Bug 65268 [projection] editor is missing collapse all action for code folding
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
*/
		if (javaSourceViewer != null && isFoldingEnabled() && (store == null || !store.getBoolean(PreferenceConstants.EDITOR_SHOW_SEGMENTS)))
			javaSourceViewer.prepareDelayedProjection();
		
		ProjectionViewer projectionViewer= (ProjectionViewer)viewer;
		fProjectionSupport= new ProjectionSupport(projectionViewer, getAnnotationAccess(), getSharedColors());
		fProjectionSupport.addSummarizableAnnotationType("org.eclipse.ui.workbench.texteditor.error"); 
		fProjectionSupport.addSummarizableAnnotationType("org.eclipse.ui.workbench.texteditor.warning"); 
		fProjectionSupport.setHoverControlCreator(new IInformationControlCreator() {
			public IInformationControl createInformationControl(Shell shell) {
				return new CustomSourceInformationControl(shell, IDocument.DEFAULT_CONTENT_TYPE);
			}
		});
		fProjectionSupport.install();
		fProjectionModelUpdater= JavaPlugin.getDefault().getFoldingStructureProviderRegistry().getCurrentFoldingProvider();
		if (fProjectionModelUpdater != null)
			fProjectionModelUpdater.install(this, projectionViewer);
		
		getSourceViewerDecorationSupport(viewer);
		return viewer;
	}
	public final ISourceViewer getViewer() {
		return getSourceViewer();
	}
	/*
	 * @see AbstractTextEditor#createSourceViewer(Composite, IVerticalRuler, int)
	 */
	protected ISourceViewer createJavaSourceViewer(Composite parent, IVerticalRuler verticalRuler, IOverviewRuler overviewRuler, boolean isOverviewRulerVisible, int styles, IPreferenceStore store) {
		return new JavaSourceViewer(parent, verticalRuler, getOverviewRuler(), isOverviewRulerVisible(), styles, store);
	}