IExtensionTracker tracker = PlatformUI.getWorkbench().getExtensionTracker();
tracker.registerHandler(this, ExtensionTracker.createExtensionPointFilter(getExtensionPointFilter()));
// add a listener for keyword deltas. If any occur clear all page caches
Platform.getExtensionRegistry().addRegistryChangeListener(
new IRegistryChangeListener() {
public void registryChanged(IRegistryChangeEvent event) {
if (event.getExtensionDeltas(StyleEditorPage.XPID, PL_KEYWORDS).length > 0) {
for (Iterator<?> j = getElements(
PreferenceManager.POST_ORDER).iterator(); j