Question

Well I guess I ran into some bugs.

There seems to be a bug with Bitmaps in LayerLists: http://www.michaelpardo.com/2011/10/repeating-bitmaps-inside-layerlists/

I have Layer-List that I want to use as a Background-Drawable in my custom titlebar.

<style name="custom_titlebar_background">
<item name="android:background">@drawable/custom_titlebar_background</item>
</style>

EDIT:
To use the linked workaround I need to set the background of the titlebar programmatically, but I have no idea how. This doesn’t seem to work, It changes the background of the whole screen (including the actual content view):

LayerDrawable layer = (LayerDrawable)getResources().getDrawable(R.drawable.custom_titlebar_background);
        setLayerDrawableBitmapsRepeating(layer);
        getWindow().setBackgroundDrawable(layer);

Is there any way to get a reference to a custom titlebar to call setBackgroundDrawable() or any other way to set the background of a custom titlebar?

Answer 1

I found a solution. It is completely dirty and makes use of undocumented Members. This will work at least for me since my custom title bar is only use on 2.x devices to get a Holo-like Look.

It seems that the android title view has always the same id.

// http://stackoverflow.com/questions/820398/android-change-custom-title-view-at-run-time
        LayerDrawable layer = (LayerDrawable)getResources().getDrawable(R.drawable.custom_titlebar_background);
        setLayerDrawableBitmapsRepeating(layer);

        // get title view and set new background view
        try
        {
            // retrieve value for com.android.internal.R.id.title_container(=0x1020149)
            int titleContainerId = (Integer) Class.forName("com.android.internal.R$id").getField("title_container").get(null);
            View titleView = findViewById(titleContainerId);

            if(titleView != null)
            {
                titleView.setBackgroundDrawable(layer);
            }
        }
        catch(Exception e)
        {
            // nothing, just skip
        }

As long as you are not doing important stuff and your application will still work without it, I see no reason to not use this workaround to fix tileable bitmaps on older Android builds.