New in version 4.6.
A history state is a pseudo-state that represents the child state that the parent state was in the last time the parent state was exited. A transition with a history state as its target is in fact a transition to one or more other child states of the parent state.
QHistoryStateis part of The State Machine Framework .
setDefaultState()function to set the state that should be entered if the parent state has never been entered. Example:machine = QStateMachine() s1 = QState() s11 = QState(s1) s12 = QState(s1) s1h = QHistoryState(s1) s1h.setDefaultState(s11) machine.addState(s1) s2 = QState() machine.addState(s2) button = QPushButton() # Clicking the button will cause the state machine to enter the child state # that s1 was in the last time s1 was exited, or the history state's default # state if s1 has never been entered. s1.addTransition(button.clicked, s1h)
If more than one default state has to be entered, or if the transition to the default state(s) has to be acted upon, the
defaultTransitionshould be set instead. Note that the eventTest() method of that transition will never be called: the selection and execution of the transition is done automatically when entering the history state.
By default a history state is shallow, meaning that it won’t remember nested states. This can be configured through the
- param type
- param parent
Constructs a new history state of the given
type, with the given
Constructs a new shallow history state with the given
This enum specifies the type of history that a
Only the immediate child states of the parent state are recorded. In this case a transition with the history state as its target will end up in the immediate child state that the parent was in the last time it was exited. This is the default.
Nested states are recorded. In this case a transition with the history state as its target will end up in the most deeply nested descendant state the parent was in the last time it was exited.
- Return type
Returns this history state’s default state. The default state indicates the state to transition to if the parent state has never been entered before.
- Return type
Returns this history state’s default transition. The default transition is taken when the history state has never been entered before. The target states of the default transition therefore make up the default state.
- Return type
Returns the type of history that this history state records.
Sets this history state’s default state to be the given
statemust be a sibling of this history state.
Note that this function does not set
stateas the initial state of its parent.
Sets this history state’s default transition to be the given
transition. This will set the source state of the
transitionto the history state.
Note that the eventTest method of the
transitionwill never be called.
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