Bug 63420 [R21PRES] Flash on tab switch
bundles/org.eclipse.ui.presentations.r21/src/org/eclipse/ui/internal/presentations/R21EditorStackPresentation.java
/**
	 * Calculate the bounds of the client area inside the folder
	 * 
	 * @param folder
	 * @return Rectangle the bounds of the client
	 */
	public static Rectangle calculatePageBounds(CTabFolder folder) {
		if (folder == null)
			return new Rectangle(0, 0, 0, 0);
		Rectangle bounds = folder.getBounds();
		Rectangle offset = folder.getClientArea();
		bounds.x += offset.x;
		bounds.y += offset.y;
		bounds.width = offset.width;
		bounds.height = offset.height;
		return bounds;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.internal.skins.Presentation#dispose()
	 */
	public void dispose() {
		if (isDisposed())
			return;
		
		tabFolder.getShell().removeShellListener(shellListener);
		
		tabFolder.removeCTabFolderListener(closeListener);