Concurrently Supporting Both Document-Based and Object-Based Undo Operations

摘要

During operation of a program, various different editing actions can be performed on data (e.g., image or video data) in a document. The data includes multiple objects, each of which is a user-selectable element of the data, such as a line, a shape, or a filter applied to the data. A record of actions taken on objects in the data is maintained, and the actions can be undone. A document-based undo operation can be performed, which undoes the last action performed in the document. An object-based undo can also be performed, which undoes the last action performed on a selected one or more objects in the document. A document-based redo operation can be performed, which redoes the last action undone in the document. An object-based redo can also be performed, which redoes the last action undone on a selected one or more objects in the document.

主权项

1. A method comprising:
adding, in response to a user edit to data of a document, a session to an undo record in a last in first out manner, the session indicating an action performed as part of the user edit as well as one or more objects of the data on which the action was performed, each of the one or more objects comprising a user-selectable element of the data; in response to receiving a document-based undo request, performing a document-based undo operation by undoing an action in a session at a top of the undo record; and in response to receiving an object-based undo request, performing an object-based undo operation by
identifying a topmost session of the undo record that includes a first selected object,percolating the identified session to the top of the undo record, andundoing the action in the identified session.