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harbour-core/harbour/doc/en/input.txt

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/*
* $Id$
*/
/*
* The following parts are Copyright of the individual authors.
* www - http://www.harbour-project.org
*
* Copyright 1999 Chen Kedem <niki@actcom.co.il>
* Documentation for: READKEY()
*
* See doc/license.txt for licensing terms.
*
*/
/* $DOC$
* $FUNCNAME$
* INKEY()
* $CATEGORY$
* Console input
* $ONELINER$
* Extracts the next key code from the Harbour keyboard buffer.
* $SYNTAX$
* INKEY( [<nTimeout>] [,<nEvents>] ) --> nKey
* $ARGUMENTS$
* <nTimeout> is an optional timeout value in seconds, with a granularity
* of 1/10th of a second. If omitted, INKEY() returns immediately. If set
* to 0, INKEY() waits until an input event occurs. If set to any other
* value, INKEY() will return either when an input event occurs or when
* the timeout period has elapsed. If only this parameter is specified
* and it is not numeric, it will be treated as if it were 0. But if both
* parameters are specified and this parameter is not numeric, it will be
* treated as if it were not present.
*
* <nEvents> is an optional mask of input events that are to be enabled.
* If omitted, defaults to hb_set.HB_SET_EVENTMASK. Valid input masks are
* in inkey.ch and are explained below. It is recommended that the mask
* names be used rather than their numeric values, in case the numeric
* values change in future releases of Harbour. To allow more than one
* type of input event, simply add the various mask names together.
*
* <table>
* inkey.ch Meaning
*
* INKEY_MOVE Mouse motion events are allowed
* INKEY_LDOWN The mouse left click down event is allowed
* INKEY_LUP The mouse left click up event is allowed
* INKEY_RDOWN The mouse right click down event is allowed
* INKEY_RUP The mouse right click up event is allowed
* INKEY_KEYBOARD All keyboard events are allowed
* INKEY_ALL All mouse and keyboard events are allowed
* </table>
* If the parameter is not numeric, it will be treated as if it were set
* to hb_set.HB_SET_EVENTMASK.
* $RETURNS$
* 0 in case of timeout with no input event, otherwise returns a value
* in the range -39 to 386 for keyboard events or the range 1001 to 1007
* for mouse events. Mouse events and non-printable keyboard events are
* represented by the K_<event> values listed in inkey.ch. Keyboard
* event return codes in the range 32 through 127 are equivalent to the
* printable ASCII character set. Keyboard event return codes in the
* range 128 through 255 are assumed to be printable, but results may
* vary based on hardware and nationality.
* $DESCRIPTION$
* INKEY() can be used to detect input events, such as keypress, mouse
* movement, or mouse key clicks (up and/or down).
* $EXAMPLES$
* // Wait for the user to press the Esc key
* ? "Please press the ESC key."
* WHILE INKEY( 0.1 ) != K_ESC
* END
* </fixed>
* $TESTS$
* KEYBOARD "AB"; ? INKEY(), INKEY() ==> 65 66
* </fixed>
* $STATUS$
* S
* $COMPLIANCE$
* INKEY() is compliant with the Clipper 5.3 INKEY() function with one
* exception: The Harbour INKEY() function will raise an argument error
* if the first parameter is less than or equal to 0 and the second
* parameter (or the default mask) is not valid, because otherwise INKEY
* would never return, because it was, in effect, asked to wait forever
* for no events (Note: In Clipper, this also blocks SET KEY events).
* $FILES$
* Library is rtl
* $SEEALSO$
* inkey.ch
* $END$
*/
/* $DOC$
* $FUNCNAME$
* __KEYBOARD()
* $CATEGORY$
* Console input
* $ONELINER$
* DO NOT CALL THIS FUNCTION DIRECTLY!
* $SYNTAX$
* KEYBOARD <cString>
* CLEAR TYPEAHEAD
* $ARGUMENTS$
* <cString> is the optional string to stuff into the Harbour keyboard
* buffer after clearing it first. Note: The character ";" is converted
* to CHR(13) (this is an undocumented CA-Clipper feature).
* $RETURNS$
* There is no return value.
* $DESCRIPTION$
* Clears the Harbour keyboard typeahead buffer and then inserts an
* optional string into it.
