The UIComponent constructor has the logic
if (this is IFocusManagerComponent)
{
addEventListener(FocusEvent.FOCUS_IN, focusInHandler);
addEventListener(FocusEvent.FOCUS_OUT, focusOutHandler);
addEventListener(KeyboardEvent.KEY_DOWN, keyDownHandler);
addEventListener(KeyboardEvent.KEY_UP, keyUpHandler);
}
In order to receive keyboard events, your component must implement
IFocusManagerComponent:
"The base implementations of this interface are in the UIComponent
class,
but UIComponent does not implement the full IFocusManagerComponent
interface
since some UIComponents are not intended to receive focus.
Therefore, to make a UIComponent-derived component be a valid focusable
component, you simply add "implements IFocusManagerComponent" to the
class
definition."
If you're writing an MXML component, you declare that it implements an
interface with the tag attribute
implements="mx.managers.IFocusManagerComponent"
- Gordon
From: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] On
Behalf Of Danko Kozar
Sent: Wednesday, March 07, 2007 3:20 AM
To: flexcoders@yahoogroups.com
Subject: [flexcoders] UIComponent: keyUpHandler - what's it for anyway?
The livedocs suggest that every UIComponent has automatically set
event listeners for keyUp (adn keyDown) events:
http://livedocs.adobe.com/flex/2/langref/mx/core/UIComponent.html#key
<http://livedocs.adobe.com/flex/2/langref/mx/core/UIComponent.html#key>
UpHandler()
So, I expected that it's enough to override this method to make some
action on key-click. But that isn't the case.. Instead - nothing
happens.
Here's my code:
override protected function keyUpHandler(event:KeyboardEvent):void {
super.keyUpHandler(event);
if (event.keyCode == Keyboard.DELETE){
mx.controls.Alert.show("Key DELETE clicked.");
}
}
(ps. I prefer not to register key listeners by myself
(using "addEventListener"), rather use this default behaviour if
possible)