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
}
						}
					} else {
						selectedElements.add(file);
					}
				} else {
					if (selection instanceof IStructuredSelection) {
						for (Iterator iterator = ((IStructuredSelection) selection)
								.iterator(); iterator.hasNext();) {
							Object object = iterator.next();
							if (object instanceof IAdaptable) {
								ITaskListResourceAdapter taskListResourceAdapter;
								Object adapter = ((IAdaptable) object)
										.getAdapter(ITaskListResourceAdapter.class);
								if (adapter != null
										&& adapter instanceof ITaskListResourceAdapter) {
									taskListResourceAdapter = (ITaskListResourceAdapter) adapter;
								} else {
									taskListResourceAdapter = getDefaultTaskListAdapter();
								}
								IResource resource = taskListResourceAdapter
										.getAffectedResource((IAdaptable) object);
								if (resource == null) {
									Object mapping = ((IAdaptable) object)
											.getAdapter(ResourceMapping.class);
									if (mapping != null) {
										selectedElements.add(mapping);
									}
								} else {
									selectedElements.add(resource);