Android - How to determinate ViewFlipper children size when not displayed?

I'm actually making an appl开发者_StackOverflow社区ication using a ViewFlipper to display 3 differents custom views. These views are, for each one, in a ScrollView (putting the ViewFlipper in a single ScrollView isn't making my onFling gestures really efficient). And i'm actually trying to synchronize the three Scrollbars position. At this point using a single ScrollView would have been easier but i trying to not use this solution.

I'm using a ScrollListener for each ScrollView to set the others ScrollView scroll position like in this thread : Synchronise ScrollView scroll positions - android.

The problem is that this method will works but the first time. When i'm on a ScrollView, the two others are not drawn already and their height is null. So setting their scroll position isn't working.

/*Instanciate ScollViews*/
    scrollViewLeft = (ScrollableScrollView) findViewById(R.id.scroll_prev);
    scrollViewCenter =(ScrollableScrollView) findViewById(R.id.scroll_current);
    scrollViewRight = (ScrollableScrollView) findViewById(R.id.scroll_next);

/*Fill views with events*/ 
    setDayEvents(calIns.getPrevCal(),leftDayView);    
    setDayEvents(calIns.getActualCal(),centerDayView);  
    setDayEvents(calIns.getNextCal(),rightDayView); 

    scrollViewLeft.setScrollViewListener(this);
    scrollViewCenter.setScrollViewListener(this);
    scrollViewRight.setScrollViewListener(this);

So finally my question is, should i use another method to find the scroll position of the two others views ? Or can i force the view to be drawn in a ViewFlipper ?

Thanks :)

Clement.

Try saving the positions in global variables before you change the views and then just apply it to your current view.

Thanks Egor for having answered. I think it is a good idea. I already have a Singleton to handle variables. So i add the variable position with getters and setters.

The probleme here is than even if I override the method "onSizeChanged" in my custom ScrollView, this will apply only for the first view shown.

PS: I'm still starting on Android development and I don't really know how to handle with interactions on views when they aren't ready (for example getting width when they are not drawn yet).

Edit 1 day later :

Ok i found what was the problem, it is because the size of my views inside the scrollviews wasn't defined (the scrollview was drawn before the view inside it). So by setting the scroll inside the "onSizeChanged" method of the views works well.