_MOUSEINPUT

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The _MOUSEINPUT function is used to monitor any new mouse positions, button presses or movements of the scroll wheel. Must be called before other mouse information becomes available.


Syntax

infoExists%% = _MOUSEINPUT


Description

  • Returns -1 if new mouse information is available, otherwise it returns 0.
  • Must be called before reading any of the other mouse functions. The function will not miss any mouse input even during an INPUT entry.
  • Use in a loop to monitor the mouse buttons, scroll wheel and coordinate positions.
  • To clear all previous mouse data, use _MOUSEINPUT in a loop until it returns 0.


Examples

Example 1: Mouse coordinate, click and scroll events are returned sequentially inside of a _MOUSEINPUT loop.

DO
  DO WHILE _MOUSEINPUT '      Check the mouse status
    PRINT _MOUSEX, _MOUSEY, _MOUSEBUTTON(1), _MOUSEWHEEL
  LOOP
LOOP UNTIL INKEY$ <> ""
Explanation: The latest mouse function status can be read after the loop. _LIMIT and _DELAY loops will slow returns down.


Example 2: How to use a _MOUSEINPUT loop to locate PSET positions on a screen using a right mouse button click.

SCREEN 12

DO ' main program loop

  ' your program code

  DO WHILE _MOUSEINPUT'mouse status changes only
    x = _MOUSEX
    y = _MOUSEY
    IF x > 0 AND x < 640 AND y > 0 AND y < 480 THEN
      IF _MOUSEBUTTON(2) THEN
        PSET (x, y), 15
        LOCATE 1, 1: PRINT x, y
      END IF
    END IF
  LOOP

  ' your program code

LOOP UNTIL INKEY$ = CHR$(27)


Example 3: Clearing any mouse data read before or during an INPUT entry. Press "I" to enter input:

PRINT "Press I to enter input! Press Q to quit"
DO
  K$ = UCASE$(INKEY$)
  DO
    IF _MOUSEBUTTON(1) = -1 THEN PRINT "*"    'indicates a mouse click event
  LOOP WHILE _MOUSEINPUT
  IF K$ = "Q" THEN END
  IF K$ = "I" THEN                                          'press I to enter text
    INPUT "Click the mouse and enter something: ", entry$   'enter some text
    GOSUB Clickcheck                                        'clear mouse data
  END IF
LOOP

END

Clickcheck:
count = 0
DO
  count = count + 1
LOOP WHILE _MOUSEINPUT
PRINT count        'returns the number of loops before mouse data is cleared
RETURN
Explanation: Click the mouse a few times while entering INPUT text. When Enter is pressed, the number of loops are displayed.


See also



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