I'm writing a program on the desktop that takes an array of COM port and displays it on the chart dynamically. the program runs without failures for a while, but then fails with the following exception:
Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at com.sun.scenario.animation.AbstractMasterTimer.timePulseImpl(AbstractMasterTimer.java:344)
at com.sun.scenario.animation.AbstractMasterTimer$MainLoop.run(AbstractMasterTimer.java:267)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:521)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:505)
at com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$399(QuantumToolkit.java:334)
at com.sun.javafx.tk.quantum.QuantumToolkit$$Lambda$40/432581434.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$144(WinApplication.java:101)
at com.sun.glass.ui.win.WinApplication$$Lambda$36/1963387170.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
the application continues to run. continue to saved data to a text file, but the window is not active any button except the close button.
if anyone has any ideas please help.
here is some code
public class FXMLController implements Initializable {
public static XYChart.Series<Number, Number> hourDataSeries;
#FXML
public Label label;
#FXML
public Label statusbar;
#FXML
public LineChart lineChart;
#FXML
public NumberAxis xAxis;
#FXML
NumberAxis yAxis;
#FXML
MenuItem close;
#FXML
MenuItem Options;
#FXML
MenuItem about;
#FXML
Button connect;
#FXML
public Label hexString;
#FXML
private void close(ActionEvent event) throws SerialPortException {
//COMConnect.serialPort.closePort();
System.exit(0);
}
#FXML
private void connect(ActionEvent event) {
OpenScene openScene = new OpenScene("/SceneCOM.fxml", "Options");
}
#FXML
private void showStatistics(ActionEvent event) {
OpenScene openScene = new OpenScene("/SceneStatistics.fxml", "Statistics");
}
#FXML
private void aboutit(ActionEvent event) {
OpenScene openScene = new OpenScene("/SceneAbout.fxml", "About");
}
#FXML
private void getconnect(ActionEvent event) {
if (COMConnect.b == true) {
COMConnect.b = false;
try {
COMConnect.serialPort.closePort();
} catch (SerialPortException ex) {
Logger.getLogger(FXMLController.class.getName()).log(Level.SEVERE, null, ex);
}
connect.setText("Connect");
} else {
COMConnect.b = true;
COMConnect.comConnect();
}
}
#Override
public void initialize(URL url, ResourceBundle rb) {
hourDataSeries = new XYChart.Series<Number, Number>();
label.textProperty().bind(COMConnect.EventListener.valueProperty);
COMConnect.connectProperty.setValue("Connect");
connect.textProperty().bindBidirectional(COMConnect.connectProperty);
statusbar.textProperty().bind(Typewriter.status);
hexString.textProperty().bind(TypewriterHexString.hexStr);
xAxis.setLabel("Time");
xAxis.setTickUnit(1);
xAxis.setTickLabelFormatter(new NSC());
yAxis.setLabel("density," + superscript(" kg/m3"));
xAxis.setForceZeroInRange(false);
lineChart.setLegendVisible(false);
lineChart.setCursor(Cursor.CROSSHAIR);
lineChart.getData().add(hourDataSeries);
}
}
and add data to LineChart from other class
javafx.application.Platform.runLater(new Runnable() {
#Override
public void run() {
valueProperty.setValue(formatt(second) + superscript(" kg/m3"));
if (y > 10) {
hourDataSeries.getData().remove(0);
}
data = new XYChart.Data<Number, Number>(y, second);
data.setNode(new HoveredThresholdNode(0, second, ""));
hourDataSeries.getData().add(data);
System.out.println(hourDataSeries.getData().toString());
y++;
}
});
}
Thus, the solution was very simple:
lineChart.setAnimated(false);
the application works correctly for about 25 hours.
Thanks everyone!
Related
Here is my code. I am using scene builder. The code is not working.For first time it loads the hello1.html but in thread the hello2.html does not load.
public class TwavlController implements Initializable {
/**
* Initializes the controller class.
