Bug 45517 Add a 'Field comment' code template
20031024 The user should be able to specify a 'field comment' template. See 'CodeTemplateContextType.TYPE_COMMENT' as an example You have to - define a new variable type - specify the variables avaiable in this template - create an API in Codetemplates so it can be used Users are: - AddJavadocCommentAction - JavadocTagsSubProcessor.getMissingJavadocCommentProposals
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/EditTemplateDialog.java
new JavaSourcePreviewerUpdater(viewer, tools);
		
		int nLines= document.getNumberOfLines();
		if (nLines < 5) {
			nLines= 5;
		} else if (nLines > 12) {
			nLines= 12;	
		}
				
		Control control= viewer.getControl();
		GridData data= new GridData(GridData.FILL_BOTH);
		data.widthHint= convertWidthInCharsToPixels(80);
		data.heightHint= convertHeightInCharsToPixels(nLines);
		control.setLayoutData(data);
		
		viewer.addTextListener(new ITextListener() {
			public void textChanged(TextEvent event) {
				if (event .getDocumentEvent() != null)
					doSourceChanged(event.getDocumentEvent().getDocument());
			}
		});
		viewer.addSelectionChangedListener(new ISelectionChangedListener() {			
			public void selectionChanged(SelectionChangedEvent event) {
				updateSelectionDependentActions();
			}
		});
		if (viewer instanceof ITextViewerExtension) {
			 ((ITextViewerExtension) viewer).prependVerifyKeyListener(new VerifyKeyListener() {
				public void verifyKey(VerifyEvent event) {
					handleVerifyKeyPressed(event);