How to use

addRegistryChangeListener

method

in

org.eclipse.core.runtime.IExtensionRegistry

/**
 * Adds the listener that handles startup plugins
 *
 * @since 3.1
 */
private void addStartupRegistryListener() {
  registry.addRegistryChangeListener(startupRegistryListener);
}

public static void addRegistryChangeListener(IExtensionRegistry registry) {
  if (registry == null)
    return;
  // Different instances of listener required. See documentation of
  // IExtensionRegistry.addRegistryChangeListener(IRegistryChangeListener, String).
  registry.addRegistryChangeListener(runtimeExtensionListener, IContentConstants.RUNTIME_NAME);
  registry.addRegistryChangeListener(contentExtensionListener, IContentConstants.CONTENT_NAME);
}

public static void addRegistryChangeListener(IExtensionRegistry registry) {
  if (registry == null)
    return;
  // Different instances of listener required. See documentation of
  // IExtensionRegistry.addRegistryChangeListener(IRegistryChangeListener, String).
  registry.addRegistryChangeListener(runtimeExtensionListener, IContentConstants.RUNTIME_NAME);
  registry.addRegistryChangeListener(contentExtensionListener, IContentConstants.CONTENT_NAME);
}

/**
 * Connects this manager to the platform's extension registry.
 */
public void connect() {
  Platform.getExtensionRegistry().addRegistryChangeListener(this, RefactoringCore.ID_PLUGIN);
}

public void addListener(IRegistryChangeListener listener) {
  fRegistry.addRegistryChangeListener(listener);
  if (!fListeners.contains(listener))
    fListeners.add(listener);
}

/**
 * This class has a singleton instance.
 */
private InternalFileSystemCore() {
  super();
  RegistryFactory.getRegistry().addRegistryChangeListener(this);
}

public TypeExtensionManager(String extensionPoint) {
  Assert.isNotNull(extensionPoint);
  fExtensionPoint= extensionPoint;
  Platform.getExtensionRegistry().addRegistryChangeListener(this);
  initializeCaches();
}

/**
 * This class has a singleton instance.
 */
private InternalFileSystemCore() {
  super();
  RegistryFactory.getRegistry().addRegistryChangeListener(this);
}

public TypeExtensionManager(String extensionPoint) {
  Assert.isNotNull(extensionPoint);
  fExtensionPoint= extensionPoint;
  Platform.getExtensionRegistry().addRegistryChangeListener(this);
  initializeCaches();
}

public TypeExtensionManager(String extensionPoint) {
  Assert.isNotNull(extensionPoint);
  fExtensionPoint= extensionPoint;
  Platform.getExtensionRegistry().addRegistryChangeListener(this);
  initializeCaches();
}

public static void addRegistryChangeListener(IExtensionRegistry registry) {
  if (registry == null)
    return;
  registry.addRegistryChangeListener(getInstance(), IContentConstants.RUNTIME_NAME);
  registry.addRegistryChangeListener(getInstance(), IContentConstants.CONTENT_NAME);
}

public static void addRegistryChangeListener(IExtensionRegistry registry) {
  if (registry == null)
    return;
  registry.addRegistryChangeListener(getInstance(), IContentConstants.RUNTIME_NAME);
  registry.addRegistryChangeListener(getInstance(), IContentConstants.CONTENT_NAME);
}

public static synchronized void addRegistryListener() {
  if (registryListener != null)
    return;
  
  registryListener = new RegistryChangeListener();
  IExtensionRegistry registry = Platform.getExtensionRegistry();
  registry.addRegistryChangeListener(registryListener, ServerUIPlugin.PLUGIN_ID);
}

public PreferencePageParameterValues() {
  Platform.getExtensionRegistry().addRegistryChangeListener(
      event -> {
        if (event.getExtensionDeltas(PlatformUI.PLUGIN_ID,
            IWorkbenchRegistryConstants.PL_PREFERENCES).length > 0) {
          preferenceMap = null;
        }
      });
}

public void start(BundleContext context) throws Exception {
  super.start(context);
  fQuickDiffExtensionRegistry= new QuickDiffExtensionsRegistry();
  fSpellingEngineRegistry= new SpellingEngineRegistry();
  Platform.getExtensionRegistry().addRegistryChangeListener(this, PLUGIN_ID);
}

@Override
public void start(BundleContext context) throws Exception {
  super.start(context);
  fQuickDiffExtensionRegistry= new QuickDiffExtensionsRegistry();
  fSpellingEngineRegistry= new SpellingEngineRegistry();
  Platform.getExtensionRegistry().addRegistryChangeListener(this, PLUGIN_ID);
}

private void loadElements() {
  fTargets = new HashMap();
  IExtensionRegistry registry = Platform.getExtensionRegistry();
  registry.addRegistryChangeListener(this);
  IConfigurationElement[] elements = registry.getConfigurationElementsFor("org.eclipse.pde.core.targets"); //$NON-NLS-1$
  add(elements);
}

private void loadElements() {
  fTargets = new HashMap<>();
  IExtensionRegistry registry = Platform.getExtensionRegistry();
  registry.addRegistryChangeListener(this);
  IConfigurationElement[] elements = registry.getConfigurationElementsFor("org.eclipse.pde.core.targets"); //$NON-NLS-1$
  add(elements);
}

private void readRegistryImpl() {
  extensionRegistry.addRegistryChangeListener(this, namespace);
  
  IExtension[] extensions = extensionRegistry.getExtensionPoint(
      namespace, PT_ENVIRONMENTS).getExtensions();
  
  for (IExtension extension : extensions) {
    read(extension);
  }
}

/**
 * Registers listeners.
 *
 * @since 3.1
 */
private void registerListeners() {
  Platform.getExtensionRegistry().addRegistryChangeListener(
      registryListener);
  workbenchWindow.getExtensionTracker().registerHandler(
      configListener,  null);
}