*/
#FXML public WebView webPane;
private Service<Void> back_thread;
private WebEngine engine;
#Override
public void initialize(URL url, ResourceBundle rb) {
// TODO
engine = webPane.getEngine();
final String html_file = "hello1.html"; //HTML file to view in web view
URL urlHello = getClass().getResource(html_file);
engine.load(urlHello.toExternalForm());
run();
}
private File last_update,current;
public void run(){
back_thread = new Service<Void>() {
#Override
protected Task<Void> createTask() {
return new Task<Void>() {
#Override
protected Void call() throws Exception {
updateMessage("hello2.html");
return null;
}
};
}
};
engine.userAgentProperty().bind(back_thread.messageProperty());
back_thread.restart();
}
}
I'm not really clear what you're trying to do here, but I think maybe you are looking for
public void run(){
back_thread = new Service<Void>() {
#Override
protected Task<Void> createTask() {
return new Task<Void>() {
#Override
protected Void call() throws Exception {
Platform.runLater(() ->
engine.load(getClass().getResource("hello2.html").toExternalForm()));
return null;
}
};
}
};
back_thread.restart();
}
I have some signal processing data which gets fed at roughly at 50Hz. I need to update a rectangle's opacity based on the signal value in real time. I am trying to develop the UI in JavaFX 8.
For time being I am simulating the signal value using random number generator in JavaFX service in my code.
I am using Platform.runLater to update the UI, however this doesn't update values in real time, I read through similar problems encountered by others and the normal suggestion is that not to call Platform.runLater often but to batch the updates.
In my case if I batch my updates, the frequency at which the opacity changes will not be equal to the signal frequency.
Any thoughts on how to achieve this?
public class FlickerController
{
#FXML
private Rectangle leftBox;
#FXML
private Rectangle rightBox;
#FXML
private ColorPicker leftPrimary;
#FXML
private ColorPicker leftSecondary;
#FXML
private ColorPicker rightPrimary;
#FXML
private ColorPicker rightSecondary;
#FXML
private Slider leftFrequency;
#FXML
private Slider rightFrequency;
#FXML
private Button startButton;
#FXML
private Label leftfreqlabel;
#FXML
private Label rightfreqlabel;
#FXML
private Label rightBrightness;
#FXML
private Label leftBrightness;
private boolean running = false;
DoubleProperty leftopacity = new SimpleDoubleProperty(1);
DoubleProperty rightopacity = new SimpleDoubleProperty(1);
private FlickerThread ftLeft;
private FlickerThread ftRight;
public void initialize()
{
leftopacity.addListener(new ChangeListener<Number>() {
#Override
public void changed(ObservableValue<? extends Number> observable,
Number oldValue, Number newValue)
{
Platform.runLater(new Runnable()
{
#Override
public void run()
{
double brightness = leftopacity.doubleValue();
leftBrightness.setText(""+brightness);
leftBox.opacityProperty().set(brightness);
}
});
}
});
rightopacity.addListener(new ChangeListener<Number>() {
#Override
public void changed(ObservableValue<? extends Number> observable,
Number oldValue, Number newValue)
{
Platform.runLater(new Runnable()
{
#Override
public void run()
{
double brightness = rightopacity.doubleValue();
rightBrightness.setText(""+brightness);
rightBox.opacityProperty().set(brightness);
}
});
}
});
startButton.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event)
{
if(running)
{
synchronized(this)
{
running=false;
}
startButton.setText("Start");
}
else
{
running=true;
ftLeft = new FlickerThread((int)leftFrequency.getValue(),leftopacity);
ftRight = new FlickerThread((int)rightFrequency.getValue(), rightopacity);
try
{
ftLeft.start();
ftRight.start();
}
catch(Throwable t)
{
t.printStackTrace();
}
startButton.setText("Stop");
}
}
});
leftFrequency.valueProperty().addListener(new ChangeListener<Number>() {
#Override
public void changed(ObservableValue<? extends Number> observable,
Number oldValue, Number newValue)
{
leftfreqlabel.setText(newValue.intValue()+"");
}
});
rightFrequency.valueProperty().addListener(new ChangeListener<Number>() {
#Override
public void changed(ObservableValue<? extends Number> observable,
Number oldValue, Number newValue)
{
rightfreqlabel.setText(newValue.intValue()+"");
}
});
}
class FlickerThread extends Service<Void>
{
private long sleeptime;
DoubleProperty localval = new SimpleDoubleProperty(1) ;
public FlickerThread(int freq, DoubleProperty valtoBind)
{
this.sleeptime = (1/freq)*1000;
valtoBind.bind(localval);
}
#Override
protected Task <Void>createTask()
{
return new Task<Void>() {
#Override
protected Void call() throws Exception
{
while(running)
{
double val = Math.random();
System.out.println(val);
localval.setValue(val);
Thread.sleep(sleeptime);
}
return null;
}
};
}
}
}
class FlickerThread extends Thread
{
private long sleeptime;
final AtomicReference<Double> counter = new AtomicReference<>(new Double(-1.0));
private Label label;
private Rectangle myrect;
public FlickerThread(int freq, Label label,Rectangle rect)
{
this.sleeptime = (long) ((1.0/freq)*1000.0);
System.out.println("Sleep time is "+sleeptime);
this.label = label;
this.myrect = rect;
}
#Override
public void run() {
double count = 1.0 ;
while (running) {
count = Math.random();
if (counter.getAndSet(count) == -1) {
updateUI(counter, label,myrect);
try
{
Thread.sleep(sleeptime);
} catch (InterruptedException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
}
private void updateUI(final AtomicReference<Double> counter,
final Label label, final Rectangle myrect) {
Platform.runLater(new Runnable() {
#Override
public void run() {
double val = counter.getAndSet(-1.0);
final String msg = String.format("Brt: %,f", val);
label.setText(msg);
myrect.opacityProperty().set(val);
}
});
}
You have a calculation error in your code.
