Support for AnimationTimer

[danielkroeni]

In order to use javafx.animation.AnimationTimer you have to subclass it and override its handle method. This is not an option if you want to use it directly from frege. So I implemented a 'builder' where you can just pass the function you want to be called on every frame:

data AnimationTimerBuilder = mutable native graphics.AnimationTimerBuilder where
   native from graphics.AnimationTimerBuilder.from :: (Long -> IO ()) -> IO AnimationTimer

import javafx.animation.AnimationTimer;
import frege.prelude.PreludeBase;
import frege.runtime.Lambda;

public class AnimationTimerBuilder {
  public static AnimationTimer from(Lambda handler) {
    return new AnimationTimer() {
      @Override
      public void handle(long arg0) {
        frege.runtime.Delayed.<java.lang.Void>forced(
          PreludeBase.TST.performUnsafe(handler.apply(arg0).result().forced())
        );
      }
    };
  }
}

Now you can use it like this:

do animTimer <- AnimationTimerBuilder.from $ \time -> do
  println "Hi" 
  println time

animTimer.start

If you could add something similar to your fx utils module, I could drop my version.

[Dierk]

Cool, thanks!

My goal was to build sth like https://github.com/Dierk/groovyfx/blob/master/groovyfx/src/demo/groovy/AnimationDemo.groovy

But so we have sth to start with.

Thanks a lot
Dierk

sent from:mobile

Am 08.10.2015 um 09:33 schrieb Daniel Kröni notifications@github.com:

In order to use javafx.animation.AnimationTimer you have to subclass it and override its handle method. This is not an option if you want to use it directly from frege. So I implemented a 'builder' where you can just pass the function you want to be called on every frame:

data AnimationTimerBuilder = mutable native graphics.AnimationTimerBuilder where
native from graphics.AnimationTimerBuilder.from :: (Long -> IO ()) -> IO AnimationTimer
import javafx.animation.AnimationTimer;
import frege.prelude.PreludeBase;
import frege.runtime.Lambda;

public class AnimationTimerBuilder {
public static AnimationTimer from(Lambda handler) {
return new AnimationTimer() {
@OverRide
public void handle(long arg0) {
frege.runtime.Delayed.<java.lang.Void>forced(
PreludeBase.TST.performUnsafe(handler.apply(arg0).result().forced())
);
}
};
}
}
Now you can use it like this:

do animTimer <- AnimationTimerBuilder.from $ \time -> do
println "Hi"
println time

animTimer.start
If you could add something similar to your fx utils module, I could drop my version.

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[Ingo60]

I am wondering why this works. Probably because the forced value is not used and hence no cast is actually done.

Certainly, the cast to java.lang.Void doesn't feel right to me. I would've choosen Object, probably.
In fact, an IO () is under the hood a method that returns (), and the type () is an enumeration, which is currently implemented as a short that indicates the constructor value. Since () is the only constrctor of (), it should always be 0.

[danielkroeni]

You are right. No idea what I was thinking. Void is definitely the wrong choice.