I need document revison function. I use keydown event to handle back and delete key to prevent the delete content and set the text content( only text) style with strickout.
user can input new text content . then when user delete the new text delete the new content that input by user is allowed. so I must know what the new content inputed by user.
Sorry, this is not possible in a general case, only by comparing the old and the new document.
Well, you can try to use OnItemAction event to detect insertion and deletion of new items, and OnItemTextEdit to detect when the item text is modified. But I am afraid it would not be a simple work.