AnimationDrawable只工作一次

Question

I really need help to get this animation fixed. I'm tsetting an animation dynamic using addFrame(). Each generated animation consists of 5 frames. Alltogether 5 different animations are possible. The animation is started by a handler - every 5 seconds.

    setAnimation(); //inital setting of animation

    stimulusOverlay.setBackground(animation);

    final Handler recallStimulusHandler = new Handler();
    Runnable runAnimation = new Runnable() {
        @Override
        public void run() {
            stimulusOverlay.setVisibility(View.VISIBLE);
            animation.start();
            setStimulusInvisibleHandler();
            recallStimulusHandler.postDelayed(this, 5000);
        }
    };
    stimulusOverlay.post(runAnimation);

    private void setStimulusInvisibleHandler(){
        final Handler setInvisibleHandler = new Handler();
        final Runnable setStimulusInvisible = new Runnable() {
            @Override
            public void run() {
                stimulusOverlay.setVisibility(View.INVISIBLE);
                 setAnimation();
            }
        };
        setInvisibleHandler.postDelayed(setStimulusInvisible, 2000);
    }

I need to use the Handler. Otherwise the frames wouldn't be displayed for the given time. After 2 seconds (animation needs about 1,5 sec), I change the animation - for the next loop - with the function setAnimation().

    private void setAnimation() {

        Resources res = this.getResources();
        String stimulusString = getStimulusFromPref(countAnimation); // never empty
        int stimulusId = res.getIdentifier(stimulusString, "drawable", this.getPackageName());
        int stimulusLength = stimulusString.length();
        String maskingString = "mask_" + stimulusLength;
        int maskingId = res.getIdentifier(maskingString, "drawable", this.getPackageName());

        AnimationDrawable nextAnimation = new AnimationDrawable();
        nextAnimation.setOneShot(true);
        nextAnimation.addFrame(res.getDrawable(R.drawable.transparent), 300);
        nextAnimation.addFrame(res.getDrawable(maskingId), 300);
        nextAnimation.addFrame(res.getDrawable(stimulusId), 300);
        nextAnimation.addFrame(res.getDrawable(maskingId), 300);
        nextAnimation.addFrame(res.getDrawable(R.drawable.transparent), 300);
        animation = nextAnimation;

        countAnimation = (countAnimation + 1)%5;
    }

The Code is running fine for the first time. Afterwards nothing shows up anymore, without throwing an exeption or warning.

Using logs:

The code is running through for each 5 sec

the dynamic image generation works fine (for each possible combination)

I also thought about something like recursive calls at the end of setAnimation() , but I think calling the handler every 5 sec makes recursion invalid. getResources() always returns the same value, so I think everything works out here. I need to overwrite animation with a new animation because there is no possibility to reset the animation like removeFrames or something like that. There is also some further code making the ImageView visible/invisible, but thats not the problem either. I'm adding the ImageView to my windowManager like this: (don't think that's the problem, just for the sake of completeness)

    windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
    stimulusOverlay = new ImageView(this);
    stimulusOverlay.setVisibility(View.VISIBLE);

    WindowManager.LayoutParams params = new WindowManager.LayoutParams(
            WindowManager.LayoutParams.WRAP_CONTENT,
            WindowManager.LayoutParams.WRAP_CONTENT,
            WindowManager.LayoutParams.TYPE_PHONE,
            WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
            PixelFormat.TRANSLUCENT
    );

    windowManager.addView(stimulusOverlay, params);

Maybe you have an idea of what's going wrong here. Just ask for further questions or something.

Answer 1

Clearly you are calling the handler only once.After first execution handler is not called again and it stops its execution.Instead call stimulusOverlay again in loop like this.

final Handler recallStimulusHandler = new Handler();
Runnable runAnimation = new Runnable() {
    @Override
    public void run() {
        stimulusOverlay.setVisibility(View.VISIBLE);
        animation.start();
        setStimulusInvisibleHandler();
        recallStimulusHandler.postDelayed(this, 5000);
        //call this handler again
        stimulusOverlay.post(runAnimation);
    }
};
stimulusOverlay.post(runAnimation);

Also remove setInvisibleHandler.postDelayed(setStimulusInvisible, 2000) inside setStimulusInvisibleHandler() method.

Answer 2

You should remove setOneShot(true); line

setOneShot (boolean oneShot): Sets whether the animation should play once or repeat.

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