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
* Create the columns for the receiver.
	 * 
	 * @param currentColumns
	 *            the columns to refresh
	 */
	private void createColumns(TreeColumn[] currentColumns) {
		Tree tree = viewer.getTree();
		TableLayout layout = new TableLayout();
		MarkerField[] fields = builder.getVisibleFields();
		for (int i = 0; i < fields.length; i++) {
			MarkerField markerField = fields[i];
			
			int columnWidth = markerField.getDefaultColumnWidth(tree);
			if (i == 0) {
				
				GC gc = new GC(tree);
				gc.setFont(tree.getFont());
				FontMetrics fontMetrics = gc.getFontMetrics();
				gc.dispose();
				columnWidth = Math.max(columnWidth, fontMetrics
						.getAverageCharWidth() * 5);
			}
			layout.addColumnData(new ColumnPixelData(columnWidth, true, true));
			TreeViewerColumn column;
			if (i < currentColumns.length)
				column = new TreeViewerColumn(viewer, currentColumns[i]);
			else {
				column = new TreeViewerColumn(viewer, SWT.NONE);
				column.getColumn().setResizable(true);
				column.getColumn().setMoveable(true);