Bug 127629 [Markers] problems view: keep selection stable
I20050214-0010 1. Select a grouping (e.g. Java problem type) and select a marker inside 2. Switch to another grouping Selection is gone. Same when - changing filter - a build adds new marker (in a different file)
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/ProblemView.java
* 
	 * @param description
	 * @param sorter -
	 *            the sorter to select for
	 */
	public void selectCategory(String description, CategorySorter sorter) {
		if (description == null)
			selectCategoryField(null, sorter);
		Iterator definedGroups = MarkerSupportRegistry.getInstance()
				.getMarkerGroups().iterator();
		while (definedGroups.hasNext()) {
			FieldMarkerGroup group = (FieldMarkerGroup) definedGroups.next();
			if (group.getDescription().equals(description)) {
				selectCategoryField(group, sorter);
				return;
			}
		}
		selectCategoryField(null, sorter);
	}
	
	/**
	 * Select the field groupingField.
	 * @param groupingField
	 * @param sorter
	 */
	void selectCategoryField(IField groupingField, CategorySorter sorter) {
		getMarkerAdapter().getCurrentMarkers().clearGroups();
		sorter.setCategoryField(groupingField);
		refreshViewer();
	}