Consider:
1/100*1000=0
But:
1.0/100*1000=10.0
i.e. you need to use floating point arithmetic, not integer arithmetic.
There are numerous other issues with your code as pointed out in my previous comment, so this answer is more of a code review and suggested approach than anything else.
You can batch updates to runLater as in James's answer to Throttling javafx gui updates. But for an update rate of 100 hertz max, it isn't going to make a lot of difference performance-wise as JavaFX generally operates on a 60 hertz pulse cycle, unless you really overload it (which you aren't really doing in your example). So the savings you get by throttling updates will be pretty minimal.
Here is a sample you can try out (it uses James's input throttling technique):
import javafx.application.*;
import javafx.beans.property.DoubleProperty;
import javafx.concurrent.Task;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import java.util.Random;
import java.util.concurrent.atomic.AtomicLong;
public class InputApp extends Application {
private final ToggleButton controlButton = new ToggleButton("Start");
private final Rectangle box = new Rectangle(100, 100, Color.BLUE);
private final Label brightness = new Label();
private final Label frequencyLabel = new Label();
private final Slider frequency = new Slider(1, 100, 10);
private InputTask task;
#Override
public void start(Stage stage) throws Exception {
// initialize bindings.
brightness.textProperty().bind(
box.opacityProperty().asString("%.2f")
);
frequencyLabel.textProperty().bind(
frequency.valueProperty().asString("%.0f")
);
frequency.valueChangingProperty().addListener((observable, oldValue, newValue) -> {
if (controlButton.isSelected()) {
controlButton.fire();
}
});
// start and stop the input task.
controlButton.selectedProperty().addListener((observable, wasSelected, isSelected) -> {
if (isSelected) {
task = new InputTask(
(int) frequency.getValue(),
box.opacityProperty()
);
Thread inputThread = new Thread(task, "input-task");
inputThread.setDaemon(true);
inputThread.start();
controlButton.setText("Stop");
} else {
if (task != null) {
task.cancel();
}
controlButton.setText("Start");
}
});
// create the layout
VBox layout = new VBox(
10,
frequency,
new HBox(5, new Label("Frequency: " ), frequencyLabel, new Label("Hz"),
controlButton,
box,
new HBox(5, new Label("Brightness: " ), brightness)
);
layout.setPadding(new Insets(10));
// display the scene
stage.setScene(new Scene(layout));
stage.show();
}
// simulates accepting random input from an input feed at a given frequency.
class InputTask extends Task<Void> {
private final DoubleProperty changeableProperty;
private final long sleeptime;
final AtomicLong counter = new AtomicLong(-1);
final Random random = new Random(42);
public InputTask(int inputFrequency, DoubleProperty changeableProperty) {
this.changeableProperty = changeableProperty;
this.sleeptime = (long) ((1.0 / inputFrequency) * 1_000);
}
#Override
protected Void call() throws InterruptedException {
long count = 0 ;
while (!Thread.interrupted()) {
count++;
double newValue = random.nextDouble(); // input simulation
if (counter.getAndSet(count) == -1) {
Platform.runLater(() -> {
changeableProperty.setValue(newValue);
counter.getAndSet(-1);
});
}
Thread.sleep(sleeptime);
}
return null;
}
}
public static void main(String[] args) {
System.out.println(1.0/100*1000);
}
}
The following is my Task initialization
final Task<Void> vt=voiceTask();
Button btn = new Button();
btn.setText("Say");
btn.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
new Thread(vt).start();
}
});
And here is the task coding
public Task<Void> voiceTask() {
return new Task<Void>(){
#Override
protected Void call() throws Exception {
HelloWorld hw=new HelloWorld();// HelloWorld is simple .java class getting voice through sphinx
updateMessage(hw.Hello());
return null;
}
};
}
Now on clicking the btn Button for the first time,the task functions normally, but on clicking for subsequent times the task is not called.
