Framelayout Child View Not Updating Correctly On Resize

I have an Android application in which the root view is a FrameLayout which on rotation is kept and resized rather than recreated. Among the children of the FrameView is one custom

Solution 1:

As I had suspected based on the log output, something in the guts of the UI has not been updated by the time onSizeChanged() gets called. I haven't figured out what, but the takeaway is that the LayoutParams stuff needs to be deferred until everything else has finished. This can be done by wrapping the code into a Runnable and post()ing that to the FrameLayout:

staticbooleanisBandShowing= ...;    // whether the band should be shownstaticbooleanisPortrait= ...;       // whether we are in portrait mode, controls where the band is displayedstaticinthorizontalBandHeight= ...; // default height for band in portrait modestaticintverticalBandWidth= ...;    // default width for band in landscape mode

frameLayout.post(newRunnable() {
    @Overridepublicvoidrun() {
        bandView.setVisibility(isBandShowing ? View.VISIBLE : View.GONE);
        LayoutParamsbandLayoutParams=newFrameLayout.LayoutParams(
            isPortrait ? LayoutParams.MATCH_PARENT : verticalBandWidth,  // X
            isPortrait ? horizontalBandHeight : LayoutParams.MATCH_PARENT, // Y
            Gravity.BOTTOM | Gravity.RIGHT);
        bandView.setLayoutParams(bandLayoutParams);
    }
});

That solved it.