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
ErrorDialog.openError(shell, JavaEditorMessages.getString("CompilationUnitEditor.error.saving.title2"), JavaEditorMessages.getString("CompilationUnitEditor.error.saving.message2"), cx.getStatus()); 
			} else {
				MessageDialog.openError(shell, JavaEditorMessages.getString("CompilationUnitEditor.error.saving.title3"), JavaEditorMessages.getString("CompilationUnitEditor.error.saving.message3") + t.getMessage()); 
			}
			
		} finally {
			
			if (fragment == null)
				getDocumentProvider().changed(newInput);
				
			if (progressMonitor != null)
				progressMonitor.setCanceled(!success);
		}
	}
	
	/*
	 * @see AbstractTextEditor#doSetInput(IEditorInput)
	 */
	protected void doSetInput(IEditorInput input) throws CoreException {
		super.doSetInput(input);
		fJavaEditorErrorTickUpdater.setAnnotationModel(getDocumentProvider().getAnnotationModel(input));
	}
	
	private void startBracketHighlighting() {
		if (fBracketHighlighter == null) {
			ISourceViewer sourceViewer= getSourceViewer();
			fBracketHighlighter= new BracketHighlighter(sourceViewer);
			fBracketHighlighter.setHighlightColor(getColor(MATCHING_BRACKETS_COLOR));
			fBracketHighlighter.install();
		}