I want task to be called on every click.
Please advice me how to modify my code to do so...
See the JavaDocs.
As with FutureTask, a Task is a one-shot class and cannot be reused.
You need to create a new Task each time the button is pressed.
final Button btn = new Button();
btn.setText("Say");
btn.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
final Task<Void> vt=voiceTask();
vt.setOnSucceeded(new EventHandler<WorkerStateEvent>() {
#Override
public void handle(WorkerStateEvent event) {
btn.setDisable(false);
}
});
btn.setDisable(true);
new Thread(vt).start();
}
});
I've got a working example for defining a ContextMenu on a Pane in JavaFX FXML, but am not sure it is optimal. Currently, only JavaFX standard controls (e.g. Button, TextField) define a property for specifying a popup ContextMenu. Yet I wanted to have a popup menu appear anywhere in a Pane, in my case a VBox.
I took the approach of extending VBox to support a context menu. It is a 'clunky' solution but works. Is there a better approach? Am I missing some fundamental concept?
Here is my solution...
FXML:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<?import custommenu.view.ContextMenuPane?>
<AnchorPane xmlns:fx="http://javafx.com/fxml" fx:controller="custommenu.controller.CustomMenuController">
<children>
<VBox fx:id="vbox" onContextMenuRequested="#showMenu"
onMousePressed="#hideMenu" prefHeight="200" prefWidth="200">
</VBox>
<ContextMenuPane>
<contextMenu>
<ContextMenu fx:id="menu">
<items>
<MenuItem text="add" onAction="#add" />
</items>
</ContextMenu>
</contextMenu>
</ContextMenuPane>
</children>
</AnchorPane>
CustomMenuPane...
package custommenu.view;
import javafx.scene.control.ContextMenu;
import javafx.scene.layout.Pane;
public class ContextMenuPane extends Pane {
private ContextMenu contextMenu;
public void setContextMenu(ContextMenu contextMenu) {
this.contextMenu = contextMenu;
}
public ContextMenu getContextMenu() {
return contextMenu;
}
}
Controller...
package custommenu.controller;
import javafx.fxml.FXML;
import javafx.scene.control.ContextMenu;
import javafx.scene.input.ContextMenuEvent;
import javafx.scene.layout.VBox;
public class CustomMenuController {
#FXML private VBox vbox;
#FXML private ContextMenu menu;
#FXML public void add() {
System.out.println("add");
}
#FXML
public void showMenu(ContextMenuEvent event) {
System.out.println("showMenu");
menu.show(vbox, event.getScreenX(), event.getScreenY());
event.consume();
}
#FXML public void hideMenu() {
menu.hide();
}
}
Main App...
package custommenu;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
public class CustomMenuApplication extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
Pane myPane = (Pane)FXMLLoader.load(getClass().getResource("/custommenu/custom_menu_main.fxml"));
Scene scene = new Scene(myPane);
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Tried to do it within a Popup? Catch the MouseEvent check for MouseButton.SECONDARY and display your VBox in the Popup.
