All undo records are managed by the ARTX component in an undo actions list.

To use the Undo functionality, it is necessary to enable it first; use IG_ARTX_page_undo_enable to toggle this functionality. Use IG_ARTX_page_undo_is_enabled to determine if the Undo/Redo functionality is enabled.

When enabled, the history will record the following ArtX editing operations:

• Add Mark
• Remove Mark
• Change Mark’s Properties
• Resizing the Mark
• Repositioning the Mark – Move, Rotate, Flip
• Change Mark’s Selection
• Change Mark’s Z-Order
• Add Group
• Remove Group
• Change Group’s Properties
• Change Page’s Properties

Recording of undo history may be a memory consuming operation. Use IG_ARTX_page_undo_action_enable to control which ArtX operations are recorded in the history to allow undo. The function to query which ArtX operations will be recorded is IG_ARTX_page_undo_action_is_enabled.

To get the number of undo records in the undo actions list, call the IG_ARTX_page_undo_count function. To clear the undo actions list, call the IG_ARTX_page_undo_clear function.

To perform an undo operation on an ArtX page call IG_ARTX_page_undo. This will undo the last annotation operation performed to the page. Successive calls will work backwards on the undo actions list until it is empty.