Class for the ObservableStringDictionary.onDictionaryChanged observable
Contain the action that were made on the dictionary, it's one of the DictionaryChanged.xxxAction members.
Note the action's value can be used in the "mask" field of the Observable to only be notified about given action(s)
Only valid if the action is newItemAction
Only valid if the action is removedItemAction
Only valid if the action is itemValueChangedAction
The content of the dictionary was totally cleared
A new item was added, the newItem field contains the key/value pair
An existing item was removed, the removedKey field contains its key
An existing item had a value change, the changedItem field contains the key/value
The dictionary's content was reset and replaced by the content of another dictionary.