3 files changed, 77 insertions, 3 deletions

diff --git a/src/qml/qml/qqmlengine.cpp b/src/qml/qml/qqmlengine.cpp
index 20c8d53573..9c3c9de81e 100644
--- a/src/qml/qml/qqmlengine.cpp
+++ b/src/qml/qml/qqmlengine.cpp
@@ -206,8 +206,12 @@ void QQmlEnginePrivate::defineModule()
     qmlRegisterType<QQmlBind>(uri, 2, 0, "Binding");
     qmlRegisterType<QQmlBind, 8>(uri, 2, 8, "Binding"); // Only available in >= 2.8
     qmlRegisterType<QQmlBind, 14>(uri, 2, 14, "Binding");
+
+    // TODO: We won't need Connections to be a custom type anymore once we can drop the
+    //       automatic signal handler inference from undeclared properties.
     qmlRegisterCustomType<QQmlConnections>(uri, 2, 0, "Connections", new QQmlConnectionsParser);
     qmlRegisterCustomType<QQmlConnections, 1>(uri, 2, 3, "Connections", new QQmlConnectionsParser); // Only available in QtQml >= 2.3
+
 #if QT_CONFIG(qml_animation)
     qmlRegisterType<QQmlTimer>(uri, 2, 0, "Timer");
 #endif
diff --git a/src/qml/types/qqmlconnections.cpp b/src/qml/types/qqmlconnections.cpp
index 8ec754a9df..14aadb6c86 100644
--- a/src/qml/types/qqmlconnections.cpp
+++ b/src/qml/types/qqmlconnections.cpp
@@ -44,6 +44,7 @@
 #include <private/qqmlboundsignal_p.h>
 #include <qqmlcontext.h>
 #include <private/qqmlcontext_p.h>
+#include <private/qqmlvmemetaobject_p.h>
 #include <qqmlinfo.h>
 
 #include <QtCore/qdebug.h>
@@ -105,7 +106,7 @@ public:
     \qml
     MouseArea {
         Connections {
-            onClicked: foo(parameters)
+            function onClicked(mouse) { foo(mouse) }
         }
     }
     \endqml
@@ -122,7 +123,7 @@ public:
     \qml
     Connections {
         target: area
-        onClicked: foo(parameters)
+        function onClicked(mouse) { foo(mouse) }
     }
     \endqml
 
@@ -270,8 +271,73 @@ void QQmlConnections::connectSignals()
     if (!d->componentcomplete || (d->targetSet && !target()))
         return;
 
-    if (d->bindings.isEmpty())
+    if (d->bindings.isEmpty()) {
+        connectSignalsToMethods();
+    } else {
+        qmlWarning(this) << tr("Implicitly defined onFoo properties in Connections are deprecated. "
+                               "Use this syntax instead: function onFoo(<arguments>) { ... }");
+        connectSignalsToBindings();
+    }
+}
+
+void QQmlConnections::connectSignalsToMethods()
+{
+    Q_D(QQmlConnections);
+
+    QObject *target = this->target();
+    QQmlData *ddata = QQmlData::get(this);
+    if (!ddata)
         return;
+
+    QV4::ExecutionEngine *engine = ddata->context->engine->handle();
+
+    QQmlContextData *ctxtdata = ddata->outerContext;
+    for (int i = ddata->propertyCache->methodOffset(),
+             end = ddata->propertyCache->methodOffset() + ddata->propertyCache->methodCount();
+         i < end;
+         ++i) {
+
+        QQmlPropertyData *handler = ddata->propertyCache->method(i);
+        if (!handler || !handler->isVMEFunction())
+            continue;
+
+        const QString propName = handler->name(this);
+
+        QQmlProperty prop(target, propName);
+        if (prop.isValid() && (prop.type() & QQmlProperty::SignalProperty)) {
+            int signalIndex = QQmlPropertyPrivate::get(prop)->signalIndex();
+            auto *signal = new QQmlBoundSignal(target, signalIndex, this, qmlEngine(this));
+            signal->setEnabled(d->enabled);
+
+            QV4::Scope scope(engine);
+            QV4::ScopedContext global(scope, engine->rootContext());
+
+            QQmlVMEMetaObject *vmeMetaObject = QQmlVMEMetaObject::get(this);
+            Q_ASSERT(vmeMetaObject); // the fact we found the property above should guarentee this
+
+            QV4::ScopedFunctionObject method(scope, vmeMetaObject->vmeMethod(handler->coreIndex()));
+
+            QQmlBoundSignalExpression *expression =
+                    ctxtdata ? new QQmlBoundSignalExpression(
+                                       target, signalIndex, ctxtdata, this,
+                                       method->as<QV4::FunctionObject>()->function())
+                             : nullptr;
+
+            signal->takeExpression(expression);
+            d->boundsignals += signal;
+        } else if (!d->ignoreUnknownSignals && propName.startsWith("on") && propName.length() > 2
+                   && propName.at(2).isUpper()) {
+            qmlWarning(this) << tr("Detected function \"%1\" in Connections element. "
+                                   "This is probably intended to be a signal handler but no "
+                                   "signal of the target matches the name.").arg(propName);
+        }
+    }
+}
+
+// TODO: Drop this as soon as we can
+void QQmlConnections::connectSignalsToBindings()
+{
+    Q_D(QQmlConnections);
     QObject *target = this->target();
     QQmlData *ddata = QQmlData::get(this);
     QQmlContextData *ctxtdata = ddata ? ddata->outerContext : nullptr;
diff --git a/src/qml/types/qqmlconnections_p.h b/src/qml/types/qqmlconnections_p.h
index f6ad1eb46c..1acc86239f 100644
--- a/src/qml/types/qqmlconnections_p.h
+++ b/src/qml/types/qqmlconnections_p.h
@@ -91,10 +91,14 @@ Q_SIGNALS:
 
 private:
     void connectSignals();
+    void connectSignalsToMethods();
+    void connectSignalsToBindings();
+
     void classBegin() override;
     void componentComplete() override;
 };
 
+// TODO: Drop this class as soon as we can
 class QQmlConnectionsParser : public QQmlCustomParser
 {
 public: