Add extension API to QJSEngine

This allows users in a JavaScript-only environment to install extensions including:

- Translation functions (qsTr(), etc.)
- The console object (console.log(), print(), etc.)
- Garbage collection functions (gc())

This deprecates installTranslatorFunctions(). This API results in less
clutter in the API, as we'd otherwise need to have several functions
for each type of extension.

[ChangeLog][QJSEngine] Introduced an extension API that allows
installing various function and object extensions (qsTr(),
console.log(), etc.) to QJSEngine.
[ChangeLog][QJSEngine] installTranslatorFunctions() was deprecated in
favor of the new extension API (see installExtensions()).

Change-Id: I4d6eb2097c3eda6810e967b2e8f6441c28c91a16
Task-number: QTBUG-40772
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

3 files changed, 43 insertions, 25 deletions

diff --git a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
index 3242833e22..5deac8343e 100644
--- a/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
+++ b/src/qml/qml/v8/qqmlbuiltinfunctions.cpp
@@ -1390,27 +1390,30 @@ static QV4::ReturnedValue writeToConsole(ConsoleLogTypes logType, CallContext *c
         result.append(jsStack(v4));
     }
 
-    static QLoggingCategory loggingCategory("qml");
+    static QLoggingCategory qmlLoggingCategory("qml");
+    static QLoggingCategory jsLoggingCategory("js");
+
+    QLoggingCategory *loggingCategory = v4->qmlEngine() ? &qmlLoggingCategory : &jsLoggingCategory;
     QV4::StackFrame frame = v4->currentStackFrame();
     const QByteArray baSource = frame.source.toUtf8();
     const QByteArray baFunction = frame.function.toUtf8();
-    QMessageLogger logger(baSource.constData(), frame.line, baFunction.constData(), loggingCategory.categoryName());
+    QMessageLogger logger(baSource.constData(), frame.line, baFunction.constData(), loggingCategory->categoryName());
 
     switch (logType) {
     case Log:
-        if (loggingCategory.isDebugEnabled())
+        if (loggingCategory->isDebugEnabled())
             logger.debug("%s", result.toUtf8().constData());
         break;
     case Info:
-        if (loggingCategory.isInfoEnabled())
+        if (loggingCategory->isInfoEnabled())
             logger.info("%s", result.toUtf8().constData());
         break;
     case Warn:
-        if (loggingCategory.isWarningEnabled())
+        if (loggingCategory->isWarningEnabled())
             logger.warning("%s", result.toUtf8().constData());
         break;
     case Error:
-        if (loggingCategory.isCriticalEnabled())
+        if (loggingCategory->isCriticalEnabled())
             logger.critical("%s", result.toUtf8().constData());
         break;
     default:
@@ -1442,6 +1445,9 @@ QV4::ReturnedValue ConsoleObject::method_profile(CallContext *ctx)
 {
     QV4::ExecutionEngine *v4 = ctx->d()->engine;
 
+    if (!v4->qmlEngine())
+        return QV4::Encode::undefined(); // Not yet implemented for JavaScript.
+
     QV4::StackFrame frame = v4->currentStackFrame();
     const QByteArray baSource = frame.source.toUtf8();
     const QByteArray baFunction = frame.function.toUtf8();
@@ -1461,6 +1467,9 @@ QV4::ReturnedValue ConsoleObject::method_profileEnd(CallContext *ctx)
 {
     QV4::ExecutionEngine *v4 = ctx->d()->engine;
 
+    if (!v4->qmlEngine())
+        return QV4::Encode::undefined(); // Not yet implemented for JavaScript.
+
     QV4::StackFrame frame = v4->currentStackFrame();
     const QByteArray baSource = frame.source.toUtf8();
     const QByteArray baFunction = frame.function.toUtf8();
@@ -1590,31 +1599,36 @@ QV4::ReturnedValue ConsoleObject::method_exception(CallContext *ctx)
 
 
 
-void QV4::GlobalExtensions::init(QQmlEngine *qmlEngine, Object *globalObject)
+void QV4::GlobalExtensions::init(Object *globalObject, QJSEngine::Extensions extensions)
 {
     ExecutionEngine *v4 = globalObject->engine();
     Scope scope(v4);
 
