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/text/java/hover/JavaTypeHover.java
private IEditorPart fEditor;
	
	private final int LABEL_FLAGS=  JavaElementLabels.ALL_FULLY_QUALIFIED
		| JavaElementLabels.M_PRE_RETURNTYPE | JavaElementLabels.M_PARAMETER_TYPES | JavaElementLabels.M_PARAMETER_NAMES | JavaElementLabels.M_EXCEPTIONS 
		| JavaElementLabels.F_PRE_TYPE_SIGNATURE;
	
	public JavaTypeHover(IEditorPart editor) {
		fEditor= editor;
	}
	
	private ICodeAssist getCodeAssist() {
		if (fEditor != null) {
			IEditorInput input= fEditor.getEditorInput();
			if (input instanceof IClassFileEditorInput) {
				IClassFileEditorInput cfeInput= (IClassFileEditorInput) input;
				return cfeInput.getClassFile();
			}
			
			IWorkingCopyManager manager= JavaPlugin.getDefault().getWorkingCopyManager();				
			return manager.getWorkingCopy(input);
		}
		
		return null;
	}
	
	private String getInfoText(IMember member) {
		return JavaElementLabels.getElementLabel(member, LABEL_FLAGS);
	}