Bug 25370 Linked Mode: Want to define where to focus
20021022 I added a new feature that starts the linked mode on all usages of a variable. e.g. int i; i= 1; i++; would link all 3 occurrences of i, so when edited, all 3 references are changed simultanously. Problem is that the liked mode does not allow me to set the focus (where to edit) to e.g. the 'i' in 'i++'. The linked mode only allows to edit the top most linked position ('int i'). The feature can be invoked on any reference. Jumping to the top not so ideal.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/link/LinkedPositionManager.java
} catch (BadPositionCategoryException e) {
			JavaPlugin.log(e);
			Assert.isTrue(false);
		}
	}
	/**
	 * Tests if a manager is already active for a document.
	 */
	public static boolean hasActiveManager(IDocument document) {
		return fgActiveManagers.get(document) != null;
	}
	private void install() {
		LinkedPositionManager manager= (LinkedPositionManager) fgActiveManagers.get(fDocument);
		if (manager != null)
			manager.leave(true);		
		fgActiveManagers.put(fDocument, this);
		
		fDocument.addPositionCategory(LINKED_POSITION);
		fDocument.addPositionUpdater(this);		
		fDocument.addDocumentListener(this);
	}	
	
	/**
	 * Leaves the linked mode. If unsuccessful, the linked positions
	 * are restored to the values at the time they were added.
	 */
	public void uninstall(boolean success) {			
		fDocument.removeDocumentListener(this);
		try {
			Position[] positions= getPositions(fDocument);