Most efficient way to show frame by frame animation android

Question

I am trying to show frame by frame animation by changing images in a imageview. I tried animation drawable in xml and also changing the bitmap of the imageview inside a Handler.

Answer 1

I'm facing the same problem and I have solved it by overriding an AnimationDrawable. So, if the problem is you that can't load all images in array because it is too big for the memory to hold it, then load the image when you need it. My AnimationDrawable is this:

public abstract class MyAnimationDrawable extends AnimationDrawable {

    private Context context;
    private int current;
    private int reqWidth;
    private int reqHeight;
    private int totalTime;

    public MyAnimationDrawable(Context context, int reqWidth, int reqHeight) {
        this.context = context;
        this.current = 0;
        //In my case size of screen to scale Drawable
        this.reqWidth = reqWidth;
        this.reqHeight = reqHeight;
        this.totalTime = 0;
    }

    @Override
    public void addFrame(Drawable frame, int duration) {
        super.addFrame(frame, duration);
        totalTime += duration;
    }

    @Override
    public void start() {
        super.start();
        new Handler().postDelayed(new Runnable() {

            public void run() {
                onAnimationFinish();
            }
        }, totalTime);
    }

    public int getTotalTime() {
        return totalTime;
    }

    @Override
    public void draw(Canvas canvas) {
        try {
            //Loading image from assets, you could make it from resources 
            Bitmap bmp = BitmapFactory.decodeStream(context.getAssets().open("presentation/intro_000"+(current < 10 ? "0"+current : current)+".jpg"));
            //Scaling image to fitCenter
            Matrix m = new Matrix();
            m.setRectToRect(new RectF(0, 0, bmp.getWidth(), bmp.getHeight()), new RectF(0, 0, reqWidth, reqHeight), Matrix.ScaleToFit.CENTER);
            bmp = Bitmap.createBitmap(bmp, 0, 0, bmp.getWidth(), bmp.getHeight(), m, true);
            //Calculating the start 'x' and 'y' to paint the Bitmap 
            int x = (reqWidth - bmp.getWidth()) / 2;
            int y = (reqHeight - bmp.getHeight()) / 2;
            //Painting Bitmap in canvas
            canvas.drawBitmap(bmp, x, y, null);
            //Jump to next item
            current++;
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    abstract void onAnimationFinish();

}

Now to play animation you need to do what next

    //Get your ImageView
    View image = MainActivity.this.findViewById(R.id.presentation);

    //Create AnimationDrawable
    final AnimationDrawable animation = new MyAnimationDrawable(this, displayMetrics.widthPixels, displayMetrics.heightPixels) {

        @Override
        void onAnimationFinish() {
            //Do something when finish animation
        }

    };
    animation.setOneShot(true); //dont repeat animation
    //This is just to say that my AnimationDrawable has 72 frames with 50 milliseconds interval
    try {
        //Always load same bitmap, anyway you load the right one in draw() method in MyAnimationDrawable
        Bitmap bmp = BitmapFactory.decodeStream(MainActivity.this.getAssets().open("presentation/intro_00000.jpg"));
        for (int i = 0; i < 72; i++) {
            animation.addFrame(new BitmapDrawable(getResources(), bmp), 50);
        }
    } catch (IOException e) {
        e.printStackTrace();
    }

    //Set AnimationDrawable to ImageView
    if (Build.VERSION.SDK_INT < 16) {
        image.setBackgroundDrawable(animation);
    } else {
        image.setBackground(animation);
    }

    //Start animation
    image.post(new Runnable() {

        @Override
        public void run() {
            animation.start();
        }

    });

That is all, and works OK form me!!!