AnimationTimer Example

This blog entry just shows a screenshot and the code for a little JavaFX AnimationTimer test I wrote.

AnimationTimer is a JavaFX class which comes in handy if you are in need of a callback hook which should be called on every frame. With this class it is possible to implement simple animations for example, but it could be used for various other things as well. The example code below shows how to make hundreds of circles wiggle.

	package net.ladstatt.fx.animations
	import java.net.URL
	import java.util.ResourceBundle
	import javafx.animation.AnimationTimer
	import javafx.application.Application
	import javafx.fxml._
	import javafx.scene.layout.AnchorPane
	import javafx.scene.paint.Color
	import javafx.scene.shape.Circle
	import javafx.scene.{Parent, Scene}
	import javafx.stage.Stage
	import scala.collection.immutable.IndexedSeq
	import scala.util.Random
	import scala.util.control.NonFatal
	/**
	* AnimationTimer Example
	*
	* Shows an example how to use the JavaFX AnimationTimer class
	*/
	object FxAnimations {
	def main(args: Array[String]) {
	Application.launch(classOf[FxAnimationsApp], args: _*)
	}
	}
	class FxAnimationsApp extends javafx.application.Application {
	val loader = new FXMLLoader(getClass.getResource("FxAnimations.fxml"))
	override def start(stage: Stage): Unit =
	try {
	stage.setTitle("FxAnimations App")
	loader.load[Parent]()
	stage.setScene(new Scene(loader.getRoot[Parent]))
	stage.show()
	} catch {
	case NonFatal(e) => e.printStackTrace()
	}
	}
	case class CircleAnimation(circles : Seq[Circle]) extends AnimationTimer {
	// every tick this method is called - you are free to do whatever you want
	// in this method. maybe animate something, maybe something else ...
	override def handle(now: Long): Unit = {
	circles.foreach {
	case c =>
	c.setCenterX(c.getCenterX + Random.nextDouble * 4 - 2)
	c.setCenterY(c.getCenterY + Random.nextDouble * 4 - 2)
	}
	}
	}
	class FxAnimationsController extends Initializable {
	@FXML var canvasAnchorPane: AnchorPane = _
	def randColor(): Color = Color.color(Random.nextDouble, Random.nextDouble(), Random.nextDouble)
	override def initialize(location: URL, resources: ResourceBundle): Unit = {
	val width = canvasAnchorPane.getMinWidth
	val height = canvasAnchorPane.getMinHeight
	val circles: IndexedSeq[Circle] =
	for (i <- 1 to 2000) yield {
	mkCircle(width.toInt, height.toInt, Random.nextInt(20) +1 )
	}
	canvasAnchorPane.getChildren.addAll(circles: _*)
	CircleAnimation(circles).start()
	}
	def mkCircle(width: Int, height: Int, maxRadius: Int): Circle = {
	val c = new Circle(Random.nextInt(width), Random.nextInt(height), Random.nextInt(maxRadius))
	c.setFill(randColor())
	c
	}
	}

view raw FxAnimationsApp.scala hosted with ❤ by GitHub

A self contained project is available here.