Bug 40787 [plan item] Affordance for F2 opportunity in Java editor
There should be a small label explaining that F2 pins the hover.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/hover/AbstractJavaEditorTextHover.java
synchronized (resolve) {
					result= resolve.codeSelect(hoverRegion.getOffset(), hoverRegion.getLength());
				}
				
				if (result == null)
					return null;
				
				int nResults= result.length;	
				if (nResults == 0)
					return null;
				
				return getHoverInfo(result);
				
			} catch (JavaModelException x) {
				JavaPlugin.log(x.getStatus());
			}
		}
		return null;
	}
	/**
	 * Provides hover information for the given Java elements.
	 * 
	 * @return the hover information string
	 * @since 2.1
	 */
	protected String getHoverInfo(IJavaElement[] javaElements) {
		return null;
	}
}