Bug 63420 [R21PRES] Flash on tab switch
bundles/org.eclipse.ui.presentations.r21/src/org/eclipse/ui/internal/presentations/R21EditorStackPresentation.java
return idx < items.length ? items[idx] : null;
	}
	/**
	 * @param part
	 * @param property
	 */
	protected void childPropertyChanged(IPresentablePart part, int property) {
		initTab(getTab(part), part);
	}
	protected final IPresentablePart getPartForTab(CTabItem item) {
		return (IPresentablePart) item.getData(TAB_DATA);
	}
	protected CTabFolder getTabFolder() {
		return tabFolder;
	}
	/**
	 * Answer whether the receiver is disposed.
	 * 
	 * @return boolean <code>true</code> if disposed
	 */
	public boolean isDisposed() {
		return tabFolder == null || tabFolder.isDisposed();
	}
	/**
	 * Set the size of a page in the folder.
	 */
	private void setControlSize() {
		if (current != null && tabFolder != null)
			current.setBounds(calculatePageBounds(tabFolder));
	}