Provide access to signal parameters in SignalTransition::onTriggered.

Change-Id: Ib74d3f5e9a357a86b818e27dd7249e2ecdf1e513
Task-number: QTBUG-46897
Reviewed-by: Brett Stottlemyer <bstottle@ford.com>
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

5 files changed, 115 insertions, 5 deletions

diff --git a/src/imports/statemachine/plugin.cpp b/src/imports/statemachine/plugin.cpp
index 4a711a3278..2d52839f68 100644
--- a/src/imports/statemachine/plugin.cpp
+++ b/src/imports/statemachine/plugin.cpp
@@ -58,7 +58,7 @@ public:
         qmlRegisterUncreatableType<QState>(uri, 1, 0, "QState", "Don't use this, use State instead");
         qmlRegisterUncreatableType<QAbstractState>(uri, 1, 0, "QAbstractState", "Don't use this, use State instead");
         qmlRegisterUncreatableType<QSignalTransition>(uri, 1, 0, "QSignalTransition", "Don't use this, use SignalTransition instead");
-        qmlRegisterType<SignalTransition>(uri, 1, 0, "SignalTransition");
+        qmlRegisterCustomType<SignalTransition>(uri, 1, 0, "SignalTransition", new SignalTransitionParser);
         qmlRegisterType<TimeoutTransition>(uri, 1, 0, "TimeoutTransition");
         qmlProtectModule(uri, 1);
     }
diff --git a/src/imports/statemachine/signaltransition.cpp b/src/imports/statemachine/signaltransition.cpp
index 92650f7e07..33ee11cbe7 100644
--- a/src/imports/statemachine/signaltransition.cpp
+++ b/src/imports/statemachine/signaltransition.cpp
@@ -45,9 +45,10 @@
 #include <private/qjsvalue_p.h>
 #include <private/qv4scopedvalue_p.h>
 #include <private/qqmlcontext_p.h>
+#include <private/qqmlboundsignal_p.h>
 
 SignalTransition::SignalTransition(QState *parent)
-    : QSignalTransition(this, SIGNAL(invokeYourself()), parent)
+    : QSignalTransition(this, SIGNAL(invokeYourself()), parent), m_complete(false), m_signalExpression(Q_NULLPTR)
 {
     connect(this, SIGNAL(signalChanged()), SIGNAL(qmlSignalChanged()));
 }
@@ -80,6 +81,15 @@ bool SignalTransition::eventTest(QEvent *event)
     return result.toBool();
 }
 
+void SignalTransition::onTransition(QEvent *event)
+{
+    if (m_signalExpression) {
+        QStateMachine::SignalEvent *e = static_cast<QStateMachine::SignalEvent*>(event);
+        m_signalExpression->evaluate(e->arguments());
+    }
+    QSignalTransition::onTransition(event);
+}
+
 const QJSValue& SignalTransition::signal()
 {
     return m_signal;
@@ -104,6 +114,8 @@ void SignalTransition::setSignal(const QJSValue &signal)
 
     QSignalTransition::setSenderObject(sender);
     QSignalTransition::setSignal(metaMethod.methodSignature());
+
+    connectTriggered();
 }
 
 QQmlScriptString SignalTransition::guard() const
@@ -125,6 +137,60 @@ void SignalTransition::invoke()
     emit invokeYourself();
 }
 
+void SignalTransition::connectTriggered()
+{
+    if (!m_complete || !m_cdata)
+        return;
+
+    QObject *target = senderObject();
+    QQmlData *ddata = QQmlData::get(this);
+    QQmlContextData *ctxtdata = ddata ? ddata->outerContext : 0;
+
+    Q_ASSERT(m_bindings.count() == 1);
+    const QV4::CompiledData::Binding *binding = m_bindings.at(0);
+    Q_ASSERT(binding->type == QV4::CompiledData::Binding::Type_Script);
+
+    QV4::ExecutionEngine *jsEngine = QV8Engine::getV4(QQmlEngine::contextForObject(this)->engine());
+    QV4::Scope scope(jsEngine);
+    QV4::Scoped<QV4::QObjectMethod> qobjectSignal(scope, QJSValuePrivate::convertedToValue(jsEngine, m_signal));
+    Q_ASSERT(qobjectSignal);
+    QMetaMethod metaMethod = target->metaObject()->method(qobjectSignal->methodIndex());
+    int signalIndex = QMetaObjectPrivate::signalIndex(metaMethod);
+
+    QQmlBoundSignalExpression *expression = ctxtdata ?
+                new QQmlBoundSignalExpression(target, signalIndex,
+                                              ctxtdata, this, m_cdata->compilationUnit->runtimeFunctions[binding->value.compiledScriptIndex]) : 0;
+    if (expression)
+        expression->setNotifyOnValueChanged(false);
+    m_signalExpression = expression;
+}
+
+void SignalTransitionParser::verifyBindings(const QV4::CompiledData::Unit *qmlUnit, const QList<const QV4::CompiledData::Binding *> &props)
+{
+    for (int ii = 0; ii < props.count(); ++ii) {
+        const QV4::CompiledData::Binding *binding = props.at(ii);
+
+        QString propName = qmlUnit->stringAt(binding->propertyNameIndex);
+
+        if (propName != QStringLiteral("onTriggered")) {
+            error(props.at(ii), SignalTransition::tr("Cannot assign to non-existent property \"%1\"").arg(propName));
+            return;
+        }
+
+        if (binding->type != QV4::CompiledData::Binding::Type_Script) {
+            error(binding, SignalTransition::tr("SignalTransition: script expected"));
+            return;
+        }
+    }
+}
+
+void SignalTransitionParser::applyBindings(QObject *object, QQmlCompiledData *cdata, const QList<const QV4::CompiledData::Binding *> &bindings)
+{
+    SignalTransition *st = qobject_cast<SignalTransition*>(object);
+    st->m_cdata = cdata;
+    st->m_bindings = bindings;
+}
+
 /*!
     \qmltype QAbstractTransition
     \inqmlmodule QtQml.StateMachine
diff --git a/src/imports/statemachine/signaltransition.h b/src/imports/statemachine/signaltransition.h
index 1b44af4de9..dfb1ca91b9 100644
--- a/src/imports/statemachine/signaltransition.h
+++ b/src/imports/statemachine/signaltransition.h
@@ -39,12 +39,17 @@
 #include <QtQml/QJSValue>
 
