Bug 52064 Content assist in "New Class" Dialog shows interfaces
Content Assist is available for the superclass in M7. However it also lists interfaces. If an interface is selected, the generated class "extends" it instead of "implementing" it.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/wizards/NewTypeWizardPage.java
GridData gd= new GridData(GridData.HORIZONTAL_ALIGN_FILL);
		gd.horizontalSpan= nColumns - 2;
		control.setLayoutData(gd);
		
		DialogField.createEmptySpace(composite);
		
		if (fIsClass) {
			DialogField.createEmptySpace(composite);
			
			control= fOtherMdfButtons.getSelectionButtonsGroup(composite);
			gd= new GridData(GridData.HORIZONTAL_ALIGN_FILL);
			gd.horizontalSpan= nColumns - 2;
			control.setLayoutData(gd);		
	
			DialogField.createEmptySpace(composite);
		}
	}
	/**
	 * Creates the controls for the superclass name field. Expects a <code>GridLayout</code> 
	 * with at least 3 columns.
	 * 
	 * @param composite the parent composite
	 * @param nColumns number of columns to span
	 */		
	protected void createSuperClassControls(Composite composite, int nColumns) {
		fSuperClassDialogField.doFillIntoGrid(composite, nColumns);
		Text text= fSuperClassDialogField.getTextControl(null);
		LayoutUtil.setWidthHint(text, getMaxFieldWidth());
		ControlContentAssistHelper.createTextContentAssistant(text, fSuperClassCompletionProcessor);
	}