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Comment by Corun | Hacker News Reader

Did a bit of investigating. It seems you can make Android views use layers as iOS does. But it's off by default (maybe because of this OpenGL using 8MB of memory per process thing).

(Further reading: http://developer.android.com/reference/android/view/View.htm... )

Edit: Also, I missed where she said that in her post: "Starting with 3.0, if you set the flag in your app saying that hardware accelerated drawing is allowed, then all drawing to the application’s windows will be done with the GPU. The main change in this regard in Android 4.0 is that now apps that are explicitly targeting 4.0 or higher will have acceleration enabled by default".

Unfortunately only the the Samsung Galaxy Nexus has Android 4 and I'm not sure there's anything other than a few tablets that have Android 3?

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Turning on hardware acceleration doesn't cause all Android views to be FBO-backed. You still need to toggle the layerType to LAYER_TYPE_HARDWARE on each view, as far as I'm aware. I think the G+ post is a little disingenuous in that regard.

Google suggests toggling between LAYER_TYPE_NONE & LAYER_TYPE_HARDWARE pre/post animations. This need to actively manage view cache behaviour probably leads to developers being unaware of what to do.

If you want to enjoy both smooth scrolling and responsive input method in a webview, you need to juggle between those layer types.

LAYER_TYPE_HARDWARE enables smooth hardware-backed scrolling but glitches badly when the soft keyboard is visible (no resizing/panning of the webview, multiple seconds of delay between key type and text updates inside textfield forms).

LAYER_TYPE_NONE makes scrolling in the webview unbearably stuttering, but at least the soft keyboard becomes responsive, the webview pans correctly to show the field in which you're inputting text, and the key types are instant.

On top of that, there is the problem that you don't have access to keyboard show/dismiss events, so you have to inject javascript code to catch those in every page you plan your webview to display. This is at least the case on the Motorola Xoom and the Acer Iconia tablets running the latest versions of honeycomb.

There must be a different underlying issue there. Showing a keyboard view should have no performance implications on a web view. Similarly drawing text into a texture tile should not take "multiple seconds of delay".

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