Defines the ToolHistoryMixin class.
A mix-in class for tools to maintain a tool state history and to move backwards and forwards through that history stack.
This mix-in listens for keypressed events; to handle keypresses in a subclass, call self._history_handle_key(event) to have this mix-in properly process the event.
next_state_key= Instance(KeySpec, args=("Right", "control"))¶
Key to go to the next state in the history.
Handles a key being pressed, and takes appropriate action if it is one of the history keys defined for this class.
prev_state_key= Instance(KeySpec, args=("Left", "control"))¶
Key to go to the previous state in the history.
reset_state_key= Instance(KeySpec, args=("Esc",))¶
Key to go to the original or start state in the history.