Bug 77636 Code Formatter Profile Editor should be more fault-tolerant [formatter]
200411022000 The Code Formatter Profile Editor should be more fault-tolerant. Especially on 'White Space' and 'Line Wrapping' tabs, it is very easy to mess things up by changing many settings at once with a single click at the wrong spot. Two possible solutions came to my mind: (1) The dialog could support an undo/redo-stack (via keybindings and/or via additional buttons on the bottom row) (2) The dialog could offer an 'Apply' button, with which the user could save the changes done so far. The current workaround for this is to leave the dialog via OK and then re-enter it, but that's cumbersome when you want to do a pass over all options.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/formatter/ModifyDialogTabPage.java
private static final int RIGHT_SIDE_WIDTH_HINT_CHARS= 65;
	private static final int LEFT_SIDE_WIDTH_HINT_CHARS= 65;
	/**
	 * This is the default listener for any of the Preference
	 * classes. It is added by the respective factory methods and
	 * updates the page's preview on each change. 
	 */
	protected final Observer fUpdater= new Observer() {
		public void update(Observable o, Object arg) {
			doUpdatePreview();
		}
	};
	
	
	/**
	 * The base class of all Preference classes. A preference class provides a wrapper
	 * around one or more SWT widgets and handles the input of values for some key.
	 * On each change, the new value is written to the map and the listeners are notified.
	 */
	protected abstract class Preference extends Observable {