Is it possible to set an animated gif file as live wallpaper in android?

Question

I\'m new to Android platform. I wish to develop a live wallpaper application. When i was searched regarding this in search Engine\'s, many of them created a

Answer 1

See this article: How to set gif as android live wallpaper - techprpr - Medium

Jens answer use "Movie" class, but Movie class is deprecated in android api 28

so when api >= 28, I use AnimatedImageDrawable instead

Setup live wallpaper like Jens answer, and I change wallpaper service code:

wallpaper service: AnimWallpaper

public class AnimWallpaper extends WallpaperService {
    @Override
    public Engine onCreateEngine() {
        return new CustomEngine();
    }

    class CustomEngine extends Engine {
        UseAnim useAnim;

        public CustomEngine() {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
                useAnim = new UseAnim(getApplicationContext(), getSurfaceHolder(), R.raw.gif2);
            }
        }

        @Override
        public void onVisibilityChanged(boolean visible) {
            super.onVisibilityChanged(visible);
            if (visible) {
                useAnim.restart();
            } else {
                useAnim.stop();
            }
        }

        @Override
        public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
            super.onSurfaceChanged(holder, format, width, height);
            useAnim.updateScaleAndPadding2(width, height);
            useAnim.restart();
        }


        @Override
        public void onOffsetsChanged(float xOffset, float yOffset, float xOffsetStep, float yOffsetStep, int xPixelOffset, int yPixelOffset) {
            super.onOffsetsChanged(xOffset, yOffset, xOffsetStep, yOffsetStep, xPixelOffset, yPixelOffset);
            useAnim.restart();
        }

        @Override
        public void onDestroy() {
            super.onDestroy();
            useAnim.stop();
        }
    }

}

UseAnim

class UseAnim {
    SurfaceHolder holder;
    Runnable startRunnable;
    AnimatedImageDrawable gif;
    float fps = 60;
    Handler handler = new Handler();

    @RequiresApi(api = Build.VERSION_CODES.P)
    public UseAnim(Context ctx, SurfaceHolder holder, int gifResId) {
        this.holder = holder;
        final ImageDecoder.Source src = ImageDecoder.createSource(ctx.getResources(), gifResId);
        startRunnable = new Runnable() {
            @Override
            public void run() {
                start();
            }
        };

        new Handler().post(new Runnable() {
            @Override
            public void run() {
                try {
                    UseAnim.this.gif = (AnimatedImageDrawable) ImageDecoder.decodeDrawable(src);
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }

                UseAnim.this.gif.start();
            }
        });
    }

    public void restart() {
        stop();
        start();
    }

    float scale = -1;

    public void start() {
        // since get gif with AnimatedImageDrawable must be in handler.post, so gif maybe null
        if (gif != null) {
            Canvas canvas = null;
            try {
                if (scale == -1) {
                    updateScaleAndPadding();
                }

                canvas = holder.lockCanvas();

                if (canvas != null) {
                    canvas.translate(horiPadding, vertiPadding);
                    canvas.scale(scale, scale);
                    gif.draw(canvas);
                }
            } finally {
                if (canvas != null) {
                    holder.unlockCanvasAndPost(canvas);
                }
            }
        }

        handler.removeCallbacks(startRunnable);
        handler.postDelayed(startRunnable, (long) (1000L / fps));
    }

    public void stop() {
        handler.removeCallbacks(startRunnable);
    }

    int horiPadding;
    int vertiPadding;

    private void updateScaleAndPadding() {
        Canvas canvas = null;
        try {
            canvas = holder.lockCanvas();
            int cw = canvas.getWidth();
            int ch = canvas.getHeight();

            updateScaleAndPadding2(cw, ch);
        } finally {
            if (canvas != null) {
                holder.unlockCanvasAndPost(canvas);
            }
        }
    }

    public void updateScaleAndPadding2(int cw, int ch) {
        if (gif != null) {
            int gifW = gif.getIntrinsicWidth();
            int gifH = gif.getIntrinsicHeight();
            if (gifW * 1f / gifH > cw * 1f / ch) {
                scale = ch * 1f / gifH;
            } else {
                scale = cw * 1f / gifW;
            }

            horiPadding = (int) ((cw - gifW * scale) / 2);
            vertiPadding = (int) ((ch - gifH * scale) / 2);
        }
    }
}