y2 (in) - Coord. of lower-right area to be scrolled * * LinesToScroll (in) - Number of lines to scroll * * BlankLineAttr (in) - Attribute to fill the blank area with * * UpOrDown (in) - Direction to scroll the area - 0=Up, 1=Down * * NOTE(S): * * (X1,Y1), (X2,Y2) are related to the coordinates given for * * Turbo Pascal's standard Window procedure. * * ----------------------------------------------------------------------} * * * * Procedure TurnScreen(ONorOFF: Boolean); * * { * * DESCRIPTION: * * Turns the display ON or OFF software wise. If OFF, all output * * to the screen is written, but not shown. Clearing the screen * * along with a TurnScreen(ON) will reactivate the display. * * SYNTAX: * * 1. TurnScreen(OFF); - Turn Screen OFF--Software Wise * * 2. TurnScreen(ON); - Turn Screen ON * * NOTE(S): * * Note that a DIRECT screen write while the screen is OFF will * * infact show up on the display. If you wish to write to the * * screen while it is "OFF", use Turbo's WRITE and WRITELN. * * ----------------------------------------------------------------------} * * * * Procedure DirectOut(X,Y: Byte; aStr: String; Attr: Byte); * * { * * DESCRIPTION: * * Writes a string of information directly to video display memory. * * This routine is not the fastest possible, since it actually * * outputs a character at a time. * * PARAMETERS: * * X, Y (in) - Coordinates where string should be displayed * * aStr (in) - String to be displayed on screen * * Attr (in) - Attribute to be used when displaying * * NOTE(S): * * See MakeAttr function for information on procedure that need * * machine level attributes. * * ----------------------------------------------------------------------} * * * * Procedure SetBorder(BordColor: Byte); * * { * * DESCRIPTION: * * Sets screen border color. Works on all classes of PC's * * including PCjr. * * PARAMETERS: * * BorderColor (in) - Color to set the screen's border to * * NOTE(S): * * Can also be achieved on a PC with a simple Port call. This * * routine works on all PC's including PCjr. * * ----------------------------------------------------------------------} * * * * Procedure GetCursorPos(var X,Y: Byte; Page: Byte); * * { * * DESCRIPTION: * * Returns the position of the cursor on the screen on a given * * Video Display Page. * * PARAMETERS: * * X, Y (out) - Returns the coordinates of the cursor * * Page (in) - The display page to scan for the cursor position * * NOTE(S): * * Quite similar to WhereX and WhereY, but can be used on any * * given display page. Makes AdvCRT Unit dependant only on * * the DOS Unit. * * ----------------------------------------------------------------------} * * * * Procedure GetCRTMode(var Mode, Columns, ActivePage: Byte); * * { * * DESCRIPTION: * * Returns the current mode of the video display adaptor. * * PARAMETERS: * * Mode (out) - Current mode of the CRT * * 0 - 40 column B&W text mode * * 1 - 40 column color text mode * * 2 - 80 column B&W text mode * * 3 - 80 column 16 color text mode * * 4 - 4 color med-resolution graphics mode * * 5 - 4 grey color med-resolution graphics mode * * 6 - 2 color B&W high-resolution graphics mode * * 7 - 80 column monochrome mode * * 8 - 15 graphics modes for EGA Card * * Columns (out) - Current number of columns on the screen * * ActivePage (out) - Active display page number * * ----------------------------------------------------------------------} * * * * Function ActiveDisplayPage: Byte; * * { * * DESCRIPTION: * * Returns the active Video Display Page. Useful for other * * routines that demand a Page be passed into them. * * SYNTAX: * * 1. Writeln(ActiveDisplayPage); * * 2. GetCharXY(12,3, ActiveDisplayPage, Ch, Attr); * * ----------------------------------------------------------------------} * * * * Procedure SetPage(Page: Byte); * * { * * DESCRIPTION: * * Sets active display page. * * PARAMETERS: * * Page (in) - Display page to switch to * * NOTE(S): * * Page is [0-3] in 80 column text mode * * [4-7] in graphics modes. * * Can be used in conjunction with ClrPage, WriteStrPage, * * and WriteChPage procedures to produce "instant" pages of