CODEWITHSUNDEEP
androidview
Lakshman Chilukuri
Lakshman Chilukuri

Reputation: 1067

Android Custom View Performance

This is the situation - My root layout is scrollview - A custom view with multiple drawing operations is embedded in the layout My problem is that if the layout is scrolled then customview.ondraw() is being called multiple times. Since there are many operations in the ondraw() I am getting a performance hit.

What is the best strategy out of this?

Upvotes: 1

Views: 1107

Answers (2)

user529543
user529543

Reputation:

Forgot the name of the methods in Android, but there is a Swing demo with a split pane.

If there is a flag set to true ( update continuously) than the split panel is drawing wile you move the spit components. The same effect is at scroll too. You can use a draw, continuously and another only when the scrolling finished. The same thing is at iOS too.

You need to find which are those methods and embed your custom view drawing when is needed.

Upvotes: 0

Robin Davies
Robin Davies

Reputation: 7817

See the docs on View.setDrawingCacheEnabled(). Note you have to call getDrawingCache() in your onDraw implementation, and draw the returned bitmap if getDrawingCache() returns a non-null value. I'm not sure whether ScrollView will take care of calling setDrawingCacheEnabled automatically. You'll have to try it and find out. I think it does; but you still need to call getDrawingCache() in your onDraw routine.

That takes care of the non-hardware accelerated cases.

For hardware accelerated views, see the docs for setLayerType. It's far from a given that caching hardware accelerated views actually provides a performance improvement, so do this cautiously.

Upvotes: 1

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