StillDown

See if the button stayed down after it was last pressed

#include <Events.h> Event Manager

returns Is button still down since last mouseDown?

StillDown checks if the mouse button has been continuously pressed since

the most recent mouseDown event.

Returns: a Boolean value reporting activity since the most recent mouseDown.

It is one of:

FALSE button is up or there are one or more mouse events pending

in the queue. It is not "still down".

TRUE button is down and it has not been released since the most

recent mouseDown. It is "still down".

Notes: StillDown is normally called directly after detecting a mouseDown event

via GetNextEvent or WaitNextEvent. It lets you know if the mouse is

being dragged. To process the dragging, call WaitMouseUp repeatedly in a

loop; e.g.:

Point oldPt, newPt;

switch ( theEvent.what ) {

case mouseDown:

oldPt= theEvent.where;

if ( StillDown() ) {

while ( WaitMouseUp() ) {

GetMouse( &newPt);

if ( DeltaPoint(oldPt, newPt) ) { // moved ?

EraseRect( &r ); // erase old pos

OffsetRect( &r, newPt.h-oldPt.h, newPt.v-oldPt.v );

DrawPicture( thePic, &r ); // draw at new

oldPt=newPt;

}

else {

/*... process normal (non-dragging) mouseDown . . .*/

}

break;

case keyDown:

/* etc */

The advantage of testing the loop via WaitMouseUp rather than

StillDown is that it removes the mouseUp event from the queue and

simplifies checking for double clicks (see GetDblTime).

You can also test the state of the button via Button, but that function does

not indicate whether the button has been released and pressed between calls.

Referenced by (15):