CODEWITHSUNDEEP
javajavafxnullpointerexceptionjnativehook
Kingtak
Kingtak

Reputation: 125

NullPointerException Error when trying to set javafx TextField text from JnativeHook mouse events

I am trying to set javafx TextField text when JnativeHook MoseClicked event happens.But i face with "NullPointerException" error.I put my Controller class code in here:

public class FXMLDocumentController implements Initializable, NativeMouseListener {

@FXML
private TextField txt_Search;

@Override
public void initialize(URL url, ResourceBundle rb) {

   txt_Search.setText("dvdf"); //this is work and no problem is in here
           Listener();
}
public void Listener() {
    // Clear previous logging configurations.
    LogManager.getLogManager().reset();
    // Get the logger for "org.jnativehook" and set the level to off.
    Logger logger = Logger.getLogger(GlobalScreen.class.getPackage().getName());
    logger.setLevel(Level.OFF);
    try {
        GlobalScreen.registerNativeHook();
    } catch (NativeHookException ex) {
        System.err.println("There was a problem registering the native hook.");
        System.err.println(ex.getMessage());

        System.exit(1);
    }
    // Construct the example object.
    FXMLDocumentController example = new FXMLDocumentController();
    // Add the appropriate listeners.
    GlobalScreen.addNativeMouseListener(example);
}

 @Override
public void nativeMouseClicked(NativeMouseEvent nme) {
    if (nme.getClickCount() == 2) {
        System.out.println("Double Click Event");
        txt_Search.setText("Mouse clicked");
    }

}

@Override
public void nativeMousePressed(NativeMouseEvent nme) {
    // throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}

@Override
public void nativeMouseReleased(NativeMouseEvent nme) {
    //   throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}

}

And this error is occurring :

Double Click Event
Exception in thread "JNativeHook Dispatch Thread" java.lang.NullPointerException
at FXMLDocumentController.nativeMouseClicked(FXMLDocumentController.java:60)
at org.jnativehook.GlobalScreen$EventDispatchTask.processButtonEvent(Unknown Source)
at org.jnativehook.GlobalScreen$EventDispatchTask.processButtonEvent(Unknown Source)
at org.jnativehook.GlobalScreen$EventDispatchTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

Update:

I update my code and annotate txt_Search with @FXML annotation

Upvotes: 1

Views: 1021

Answers (2)

Alex Barker
Alex Barker

Reputation: 4400

You should go back and review the working with swing section of the usage wiki. The events produced by this library do not operate on the Swing event dispatch thread by default! You must wrap access to swing components OR use GlobalScreen.setEventDispatcher(new SwingDispatchService()); before registering the hook. For more information, please read about the event dispatch thread and Swing thread safety.

Upvotes: 0

Aman
Aman

Reputation: 23

@Kingtak you never initialized your 'txt_Search' variable.You can use @FXML annotation here and in fxml file assign the id to the textfield there.

Upvotes: 0

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