Class MapChanges

code/src/java/pcgen/rules/context/MapChanges.java:32–111

The Class MapChanges is responsible for tracking changes to a map so that the changes can be committed or rolled back at a later stage. Items can be added to the map, removed from the map or the map can be cleared.

 * 
 */
public class MapChanges<K, V>
{
	private final Map<K, V> positive;
	private final Map<K, V> negative;
	private final boolean clear;

	/**
	 * Instantiates a new map changes object.
	 * 
	 * @param added the map of items added
	 * @param removed the map of items removed
	 * @param globallyCleared has the map been cleared
	 */
	public MapChanges(Map<K, V> added, Map<K, V> removed, boolean globallyCleared)
	{
		positive = added;
		negative = removed;
		clear = globallyCleared;
	}

	/**
	 * Includes global clear.
	 * 
	 * @return true, if the map was cleared
	 */
	public boolean includesGlobalClear()
	{
		return clear;
	}

	/**
	 * Checks if the change set is empty.
	 * 
	 * @return true, if is empty
	 */
	public boolean isEmpty()
	{
		return !clear && !hasAddedItems() && !hasRemovedItems();
	}

	/**
	 * Gets the map of added items.
	 * 
	 * @return the added items
	 */
	public Map<K, V> getAdded()
	{
		return positive;
	}

	/**
	 * Checks for added items.
	 * 
	 * @return true, if there are items to add
	 */
	public boolean hasAddedItems()
	{
		return positive != null && !positive.isEmpty();