Bug 26271 Link-Like navigation: Pixel not removed
20021113 1. Create class public class A { private void fill(StringBuffer buffer, String s) { buffer.append(s); } } 2. CTRL pressed all the time 3. move the mouse over 'append' 4. While still presing CTRL go over 's' (same line) 5. You can see that there is still a blue pixel under 'append'
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
*/
	private void showLineNumberRuler() {
		IVerticalRuler v= getVerticalRuler();
		if (v instanceof CompositeRuler) {
			CompositeRuler c= (CompositeRuler) v;
			c.addDecorator(1, createLineNumberRulerColumn());
		}
	}
	
	/**
	 * Hides the line number ruler column.
	 */
	private void hideLineNumberRuler() {
		IVerticalRuler v= getVerticalRuler();
		if (v instanceof CompositeRuler) {
			CompositeRuler c= (CompositeRuler) v;
			c.removeDecorator(1);
		}
	}
	
	/**
	 * Return whether the line number ruler column should be 
	 * visible according to the preference store settings.
	 * @return <code>true</code> if the line numbers should be visible
	 */
	private boolean isLineNumberRulerVisible() {
		IPreferenceStore store= getPreferenceStore();
		return store.getBoolean(LINE_NUMBER_RULER);
	}