setOneShotPreviewCallback

Once register callback, one time be done callback.

It is callback function.

private Camera.PreviewCallback mPreviewListener = new Camera.PreviewCallback() {
 @Override
 public void onPreviewFrame(byte[] data, Camera camera) {
  Log.d("camera", "onPreviewFrame size=" + data.length);
 }
};

register callback.

_camera.setOneShotPreviewCallback(mPreviewListener);

Every time you touch, you can register a function callback, we confirmed that the function is called callback.

source code here.