Hover Action over own Annotation in Eclipse (Plugin)

Question

I have created a Plugin that uses an own Annotation Marker. Now I want to add a special Hover Action, when I mouseover this special Marker. I don't really know where to add this action. I allready read about the IAnnotationHover Interface, but how do I access the vertical ruler of the ordinary workbench text editor to add/change the AnnotationHover?

p.s.: just to be more precise, I use the common editor of Eclipse, not an own editor... so I think I should not override SourceViewerConfiguration or the IAnnotationHover any idea so far?

score 0 · Answer 1 · answered Nov 04 '17 at 13:34

Here's a way to create a custom Hover on the Default Java Editor.

Here's a custom implementation of @PKeidel's LangHover class from that question for your specific use case, combined with a custom script to detect java elements. Note that you should change ANNOTATION_NAME's value to the value of your custom Annotation, and the return value of getHoverInfo to whatever you want the custom hover to contain.

public class LangHover implements IJavaEditorTextHover
{
    public static final String ANNOTATION_NAME = "YourCustomAnnotation";

    @SuppressWarnings("restriction")
    public static ICodeAssist getCodeAssist(IEditorPart fEditor)
    {
        if (fEditor != null) {
            IEditorInput input= fEditor.getEditorInput();
            if (input instanceof IClassFileEditorInput) {
                IClassFileEditorInput cfeInput= (IClassFileEditorInput) input;
                return cfeInput.getClassFile();
            }

            WorkingCopyManager manager= JavaPlugin.getDefault().getWorkingCopyManager();
            return manager.getWorkingCopy(input, false);
        }

        return null;
    }

    public static IEditorPart getActiveEditor()
    {
        IWorkbenchWindow window= PlatformUI.getWorkbench().getActiveWorkbenchWindow();
        if (window != null) {
            IWorkbenchPage page= window.getActivePage();
            if (page != null) {
                return page.getActiveEditor();
            }
        }
        return null;
    } 

    // When this returns true, the custom hover should be shown.
    public static boolean elementIsCustomAnnotation(ITextViewer textViewer, IRegion hoverRegion)
    {
        IEditorPart activeEditor = getActiveEditor();
        ICodeAssist resolve = getCodeAssist(activeEditor);
        IJavaElement[] detectedJavaElements = null;

        if (resolve != null)
        {
            try
            {
                detectedJavaElements = resolve.codeSelect(hoverRegion.getOffset(), hoverRegion.getLength());
            }
            catch (JavaModelException x)
            {
                System.out.println("JavaModelException occured");
            }
        }

        for (IJavaElement javaElement : detectedJavaElements)
        {
            // If I found an element of type IJavaElement.ANNOTATION
            // and its name equals ANNOTATION_NAME, return true
            if (javaElement.getElementType() == IJavaElement.ANNOTATION && javaElement.getElementName().equals(ANNOTATION_NAME))
            {
                return true;
            }
        }
        return false;           
    }

    @Override
    public String getHoverInfo(ITextViewer textviewer, IRegion region)
    {
        if(elementIsCustomAnnotation(textviewer, region))
        {
            return "Your own hover text goes here"";
        }
        return null; // Shows the default Hover (Java Docs)
    }
}

Basically, what is happening here is that elementIsCustomAnnotation is checking the java element(s) the user is hovering over, puts them in the detectedJavaElements array, and then checks that array to find an Annotation with name equal to ANNOTATION_NAME.

Hover Action over own Annotation in Eclipse (Plugin)

1 Answers1