Hi,

I've got a problem in a game i'm making with jumping. I'm trying to implement a double jump, and I think I need a way of checking if a key has been pressed, but that doesnt continue checking if the key is being held.

I found a nice class on the web to replace the class we lost with AS3, which is below. using it, i can do:

if(Key.isDown(Keyboard.UP)){ //code }

and it works really well. however for the jump, i need a method inside the key class that just returns true the moment the key is pressed, and then goes back to false.

I think that's what i need, anyway.. if anyone has any suggestions as to how to implement as double jump, i'd love to hear them too!

the code's below

thanks for any help!


Code:
// Key.as
package {
    
    import flash.display.Stage;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    
    /*
     * The Key class recreates functionality of
     * Key.isDown of ActionScript 1 and 2. Before using
     * Key.isDown, you first need to initialize the
     * Key class with a reference to the stage using
     * its Key.initialize() method. For key
     * codes use the flash.ui.Keyboard class.
     *
     * Usage:
     * Key.initialize(stage);
     * if (Key.isDown(Keyboard.LEFT)) {
     *    // Left key is being pressed
     * }
     */
    public class Key 
	{
        
        private static var initialized:Boolean = false;  // marks whether or not the class has been initialized
        private static var keysDown:Object = new Object();  // stores key codes of all keys pressed
        
        /*
         * Initializes the key class creating assigning event
         * handlers to capture necessary key events from the stage
         */
        public static function initialize(stage:Stage) 
		{
            if (!initialized) 
			{
                // assign listeners for key presses and deactivation of the player
                stage.addEventListener(KeyboardEvent.KEY_DOWN, keyPressed);
                stage.addEventListener(KeyboardEvent.KEY_UP, keyReleased);
                stage.addEventListener(Event.DEACTIVATE, clearKeys);
                
                // mark initialization as true so redundant
                // calls do not reassign the event handlers
                initialized = true;
            }
        }
        
        /*
         * Returns true or false if the key represented by the
         * keyCode passed is being pressed
         */
        public static function isDown(keyCode:uint):Boolean 
		{
            if (!initialized) 
			{
                // throw an error if isDown is used
                // prior to Key class initialization
                throw new Error("Key class has yet been initialized.");
            }
            return Boolean(keyCode in keysDown);
        }
	


	
        /**
         * Event handler for capturing keys being pressed
         */
        private static function keyPressed(event:KeyboardEvent):void 
		{
            // create a property in keysDown with the name of the keyCode
            keysDown[event.keyCode] = true;
			
        }
        
        /**
         * Event handler for capturing keys being released
         */
        private static function keyReleased(event:KeyboardEvent):void 
		{
            if (event.keyCode in keysDown) 
			{
                // delete the property in keysDown if it exists
                delete keysDown[event.keyCode];
            }
        }
        
        /**
         * Event handler for Flash Player deactivation
         */
        private static function clearKeys(event:Event):void 
		{
            // clear all keys in keysDown since the player cannot
            // detect keys being pressed or released when not focused
            keysDown = new Object();
        }
    }
}