 #include <QtQml/qqmlscriptstring.h>
+#include <QtQml/qqmlparserstatus.h>
+#include <private/qqmlcustomparser_p.h>
+#include <private/qqmlboundsignalexpressionpointer_p.h>
+#include <private/qqmlcompiler_p.h>
 
 QT_BEGIN_NAMESPACE
 
-class SignalTransition : public QSignalTransition
+class SignalTransition : public QSignalTransition, public QQmlParserStatus
 {
     Q_OBJECT
+    Q_INTERFACES(QQmlParserStatus)
     Q_PROPERTY(QJSValue signal READ signal WRITE setSignal NOTIFY qmlSignalChanged)
     Q_PROPERTY(QQmlScriptString guard READ guard WRITE setGuard NOTIFY guardChanged)
 
@@ -54,7 +59,8 @@ public:
     QQmlScriptString guard() const;
     void setGuard(const QQmlScriptString &guard);
 
-    bool eventTest(QEvent *event);
+    bool eventTest(QEvent *event) Q_DECL_OVERRIDE;
+    void onTransition(QEvent *event) Q_DECL_OVERRIDE;
 
     const QJSValue &signal();
     void setSignal(const QJSValue &signal);
@@ -70,9 +76,24 @@ Q_SIGNALS:
     void qmlSignalChanged();
 
 private:
-    QByteArray m_data;
+    void classBegin() Q_DECL_OVERRIDE { m_complete = false; }
+    void componentComplete() Q_DECL_OVERRIDE { m_complete = true; connectTriggered(); }
+    void connectTriggered();
+
+    friend class SignalTransitionParser;
     QJSValue m_signal;
     QQmlScriptString m_guard;
+    bool m_complete;
+    QQmlRefPointer<QQmlCompiledData> m_cdata;
+    QList<const QV4::CompiledData::Binding *> m_bindings;
+    QQmlBoundSignalExpressionPointer m_signalExpression;
+};
+
+class SignalTransitionParser : public QQmlCustomParser
+{
+public:
+    void verifyBindings(const QV4::CompiledData::Unit *qmlUnit, const QList<const QV4::CompiledData::Binding *> &props) Q_DECL_OVERRIDE;
+    void applyBindings(QObject *object, QQmlCompiledData *cdata, const QList<const QV4::CompiledData::Binding *> &bindings) Q_DECL_OVERRIDE;
 };
 
 QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmlboundsignal.cpp b/src/qml/qml/qqmlboundsignal.cpp
index 477a517e32..6d8f883e4c 100644
--- a/src/qml/qml/qqmlboundsignal.cpp
+++ b/src/qml/qml/qqmlboundsignal.cpp
@@ -239,6 +239,28 @@ void QQmlBoundSignalExpression::evaluate(void **a)
     ep->dereferenceScarceResources(); // "release" scarce resources if top-level expression evaluation is complete.
 }
 
+void QQmlBoundSignalExpression::evaluate(const QList<QVariant> &args)
+{
+    Q_ASSERT (context() && engine());
+
+    if (!expressionFunctionValid())
+        return;
+
+    QQmlEnginePrivate *ep = QQmlEnginePrivate::get(engine());
+    QV4::Scope scope(ep->v4engine());
+
+    ep->referenceScarceResources(); // "hold" scarce resources in memory during evaluation.
+
+    QV4::ScopedCallData callData(scope, args.count());
+    for (int ii = 0; ii < args.count(); ++ii) {
+        callData->args[ii] = scope.engine->fromVariant(args[ii]);
+    }
+
+    QQmlJavaScriptExpression::evaluate(callData, 0);
+
+    ep->dereferenceScarceResources(); // "release" scarce resources if top-level expression evaluation is complete.
+}
+
 ////////////////////////////////////////////////////////////////////////
 
 
diff --git a/src/qml/qml/qqmlboundsignal_p.h b/src/qml/qml/qqmlboundsignal_p.h
index 3742317484..147752882d 100644
--- a/src/qml/qml/qqmlboundsignal_p.h
+++ b/src/qml/qml/qqmlboundsignal_p.h
@@ -78,6 +78,7 @@ public:
 
     // evaluation of a bound signal expression doesn't return any value
     void evaluate(void **a);
+    void evaluate(const QList<QVariant> &args);
 
     QQmlSourceLocation sourceLocation() const;
     QString expression() const;