Implement debugtranslationservice

- moves the language feature from the preview service
  to an own debugtranslationservice
- with the help of a proxytranslator the service gets all
  translate requests

Change-Id: Ic26677bb1706abbea2db23e6aafe7a3f00648962
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>

12 files changed, 677 insertions, 105 deletions

diff --git a/src/plugins/qmltooling/qmldbg_messages/qdebugmessageservice.h b/src/plugins/qmltooling/qmldbg_messages/qdebugmessageservice.h
index 24fd27514b..eb78afe900 100644
--- a/src/plugins/qmltooling/qmldbg_messages/qdebugmessageservice.h
+++ b/src/plugins/qmltooling/qmldbg_messages/qdebugmessageservice.h
@@ -59,8 +59,6 @@
 
 QT_BEGIN_NAMESPACE
 
-class QDebugMessageServicePrivate;
-
 class QDebugMessageServiceImpl : public QDebugMessageService
 {
     Q_OBJECT
diff --git a/src/plugins/qmltooling/qmldbg_preview/CMakeLists.txt b/src/plugins/qmltooling/qmldbg_preview/CMakeLists.txt
index 2874580a03..2b3611b90d 100644
--- a/src/plugins/qmltooling/qmldbg_preview/CMakeLists.txt
+++ b/src/plugins/qmltooling/qmldbg_preview/CMakeLists.txt
@@ -8,7 +8,6 @@ qt_internal_add_plugin(QQmlPreviewServiceFactory
     OUTPUT_NAME qmldbg_preview
     TYPE qmltooling
     SOURCES
-        qqmldebugtranslationservice.cpp qqmldebugtranslationservice.h
         qqmlpreviewblacklist.cpp qqmlpreviewblacklist.h
         qqmlpreviewfileengine.cpp qqmlpreviewfileengine.h
         qqmlpreviewfileloader.cpp qqmlpreviewfileloader.h
@@ -29,3 +28,11 @@ qt_internal_add_plugin(QQmlPreviewServiceFactory
 
 #### Keys ignored in scope 1:.:.:qmldbg_preview.pro:<TRUE>:
 # OTHER_FILES = "$$PWD/qqmlpreviewservice.json"
+
+qt_internal_extend_target(QQmlPreviewServiceFactory CONDITION QT_FEATURE_translation
+    SOURCES
+        proxytranslator.cpp proxytranslator.h
+        qqmldebugtranslationservice.cpp qqmldebugtranslationservice.h
+    PUBLIC_LIBRARIES
+        Qt::Gui
+)
diff --git a/src/plugins/qmltooling/qmldbg_preview/proxytranslator.cpp b/src/plugins/qmltooling/qmldbg_preview/proxytranslator.cpp
new file mode 100644
index 0000000000..7f5227296a
--- /dev/null
+++ b/src/plugins/qmltooling/qmldbg_preview/proxytranslator.cpp
@@ -0,0 +1,156 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "proxytranslator.h"
+
+#include <QtCore/qlibraryinfo.h>
+
+QT_BEGIN_NAMESPACE
+
+void ProxyTranslator::addEngine(QQmlEngine *engine)
+{
+    m_engines.append(engine);
+}
+
+void ProxyTranslator::removeEngine(QQmlEngine *engine)
+{
+    m_engines.removeOne(engine);
+}
+
+bool ProxyTranslator::hasTranslation(const TranslationBindingInformation &translationBindingInformation) const
+{
+    resetTranslationFound();
+    translationFromInformation(translationBindingInformation);
+    return translationFound();
+}
+
+QString ProxyTranslator::translationFromInformation(const TranslationBindingInformation &translationBindingInformation)
+{
+    return translationBindingInformation.compilationUnit->bindingValueAsString(
+        translationBindingInformation.compiledBinding);
+}
+
+
+QString ProxyTranslator::originStringFromInformation(const TranslationBindingInformation &translationBindingInformation)
+{
+    return translationBindingInformation.compilationUnit->stringAt(
+        translationBindingInformation.compiledBinding->stringIndex);
+}
+
+QQmlSourceLocation ProxyTranslator::sourceLocationFromInformation(const TranslationBindingInformation &translationBindingInformation)
+{
+    return QQmlSourceLocation(translationBindingInformation.compilationUnit->fileName(),
+                              translationBindingInformation.compiledBinding->valueLocation.line,
+                              translationBindingInformation.compiledBinding->valueLocation.column);
+}
+
+
+void ProxyTranslator::setLanguage(const QUrl &context, const QLocale &locale)
+{
+    m_enable = true;
+    m_currentUILanguages = locale.uiLanguages().join(QLatin1Char(' '));
+
+    m_qtTranslator.reset(new QTranslator());
+    if (!m_qtTranslator->load(locale, QLatin1String("qt"), QLatin1String("_"),
+                              QLibraryInfo::path(QLibraryInfo::TranslationsPath))) {
+        m_qtTranslator.reset();
+    }
+
+    m_qmlTranslator.reset(new QTranslator(this));
+    if (!m_qmlTranslator->load(locale, QLatin1String("qml"), QLatin1String("_"),
+                              context.toLocalFile() + QLatin1String("/i18n"))) {
+        m_qmlTranslator.reset();
+    }
+
+    // unfortunately setUiLanguage set new translators, so do this first
+    for (QQmlEngine *engine : qAsConst(m_engines))
+        engine->setUiLanguage(locale.bcp47Name());
+
+    // make sure proxy translator is the first used translator
+    QCoreApplication::removeTranslator(this);
+    QCoreApplication::installTranslator(this);
+
+    for (QQmlEngine *engine : qAsConst(m_engines)) {
+        // have two retranslate runs to get elided warning even the same language was set
+        m_enable = false;
+        engine->retranslate();
+        m_enable = true;
+        engine->retranslate();
+    }
+    emit languageChanged(locale);
+}
+
+QString ProxyTranslator::translate(const char *context, const char *sourceText, const char *disambiguation, int n) const
+{
+    if (!m_enable)
+        return {};
+    QString result;
+    if (result.isNull() && m_qtTranslator)
+        result = m_qtTranslator->translate(context, sourceText, disambiguation, n);
+    if (result.isNull() && m_qmlTranslator)
+        result = m_qmlTranslator->translate(context, sourceText, disambiguation, n);
+    m_translationFound = !result.isNull();
+    return result;
+}
+
+void ProxyTranslator::resetTranslationFound() const
+{
+    m_translationFound = false;
+}
+
+bool ProxyTranslator::translationFound() const
+{
+    return m_translationFound;
+}
+
+bool ProxyTranslator::isEmpty() const
+{
+    if (m_qtTranslator && m_qtTranslator->isEmpty())
+        return false;
+    if (m_qmlTranslator && m_qmlTranslator->isEmpty())
+        return false;
+    return true;
+}
+
+QString ProxyTranslator::currentUILanguages() const
+{
+    return m_currentUILanguages;
+}
+
+QT_END_NAMESPACE
diff --git a/src/plugins/qmltooling/qmldbg_preview/proxytranslator.h b/src/plugins/qmltooling/qmldbg_preview/proxytranslator.h
new file mode 100644
index 0000000000..b53f81105a
--- /dev/null
+++ b/src/plugins/qmltooling/qmldbg_preview/proxytranslator.h
@@ -0,0 +1,97 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef PROXYTRANSLATOR_H
+#define PROXYTRANSLATOR_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <private/qqmldebugserviceinterfaces_p.h>
+#include <private/qqmlglobal_p.h>
+
+#include <QtCore/qstring.h>
+#include <QtCore/qurl.h>
+#include <QtCore/qtranslator.h>
+
+#include <memory>
+
+QT_BEGIN_NAMESPACE
+
+class ProxyTranslator : public QTranslator
+{
+    Q_OBJECT
+public:
+    QString translate(const char *context, const char *sourceText, const char *disambiguation, int n) const override;
+    bool isEmpty() const override;
+
+    QString currentUILanguages() const;
+    void setLanguage(const QUrl &context, const QLocale &locale);
+    void addEngine(QQmlEngine *engine);
+    void removeEngine(QQmlEngine *engine);
+
+    bool hasTranslation(const TranslationBindingInformation &translationBindingInformation) const;
+    static QString translationFromInformation(const TranslationBindingInformation &translationBindingInformation);
+    static QString originStringFromInformation(const TranslationBindingInformation &translationBindingInformation);
+    static QQmlSourceLocation sourceLocationFromInformation(const TranslationBindingInformation &translationBindingInformation);
+signals:
+    void languageChanged(const QLocale &locale);
+
+private:
+    void resetTranslationFound() const;
+    bool translationFound() const;
+    QList<QQmlEngine *> m_engines;
+    std::unique_ptr<QTranslator> m_qtTranslator;
+    std::unique_ptr<QTranslator> m_qmlTranslator;
+    bool m_enable = false;
+    QString m_currentUILanguages;
+    mutable bool m_translationFound = false;
+};
+
+QT_END_NAMESPACE
+
+#endif // PROXYTRANSLATOR_H
diff --git a/src/plugins/qmltooling/qmldbg_preview/qqmldebugtranslationservice.cpp b/src/plugins/qmltooling/qmldbg_preview/qqmldebugtranslationservice.cpp
index 785fca6427..4f9d76432f 100644
--- a/src/plugins/qmltooling/qmldbg_preview/qqmldebugtranslationservice.cpp
+++ b/src/plugins/qmltooling/qmldbg_preview/qqmldebugtranslationservice.cpp
@@ -38,33 +38,406 @@
 ****************************************************************************/
 
