Bug 76643 Code Formater UI: Allow multi-selection in Line Wrapping tree
20041020 To configure the line wrapping settings it is currently necessary to do that separatly for each setting. It would be nice if this could be done once for all or for a subset. The idea would be to allow multiple selection of the tree (including parent nodes) and allow to use the configuration controls on the bottom. If the selected entries have non-compatible settings, the control should take the most chosen but show the conflict shomehow (e.g. by an extra label or symbol or different background color) It is ok to not show a preview when multiple nodes are selected (or merge as done on the 'white space' page
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/formatter/LineWrappingTabPage.java
protected Button fForceSplit;
	protected CompilationUnitPreview fPreview;
	protected Group fOptionsGroup;
	/**
	 * A collection containing the categories tree. This is used as model for the tree viewer.
	 * @see TreeViewer
	 */
	private final List fCategories;
	
	/**
	 * The category listener which makes the selection persistent.
	 */
	protected final CategoryListener fCategoryListener;
	/**
	 * The key representing the category for which the options are currently shown. 
	 */
	protected String fCurrentKey;
	
	/**
	 * A special options store wherein the preview line width is kept.
	 */
	protected final Map fPreviewPreferences;
	
	/**
	 * The key for the preview line width.
	 */
	private final String LINE_SPLIT= DefaultCodeFormatterConstants.FORMATTER_LINE_SPLIT;
	
	/**
	 * Create a new line wrapping tab page.