Qt object: Add exit(int)

This is similar to the Qt.quit() function but also specifies the return
code that the event loop will return.

[ChangeLog][QtQml] Added exit(int retCode) method to the Qt global object.
An application can call Qt.exit to specify a return code of the engine.

Task-number: QTBUG-54360
Change-Id: Iaa319e6dc4d6b99dc3a5c01845e87b936fd2cab0
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

6 files changed, 48 insertions, 0 deletions

diff --git a/src/qml/qml/qqmlapplicationengine.cpp b/src/qml/qml/qqmlapplicationengine.cpp
index 30fc186391..fef2da753b 100644
--- a/src/qml/qml/qqmlapplicationengine.cpp
+++ b/src/qml/qml/qqmlapplicationengine.cpp
@@ -69,6 +69,7 @@ void QQmlApplicationEnginePrivate::init()
     q->connect(&statusMapper, SIGNAL(mapped(QObject*)),
             q, SLOT(_q_finishLoad(QObject*)));
     q->connect(q, SIGNAL(quit()), QCoreApplication::instance(), SLOT(quit()));
+    q->connect(q, &QQmlApplicationEngine::exit, QCoreApplication::instance(), &QCoreApplication::exit);
 #ifndef QT_NO_TRANSLATION
     QTranslator* qtTranslator = new QTranslator;
     if (qtTranslator->load(QLatin1String("qt_") + QLocale::system().name(), QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
diff --git a/src/qml/qml/qqmlengine.cpp b/src/qml/qml/qqmlengine.cpp
index 2b49eae4de..cdaa9e83e9 100644
--- a/src/qml/qml/qqmlengine.cpp
+++ b/src/qml/qml/qqmlengine.cpp
@@ -982,8 +982,19 @@ QQmlEngine::~QQmlEngine()
 
 /*! \fn void QQmlEngine::quit()
     This signal is emitted when the QML loaded by the engine would like to quit.
+
+    \sa exit()
  */
 
+/*! \fn void QQmlEngine::exit(int retCode)
+    This signal is emitted when the QML loaded by the engine would like to exit
+    from the event loop with the specified return code.
+
+    \since 5.8
+    \sa quit()
+ */
+
+
 /*! \fn void QQmlEngine::warnings(const QList<QQmlError> &warnings)
     This signal is emitted when \a warnings messages are generated by QML.
  */
@@ -1837,6 +1848,14 @@ void QQmlEnginePrivate::sendQuit()
     }
 }
 
+void QQmlEnginePrivate::sendExit(int retCode)
+{
+    Q_Q(QQmlEngine);
+    if (q->receivers(SIGNAL(exit(int))) == 0)
+        qWarning("Signal QQmlEngine::exit() emitted, but no receivers connected to handle it.");
+    emit q->exit(retCode);
+}
+
 static void dumpwarning(const QQmlError &error)
 {
     QMessageLogger(error.url().toString().toLatin1().constData(),
diff --git a/src/qml/qml/qqmlengine.h b/src/qml/qml/qqmlengine.h
index 132af78f80..bbb9c36ce9 100644
--- a/src/qml/qml/qqmlengine.h
+++ b/src/qml/qml/qqmlengine.h
@@ -155,6 +155,7 @@ protected:
 
 Q_SIGNALS:
     void quit();
+    void exit(int retCode);
     void warnings(const QList<QQmlError> &warnings);
 
 private:
diff --git a/src/qml/qml/qqmlengine_p.h b/src/qml/qml/qqmlengine_p.h
index 949060f395..713b03dbf3 100644
--- a/src/qml/qml/qqmlengine_p.h
+++ b/src/qml/qml/qqmlengine_p.h
@@ -227,6 +227,7 @@ public:
     bool isScriptLoaded(const QUrl &url) const;
 
     void sendQuit();
+    void sendExit(int retCode = 0);
     void warning(const QQmlError &);
     void warning(const QList<QQmlError> &);
     void warning(QQmlDelayedError *);
diff --git a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
index 76a900c846..db0439ab9e 100644
--- a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
+++ b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
@@ -137,6 +137,7 @@ Heap::QtObject::QtObject(QQmlEngine *qmlEngine)
         o->defineDefaultProperty(QStringLiteral("darker"), QV4::QtObject::method_darker);
         o->defineDefaultProperty(QStringLiteral("tint"), QV4::QtObject::method_tint);
         o->defineDefaultProperty(QStringLiteral("quit"), QV4::QtObject::method_quit);
+        o->defineDefaultProperty(QStringLiteral("exit"), QV4::QtObject::method_exit);
         o->defineDefaultProperty(QStringLiteral("createQmlObject"), QV4::QtObject::method_createQmlObject);
         o->defineDefaultProperty(QStringLiteral("createComponent"), QV4::QtObject::method_createComponent);
     }
@@ -992,6 +993,8 @@ This function causes the QQmlEngine::quit() signal to be emitted.
 Within the \l {Prototyping with qmlscene}, this causes the launcher application to exit;
 to quit a C++ application when this method is called, connect the
 QQmlEngine::quit() signal to the QCoreApplication::quit() slot.
+
+\sa exit()
 */
 ReturnedValue QtObject::method_quit(CallContext *ctx)
 {
@@ -1000,6 +1003,28 @@ ReturnedValue QtObject::method_quit(CallContext *ctx)
 }
 
 /*!
+    \qmlmethod Qt::exit(int retCode)
+
+    This function causes the QQmlEngine::exit(int) signal to be emitted.
+    Within the \l {Prototyping with qmlscene}, this causes the launcher application to exit
+    the specified return code. To exit from the event loop with a specified return code when this
+    method is called, a C++ application can connect the QQmlEngine::exit(int) signal
+    to the QCoreApplication::exit(int) slot.
+
+    \sa quit()
+*/
+ReturnedValue QtObject::method_exit(CallContext *ctx)
+{
+    if (ctx->argc() != 1)
+        V4THROW_ERROR("Qt.exit(): Invalid arguments");
+
+    int retCode = ctx->args()[0].toNumber();
+
+    QQmlEnginePrivate::get(ctx->engine()->qmlEngine())->sendExit(retCode);
+    return QV4::Encode::undefined();
+}
+
+/*!
 \qmlmethod object Qt::createQmlObject(string qml, object parent, string filepath)
 
 Returns a new object created from the given \a string of QML which will have the specified \a parent,
diff --git a/src/qml/qml/v8/qqmlbuiltinfunctions_p.h b/src/qml/qml/v8/qqmlbuiltinfunctions_p.h
index d29983c476..8c0759679a 100644
--- a/src/qml/qml/v8/qqmlbuiltinfunctions_p.h
+++ b/src/qml/qml/v8/qqmlbuiltinfunctions_p.h
@@ -122,6 +122,7 @@ struct QtObject : Object
     static ReturnedValue method_btoa(CallContext *ctx);
     static ReturnedValue method_atob(CallContext *ctx);
     static ReturnedValue method_quit(CallContext *ctx);
+    static ReturnedValue method_exit(CallContext *ctx);
     static ReturnedValue method_resolvedUrl(CallContext *ctx);
     static ReturnedValue method_createQmlObject(CallContext *ctx);
     static ReturnedValue method_createComponent(CallContext *ctx);