Efficiently update RecyclerView Grid or otherwise Display Complex Grid

Question

I have a grid of pixels being displayed using a RecyclerView (as shown in image). When the button is pushed, most of the pixels will be changing colors. I want this update to process each pixels color change more uniformly, even if it takes a very long time to complete (there may be hundreds of thousands of pixels) without blocking the main thread. How is this possible?

If possible I'd like a smooth flow as individual pixels change. The most important thing here is not completing the action quickly but smoothly. I'm not attached to RecyclerView if this isn't the best choice - I was just lead to believe it would be better for performance. I don't need listeners of any kind for the cells. Eventually the cells will become more complex, each housing other cells (Layered Views with background colors). I will be using an SQL database and the Room library for data storage and edit.

The process should be happening over a background thread so as not to halt the UI. Currently I am updating my RecyclerView via myRecyclerAdapter.notifyItemChanged(i); on the onClickListener of the button and my UI will halt while it completes.

Answer 1

Try the CustomView,there are very good reasons to use CustomView for creating views that are not provided by the standard widgets. You shoud be able to use a background thread to implement the time sync or delay between each transition,to make it smooth.And use runOnUiThread() method to change the ui i.e pixel colors in your case. for example- you can try stuff like this-

 Runnable onAnimationStarted=new Runnable() {
            @Override
            public void run() {
            //change ui
            }
        };
Runnable onAnimationStopped=new Runnable() {
            @Override
            public void run() {
            //change ui
            }
        };
       Thread thread = new Thread(){
                @Override
                public void run() {
    runOnUiThread(onAnimationStarted);
              long start= System.currentTimeMillis();;
              while(System.currentTimeMillis()-start<1000) //waits one second
            {

            };
    runOnUiThread(onAnimationStopped);                 
        }

        };
            thread.start();

Answer 2

What you can do is one by one update the cells you want to update. Then call notifyDataSetChanged. An example can be found here.

If you encounter rendering problems try requestLayout and forceLayout.

I recommend reading this answer to better understand what going on in the background.