EmTintManager.java 文件源码

private static boolean shouldMutateBackground(Drawable drawable) {
    if (Build.VERSION.SDK_INT >= 16) {
        // For SDK 16+, we should be fine mutating the drawable
        return true;
    }

    if (drawable instanceof LayerDrawable) {
        return Build.VERSION.SDK_INT >= 16;
    } else if (drawable instanceof InsetDrawable) {
        return Build.VERSION.SDK_INT >= 14;
    } else if (drawable instanceof DrawableContainer) {
        // If we have a DrawableContainer, let's traverse it's child array
        final Drawable.ConstantState state = drawable.getConstantState();
        if (state instanceof DrawableContainer.DrawableContainerState) {
            final DrawableContainer.DrawableContainerState containerState =
                    (DrawableContainer.DrawableContainerState) state;
            for (Drawable child : containerState.getChildren()) {
                if (!shouldMutateBackground(child)) {
                    return false;
                }
            }
        }
    }
    return true;
}