-#ifndef QT_NO_TRANSLATION
-    globalObject->defineDefaultProperty(QStringLiteral("qsTranslate"), method_qsTranslate);
-    globalObject->defineDefaultProperty(QStringLiteral("QT_TRANSLATE_NOOP"), method_qsTranslateNoOp);
-    globalObject->defineDefaultProperty(QStringLiteral("qsTr"), method_qsTr);
-    globalObject->defineDefaultProperty(QStringLiteral("QT_TR_NOOP"), method_qsTrNoOp);
-    globalObject->defineDefaultProperty(QStringLiteral("qsTrId"), method_qsTrId);
-    globalObject->defineDefaultProperty(QStringLiteral("QT_TRID_NOOP"), method_qsTrIdNoOp);
-#endif
+    if (extensions.testFlag(QJSEngine::TranslationExtension)) {
+    #ifndef QT_NO_TRANSLATION
+        globalObject->defineDefaultProperty(QStringLiteral("qsTranslate"), QV4::GlobalExtensions::method_qsTranslate);
+        globalObject->defineDefaultProperty(QStringLiteral("QT_TRANSLATE_NOOP"), QV4::GlobalExtensions::method_qsTranslateNoOp);
+        globalObject->defineDefaultProperty(QStringLiteral("qsTr"), QV4::GlobalExtensions::method_qsTr);
+        globalObject->defineDefaultProperty(QStringLiteral("QT_TR_NOOP"), QV4::GlobalExtensions::method_qsTrNoOp);
+        globalObject->defineDefaultProperty(QStringLiteral("qsTrId"), QV4::GlobalExtensions::method_qsTrId);
+        globalObject->defineDefaultProperty(QStringLiteral("QT_TRID_NOOP"), QV4::GlobalExtensions::method_qsTrIdNoOp);
+
+        // string prototype extension
+        scope.engine->stringPrototype()->defineDefaultProperty(QStringLiteral("arg"), QV4::GlobalExtensions::method_string_arg);
+    #endif
+    }
 
-    globalObject->defineDefaultProperty(QStringLiteral("print"), ConsoleObject::method_log);
-    globalObject->defineDefaultProperty(QStringLiteral("gc"), method_gc);
+    if (extensions.testFlag(QJSEngine::ConsoleExtension)) {
+        globalObject->defineDefaultProperty(QStringLiteral("print"), QV4::ConsoleObject::method_log);
 
-    ScopedObject console(scope, v4->memoryManager->allocObject<QV4::ConsoleObject>());
-    globalObject->defineDefaultProperty(QStringLiteral("console"), console);
 
-    ScopedObject qt(scope, v4->memoryManager->allocObject<QV4::QtObject>(qmlEngine));
-    globalObject->defineDefaultProperty(QStringLiteral("Qt"), qt);
+        QV4::ScopedObject console(scope, globalObject->engine()->memoryManager->allocObject<QV4::ConsoleObject>());
+        globalObject->defineDefaultProperty(QStringLiteral("console"), console);
+    }
 
-    // string prototype extension
-    v4->stringPrototype()->defineDefaultProperty(QStringLiteral("arg"), method_string_arg);
+    if (extensions.testFlag(QJSEngine::GarbageCollectionExtension)) {
+        globalObject->defineDefaultProperty(QStringLiteral("gc"), QV4::GlobalExtensions::method_gc);
+    }
 }
 
 
diff --git a/src/qml/qml/v8/qqmlbuiltinfunctions_p.h b/src/qml/qml/v8/qqmlbuiltinfunctions_p.h
index bb05376fc0..d373fb6ee6 100644
--- a/src/qml/qml/v8/qqmlbuiltinfunctions_p.h
+++ b/src/qml/qml/v8/qqmlbuiltinfunctions_p.h
@@ -47,6 +47,7 @@
 
 #include <private/qqmlglobal_p.h>
 #include <private/qv4functionobject_p.h>
+#include <private/qjsengine_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -142,7 +143,7 @@ struct ConsoleObject : Object
 };
 
 struct GlobalExtensions {
-    static void init(QQmlEngine *qmlEngine, Object *globalObject);
+    static void init(Object *globalObject, QJSEngine::Extensions extensions);
 
 #ifndef QT_NO_TRANSLATION
     static ReturnedValue method_qsTranslate(CallContext *ctx);
diff --git a/src/qml/qml/v8/qv8engine.cpp b/src/qml/qml/v8/qv8engine.cpp
index effc37a0eb..dae932e705 100644
--- a/src/qml/qml/v8/qv8engine.cpp
+++ b/src/qml/qml/v8/qv8engine.cpp
@@ -174,7 +174,10 @@ const QSet<QString> &QV8Engine::illegalNames() const
 void QV8Engine::initializeGlobal()
 {
     QV4::Scope scope(m_v4Engine);
-    QV4::GlobalExtensions::init(m_engine, m_v4Engine->globalObject);
+    QV4::GlobalExtensions::init(m_v4Engine->globalObject, QJSEngine::AllExtensions);
+
+    QV4::ScopedObject qt(scope, m_v4Engine->memoryManager->allocObject<QV4::QtObject>(m_engine));
+    m_v4Engine->globalObject->defineDefaultProperty(QStringLiteral("Qt"), qt);
 
     QQmlLocale::registerStringLocaleCompare(m_v4Engine);
     QQmlDateExtension::registerExtension(m_v4Engine);