private void showContextMenu() // showContextMenu(MouseEvent event)
{
Popup popup = new Popup();
VBox content = new VBox();
Button b = new Button("Click Me!");
b.setOnAction(new EventHandler<ActionEvent>() { });
content.getChildren().addAll(b);
popup.getContent().add(content);
popup.setX(0); // or get mouse event x and y
popup.setY(0); // event.getY()
popup.setAutoHide(true);
popup.show(your popup owner);
}
In This example there is button which has context menu when click on left/right it will open the popup when you click on other area except button it will hide the popup context menu
public class Main extends Application{
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage stage) {
Scene scene = new Scene(new Group(), 450, 250);
Button notification = new Button();
MenuItem item1 = new MenuItem("About");
item1.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent e) {
System.out.println("About");
}
});
MenuItem item2 = new MenuItem("Preferences");
item2.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent e) {
System.out.println("Preferences");
}
});
MenuItem item3 = new MenuItem("About");
item1.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent e) {
System.out.println("About");
}
});
MenuItem item4 = new MenuItem("Preferences");
item2.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent e) {
System.out.println("Preferences");
}
});
MenuItem item5 = new MenuItem("About");
item1.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent e) {
System.out.println("About");
}
});
MenuItem item6 = new MenuItem("Preferences");
item2.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent e) {
System.out.println("Preferences");
}
});
MenuItem item7 = new MenuItem("About");
item1.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent e) {
System.out.println("About");
}
});
MenuItem item8 = new MenuItem("Preferences");
item2.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent e) {
System.out.println("Preferences");
}
});
final ContextMenu contextMenu = new ContextMenu(item1, item2,item3, item4,item5, item6,item7, item8);
contextMenu.setMaxSize(50, 50);
contextMenu.setOnShowing(new EventHandler<WindowEvent>() {
public void handle(WindowEvent e) {
System.out.println("showing");
}
});
contextMenu.setOnShown(new EventHandler<WindowEvent>() {
public void handle(WindowEvent e) {
System.out.println("shown");
}
});
// contextMenu.hide();
notification.setContextMenu(contextMenu);
GridPane grid = new GridPane();
grid.setVgap(4);
grid.setHgap(10);
grid.setPadding(new Insets(5, 5, 5, 5));
grid.add(new Label("To: "), 0, 0);
grid.add(notification, 1, 0);
Group root = (Group) scene.getRoot();
root.getChildren().add(grid);
stage.setScene(scene);
stage.show();
notification.addEventHandler(MouseEvent.MOUSE_CLICKED, (MouseEvent me)->{
if(me.getButton()==MouseButton.PRIMARY ){
System.out.println("Mouse Left Pressed");
System.out.println(notification.getScaleX());
System.out.println(notification.getScaleY());
System.out.println(me.getScreenX());
System.out.println(me.getScreenY());
contextMenu.show(notification,me.getScreenX(),me.getScreenY());
}else{
contextMenu.hide();
}
});
}
}
I have a problem with a Context menu in JavaFx 2:it never disappers when I left click on the graph of the JFXPanel
Does anybody knows how to solve this problem?
Thanks
Here is my code
final ContextMenu cm = new ContextMenu();
MenuItem chartItem1 = new MenuItem("Chart Settings");
cm.getItems().add(chartItem1);
getScene().setOnMouseReleased(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent mouseEvent) {
if(cm.isShowing()){
cm.hide();
}
if(mouseEvent.getButton() == MouseButton.SECONDARY)
{
cm.show(getScene().getRoot(), mouseEvent.getScreenX(), mouseEvent.getScreenY());
}
}
});
chartItem1.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent t) {
dialogs.ChartFormat cs = new dialogs.ChartFormat(null, true);
cs.setLocationRelativeTo(null);
cs.setVisible(true);
}
});
Reproduced the described behavior. Don't know the reason but you can use ContextMenu#hide():
final ContextMenu cm = new ContextMenu();
MenuItem menuItem = new MenuItem("Item 1");
menuItem.addEventHandler(EventType.ROOT, new EventHandler<Event>() {
#Override
public void handle(Event t) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JPanel messagePane = new JPanel();
messagePane.add(new JLabel("label"));
JDialog jDialog = new JDialog();
jDialog.getContentPane().add(messagePane);
jDialog.pack();
jDialog.setVisible(true);
}
});
}
});
cm.getItems().add(menuItem);
scene.setOnMouseReleased(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent mouseEvent) {
// if(cm.isShowing())
cm.hide();
if (mouseEvent.getButton() == MouseButton.SECONDARY) {
cm.show(lineChart, mouseEvent.getScreenX(), mouseEvent.getScreenY());
}
}
});
Also you can check out these links:
http://pixelduke.wordpress.com/2011/12/11/popupmenu-in-javafx/
http://javafx-jira.kenai.com/browse/RT-17853
http://javafx-jira.kenai.com/browse/RT-14899
Adding sample code to your question would be more descriptive.