<div dir="auto">After playing around with the code sample, I think that this is not the right way to use the animation. The reason is that there is no point in starting the animation before the control is attached to the scenegraph, or even made visible. A small refactoring where, e.g., the controller class exposes a method to start the animation in onSucceeded or just calls it on the FX thread is enough. I never start an animation as part of the construction because it's not the right time. John suggested tying the lifecycle of the animation to the showing of the node, which also solves the problem. <div dir="auto"><br></div><div dir="auto">There are animations like PauseTransition or other non-interfering Timelines that could reasonably be run on a background thread. Or maybe just on an unconnected control. This could be a reason to not limit animation methods to the FX thread at the expense of possible user errors, but document the pitfall.</div><div dir="auto"><br></div><div dir="auto">I don't see a good use case for modifying controls in a background thread while still interacting with the scenegraph, hence for adding multithread support. </div><div dir="auto"><br></div><div dir="auto">- Nir</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Jan 22, 2024, 12:59 Jurgen Doll <<a href="mailto:javafx@ivoryemr.co.za">javafx@ivoryemr.co.za</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><u></u>
<div><div><big>Here's an example as requested by Nir:</big></div><div><big><br></big></div><div><span style="color:#7f0055;font-weight:bold">public</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">class</span><span style="color:#000000"> FxTimeLineTest </span><span style="color:#7f0055;font-weight:bold">extends</span><span style="color:#000000"> Application</span></div><div><div style="background-color:#ffffff;padding:0px 2px 0px 2px"><div style="color:#000000;background-color:#ffffff;font-family:"Consolas";font-size:10pt;white-space:pre-wrap"><p style="margin:0"><span style="color:#000000">{</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">private</span><span style="color:#000000"> BorderPane </span><span style="color:#0000c0">bp</span><span style="color:#000000"> = </span><span style="color:#7f0055;font-weight:bold">new</span><span style="color:#000000"> BorderPane( </span><span style="color:#7f0055;font-weight:bold">new</span><span style="color:#000000"> Label(</span><span style="color:#2a00ff">"Loading"</span><span style="color:#000000">) );</span></p><p style="margin:0"><br></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">public</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">static</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">void</span><span style="color:#000000"> main( String[] </span><span style="color:#6a3e3e">args</span><span style="color:#000000"> ) {</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#000000;font-style:italic">launch</span><span style="color:#000000">( FxTimeLineTest.</span><span style="color:#7f0055;font-weight:bold">class</span><span style="color:#000000">, </span><span style="color:#6a3e3e">args</span><span style="color:#000000"> );</span></p><p style="margin:0"><span style="color:#000000"> }</span></p><p style="margin:0"><br></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#646464">@Override</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">public</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">void</span><span style="color:#000000"> start( Stage </span><span style="color:#6a3e3e">primaryStage</span><span style="color:#000000"> ) </span><span style="color:#7f0055;font-weight:bold">throws</span><span style="color:#000000"> Exception {</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">new</span><span style="color:#000000"> Thread( </span><span style="color:#7f0055;font-weight:bold">new</span><span style="color:#000000"> LoadScene() ).start();</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#6a3e3e">primaryStage</span><span style="color:#000000">.setScene( </span><span style="color:#7f0055;font-weight:bold">new</span><span style="color:#000000"> Scene( </span><span style="color:#0000c0">bp</span><span style="color:#000000">, 300, 200 ) );</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#6a3e3e">primaryStage</span><span style="color:#000000">.setTitle( </span><span style="color:#2a00ff">"Memory Usage"</span><span style="color:#000000"> );</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#6a3e3e">primaryStage</span><span style="color:#000000">.show();</span></p><p style="margin:0"><span style="color:#000000"> }</span></p><p style="margin:0"><br></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">private</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">class</span><span style="color:#000000"> LoadScene </span><span style="color:#7f0055;font-weight:bold">extends</span><span style="color:#000000"> Task<Parent> {</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#646464">@Override</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">protected</span><span style="color:#000000"> Parent call() </span><span style="color:#7f0055;font-weight:bold">throws</span><span style="color:#000000"> Exception {</span></p><p style="margin:0"><span style="color:#000000"> Parent </span><span style="color:#6a3e3e">p</span><span style="color:#000000"> = FXMLLoader.