Determine if view was invalidated (changed)

Question

How I can determine if a view was invalidated? I see that the View class has isDirty() method but it doesn't seem to work in my case.

I'm making a custom layout that can animate blurring of it's content. It extends FrameLayout. So at first the layout draws it's first child to a bitmap, and than displays the bitmap instead of actual view. Also it starts AsyncTask that creates blur animation steps.

So I need to know when the child view was changed so I can redraw the bitmap and restart AsyncTask.

http://stackoverflow.com/questions/13622081/imageview-onimagechangedlistener-android — Kristy Welsh, Oct 28 '15 at 20:52
@KristyWelsh thank you but that doesn't cover my situation. A child view may be not only an ImageView. — 0neel, Oct 28 '15 at 20:56

score 1 · Accepted Answer · answered May 31 '17 at 13:21

1

I've found that this can be implemented using ViewTreeObserver.OnPreDrawListener

answered May 31 '17 at 13:21

0neel

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Determine if view was invalidated (changed)

1 Answers1