Clearing mouse events

[Michael Bell]

Anyone know how to clear the buffer of pending mouse events in a graphics window?

I'm finding GRAPHIC WINDOW CLICK very useful for making an easy graphics console, but incautious mouse clicks can result in the program getting ahead of itself.

Code structure is something like...

DO

GRAPHIC WINDOW CLICK hWin TO clickval,x,y

IF clickval THEN
... various actions based on location of x,y in the graphics window
END IF

clickval=0

GRAPHIC INPUT FLUSH

SLEEP 100

LOOP

The GRAPHIC INPUT FLUSH statement appears to clear keyboard events, but not mouse clicks, so extra clicking whilst executing statements within the IF block causes an immediate jump back into the block as soon as those statements are done. Presumably this is because the click event is stored, so that even after clickval is reset to zero, it immediately becomes TRUE again on the next cycle of the loop.

Any (easy!?) way to solve this?

Any help much appreciated...

[Mike Doty]

This is related: http://www.powerbasic.com/support/pb...ad.php?t=38829

[Michael Mattias]

The GRAPHIC INPUT FLUSH statement appears to clear keyboard events, but not mouse clicks

I don't "do" GRAPHIC windows, but for those who do, a New Feature Suggestion, "Please provide a facility to flush queued mouse clicks similar to the way GRAPHIC INPUT FLUSH flushes keystrokes" might be in order.... send those NFSs to [email protected]

You might go as far as suggesting a useful and backward compatible syntax:

 GRAPHIC INPUT FLUSH  [,MOUSE]

If the optional key word MOUSE is provided, mouse clicks are flushed, otherwise only keystrokes are flushed.

MCM

[Michael Bell]

Mike - thanks. That's useful to see, though I don't think I can use it in my current CC application. I think my answer is to change the routine so that the next click will always be meaningful. At the moment I have GRAPHIC INPUT statements waiting for the Enter key to be pressed, which means that extra mouse clicks (or at least the last of any extra clicks) wait to be dealt with until GRAPHIC INPUT is done. If I use GRAPHIC INKEY$ to accumulate input one character at a time then no Enter is necessary and I can any mouse clicks to terminate an input loop. This would make the program responses more intuitive for the user anyway (though this scarcely matters, as I'll be the main user...).

[Michael Bell]

MCM - consider it sent...

[Michael Mattias]

I would not normally suggest anything like this, but since this seems to be serious oversight in the design of the GRAPHIC INPUT FLUSH statement (hey, guys, mouse clicks are input, too!) ............

You actually could flush these yourself, by inserting a PeekMessage (with remove option) loop in your code, filtering for only mouse messages so you don't lose anything important.

This would be totally unsupported, but may well work. If you are not quite up to writing this yourself, don't worry, no doubt someone will write it for you and post it.

MCM

[Mel Bishop]

Since (graphic)INKEY$ is supposed to trap both keyboard and mouse events, seems reasonable that:

do until (graphic)inkey$ = ""
loop

or something like that would work.

Or do I need to RTFM again?

[Michael Mattias]

do until (graphic)inkey$ = ""
loop

I told you I don't 'do' GRAPHIC ANYTHING....

[Michael Bell]

Mel - thanks anyway, but the problem isn't one of trapping the mouse events. That's already happening with GRAPHIC WINDOW CLICK. The problem is one of getting rid of unwanted clicks so that they're not hanging around waiting to be trapped.

[Mike Doty]

"INPUT FLUSH" is supposed to clear keyboard and mouse buffers.
I just read the docs and GRAPHIC INKEY$ etc only deal with the keyboard.
I do not use GRAPHICS with consoles.
Have you tried "INPUT FLUSH" instead of "GRAPHIC INPUT FLUSH?"

[Michael Bell]

Mike - yes, tried that: no luck... I think that just works with the console and leaves the graphics window alone.

[Mike Doty]

How about this?
Multiple mouse buffers?

SUB FlushMouse
  LOCAL x AS LONG
  FOR x = 1 TO 4
    INPUT FLUSH
    SLEEP 10
  NEXT
END SUB

I had a similar problem with GUI apps.

[Michael Bell]

Mike - thanks. FlushMouse didn't work, but it made me think of something that did... I simply inserted another GRAPHIC WINDOW CLICK to deal with the stored mouse events...

DO
GRAPHIC WINDOW CLICK hWin to clickval,x,y ' deals with wanted clicks

IF clickval THEN

... do useful things

GRAPHIC WINDOW CLICK hWin to clickval2,x,y ' deals with unwanted clicks
IF clickval2 THEN clickval=0

END IF
SLEEP 100
LOOP
This seems to do the trick, as just one spare click seems to be stored.

[Manuel Valdes]

Michael:

DO

DO UNTIL CLICKVAL=0

GRAPHIC WINDOW CLICK hWin to clickval,x,y

LOOP

GRAPHIC WINDOW CLICK hWin to clickval,x,y ' deals with wanted clicks

IF clickval THEN

... do useful things


END IF

SLEEP 100

LOOP

[Michael Bell]

Manuel - thanks, that does the trick more neatly.