diff options
Diffstat (limited to 'src/imports/statemachine/signaltransition.cpp')
-rw-r--r-- | src/imports/statemachine/signaltransition.cpp | 41 |
1 files changed, 33 insertions, 8 deletions
diff --git a/src/imports/statemachine/signaltransition.cpp b/src/imports/statemachine/signaltransition.cpp index 9b64550678..634ec5a43b 100644 --- a/src/imports/statemachine/signaltransition.cpp +++ b/src/imports/statemachine/signaltransition.cpp @@ -38,6 +38,7 @@ #include <QQmlInfo> #include <QQmlEngine> #include <QQmlContext> +#include <QQmlExpression> #include <private/qv4qobjectwrapper_p.h> #include <private/qv8engine_p.h> @@ -46,7 +47,6 @@ SignalTransition::SignalTransition(QState *parent) : QSignalTransition(this, SIGNAL(invokeYourself()), parent) - , m_guard(true) { connect(this, SIGNAL(signalChanged()), SIGNAL(qmlSignalChanged())); } @@ -57,7 +57,23 @@ bool SignalTransition::eventTest(QEvent *event) if (!QSignalTransition::eventTest(event)) return false; - return m_guard; + if (m_guard.isEmpty()) + return true; + + QQmlContext context(QQmlEngine::contextForObject(this)); + + QStateMachine::SignalEvent *e = static_cast<QStateMachine::SignalEvent*>(event); + + // Set arguments as context properties + int count = e->arguments().count(); + QMetaMethod metaMethod = e->sender()->metaObject()->method(e->signalIndex()); + for (int i = 0; i < count; i++) + context.setContextProperty(metaMethod.parameterNames()[i], QVariant::fromValue(e->arguments().at(i))); + + QQmlExpression expr(m_guard, &context, this); + QVariant result = expr.evaluate(); + + return result.toBool(); } const QJSValue& SignalTransition::signal() @@ -89,17 +105,18 @@ void SignalTransition::setSignal(const QJSValue &signal) QSignalTransition::setSignal(metaMethod.methodSignature()); } -bool SignalTransition::guard() const +QQmlScriptString SignalTransition::guard() const { return m_guard; } -void SignalTransition::setGuard(bool guard) +void SignalTransition::setGuard(const QQmlScriptString &guard) { - if (guard != m_guard) { - m_guard = guard; - emit guardChanged(); - } + if (m_guard == guard) + return; + + m_guard = guard; + emit guardChanged(); } void SignalTransition::invoke() @@ -227,4 +244,12 @@ void SignalTransition::invoke() 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. + + \snippet qml/statemachine/guardcondition.qml document + + \sa signal */ |