QUndoStack is a class in the Qt framework that provides support for undo and redo operations. It manages a sequence of undoable command objects, which can be executed, undone, and redone as the user interacts with an application. The QUndoStack maintains a list of these commands, and allows the user to undo and redo them using standard keyboard shortcuts or menu options.
The QUndoStack operates on a collection of QUndoCommand objects, which represent individual actions that can be undone or redone. The QUndoCommand class provides methods for executing and undoing a command, as well as a destructor for cleaning up any resources created by the command.
Using the QUndoStack, an application can implement an undo/redo feature that allows users to undo the effects of their actions and restore previous states of the application. This can be useful in a wide range of applications, from text editors to image processing tools to CAD software.