* $EXAMPLES$
* // Stuff an Enter key into the keyboard buffer
* KEYBOARD CHR(13)
* // Clear the keyboard buffer
* CLEAR TYPEAHEAD
* </fixed>
* $TESTS$
* KEYBOARD CHR(13); ? INKEY() ==> 13
* KEYBOARD ";" ? INKEY() ==> 13
* KEYBOARD "HELLO"; CLEAR TYPEAHEAD; ? INKEY() ==> 0
* </fixed>
* $STATUS$
* R
* $COMPLIANCE$
* __KEYBOARD() is compliant with CA-Clipper 5.3
* $FILES$
* Library is rtl
* $SEEALSO$
* CLEAR TYPEAHEAD,KEYBOARD
* $END$
*/
/* $DOC$
* $FUNCNAME$
* HB_KEYPUT()
* $CATEGORY$
* Console input
* $ONELINER$
* Put an inkey code to the keyboard buffer.
* $SYNTAX$
* HB_KEYPUT( <nInkeyCode> )
* $ARGUMENTS$
* <nInkeyCode> is the inkey code, which should be inserted into the
* keyboard buffer.
* $RETURNS$
* There is no return value.
* $DESCRIPTION$
* Inserts an inkey code to the string buffer. The buffer is *not*
* cleared in this operation. This function allows to insert such
* inkey codes which are not in the range of 0 to 255. To insert more
* than one code, call the function repeatedly. The zero code cannot
* be inserted.
* $EXAMPLES$
* // Stuff an Alt+PgDn key into the keyboard buffer
* HB_KEYPUT( K_ALT_PGDN )
* </fixed>
* $TESTS$
* HB_KEYPUT( K_ALT_PGDN ) ; ? INKEY() ==> 417
* HB_KEYPUT( K_F11 ) ; ? INKEY() ==> -40
* </fixed>
* $STATUS$
* R
* $COMPLIANCE$
* HB_KEYPUT() is a Harbour extension.
* $FILES$
* Library is rtl
* $SEEALSO$
* KEYBOARD,CLEAR TYPEAHEAD,INKEY()
* $END$
*/
/* $DOC$
* $FUNCNAME$
* NEXTKEY()
* $CATEGORY$
* Console input
* $ONELINER$
* Get the next key code in the buffer without extracting it.
* $SYNTAX$
* NEXTKEY() --> nKey
* $ARGUMENTS$
* None
* $RETURNS$
* <nKey> The value of the next key in the Harbour keyboard buffer.
* $DESCRIPTION$
* Returns the value of the next key in the Harbour keyboard buffer
* without extracting it.
* $EXAMPLES$
* // Use NEXTKEY() with INKEY() to change display characters, or by
* // itself to exit the loop, so that the caller can detect the Esc.
* LOCAL nKey, cChar := "+"
* WHILE TRUE
* ?? cChar
* nKey := NEXTKEY()
* IF nKey == K_ESC
* EXIT
* ELSE
* IF nKey != 0
* cChar := CHR( nKey )
* END IF
* END IF
* END WHILE
* </fixed>
* $TESTS$
* KEYBOARD "AB"; ? NEXTKEY(), NEXTKEY() ==> 65 65
* </fixed>
* $STATUS$
* R
* $COMPLIANCE$
* NEXTKEY() is compliant with CA-Clipper 5.3
* $FILES$
* Library is rtl
* $SEEALSO$
* INKEY(),LASTKEY()
* $END$
*/
/* $DOC$
* $FUNCNAME$
* LASTKEY()
* $CATEGORY$
* Console input
* $ONELINER$
* Get the last key extracted from the keyboard buffer.
* $SYNTAX$
* LASTKEY() --> nKey
* $ARGUMENTS$
* None
* $RETURNS$
* <nKey> The last key extracted from the keyboard buffer.
* $DESCRIPTION$
* Returns the value of the last key exttracted from the Harbour
* keyboard buffer
* $EXAMPLES$
* // Continue looping unless the ESC key was pressed in MainFunc()
* WHILE TRUE
* MainFunc()
* IF LASTKEY() == K_ESC
* EXIT
* ENDIF
* END WHILE
* </fixed>
* $TESTS$
* KEYBOARD "AB"; ? INKEY(), LASTKEY() ==> 65 65
* </fixed>
* $STATUS$
* R
* $COMPLIANCE$
* LASTKEY() is compliant with CA-Clipper 5.3
* $FILES$
* Library is rtl
* $SEEALSO$
* INKEY(),LASTKEY()
* $END$
*/
/* $DOC$
* $FUNCNAME$
* KEYBOARD
* $CATEGORY$
* Command
* $ONELINER$
* Stuffs the keyboard with a string.
