Bug 216811 [Markers] ExtendedMarkersView#setFocus doesn't
The result is that focus is lost if you drag the view to another stack... The most common implementation seems to be 'viewer.getControl().setFocus()... To test: select an element in the Problems or Tasks view. Drag the view to a new location (could be in an existing stack or a new one) notice that while the view is the active view the arrow keys don't navigate...
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
}
	/**
	 * Log that a generator id is invalid.
	 * 
	 * @param id
	 */
	void logInvalidGenerator(String id) {
		StatusManager.getManager().handle(
				new Status(IStatus.WARNING, IDEWorkbenchPlugin.IDE_WORKBENCH,
						NLS.bind("Invalid markerContentGenerator {0} ", 
								id)));
	}
	/**
	 * Return whether or not group is enabled.
	 * 
	 * @param group
	 * @return boolean
	 */
	boolean isEnabled(MarkerFieldFilterGroup group) {
		return builder.getEnabledFilters().contains(group);
	}
	/**
	 * Return the main sort field for the receiver.
	 * 
	 * @return {@link MarkerField}
	 */
	boolean isPrimarySortField(MarkerField field) {
		return builder.getPrimarySortField().equals(field);
	}
	/**