text. * * ----------------------------------------------------------------------} * * * * Procedure SetCurPosPage(X,Y, Page: Byte); * * { * * DESCRIPTION: * * Sets the cursor position on a give page. Used primarily by * * other procedures within this Unit, but can be called * * separately. * * PARAMETERS: * * X, Y (in) - Coordinates on which the cursor should be placed * * Page (in) - Display page to use * * NOTE(S): * * Remember that the display page on which you may be positioning * * the cursor may not be the ACTIVE display page. * * ----------------------------------------------------------------------} * * * * Procedure GetCharXY(X,Y, Page: Byte; var Ch: Char; var Attr: Byte); * * { * * DESCRIPTION: * * Scans the CRT for the character and its attribute at a given * * position on a given display page. * * PARAMETERS: * * X, Y (in) - Coordinates of position to be scanned * * Page (in) - Display page to scan * * Ch (out) - Character found at requested position * * Attr (out) - Attribute of the character found * * NOTE(S): * * Since a character does exist at every position on the screen * * on any page, Ch will return a "blank" character (#32) if no * * other character was found. * * ----------------------------------------------------------------------} * * * * Procedure WriteChPage(X,Y, Page: Byte; Ch: Char; NumReps: Integer; * * Attr: Byte); * * { * * DESCRIPTION: * * Writes a character at screen coordinates X, Y (Column, Row * * respectively) on a given Display Page with a given * * Attribute. * * PARAMETERS: * * X, Y (in) - Coordinates at which to write the character * * Page (in) - Display page to write to * * Ch (in) - Actual character to write * * NumReps (in) - Number of times to write the character * * Attr (in) - Attribute to use when writing the character * * SYNTAX: * * 1. WriteChPage(12,3, ActiveDisplayPage, 'G', 1, MakeAttr(15,1)); * * 2. WriteChPage(13,4, 0, 'a', 2, 7); * * NOTE(S): * * Use with other page routines to create instant pages of text. * * ----------------------------------------------------------------------} * * * * Procedure WriteStrPage(X,Y, Page: Byte; aStr: String; Attr: Byte); * * { * * DESCRIPTION: * * Writes a string at screen coordinates X, Y on a given Display * * Page with a give Attribute. * * PARAMETERS: * * X, Y (in) - Coordinates at which to write the string * * Page (in) - Display page to write to * * aStr (in) - Actual string to write * * Attr (in) - Attribute to use when writing the string * * SYNTAX: * * 1. WriteStrPage(1,10, ActiveDisplayPage, 'Turbo', 7); * * 2. WriteStrPage(2,23, 1, 'Hello', MakeAttr(0,3)); * * NOTE(S): * * Use with other page routines to create instant pages of text. * * ----------------------------------------------------------------------} * * * * Procedure ClrPage(Page: Byte); * * { * * DESCRIPTION: * * Clears a given Display Page and sets the cursor to the upper * * left hand corner of that page. Similar to ClrScr procedure. * * PARAMETERS: * * Page (in) - Display page to clear * * NOTE(S): * * Should be called before writing to a given display page, since * * that page may have "garbage" from previous applications. * * ----------------------------------------------------------------------} * * * * Procedure GetKey(var Code: Byte; var Extkey: Boolean); * * { * * DESCRIPTION: * * Gets a key from the keyboard--returns it's ASCII value and * * whether or not it is "extended". * * PARAMETERS: * * Code (out) - ASCII value of key pressed (See Turbo Manual) * * Extkey (out) - TRUE if key is "extended", FALSE otherwise * * SYNTAX: * * GetKey(Code, Extended); * * NOTE(S): * * Normal keys return a single code with Extkey set to FALSE, * * extended keys (Alt-A, F10, Alt-F3, etc) return a single * * code (See Turbo Manual) with Extkey set to TRUE. * * ----------------------------------------------------------------------} * * * * Function CapsLockON: Boolean; * * { * * DESCRIPTION: * * Returns TRUE if Caps-Lock key is active--FALSE otherwise. * * SYNTAX: * * If CapsLockON Then * * WriteLn('Caps-Lock key is currently ENABLED'); * * ----------------------------------------------------------------------} * * * * Function