</span><span style="color:#000000;font-style:italic">load</span><span style="color:#000000">( getClass().getResource(</span><span style="color:#2a00ff">"TestView.fxml"</span><span style="color:#000000">) );</span></p><p style="margin:0"><span style="color:#000000"> Thread.</span><span style="color:#000000;font-style:italic">sleep</span><span style="color:#000000">( 1000 );</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">return</span><span style="color:#000000"> </span><span style="color:#6a3e3e">p</span><span style="color:#000000">;</span></p><p style="margin:0"><span style="color:#000000"> }</span></p><p style="margin:0"><br></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#646464">@</span><span style="color:#646464">Override</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">protected</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">void</span><span style="color:#000000"> succeeded() {</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#0000c0">bp</span><span style="color:#000000">.setCenter( getValue() );</span></p><p style="margin:0"><span style="color:#000000"> }</span></p><p style="margin:0"><br></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#646464">@</span><span style="color:#646464">Override</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">protected</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">void</span><span style="color:#000000"> failed() {</span></p><p style="margin:0"><span style="color:#000000"> getException().printStackTrace();</span></p><p style="margin:0"><span style="color:#000000"> }</span></p><p style="margin:0"><span style="color:#000000"> }</span></p><p style="margin:0"><span style="color:#000000">}<br><br></span></p></div></div></div><div><div style="background-color:#ffffff;padding:0px 2px 0px 2px"><div style="color:#000000;background-color:#ffffff;font-family:"Consolas";font-size:10pt;white-space:pre-wrap"><p style="margin:0">------------------------------------------------------------------------------------------------------</p></div></div></div><div><br></div><div><div style="background-color:#ffffff;padding:0px 2px 0px 2px"><div style="color:#000000;background-color:#ffffff;font-family:"Consolas";font-size:10pt;white-space:pre-wrap"><p style="margin:0"><span style="color:#7f0055;font-weight:bold">public</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">class</span><span style="color:#000000"> TestView</span></p><p style="margin:0"><span style="color:#000000">{</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#646464">@</span><span style="color:#646464">FXML</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">private</span><span style="color:#000000"> Label </span><span style="color:#0000c0">memory</span><span style="color:#000000">;</span></p><p style="margin:0"><br></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">private</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">static</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">final</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">double</span><span style="color:#000000"> </span><span style="color:#0000c0;font-style:italic;font-weight:bold">MEGABYTE</span><span style="color:#000000"> = 1024 * 1024;</span></p><p style="margin:0"><br></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#646464">@</span><span style="color:#646464">FXML</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">private</span><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">void</span><span style="color:#000000"> initialize()</span></p><p style="margin:0"><span style="color:#000000"> {</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">var</span><span style="color:#000000"> </span><span style="color:#6a3e3e">updater</span><span style="color:#000000"> = </span><span style="color:#7f0055;font-weight:bold">new</span><span style="color:#000000"> Timeline</span></p><p style="margin:0"><span style="color:#000000"> (</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">new</span><span style="color:#000000"> KeyFrame( Duration.</span><span style="color:#000000;font-style:italic">seconds</span><span style="color:#000000">(2.5), </span><span style="color:#6a3e3e">event</span><span style="color:#000000"> -></span></p><p style="margin:0"><span style="color:#000000"> {</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">var</span><span style="color:#000000"> </span><span style="color:#6a3e3e">runtime</span><span style="color:#000000"> = Runtime.