SeekBarWidget.java 文件源码

/**
 * Wraps the given <var>drawable</var> into instance of {@link ScaleDrawable} if it is valid
 * and not ScaleDrawable yet.
 *
 * @param drawable The drawable to wrap and make scaleable.
 * @param gravity  The gravity determining a pivot along which can be the given drawable scaled.
 * @return Instance of ScaleDrawable with the specified drawable wrapped or {@code null}
 * if the given drawable was also {@code null}.
 */
static Drawable makeDrawableScaleable(Drawable drawable, int gravity) {
    if (drawable == null || drawable instanceof ScaleDrawable) return drawable;
    final ScaleDrawable scaleDrawable = new ScaleDrawable(drawable, gravity, 1f, 1f);
    scaleDrawable.setLevel(MAX_LEVEL);
    return scaleDrawable;
}