_MOUSEINPUT

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

• Featured in our "Keyword of the Day" series
• _MOUSEX, _MOUSEY, _MOUSEBUTTON, _MOUSEWHEEL
• _MOUSESHOW, _MOUSEHIDE, _MOUSEMOVE
• Controller Devices

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