Thanks, Gordon!
This was very helpful indeed! I implemented it and - it works.
Your explanation was excellent because at the first moment I was
wondering how declaring an interface (without writing actual
methods) can make a change. But since UIComponent checks if it
implements this interface and does it's stuff... :-)
--- In flexcoders@yahoogroups.com, "Gordon Smith" <[EMAIL PROTECTED]>
wrote:
>
> 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#ke
y>
> 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)
>
