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
/**
	 * Returns <samp>true </samp> if the composite is fixed i.e. cannot be
	 * expanded or collapsed. Fixed control will still contain the title,
	 * separator and description (if present) as well as the client, but will be
	 * in the permanent expanded state and the toggle affordance will not be
	 * shown.
	 * 
	 * @return <samp>true </samp> if the control is fixed in the expanded state,
	 *         <samp>false </samp> if it can be collapsed.
	 */
	protected boolean isFixedStyle() {
		return (expansionStyle & TWISTIE) == 0
				&& (expansionStyle & TREE_NODE) == 0;
	}
	/**
	 * Returns the text client control.
	 * 
	 * @return Returns the text client control if specified, or
	 *         <code>null</code> if not.
	 */
	public Control getTextClient() {
		return textClient;
	}
	/**
	 * Sets the text client control. Text client is a control that is a child of
	 * the expandable composite and is placed to the right of the text. It can
	 * be used to place small image hyperlinks. If more than one control is
	 * needed, use Composite to hold them. Care should be taken that the height
	 * of the control is comparable to the height of the text.
	 *