Bug 313328 Close parts under part stacks with middle mouse click
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/ui/workbench/renderers/swt/StackRenderer.java
cti = findItemForPart(element, element.getParent());
		}
		Control ctrl = (Control) element.getWidget();
		if (ctrl != null && ctrl.getParent() != ctf) {
			ctrl.setParent(ctf);
			cti.setControl(ctrl);
		} else if (element.getWidget() == null) {
			Control tabCtrl = (Control) renderer.createGui(element);
			cti.setControl(tabCtrl);
		}
		ignoreTabSelChanges = true;
		ctf.setSelection(cti);
		ignoreTabSelChanges = false;
		
		if (ctf.getTopRight() != null) {
			Control curTB = ctf.getTopRight();
			ctf.setTopRight(null);
			if (!curTB.isDisposed()) {
				MUIElement tbME = (MUIElement) curTB
						.getData(AbstractPartRenderer.OWNING_ME);
				if (tbME instanceof MRenderedToolBar)
					renderer.removeGui(tbME);
				else
					curTB.dispose();
			}
		}
		
		MPart part = (MPart) ((element instanceof MPart) ? element
				: ((MPlaceholder) element).getRef());
		MMenu viewMenu = getViewMenu(part);