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
/**
	 * If this style is used, the control will be created in the expanded state.
	 * This state can later be changed programmatically or by the user if
	 * TWISTIE or TREE_NODE style is used.
	 */
	public static final int EXPANDED = 1 << 6;
	/**
	 * If this style is used, title bar decoration will be painted behind the
	 * text.
	 */
	public static final int TITLE_BAR = 1 << 8;
	/**
	 * If this style is used, a short version of the title bar decoration will
	 * be painted behind the text. This style is useful when a more descrete
	 * option is needed for the title bar.
	 * 
	 * @since 3.1
	 */
	public static final int SHORT_TITLE_BAR = 1 << 9;
	/**
	 * If this style is used, title will not be rendered.
	 */
	public static final int NO_TITLE = 1 << 12;
	/**
	 * By default, text client is right-aligned. If this style is used, it will
	 * be positioned after the text control and vertically centered with it.
	 */
	public static final int LEFT_TEXT_CLIENT_ALIGNMENT = 1 << 13;
	/**
	 * Width of the margin that will be added around the control (default is 0).