javanetbeansrcpnetbeans-platformwindow-managers

Issue with Opening NetBeans TopComponent at Startup


I'm working on a NetBeans Platform application and I want to open a TopComponent automatically when the application starts. Despite following the typical steps, my TopComponent does not open at startup.

Here are the steps I have followed:

  1. Created the TopComponent:

    package com.example.myapp;
    
    import org.openide.windows.TopComponent;
    import org.openide.awt.ActionID;
    import org.openide.awt.ActionReference;
    import org.openide.util.NbBundle.Messages;
    
    @TopComponent.Description(
            preferredID = "MyTopComponent",
            persistenceType = TopComponent.PERSISTENCE_ALWAYS
    )
    @TopComponent.Registration(
            mode = "editor",
            openAtStartup = false // I handle the opening manually
    )
    @ActionID(category = "Window", id = "com.example.myapp.MyTopComponent")
    @ActionReference(path = "Menu/Window", position = 0)
    @Messages({
        "CTL_MyTopComponent=My TopComponent",
        "HINT_MyTopComponent=This is a MyTopComponent window"
    })
    public final class MyTopComponent extends TopComponent {
    
        public MyTopComponent() {
            initComponents();
            setName(Bundle.CTL_MyTopComponent());
            setToolTipText(Bundle.HINT_MyTopComponent());
        }
    
        private void initComponents() {
            // Initialize your components here
        }
    
        public static synchronized MyTopComponent getInstance() {
            MyTopComponent instance = (MyTopComponent) WindowManager.getDefault().findTopComponent("MyTopComponent");
            if (instance == null) {
                instance = new MyTopComponent();
            }
            return instance;
        }
    } 
    
    
  2. Created an Installer class to handle the startup logic:

package com.example.myapp;

import org.openide.modules.ModuleInstall;
import org.openide.windows.WindowManager;

public class Installer extends ModuleInstall {

    @Override
    public void restored() {
        WindowManager.getDefault().invokeWhenUIReady(() -> {
            MyTopComponent tc = MyTopComponent.getInstance();
            if (tc != null) {
                tc.open();
                tc.requestActive();
            }
        });
    }
}
  1. Registered the Installer class in the manifest.mf file:
Manifest-Version: 1.0
OpenIDE-Module: com.example.myapp
OpenIDE-Module-Specification-Version: 1.0
OpenIDE-Module-Install: com/example/myapp/Installer.class

Despite following these steps, the TopComponent does not open at startup. Here are additional details and steps I've taken to debug the issue:

What could be causing the TopComponent to not open at startup, and how can I resolve this issue?

Any help or suggestions would be greatly appreciated.


Solution

  • Using ModuleInstall/restored() is probably too early, Netbeans UI is not ready yet.

    Instead, try the same with @onShowing, so that your code is called when UI is ready:

    @onShowing
    public class OpenStart implements Runnable {
    
        @Override
        public void run() {
            WindowManager.getDefault().invokeWhenUIReady(() -> {
                MyTopComponent tc = MyTopComponent.getInstance();
                if (tc != null) {
                    tc.open();
                    tc.requestActive();
                }
            });
        }
    }