public class ScrollableImageView extends ImageView {
    private GestureDetectorCompat gestureDetectorCompat;
    private Matrix imageMatrix;

    public ScrollableImageView(Context context) {
        this(context, null);
    }

    public ScrollableImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
        new Matrix();
    }

    public ScrollableImageView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        setScaleType(ScaleType.MATRIX);

        imageMatrix = new Matrix();

        gestureDetectorCompat = new GestureDetectorCompat(context,
                new MySimpleOnGestureListener(this));
    }

    @Override
    public boolean onTouchEvent(@NonNull MotionEvent event) {
        gestureDetectorCompat.onTouchEvent(event);
        return true;
    }

    public void scroll(float distance) {
        imageMatrix.postTranslate(distance, 0);
        setImageMatrix(imageMatrix);
        invalidate();
    }

    private static class MySimpleOnGestureListener extends GestureDetector.SimpleOnGestureListener {
        private ScrollableImageView scrollableImageView;

        public MySimpleOnGestureListener(ScrollableImageView scrollableImageView) {
            this.scrollableImageView = scrollableImageView;
        }

        @Override
        public boolean onDown(MotionEvent e) {
            Utils.log("onDown");
            return true;
        }

        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
            scrollableImageView.scroll(-distanceX);
            return true;
        }
    }
}