DrawableUtils.java 文件源码

static boolean canSafelyMutateDrawable(@NonNull Drawable drawable) {
    if (drawable instanceof LayerDrawable) {
        if (VERSION.SDK_INT >= 16) {
            return true;
        }
        return false;
    } else if (drawable instanceof InsetDrawable) {
        if (VERSION.SDK_INT < 14) {
            return false;
        }
        return true;
    } else if (drawable instanceof StateListDrawable) {
        if (VERSION.SDK_INT < 8) {
            return false;
        }
        return true;
    } else if (drawable instanceof GradientDrawable) {
        if (VERSION.SDK_INT < 14) {
            return false;
        }
        return true;
    } else if (drawable instanceof DrawableContainer) {
        ConstantState state = drawable.getConstantState();
        if (!(state instanceof DrawableContainerState)) {
            return true;
        }
        for (Drawable child : ((DrawableContainerState) state).getChildren()) {
            if (!canSafelyMutateDrawable(child)) {
                return false;
            }
        }
        return true;
    } else if (drawable instanceof DrawableWrapper) {
        return canSafelyMutateDrawable(((DrawableWrapper) drawable).getWrappedDrawable());
    } else {
        if (drawable instanceof android.support.v7.graphics.drawable.DrawableWrapper) {
            return canSafelyMutateDrawable(((android.support.v7.graphics.drawable.DrawableWrapper) drawable).getWrappedDrawable());
        }
        return true;
    }
}