NumLockON: Boolean; * * { * * DESCRIPTION: * * Returns TRUE if Num-Lock key is active--FALSE otherwise. * * ----------------------------------------------------------------------} * * * * Function ScrollLockON: Boolean; * * { * * DESCRIPTION: * * Returns TRUE if Scroll-Lock key is active--FALSE otherwise. * * ----------------------------------------------------------------------} * * * * Function RightShift: Boolean; * * { * * DESCRIPTION: * * Returns TRUE if the Right Shift key is depressed at the time of * * the call to the function--FALSE otherwise. * * ----------------------------------------------------------------------} * * * * Function LeftShift: Boolean; * * { * * DESCRIPTION: * * Returns TRUE if the Left Shift key is depressed at the time of * * the call to the function--FALSE otherwise. * * ----------------------------------------------------------------------} * * * * Function AltPressed: Boolean; * * { * * DESCRIPTION: * * Returns TRUE if the Alt key is depressed at the time of the * * call to the function--FALSE otherwise. * * ----------------------------------------------------------------------} * * * * Function CtrlPressed: Boolean; * * { * * DESCRIPTION: * * Returns TRUE if the Ctrl key is depressed at the time of the * * call to the function--FALSE otherwise. * * ----------------------------------------------------------------------} * * * * Function InsertModeON: Boolean; * * { * * DESCRIPTION: * * Returns TRUE if the machine global insert mode is active at * * the time of the call to the function--FALSE otherwise. * * * ----------------------------------------------------------------------} * * * * Procedure SaveScreen(var aScreen: ScreenType; Height: Byte; * * var Status: Byte); * * { * * DESCRIPTION: * * Saves the contents of the TEXT screen to memory. Each screen * * needs about 4000 bytes (4k) of memory. You may have as many * * screens saved to memory as you wish, however one page * * (VirtualPage, of type ScreenType) is supplied for you at the * * VARiable declaration of this UNIT. * * PARAMETERS: * * aScreen (out) - Screen is saved to this varialbe: All Chars, * * their attributes, and the Height of the Screen. * * Height (in) - The height of your screen--usually 25, may differ * * according to Display Adaptor (VGA/EGA/etc). * * Status (out) - Returns 0 if Screen Save was successful, 1 * * otherwise (lack of memory). * * SYNTAX: * * SaveScreen(VirtualScreen, 25, Result); * * NOTE(S): * * See also RestoreScreen procedure. * * ----------------------------------------------------------------------} * * * * Procedure RestoreScreen(aScreen: ScreenType); * * { * * DESCRIPTION: * * Restores a text screen stored in variable aScreen to Video * * Display Memory instantly. * * PARAMETERS: * * aScreen (in) - "Screen" [variable] to restore. Will be place * * directly to Video Display Memory for an * * instantaneous text display. * * SYNTAX: * * RestoreScreen(VirtualScreen); * * NOTE(S): * * See also SaveScreen procedure. It is not necessary to pass in * * the height of the screen again since it is saved when you make * * a call to SaveScreen. * * ----------------------------------------------------------------------} * * * * Function NumSecsMidNight: Real; * * { * * DESCRIPTION: * * Returns the number of seconds elapsed since Midnight. * * SYNTAX: * * 1. Writeln(NumSecsMidNight:0:2); * * 2. r := NumSecsMidNight; * * NOTE(S): * * Used primarily by CheckTime procedure. * * ----------------------------------------------------------------------} * * Procedure DelaySeconds(NumSecs: Real; KeyIntr: Boolean); * * { * * DESCRIPTION: * * Delays a specified number of seconds. * * PARAMETERS: * * NumSecs (in) - Number of seconds to wait. * * KeyIntr (in) - Pass in ON or OFF to specify whether or not * * to allow a keypress to bypass the full wait. * * SYNTAX: * * DelaySeconds(5.0, ON); * * - Pauses system for about five seconds. If a key is pressed * * before time has expired. * * NOTE(S): * * Useful for programs which may half to run on various levels * * of PCs, since Turbo's Delay