Bug 4369 F2 should work even if "Hide Text Hover" is enabled
- enable "Hide Text Hover" - position the cursor on a type - press F2 observe: nothing happens although I explicitly requested JavaDoc help.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
control.getDisplay().asyncExec(new Runnable() {
					public void run() {
						if (fTextChanged && fHighlightBrackets != null) 
							fHighlightBrackets.run();
					}
				});
			}
		}
		
		/*
		 * @see ITextInputListener#inputDocumentAboutToBeChanged(IDocument, IDocument)
		 */
		public void inputDocumentAboutToBeChanged(IDocument oldInput, IDocument newInput) {
			if (oldInput != null) {
				fHighlightBrackets.deactivate(false);
				fManager.uninstall(oldInput);
			}
		}
		
		/*
		 * @see ITextInputListener#inputDocumentChanged(IDocument, IDocument)
		 */
		public void inputDocumentChanged(IDocument oldInput, IDocument newInput) {
			if (newInput != null)
				fManager.install(newInput);
		}
	};
	
	
	class InternalSourceViewer extends SourceViewer {