DrawableUtils.java 文件源码

/**
 * Some drawable implementations have problems with mutation. This method returns false if
 * there is a known issue in the given drawable's implementation.
 */
static boolean canSafelyMutateDrawable(@NonNull Drawable drawable) {
    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 StateListDrawable) {
        // StateListDrawable has a bug in mutate() on API 7
        return Build.VERSION.SDK_INT >= 8;
    } else if (drawable instanceof GradientDrawable) {
        // GradientDrawable has a bug pre-ICS which results in mutate() resulting
        // in loss of color
        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 (!canSafelyMutateDrawable(child)) {
                    return false;
                }
            }
        }
    } else if (drawable instanceof android.support.v4ox.graphics.drawable.DrawableWrapper) {
        return canSafelyMutateDrawable(
                ((android.support.v4ox.graphics.drawable.DrawableWrapper) drawable)
                        .getWrappedDrawable());
    } else if (drawable instanceof android.support.v7ox.graphics.drawable.DrawableWrapper) {
        return canSafelyMutateDrawable(
                ((android.support.v7ox.graphics.drawable.DrawableWrapper) drawable)
                        .getWrappedDrawable());
    }
    return true;
}