command produces unpredictable * * affects. AdvCRT's procedure uses the system clock to delay. * * DelaySeconds is a close approximation, but the time will not * * be exactly NumSecs seconds. * * ----------------------------------------------------------------------} * * * * Procedure CheckTime(Action: Byte); * * { * * DESCRIPTION: * * Checks the length of time a specific task takes. Can be used * * as a programming aid to time procedures, etc. * * PARAMETERS: * * Action (in) - 0, 1, or 2 are valid parameters. * * 0 to reset timer * * 1 to start timer * * 2 to stop timer * * ElapsedTime N/A - Global variable which stores the elapsed * * time since the timer was turned on. * * SYNTAX: * * CheckTime(0); * * - Resets AdvCRT's internal timer. * * CheckTime(1); * * - Turns timer ON. * * CheckTime(2); Writeln(ElapsedTime); * * - Turns timer OFF. Displays the amount of time elapsed since * * the timer was turned on. * * NOTE(S): * * AdvCRT's internal "timer" is a real global variable "StoreTime" * * and may be manipulated if need be. * * ----------------------------------------------------------------------} * * * * Procedure CapsLockKey(ONorOFF: Boolean); * * { * * DESCRIPTION: * * Sets the keyboard CAPS-LOCK state to Upper Case or Lower Case. * * PARAMETERS: * * ONorOFF (in) - Pass in ON to set keyboard to Upper Case state, * * or OFF to set keyboard to Lower Case state * * SYNTAX: * * 1. CapsLockKey(ON); - Turns CAPS-LOCK state ON * * 2. CapsLockKey(OFF); - Turns CAPS-LOCK state OFF * * NOTE(S): * * Sets the CAPS-LOCK state regardless of what the current state * * happens to be. * * ----------------------------------------------------------------------} * * * * Procedure NumLockKey(ONorOFF: Boolean); * * { * * DESCRIPTION: * * Sets the keypad to its Cursor Control or Numeric state. * * PARAMETERS: * * ONorOFF (in) - Pass in ON to set the keypad to its Numeric * * state, or OFF keypad to its Cursor Control state * * SYNTAX: * * 1. NumLockKey(ON); - Turns NUM-LOCK state ON * * 2. NumLockKey(OFF); - Turns NUM-LOCK state OFF * * NOTE(S): * * Sets the NUM-LOCK state regardless of what the current state * * happens to be. * * ----------------------------------------------------------------------} * * * * Procedure PrintScreen(var Status: Byte); * * { * * DESCRIPTION: * * Causes the current text or graphics screen to be printed to * * printer 0, the default printer. * * PARAMETERS: * * Status (out) - Status of the Print-Screen procedure * * 00 - OK status * * 01 - A Print-Screen operation is currently in progress * * 255 - An error occured during a Print-Screen * * SYNTAX: * * PrintScreen(Status); * * NOTE(S): * * Identical to standard "Shift-PrtSc" key on the keyboard. * * Note that in order to print graphics screens, it may be * * necessary to first install the GRAPHICS.COM program found on * * your DOS distribution diskette. * * ----------------------------------------------------------------------} * * * * Procedure PurgeKBDBuffer; * * { * * DESCRIPTION: * * Causes a purge of the type-ahead keyboard buffer. Any characters * * which may have existed between the HEAD and TAIL of the keyboard * * buffer [circular] queue are cleared. * * SYNTAX: * * ClrScr; * * PurgeKBDBuffer; * * Write('Press any key to continue...'); * * GetKey(Code, ExtendedKey); * * NOTE(S): * * This procedure uses the global addresses KBDBufferHead and * * KBDBufferTail which point to the PC's internal type-ahead * * keyboard buffer. * * ----------------------------------------------------------------------} * * * * Function SizeKBDBuffer: Integer; * * { * * DESCRIPTION: * * Returns the size (in bytes) of the type-ahead keyboard buffer. * * Default size for PCs is 16 bytes. * * * SYNTAX: * * Writeln('Keyboard buffer size: ', SizeKBDBuffer); * * NOTE(S): * * This function is type Integer (instead of Byte) because of the * * fact that the size of the buffer may indeed be greater than * * a Byte's maximum value of 255. * * ----------------------------------------------------------------------} * * * *****************************************************************************)