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
column.getColumn().addSelectionListener(getHeaderListener());
			}
			column.getColumn().setData(MARKER_FIELD, markerField);
			
			column.setLabelProvider(new MarkerColumnLabelProvider(markerField,
					i == 0));
			column.getColumn().setText(markerField.getColumnHeaderText());
			column.getColumn().setToolTipText(
					markerField.getColumnTooltipText());
			column.getColumn().setImage(markerField.getColumnHeaderImage());
			EditingSupport support = markerField.getEditingSupport(viewer);
			if (support != null)
				column.setEditingSupport(support);
			if (builder.getPrimarySortField().equals(markerField))
				updateDirectionIndicator(column.getColumn(), markerField);
		}
		
		if (currentColumns.length > fields.length) {
			for (int i = fields.length; i < currentColumns.length; i++) {
				currentColumns[i].dispose();
			}
		}
		viewer.getTree().setLayout(layout);
		tree.setLinesVisible(true);
		tree.setHeaderVisible(true);
		tree.layout(true);
	}
	/*
	 * (non-Javadoc)
	 *