[flexcoders] Re: What is the correct way to detect activation of a Canvas in a ViewStack?

[wdsnapper]

Thanks Tim.  I initially tried using the "show" event on the
component's canvas but it never got invoked.  Then I realized that I
had a canvas in the view stack that included my component:

<mx:ViewStack>
  <mx:Canvas id="myComponent1">
    <view:MyComponent/>
  </mx:Canvas>
  <mx:Canvas id="myComponent2">
    <view:MyComponent/>
  </mx:Canvas>
  <mx:Canvas id="myComponent3">
    <view:MyComponent/>
  </mx:Canvas>
  <mx:Canvas id="myComponent4">
    <view:MyComponent/>
  </mx:Canvas>
</mx:ViewStack>


<view:MyComponent>
  <mx:Script>
    <![CDATA[
      private function myShowMethod1():void {
      }
      private function myShowMethod2():void {
      }
    ]]>
    </mx:Script>

  <mx:ViewStack>
    <mx:Canvas id="myCanvas2" show="myShowMethod1()">
      <view:MyView1/>
    </mx:Canvas>

    <mx:Canvas id="myCanvas2" show="myShowMethod2()">
      <view:MyView2/>
    </mx:Canvas>
  </mx:ViewStack>
</view:MyComponent>

I was expecting the myShowMethod1() and myShowMethod2() to be invoked
when the view:MyComponent was brought into view and this was not the case.

I ended up hooking the show event in "myComponent1" and had this
invoke a method in view:MyComponent and this worked.

Is there a way to make sure the "show" gets invoked on my component?

The problem is solved for now though just does not feel like the right
way.

Thanks.


--- In flexcoders@yahoogroups.com, "Tim Walling" <[EMAIL PROTECTED]> wrote:
>
> You could try setting up a show event listener to trigger your
> initialization code. Something like this:
> 
> <mx:ViewStack>
>     <mx:Canvas show="handleShowEvent()"/>
> </mx:ViewStack>
> 
> 
> Whenever the ViewStack makes the canvas the visible/active one, the show
> event would fire.
> 
> or if your Canvas is an mxml component, it could handle the show event
> internally:
> 
> <mx:ViewStack>
>     <view:MyCanvas/>
> </mx:ViewStack>
> 
> MyCanvas.mxml
> <mx:Canvas show="handleShowEvent()">
>     <mx:Script>
>         private function handleShowEvent(event:FlexEvent):void
>         {
>             // call initialize code
>         }
>     </mx:Script>
> </mx:Canvas>
> 
> Then each of your components in the ViewStack would manage their
respective
> show events.
> 
> 
> Tim
> 
> 
> On 23 Mar 2007 17:02:56 -0700, wdsnapper <[EMAIL PROTECTED]> wrote:
> >
> >   I am using a ViewStack to contain a set of Canvas'. I switch between
> > items in the stack by clicking on buttons. I want to be able to
> > detect when a Canvas gains focus and run a method to initialize
> > content on that Canvas.
> >
> > What is the correct event to monitor to achieve this behavior?
> >
> > Thanks in advance.
> >
> >  
> >
> 
> 
> 
> -- 
> Tim
> timwalling.com
>