how to wait for Android runOnUiThread to be finished?

Question

I have a worker thread that creates a runnable object and calls runOnUiThread on it, because it deals with Views and controls. I'd like to use the result of the work of the runnable object right away. How do I wait for it to finish? It doesn't bother me if it's blocking.

Answer 1

Just scratching out the highlights

synchronized( myRunnable ) {    activity.runOnUiThread(myRunnable) ;     myRunnable.wait() ; // unlocks myRunable while waiting } 

Meanwhile... in myRunnable...

void run() {    // do stuff     synchronized(this)    {       this.notify();    } } 

Answer 2

Perhaps a little simplistic but a mutex will do the job:

final Semaphore mutex = new Semaphore(0); activity.runOnUiThread(new Runnable() {     @Override     public void run() {         // YOUR CODE HERE         mutex.release();     } });  try {     mutex.acquire(); } catch (InterruptedException e) {     e.printStackTrace(); }