added .then function to tweens

com/danitheskunk/skunkworks/TestNode.java

@@ -11,7 +11,10 @@ public class TestNode extends BaseGame {
 		sprite.setTexture(window.loadTexture("demoassets/test.png"));
 		sprite.setPos(new Vec2f(100, 100));
 		rootNode.add(sprite);
-		sprite.tweenPos(new Vec2f(800, 400), 120).delay(600);
+		sprite.tweenPos(new Vec2f(800, 400), 120).delay(60).then(() -> {
+			System.out.println("yay! got there! now lets go home");
+			sprite.tweenPos(new Vec2f(100, 100), 120);
+		});
 	}
 
 	public static void main(String[] args) {

com/danitheskunk/skunkworks/nodes/BaseTween.java

@@ -4,18 +4,26 @@ public abstract class BaseTween {
 	protected double progress;
 	protected int startFrame;
 	protected int endFrame;
+	protected Runnable thenFunc;
 
 	public BaseTween() {
 		progress = 0;
+		thenFunc = null;
 	}
 
 	public void setProgress(double progress) {
 		this.progress = progress;
 	}
 
-	public void delay(int frames) {
+	public BaseTween delay(int frames) {
 		startFrame += frames;
 		endFrame += frames;
+		return this;
+	}
+
+	public BaseTween then(Runnable func) {
+		thenFunc = func;
+		return this;
 	}
 
 	protected abstract void apply();

com/danitheskunk/skunkworks/nodes/Tweener.java

@@ -36,6 +36,9 @@ public class Tweener {
 			}
 		}
 		for(var tween : toRemove) {
+			if(tween.thenFunc != null) {
+				tween.thenFunc.run();
+			}
 			tweens.remove(tween);
 		}
 		++currentFrame;