Set a delay in libGDX

Question

I have now tried to set up a delay in libGDX in three different ways.

First I tried to use a Timer, but if I restart the activity, the timer won't start again. This is a known issue when using GestureDetector: https://github.com/libgdx/libgdx/issues/2274

Then I tried setting up a timer using Gdx.graphics.getDeltaTime in my render method, but this doesn't work for me as I have set it to non-continous rendering. Described in answer #2 set a delay in libgdx game

Finally I tried using a while loop and System.getCurrentTimeMilliseconds, however this prevented the application from recognizing a tap while the while loop was looping.

I have also heard of DelayAction, but how does one implement that into the code? https://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/scenes/scene2d/actions/DelayAction.html

Is there another way of setting a delay? How do one implement DelayAction? Or how does one fix the Timer bug in libGDX?

Answer 1

Inspired by Barodapride's comment, I found a solution where I make a new thread, and put the while loop here. This code will wait for 1000 ms, and then run foo() on the main thread.

new Thread(new Runnable() {
            @Override
            public void run() {
                long time = System.currentTimeMillis();
                while (System.currentTimeMillis() < time + 1000){}
                Gdx.app.postRunnable(new Runnable() {
                    @Override
                    public void run() {
                        foo();
                    }
                });
            }
        }).start();

Answer 2

Well i just create an interface like this:

public interface TimeEvents {
    public void handleTime(float secondsToEvent,Events event, Object obj);
    public void resetTimer();
    public void handleEvent(Events event,Object obj);
}

and create a class implementing it for the game entity i want, the Events for my case is an enum with the event to process (Like wait for x seconds, walk for x seconds, fire for x seconds..), the object is the instance of target object i want to handle by event..

 public class FooTimeEvents implements TimeEvents{
     [...]
        private float timeSeconds = 0;
        @Override
        public void handleTime(float secondsToEvent,Events event, Object obj){
            timeSeconds +=Gdx.graphics.getRawDeltaTime();
            if(timeSeconds > secondsToEvent){
                timeSeconds-=secondsToEvent;
                handleEvent(event,obj);
            }
        }

    @Override
      public void handleEvent(Events event,Object obj){
        switch (event) {
            case EVENT_FOO_1:
                executeEventFoo1((Foo1Obj)obj);
                break;
            case EVENT_FOO_2:
                 executeEventFoo2((Foo2Obj)obj);
                break;
            default:
                break;
        }
    }
    [...]

you call the handleTime on render method of the entity, and the event will only execute each timeSeconds it was set to..

Answer 3

You can use a RunnableAction with a DelayAction. Here are the steps you would take:

1. Instantiate a RunnableAction and provide it with a Runnable:

   RunnableAction runnableAction = Actions.run(new Runnable(){

   public void run(){

   // Put whatever you want to do here

   }

   }

2. Instantiate a DelayAction and provide it with your RunnableAction:

   DelayAction delayAction = Actions.delay(secondsOfDelay, runnableAction);

3. Now in your render or update method you need to tell your delayAction to 'act':

   delayAction.act(delta);

Once the delay has passed the code in your runnable should run. I'm sorry if this syntax isn't exactly correct but this should be the easiest way to go. Let me know if something doesn't work for you and I can help.