using interfaces for callback

gistfile1.txt

Create an interface to describe the "callbacks" available on my main activity so that a worker thread can callback and have the activity update certain mainthread views.

,----
| public interface HoneyBeezListener {
| 	public void frameRate(int frameCount);
|       /* add other callbacks here */
| }
`----

In my customview create a holder for the callback interface and a setter

,----
| 	private HoneyBeezListener honeyBeezListener;
| 
| 	public void setHoneyBeezListener(HoneyBeezListener listener) {
| 		honeyBeezListener = listener;
| 	}
`----

In my main acitivity which manages various mainthread views assign a listener to my customview so it can callback.

,----
| 		gardenView.setHoneyBeezListener(new HoneyBeezListener() {
| 			@Override
| 			public void frameRate(int frameCount) {
| 				displayFrameRate(frameCount);
| 			}
| 		});
`----

also define the function to update a mainthread frame rate view in the mainactivity: (yes not optimised)

,----
| 	private void displayFrameRate(int frameRate) {
| 		((TextView) findViewById(R.id.framerate)).setText(getString(R.string.framerate) + frameRate);
| 	}
`----

when we want to callback we create a runnable an post back to the mainuithread


,----
| 					if (curTime >= lastFrameTime + 1000) { /* frames per second */
| 						lastFrameTime = curTime;
| 						((Activity)context).runOnUiThread(new Runnable() {
| 							int f=frameCount;
| 							@Override
| 							public void run() {
| 								honeyBeezListener.frameRate(f);
| 							}
| 						});
| 						frameCount = 0;
| 					}
`----