SkinCompatProgressBarHelper.java 文件源码

/**
 * Convert a AnimationDrawable for use as a barberpole animation.
 * Each frame of the animation is wrapped in a ClipDrawable and
 * given a tiling BitmapShader.
 */
private Drawable tileifyIndeterminate(Drawable drawable) {
    if (drawable instanceof AnimationDrawable) {
        AnimationDrawable background = (AnimationDrawable) drawable;
        final int N = background.getNumberOfFrames();
        AnimationDrawable newBg = new AnimationDrawable();
        newBg.setOneShot(background.isOneShot());

        for (int i = 0; i < N; i++) {
            Drawable frame = tileify(background.getFrame(i), true);
            frame.setLevel(10000);
            newBg.addFrame(frame, background.getDuration(i));
        }
        newBg.setLevel(10000);
        drawable = newBg;
    }
    return drawable;
}