Question

I have 2 eventListeners:

1) key listener(A, S, D ,W); – for move object

2) key listener(WhiteSpace) – for jump object

so when i have pressed the A OR S OR D OR W keys then i press the whitespace to before this moment its all okey, the object is moving and jumping at the same time, but if i release the whitespace key while moving, the object stops…

so how can i make that when i release the key white space, the object will still moving?? don’t paying attention to the other key releasing or pressing?

private function onKeyDown(e:KeyboardEvent):void {

    //trace(e.keyCode);
    switch(e.keyCode)
    {

    case 68:
    direction = 'left';
    stage.addEventListener(Event.ENTER_FRAME, moveRight);
    break;
    case 65:
    direction = 'right';
    stage.addEventListener(Event.ENTER_FRAME, moveLeft);
    break;
    case 32:
    jump() // the whitespace key
        break;

    }

private function moveRight(e:Event):void {

shape.x += 5;

}

private function moveLeft(e:Event):void {

shape.x += 5;

}

private function jump():void {

    stage.addEventListener(Event.ENTER_FRAME, jumpAnimation);
}

private function jumpAnimation(e:Event):void {

   //here code for jumping increasing the y and decreasing....
}

private function onKeyUp(e:Event):void {


    stage.removeEventListener(Event.ENTER_FRAME, moveRight);
    stage.removeEventListener(Event.ENTER_FRAME, moveLeft);


}

Answer 1

You could implement a key up/down listeners and an enter frame listener and use some booleans to indicate what keys are down and update accordingly. Something like this might work:

var keyMap:Dictionary = new Dictionary();

addEventListener( KeyboardEvent.KEY_DOWN, onKeyDown );
addEventListener( KeyboardEvent.KEY_UP, onKeyUp );
addEventListener( Event.ENTER_FRAME, onEnterFrame );

function onKeyDown( event:KeyboardEvent ):void 
{
    keyMap[ event.keyCode ] = true;
}

function onKeyUp( event:KeyboardEvent ):void 
{
    keyMap[ event.keyCode ] = false;
}

function onEnterFrame( event:EnterFrame ):void 
{
    if( keyMap[ 68 ] ) 
    {
        // -- move left
    }

    if( keyMap[ 65 ] ) 
    {
        // -- move right 
    }

    // -- ect...
}

This would avoid a situation where one key up is causing all other keys from firing continuously because you would only be relying on a single key up or down from each key. The code to update your scene would be running continuously.