> It seems on official Android 4.0.2 on the GN there's a slight stutter > when starting to scroll a page for the first time, but removing the > call to setLayerType(LAYER_TYPE_HARDWARE, null); does prevent > the stutter. I didn't notice a difference on AOSP Android 4.0.3 on the > GN (and official 4.0.3 on the NS, but lower resolution which effects > things also).
Using a layer will cause the first draw to allocate a graphics buffer, thus possibly skipping a frame. I believe the Launcher team fixed that by allocating the buffers ahead of time in 4.0.3. > Also interestingly, the animation does a setAlpha and the > documentation > http://developer.android.com/reference/android/view/View.html#setAlpha(float) > states that this implies calling setLayerType with a hardware layer. It won't change the layer type but the performance profile will be the same. I should probably clarify this in the documentation. If you only call setAlpha() the view will be rendered into a graphics buffer on every frame. This buffer will then be copied on screen. If you use setLayerType() however, the view will be rendered into a graphics buffer *once*. Using setLayerType() is much more efficient. Once you've set a layer on a View, setAlpha() applies directly to the layer. You can also use the Paint supplied with the call to setLayerType() to change the alpha. -- Romain Guy Android framework engineer [email protected] -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
