SignalTransition QML Type
The SignalTransition type provides a transition based on a Qt signal. More...
| Import Statement: | import QtQml.StateMachine 1.15 |
| Since: | Qt 5.4 |
| Inherits: |
Properties
Detailed Description
SignalTransition is part of The Declarative State Machine Framework.
Example Usage
import QtQuick 2.0 import QtQml.StateMachine 1.0 as DSM Rectangle { DSM.StateMachine { id: stateMachine initialState: state running: true DSM.State { id: state DSM.SignalTransition { targetState: finalState signal: button.clicked guard: guardButton.checked } } DSM.FinalState { id: finalState } onFinished: Qt.quit() } Row { spacing: 2 Button { id: button text: "Finish state" } Button { id: guardButton checkable: true text: checked ? "Press to block the SignalTransition" : "Press to unblock the SignalTransition" } } }
See also StateMachine, FinalState, and TimeoutTransition.
Property Documentation
guard : bool |
Guard conditions affect the behavior of a state machine by enabling transitions only when they evaluate to true and disabling them when they evaluate to false.
When the signal associated with this signal transition is emitted the guard condition is evaluated. In the guard condition the arguments of the signal can be used as demonstrated in the example below.
import QtQuick 2.0 import QtQml.StateMachine 1.0 as DSM Rectangle { Button { anchors.fill: parent id: button DSM.StateMachine { DSM.State { DSM.SignalTransition { targetState: finalState signal: button.mysignal // the guard condition uses the mystr string argument from mysignal guard: mystr == "test" } } DSM.FinalState { id: finalState } } // define the signal the SignalTransition is connected with signal mysignal(mystr: string) // on clicking the button emit the signal with a single string argument onClicked: button.mysignal("test") } }
See also signal.
The signal which is associated with this signal transition.
import QtQuick 2.0 import QtQml.StateMachine 1.0 as DSM Rectangle { Button { anchors.fill: parent id: button DSM.StateMachine { DSM.State { DSM.SignalTransition { targetState: finalState signal: button.clicked } } DSM.FinalState { id: finalState } } } }