Notify fragment`s view childs

Question

I have some fragments that I need to run some animations when they get visible.

Those fragments are inside a ViewPager. Thanks to that answer - How to determine when Fragment becomes visible in ViewPager - I know that I get notified when my fragment is visible by the method getUserVisibleHint.

Because I have a lot of animations, I made custom views that know how to animate itself. And now I need to notify all the views inside the fragment in the method getUserVisibleHint of the fragment to they know that is time do animate themselves.

So my question is: How can I notify all the views inside a fragment?

Any solution is welcome, but how I said, the views that I need to notify are custom views created by me, so I believe that I need some kind of custom notification too.

score 1 · Accepted Answer · edited Aug 19 '13 at 14:45

1

You said all your views are custom. I'm assuming they all implement a specific interface (lets say, InterfaceA).

The following code will call the notificationMethod() on every custom view that implements your InterfaceA interface. The viewGroup is your root view (for example, a LinearLayout).

int childcount = viewGroup.getChildCount();
for (int i=0; i < childcount; i++){
   View view = viewGroup.getChildAt(i); 
   if (view instanceof InterfaceA) { 
       ((InterfaceA)view).notificationMethod();
   }
}

edited Aug 19 '13 at 14:45

jonathanrz

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answered Aug 17 '13 at 01:22

Brian Attwell

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I would suggest instead of a direct cast: `View child = viewGroup.getChildAt(i); if (child instanceof InterfaceA) { ((InterfaceA)child).notificationMethod();`. That way it will continue gracefully if there are any views in the layout that do not implement the interface. – Kevin Coppock Aug 17 '13 at 03:53

Notify fragment`s view childs

1 Answers1