Why isnt my JavaFX Progress Indicator not updating? - javafx

Question

I have the following layout in my JavaFX application,
StackPane
- BorderPane
- Text (on Top)
- Vbox (on Center)
- ProgressIndicator
- Label
- BorderPane
- Scroll Pane (with Tile Pane inside) (Center of Border Pane)
- Button (Bottom of Border)
- BorderPane
- Vbox (on Center)
- Progress Indicator
- Label
- Button ( Bottom)
When showing the first Border Pane, the Progress Indicator works perfectly. I set it up using the following code,
progress.progressProperty().bind(iconLoadTask.progressProperty());
progresspane.visibleProperty().bind(iconLoadTask.runningProperty());
When the iconLoadTask completes, the progress pane becomes invisible and the next pane is shown correctly.
From the next BorderPane (which has the Scroll pane), I show the last border pane (with a progress indicator - indeterminate). This progress indicator doesnt animate at all.
Edit:
As suggested, I have tried reproducing this issue,
I have the following controller file. Here you can see two progress indicators (progress and stopProfInd). progress is updated from the task appLoadTask. This is a finite task and I can update progress from the task. This works fine.
I have another indicator called stopProfInd. This is set indeterminate from Scene Builder. Here you can see that I make that pane visible. I expect the indicator to animate, but it doesn't.
public class AppController
implements Initializable {
#FXML
private StackPane stackpaneapps;
#FXML
private BorderPane progresspane;
#FXML
private ProgressIndicator progress;
#FXML
private ProgressIndicator stopProfInd;
#FXML
private BorderPane profilingpane;
#FXML
private Label devicename;
private ObservableValue<Number> profProperty;
// Reference to the main application.
private Main mainApp;
private AppIconsTask appLoadTask;
private ProfilingTask prTask;
private Queue<MyVbox> clickedAppQueue;
#Override // This method is called by the FXMLLoader when initialization is complete
public void initialize(URL fxmlFileLocation, ResourceBundle resources) {
clickedAppQueue = new LinkedList<MyVbox>();
}
/**
* Is called by the main application to give a reference back to itself.
*
* #param mainApp
*/
public void setMainApp(Main mainApp) {
this.mainApp = mainApp;
}
/**
* Is called by the main application to give a reference back to itself.
*
* #param task
*
*/
public void setAppLoadTask(AppIconsTask task) {
this.appLoadTask = task;
progress.progressProperty().bind(appLoadTask.progressProperty());
progresspane.visibleProperty().bind(appLoadTask.runningProperty());
appLoadTask.setOnSucceeded(t -> drawAppIcons(appLoadTask.getApps()));
profilingpane.setVisible(false);
}
void drawAppIcons(ObservableList<App> apps){
progress.setVisible(false);
profilingpane.setVisible(true);
prTask = new ProfilingTask();
stopProfInd.progressProperty().bind(prTask.progressProperty());
new Thread(prTask).start();
}
}
Any clues?
FXML:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.geometry.*?>
<?import javafx.scene.text.*?>
<?import javafx.scene.paint.*?>
<?import javafx.scene.effect.*?>
<?import javafx.scene.*?>
<?import javafx.scene.image.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<AnchorPane prefHeight="263.0" prefWidth="304.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.gamebench.ios.controller.AppController">
<children>
<StackPane fx:id="stackpaneapps" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="5.0" AnchorPane.rightAnchor="5.0" AnchorPane.topAnchor="10.0">
<children>
<BorderPane fx:id="profilingpane" prefHeight="200.0" prefWidth="200.0">
<center>
<VBox alignment="CENTER" prefHeight="200.0" prefWidth="100.0" BorderPane.alignment="CENTER">
<children>
<ProgressIndicator fx:id="stopProfInd" />
</children>
</VBox>
</center>
</BorderPane>
<BorderPane fx:id="progresspane" prefHeight="200.0" prefWidth="200.0">
<center>
<VBox alignment="CENTER" prefHeight="200.0" prefWidth="100.0" BorderPane.alignment="CENTER">
<children>
<ProgressIndicator fx:id="progress" maxHeight="100.0" maxWidth="100.0" prefHeight="68.0" prefWidth="77.0" />
</children>
</VBox>
</center>
</BorderPane>
</children>
</StackPane>
</children>
</AnchorPane>
Adding Task implementation as requested. The following is for appIconsTask which works well.
protected ObservableList<App> call() throws Exception {
String deviceId = "blah";
/* We will start before we get the list of installed apps */
updateProgress(0.0f , 100);
// Get list of installed apps
App[] installedApps = getAppsList(deviceId , false);
appList = FXCollections.observableList(new ArrayList<App>());
int numApps = installedApps.length;
double progress = 1.0f;
for(App app: installedApps){
byte[] pngData;
pngData = comm.getAppIcon(deviceId, app.getBundleId());
app.setAppIcon(pngData);
appList.add(app);
updateProgress((progress/numApps)*100, 100);
progress += 1.0f;
}
return appList;
}
Task implementation for the next progress indicator,
protected Void call() throws Exception {
double f = 1.0;
while(!getStopProf()){
Thread.sleep(30);
}
return null;
}
Reproduction of the issue here,
https://github.com/h-karthik/BugReproStackOverflow

