Detecting MOUSE_LEAVE when mouse down

[Harry Kunz]

I need to be able to detect a MOUSE_LEAVE on the instant the mouse leaves the stage no matter if the mouse is DOWN or UP. This seems to be impossible or a limitation in AS3. The MOUSE_LEAVE only gets dispatched if mouse is UP or after the mouse is released outside stage. Is there any API like isMouseOutsideStage instead of using listeners which i can use instead? stage.addEventListener(MouseEvent.MOUSE_OUT) is also not applicable because whenever my slide show changes images, MOUSE_OUT of stage gets dispatched which is undesirable. The code below works perfectly where it detects a release or release outside if event.target is other than myButton. The weird thing or perhaps an undesirable behavior is that if i release outside stage, event.target equals myButton thus detecting a "release" instead of "release outside". I think that when we release outside stage, the want event.target to be null. There is no other work around i can think of or find.

myButton.addEventListener(MouseEvent.MOUSE_DOWN, function(event:MouseEvent):void{
                MouseHandler.addEventListener(MouseEvent.MOUSE_UP, function(event:MouseEvent):void{
                    MouseHandler.removeEventListener(MouseEvent.MOUSE_UP, arguments.callee);
                    if(event.target == myButton){
                        dispatchEvent(new ButtonEvent(ButtonEvent.RELEASE));
                    }else{
                        dispatchEvent(new ButtonEvent(ButtonEvent.RELEASE_OUTSIDE));
                    }
                });
            });

I created a MouseHandler class that keeps boolean values such as isDown and tried isOnStage by setting it to true on MOUSE_MOVE and false on MOUSE_LEAVE and added the checking:

if(event.target == myButton && MouseHandler.isOnStage()){
        dispatchEvent(new ButtonEvent(ButtonEvent.RELEASE));
}else{
        dispatchEvent(new ButtonEvent(ButtonEvent.RELEASE_OUTSIDE));
}

but it can't work because MOUSE_UP is dispatched first and uses isOnStage=true before isOnStage can be set to false on MOUSE_LEAVE event.

[kglad · Accepted solution]

you can use:

stage.addEventListener(Event.MOUSE_LEAVE,f);

function f(e:Event):void{
    trace(e);
}

stage.addEventListener(MouseEvent.MOUSE_DOWN,ff);
stage.addEventListener(MouseEvent.MOUSE_UP,fff);

function fff(e:MouseEvent):void{
    stage.removeEventListener(MouseEvent.MOUSE_MOVE,ffff);
}

function ff(e:MouseEvent):void{
    stage.addEventListener(MouseEvent.MOUSE_MOVE,ffff);
}

function ffff(e:MouseEvent):void{
    if(e.stageX<0 || e.stageX>stage.stageWidth || e.stageY<0 || e.stageY>stage.stageHeight){
        stage.dispatchEvent(new Event(Event.MOUSE_LEAVE));
        stage.removeEventListener(MouseEvent.MOUSE_MOVE,ffff);
    }
}

[Harry Kunz]

cooL i didn't know that the MouseEvent class had a stageX and stageY. Thanks alot kglad! I did something similar but used MOUSE_MOVE and tried detecting Sprite.mouseX which ofcourse never gave me a value greater than stageWidth or lesser than zero. stageX/Y on the other hand helped! Thank you again.

[kglad]

you're welcome.