AppCompatProgressBarHelper.java 文件源码

private Drawable tileifyIndeterminate(Drawable drawable) {
    if (!(drawable instanceof AnimationDrawable)) {
        return drawable;
    }
    AnimationDrawable background = (AnimationDrawable) drawable;
    int N = background.getNumberOfFrames();
    Drawable 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);
    return newBg;
}