</span><span style="color:#000000;font-style:italic">getRuntime</span><span style="color:#000000">();</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">double</span><span style="color:#000000"> </span><span style="color:#6a3e3e">maxMemory</span><span style="color:#000000"> = </span><span style="color:#6a3e3e">runtime</span><span style="color:#000000">.maxMemory() / </span><span style="color:#0000c0;font-style:italic;font-weight:bold">MEGABYTE</span><span style="color:#000000">;</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#7f0055;font-weight:bold">double</span><span style="color:#000000"> </span><span style="color:#6a3e3e">usedMemory</span><span style="color:#000000"> = (</span><span style="color:#6a3e3e">runtime</span><span style="color:#000000">.totalMemory() - </span><span style="color:#6a3e3e">runtime</span><span style="color:#000000">.freeMemory()) / </span><span style="color:#0000c0;font-style:italic;font-weight:bold">MEGABYTE</span><span style="color:#000000">;</span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#0000c0">memory</span><span style="color:#000000">.setText( (</span><span style="color:#7f0055;font-weight:bold">int</span><span style="color:#000000">) </span><span style="color:#6a3e3e">usedMemory</span><span style="color:#000000"> + </span><span style="color:#2a00ff">" MB / "</span><span style="color:#000000"> + (</span><span style="color:#7f0055;font-weight:bold">int</span><span style="color:#000000">) </span><span style="color:#6a3e3e">maxMemory</span><span style="color:#000000"> +</span><span style="color:#2a00ff">" MB"</span><span style="color:#000000"> );</span></p><p style="margin:0"><span style="color:#000000"> })</span></p><p style="margin:0"><span style="color:#000000"> );</span></p><p style="margin:0"><br></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#6a3e3e">updater</span><span style="color:#000000">.setCycleCount(Animation.</span><span style="color:#0000c0;font-style:italic;font-weight:bold">INDEFINITE</span><span style="color:#000000">);<br> // This FXML is being loaded on a background thread<br></span></p><p style="margin:0"><span style="color:#000000"> </span><span style="color:#6a3e3e">updater</span><span style="color:#000000">.play();</span></p><p style="margin:0"><span style="color:#000000"> }</span></p><p style="margin:0"><span style="color:#000000">}<br><br></span></p></div></div></div><div><div style="background-color:#ffffff;padding:0px 2px 0px 2px"><div style="color:#000000;background-color:#ffffff;font-family:"Consolas";font-size:10pt;white-space:pre-wrap"><p style="margin:0">------------------------------------------------------------------------------------------------------</p></div></div></div><div><br></div><div>
<span style="color:#000000"><big>TestView.fxml</big></span>
</div><div><br></div><div><div style="background-color:#ffffff;padding:0px 2px 0px 2px"><div style="color:#000000;background-color:#ffffff;font-family:"Consolas";font-size:10pt;white-space:pre-wrap"><p style="margin:0"><div style="background-color:#ffffff;padding:0px 2px 0px 2px"><div style="color:#000000;background-color:#ffffff;font-family:"Consolas";font-size:10pt;white-space:pre-wrap"><p style="margin:0"><?xml version="1.0" encoding="UTF-8"?></p><p style="margin:0"><br></p><p style="margin:0"><?import javafx.scene.control.Label?></p><p style="margin:0"><?import javafx.scene.layout.StackPane?></p><p style="margin:0"><br></p><p style="margin:0"><StackPane xmlns:fx="<a href="http://javafx.com/fxml/1" target="_blank" rel="noreferrer">http://javafx.com/fxml/1</a>" fx:controller="TestView"></p><p style="margin:0"> <children></p><p style="margin:0"> <Label fx:id="memory" text="Current / Max MB" ></p><p style="margin:0"> <properties hashCode="12345" /></p><p style="margin:0"> </Label></p><p style="margin:0"> </children></p><p style="margin:0"></StackPane></p></div></div></p></div></div></div><div><br></div><div><br></div><div><br></div><div>On Sat, 20 Jan 2024 17:08:41 +0200, Nir Lisker <<a href="mailto:nlisker@gmail.com" target="_blank" rel="noreferrer">nlisker@gmail.com</a>> wrote:<br></div><br><blockquote style="margin:0 0 0.80ex;border-left:#0000ff 2px solid;padding-left:1ex"><div dir="ltr">Hi Jurgen,<div><br></div><div>What I'm confused about the most is what it is you are actually trying to do that necessitates the use of animations outside of the FX thread. You said that you need to initialize controls on another thread, and that you are using Task (both of which are fine), but how does playing animations relate? Playing an animation is something that is done explicitly, usually in order to manipulate data. Can you give a real use case, like a minimized version of what you're doing?</div><div><br></div><div>- Nir</div></div></blockquote></div></blockquote></div>