wait for thread to finish before starting new one

include/aolayer.h

@@ -143,6 +143,9 @@ protected:
   // Populates the frame and delay vectors with the next frame's data.
   void load_next_frame();
 
+  // used in load_next_frame
+  QFuture<void> future;
+
 signals:
   void done();
 

src/aolayer.cpp

@@ -529,8 +529,8 @@ void CharLayer::movie_ticker()
 void AOLayer::movie_ticker()
 {
   ++frame;
-  QFuture<void> future;
   if (frame >= movie_frames.size() && frame < max_frames) { // need to load the image
+      future.waitForFinished(); // Do Not want this to be running twice
       future = QtConcurrent::run(this, &AOLayer::load_next_frame);
   }
   else if (frame >= max_frames) {