How to use FadeTransition

gistfile1.txt

import javafx.animation.*;
import javafx.animation.transition.*;
import javafx.scene.*;
import javafx.scene.image.*;
import javafx.scene.layout.*;
import javafx.scene.shape.*;
import javafx.stage.*;

public function run(args: String[]) {

    var node = ImageView {
        image: Image { url: args[0] }
    };

    var t: Transition = FadeTransition {
        node: node
        duration:  0.5s
        fromValue: 1.0
        toValue:   0.0
        action: function() {
            node.visible = not node.visible;
        }
        override function play() {
            t.rate = if (node.visible) 1 else -1;
            super.play();
        }
    }

    Stage {
        scene: Scene {
            content: Stack {
                content: [
                    Rectangle {
                        width:  300
                        height: 300
                        onMouseClicked: function(e) {
                            if (not t.running) {
                                t.play();
                            }
                        }
                    }
                    node
                ]
            }
        }
    }
}