_MOUSEINPUT - QB64Official/qb64 GitHub Wiki

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.

Example(s)

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.

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)

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