ToolbarColorizeHelper.java 文件源码

/**
 * It's important to set overflowDescription atribute in styles, so we can grab the reference
 * to the overflow icon. Check: res/values/styles.xml
 *
 * @param activity
 * @param colorFilter
 */
private static void setOverflowButtonColor(final Activity activity, final PorterDuffColorFilter colorFilter) {
    final String overflowDescription = activity.getString(R.string.abc_action_menu_overflow_description);
    final ViewGroup decorView = (ViewGroup) activity.getWindow().getDecorView();
    final ViewTreeObserver viewTreeObserver = decorView.getViewTreeObserver();
    viewTreeObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            final ArrayList<View> outViews = new ArrayList<View>();
            decorView.findViewsWithText(outViews, overflowDescription,
                    View.FIND_VIEWS_WITH_CONTENT_DESCRIPTION);
            if (outViews.isEmpty()) {
                return;
            }
            AppCompatImageView overflow = (AppCompatImageView) outViews.get(0);
            overflow.setColorFilter(colorFilter);
            removeOnGlobalLayoutListener(decorView, this);
        }
    });
}