WindowManager laggy when updating multiple views

  • Replies:0
  • OpenNot stickiedUnanswered
  • Forum posts: 19

Jul 5, 2016 9:08:11 PM via Website

I'm not sure if this is the appropriate thread for this, I'm sorry if it's not.

I am trying to move multiple ImageViews attached to the WindowManager but after adding three views, the movement becomes very choppy.

After some investigation I think this is caused by calling updateViewLayout too many times and on different views.

The code below is a simplified version of what I am trying to do and illustrates the problem.

public class MainActivity extends AppCompatActivity {

    WindowManager windowManager;
    ArrayList<ImageView> imageViews = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        windowManager = (WindowManager)this.getSystemService(Context.WINDOW_SERVICE);
        addImageView();
        addImageView();
        addImageView();
    }

    private void addImageView() {
        final 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);
        params.gravity = Gravity.TOP | Gravity.START;
        ImageView imageView = new ImageView(this);
        imageView.setImageResource(R.mipmap.ic_launcher);
        imageView.setOnTouchListener(new ImageViewTouchListener());
        imageViews.add(imageView);
        windowManager.addView(imageView, params);
    }

    private class ImageViewTouchListener implements View.OnTouchListener {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            switch(event.getAction()) {
                case MotionEvent.ACTION_MOVE:
                    for(ImageView imageView : imageViews) {
                        WindowManager.LayoutParams params = (WindowManager.LayoutParams)imageView.getLayoutParams();
                        params.x = (int)event.getRawX();
                        params.y = (int)event.getRawY();
                        windowManager.updateViewLayout(imageView, params);
                    }
                    return true;
            }
            return false;
        }
    }
}

As you can see, I am adding three ImageViews in onCreate, and each ImageView has a TouchListener that updates the layout of every bubble in ACTION_MOVE.

When adding one or two ImageViews, the movement is fluid, but three or more and it lags badly.

Anyone have any ideas? Thank you very much!