Bug 5120 Empty popup doc in java editor
1. Go to Java Perspective. 2. Double click on a java file. 3. Move the i-beam over the beginning prefixes of an import statement. For example, the "org" of "import org.eclipse.swt.SWT". An empty hover help box is displayed.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/hover/JavaTypeHover.java
fEditor= editor;
		fTextRenderer= new JavaTextLabelProvider(JavaElementLabelProvider.SHOW_CONTAINER_QUALIFICATION | JavaElementLabelProvider.SHOW_PARAMETERS);
	}
	
	private ICodeAssist getCodeAssist() {
		if (fEditor != null) {
			IEditorInput input= fEditor.getEditorInput();
			if (input instanceof ClassFileEditorInput) {
				ClassFileEditorInput cfeInput= (ClassFileEditorInput) input;
				return cfeInput.getClassFile();
			}
			
			IWorkingCopyManager manager= JavaPlugin.getDefault().getWorkingCopyManager();				
			return manager.getWorkingCopy(input);
		}
		
		return null;
	}
	
	private String getInfoText(IMember member) {
		if (member.getElementType() != IJavaElement.TYPE) {
			StringBuffer buffer= new StringBuffer();
			buffer.append(fTextRenderer.getTextLabel(member.getDeclaringType()));
			buffer.append('.');
			buffer.append(fTextRenderer.getTextLabel(member));
			return buffer.toString();
		}
		
		return fTextRenderer.getTextLabel(member);
	}