* $SYNTAX$
* KEYBOARD <cString>
* $ARGUMENTS$
* <cString> String to be processed, one character at a time,
* by the Harbour keyboard processor
* $DESCRIPTION$
* This command stuffs the input buffer with <cString>. The
* number of characters that can be stuffed into the keyboard
* buffer is controlled by the SET TYPEAHEAD command and may range
* from 0 to 32,622, with each character appearing in the ASCII
* range of 0 to 255. None of the extended keys may be stuffed
* into the keyboard buffer.
* Issuing a KEYBOARD " " will clear the keyboard buffer.
* $EXAMPLES$
* // Stuff an Enter key into the keyboard buffer
* KEYBOARD CHR(13)
* // Clear the keyboard buffer
* CLEAR TYPEAHEAD
* </fixed>
* $TESTS$
* KEYBOARD CHR(13); ? INKEY() ==> 13
* KEYBOARD "HELLO"; CLEAR TYPEAHEAD; ? INKEY() ==> 0
* </fixed>
* $STATUS$
* R
* $COMPLIANCE$
* __KEYBOARD() is compliant with CA-Clipper 5.3
* $SEEALSO$
* CLEAR TYPEAHEAD,__KEYBOARD()
* $END$
*/
/* $DOC$
* $FUNCNAME$
* READKEY()*
* $CATEGORY$
* Data input and output
* $ONELINER$
* Find out which key terminated a READ.
* $SYNTAX$
* READKEY() --> nKeyCode
* $ARGUMENTS$
* None.
* $RETURNS$
* READKEY() returns a numeric code representing the key that caused READ
* to terminate.
* $DESCRIPTION$
* READKEY() is used after a READ was terminated to determine the exit
* key pressed. If the GET buffer was updated during READ, 256 is added
* to the return code.
*
* <table>
* Exit Return code Return code
* Key (not updated) (updated)
* Up 4 260
* Down 5 261
* Page-Up 6 262
* Page-Down 7 263
* Ctrl Page-Up 34 290
* Ctrl Page-Down 35 291
* Esc 12 268
* Ctrl End 14 270
* Enter 15 271
* Key >= 32 15 271
* otherwise 0 0
* </table>
* READKEY() is a compatibility function so try not to use it.
* READKEY() is superseded by LASTKEY() which returns the INKEY()
* code for that key. UPDATED() could be used to find if the
* GET buffer was changed during the READ.
* $STATUS$
* R
* $COMPLIANCE$
* READKEY() is compliant with CA-Clipper 5.3
* $FILES$
* Library is rtl
* $SEEALSO$
* @...GET,INKEY(),LASTKEY(),READ,READEXIT(),UPDATED()
* $END$
*/
/* $DOC$
* $FUNCNAME$
* MROW()
* $CATEGORY$
* Console input
* $ONELINER$
* Returns the mouse cursor row position.
* $SYNTAX$
* MRow() --> nMouseRow
* $ARGUMENTS$
* None
* $RETURNS$
* <nMouseRow> The mouse cursor row position.
* $DESCRIPTION$
* This function returns the current mouse row cursor position.
* On graphical systems the value represents pixel rows.
* On character-based systems the value represents character
* rows as in Clipper.
* $EXAMPLES$
* IF MRow() < 1
* ? "Mouse is on top row!"
* ENDIF
* </fixed>
* $STATUS$
* R
* $COMPLIANCE$
* MROW() is compliant with CA-Clipper 5.3, but has been extended
* to work on graphical systems as well as character-based systems.
* $PLATFORMS$
* $FILES$
* Library is rtl
* $SEEALSO$
* MCOL()
* $END$
*/
/* $DOC$
* $FUNCNAME$
* MCOL()
* $CATEGORY$
* Console input
* $ONELINER$
* Returns the mouse cursor column position.
* $SYNTAX$
* MCol() --> nMouseColumn
* $ARGUMENTS$
* None
* $RETURNS$
* <nMouseColumn> The mouse cursor column position.
* $DESCRIPTION$
* This function returns the column position of the mouse cursor.
* On graphical systems the value represents pixels.
* On character-based systems the value represents character
* columns as in Clipper.
* $EXAMPLES$
* IF MCol() < 1
* ? "Mouse is on left edge!"
* ENDIF
* </fixed>
* $STATUS$
* R
* $COMPLIANCE$
* MROW() is compliant with CA-Clipper 5.3, but has been extended
* to work on graphical systems as well as character-based systems.
* $PLATFORMS$
* All
* $FILES$
* Library is rtl
* $SEEALSO$
* MROW()
* $END$
*/