Bug 156456 [Forms] widgets accept focus even though they can't do anything with it
Many of the widgets in the Forms library (Section, BusyIndicator, FormHeading) will accept keyboard focus even though they can't do anything with it. The impact is that when someone calls setFocus on a Form that contains a FormHeading at its top (which is quite common), keyboard focus ends up nowhere. Looking at the patterns in SWT, it appears that the correct protocol is for controls to return false from setFocus if they can't do anything with the focus so that the caller can try assigning focus somewhere else.
bundles/org.eclipse.ui.forms/src/org/eclipse/ui/forms/widgets/ExpandableComposite.java
* @param parent
	 *            the parent composite
	 * @param style
	 *            SWT style bits
	 */
	public ExpandableComposite(Composite parent, int style) {
		this(parent, style, TWISTIE);
	}
	/**
	 * Creates the expandable composite in the provided parent.
	 * 
	 * @param parent
	 *            the parent
	 * @param style
	 *            the control style (as expected by SWT subclass)
	 * @param expansionStyle
	 *            the style of the expansion widget (TREE_NODE, TWISTIE,
	 *            CLIENT_INDENT, COMPACT, FOCUS_TITLE,
	 *            LEFT_TEXT_CLIENT_ALIGNMENT, NO_TITLE)
	 */
	public ExpandableComposite(Composite parent, int style, int expansionStyle) {
		super(parent, style);
		this.expansionStyle = expansionStyle;
		if ((expansionStyle & TITLE_BAR) != 0)
			setBackgroundMode(SWT.INHERIT_DEFAULT);
		super.setLayout(new ExpandableLayout());
		if (hasTitleBar()) {
			this.addPaintListener(new PaintListener() {
				public void paintControl(PaintEvent e) {
					onPaint(e);