Libgdx how to stop for loop until actor action has finished/completed

Question

I have actors added to a group called cells, and in a for loop I add actions to a specific set of cells within the group.

I would like it so that the next iteration of the loop is not started until the cell's action has completed.

for (int i = 0; i < cells.length; ++i) {

     cell.addAction(fadeIn(1f));
     // I need to wait here until the action has completed!
}

Is there a blocking action I can use or something in libgdx? Or is there a specific way I should do this?

Obviously I need libgdx to keep running in the background otherwise the action will not complete at all, I really have no idea on how to do this.

I cannot use RunnableAction as that is for calling code after execution, I simply want to stop the loop iterating.

Thanks,

Answer 1

Instead of blocking the loop, you could try setting a delay on each action for the calculated time it will take for the fadeIn to start running.

Something like this:

float delay = 0;
for (int i = 0; i < cells.length; ++i) {
    SequenceAction sa = Actions.sequence(Actions.delay(delay), 
                          Actions.fadeIn(1f));
    cell.addAction(sa);
    delay += 1f; //Increase the delay for the duration of each fadeIn
}

Didn't test this tho.