Answer 1

I think you are running into this bug which, at the time of writing, is fixed in the latest GA release (JDK 8u20). The easiest fix, if it's possible for you to do, is to upgrade to and require that version.
If you can't do that, the next most intuitive option is to avoid use of setVisible(...) and just add the progress indicator to the scene graph when you need it. You can define elements in FXML which are not contained in the scene graph by using <fx:define>. Inject this as usual, and then just add the element to the scene graph as you need it. (You can remove it in similar fashion, if you need.)
Your FXML file becomes:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.geometry.*?>
<?import javafx.scene.text.*?>
<?import javafx.scene.paint.*?>
<?import javafx.scene.effect.*?>
<?import javafx.scene.*?>
<?import javafx.scene.image.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<AnchorPane prefHeight="263.0" prefWidth="304.0"
xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1"
fx:controller="com.stackoverflow.repro.controller.AppController">
<children>
<StackPane fx:id="stackpaneapps" AnchorPane.bottomAnchor="0.0"
AnchorPane.leftAnchor="5.0" AnchorPane.rightAnchor="5.0"
AnchorPane.topAnchor="10.0">
<children>
<BorderPane fx:id="progresspane" prefHeight="200.0"
prefWidth="200.0">
<center>
<VBox alignment="CENTER" prefHeight="200.0" prefWidth="100.0"
BorderPane.alignment="CENTER">
<children>
<ProgressIndicator fx:id="progress" maxHeight="100.0"
maxWidth="100.0" prefHeight="68.0" prefWidth="77.0" />
</children>
</VBox>
</center>
</BorderPane>
</children>
</StackPane>
</children>
<fx:define>
<BorderPane prefHeight="200.0" prefWidth="200.0" fx:id="profilingpane">
<center>
<VBox alignment="CENTER" prefHeight="200.0" prefWidth="100.0"
BorderPane.alignment="CENTER">
<children>
<ProgressIndicator fx:id="stopProfInd" />
</children>
</VBox>
</center>
</BorderPane>
</fx:define>
</AnchorPane>
and the controller becomes
package com.stackoverflow.repro.controller;
import java.io.IOException;
import java.net.URL;
import java.util.ResourceBundle;
import com.stackoverflow.repro.Main;
import com.stackoverflow.repro.tasks.AppIconsTask;
import com.stackoverflow.repro.tasks.ProfilingTask;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;
import javafx.scene.control.ProgressIndicator;
import javafx.scene.layout.*;
public class AppController
implements Initializable {
#FXML
private StackPane stackpaneapps;
#FXML
private BorderPane progresspane;
#FXML
private ProgressIndicator progress;
#FXML
private ProgressIndicator stopProfInd;
#FXML
private BorderPane profilingpane;
// Reference to the main application.
private Main mainApp;
private AppIconsTask appLoadTask;
private ProfilingTask prTask;
#Override // This method is called by the FXMLLoader when initialization is complete
public void initialize(URL fxmlFileLocation, ResourceBundle resources) {
}
/**
* Is called by the main application to give a reference back to itself.
*
* #param mainApp
*/
public void setMainApp(Main mainApp) {
this.mainApp = mainApp;
}
/**
* Is called by the main application to give a reference back to itself.
*
* #param task
*
*/
public void setAppLoadTask(AppIconsTask task) {
this.appLoadTask = task;
progress.progressProperty().bind(appLoadTask.progressProperty());
progresspane.visibleProperty().bind(appLoadTask.runningProperty());
// profilingpane.setVisible(false);
appLoadTask.setOnSucceeded(t -> drawAppIcons());
}
void drawAppIcons(){
// profilingpane.setVisible(true);
stackpaneapps.getChildren().add(profilingpane);
prTask = new ProfilingTask();
new Thread(prTask).start();
}
}
Your workaround with the opacity works as well, but this just feels like a more natural approach. There is a slight difference in functionality, which is not evident from everything being in a StackPane. With both setVisible (when it works correctly) and the setOpacity(...) workaround, the progress indicator will take up space in the layout. With adding and removing it when it is required, it will not take up space in the layout when it is not present. So the choice of approach probably depends on how you want it to behave in terms of layout.
Just a couple of other comments about your code:
If you make the thread running the prTask a daemon thread, it will not prevent the JVM from exiting when you close the last window. Obviously you may have other mechanisms for shutting this down in your real app, but it can be a useful trick (and is less annoying if you're testing this from Eclipse...):
Thread prThread = new Thread(prTask);
prThread.setDaemon(true);
prThread.start();
Also, your threading code in the profiling task looks like it is not quite correct. The stopProf field is almost certainly changed on a different thread to the one on which it is read. This means there is no guarantee of liveness of the field (there can be an arbitrary delay, possible indefinite, between it being changed in one thread and that change being visible in another). You should do one of the following:
Mark the field as volatile, or
Mark the getStopProf() and setStopProf(...) methods as synchronized, or
Replace the boolean field with an AtomicBoolean.
This third option is the one I prefer (favor high-level APIs over low-level primitives):
package com.stackoverflow.repro.tasks;
import java.util.concurrent.atomic.AtomicBoolean;
import javafx.concurrent.Task;
/**
* Created by karthik on 17/02/15.
*/
public class ProfilingTask extends Task<Void> {
AtomicBoolean stopProf;
#Override
protected Void call() throws Exception {
double f = 1.0;
while(!getStopProf()){
Thread.sleep(30);
}
return null;
}
public boolean getStopProf(){
return stopProf.get();
}
public void setStopProf(boolean stop){
stopProf.set(stop);
}
}

Answer 2

So, it turns out that it might be my ignorance or possibly a bug.
In my code instead of the following line
profilingpane.setVisible(true);
I use the following and the problem goes away. This is more of a hack to solve the problem.
profilingpane.setOpacity(0.0);
And then when I want the pane to show up,
profilingpane.setOpacity(1.0);