 #include "qqmldebugtranslationservice.h"
+#include "proxytranslator.h"
+
+#include <QtCore/qtranslator.h>
+#include <QtCore/qdebug.h>
+#include <QtCore/qlibraryinfo.h>
+#include <QtCore/qdir.h>
+#include <QtCore/qfile.h>
+#include <QtCore/qtimer.h>
+#include <QtCore/qhash.h>
+#include <QtCore/qpointer.h>
+
+#include <private/qqmldebugtranslationprotocol_p.h>
+#include <private/qqmldebugconnector_p.h>
+#include <private/qversionedpacket_p.h>
+
+#include <private/qqmlbinding_p.h>
+#include <private/qqmlbinding_p.h>
+#include <private/qquickstategroup_p.h>
+#include <private/qquickitem_p.h>
+#include <private/qdebug_p.h>
+
+#include <QtQuick/qquickitem.h>
+
+#include <qquickview.h>
 
 QT_BEGIN_NAMESPACE
 
-QQmlDebugTranslationServiceImpl::QQmlDebugTranslationServiceImpl(QObject *parent) :
-    QQmlDebugTranslationService(1, parent)
+Q_LOGGING_CATEGORY(lcQmlTooling, "qt.quick.qmltooling.debugtranslation")
+
+using namespace QQmlDebugTranslation;
+
+QDebug operator<<(QDebug debug, const TranslationBindingInformation &translationBindingInformation)
+{
+    QQmlError error;
+    error.setUrl(translationBindingInformation.compilationUnit->url());
+    error.setLine(translationBindingInformation.compiledBinding->valueLocation.line);
+    error.setColumn(translationBindingInformation.compiledBinding->valueLocation.column);
+    error.setDescription(
+        QString(QLatin1String(
+            "QDebug translation binding"
+        )));
+    return debug << qPrintable(error.toString());
+}
+
+class QQmlDebugTranslationServicePrivate : public QObject
+{
+    Q_OBJECT
+public:
+    QQmlDebugTranslationServicePrivate(QQmlDebugTranslationServiceImpl *parent)
+        : q(parent)
+        , proxyTranslator(new ProxyTranslator)
+    {
+        connect(&translatableTextOccurrenceTimer, &QTimer::timeout,
+            this, &QQmlDebugTranslationServicePrivate::sendTranslatableTextOccurrences);
+    }
+
+    void setState(const QString &stateName)
+    {
+        if (currentQuickView) {
+            QQuickItem *rootItem = currentQuickView->rootObject();
+            QQuickStateGroup *stateGroup = QQuickItemPrivate::get(rootItem)->_states();
+            if (stateGroup->findState(stateName)) {
+                connect(stateGroup, &QQuickStateGroup::stateChanged,
+                        this, &QQmlDebugTranslationServicePrivate::sendStateChanged,
+                        Qt::ConnectionType(Qt::QueuedConnection | Qt::UniqueConnection));
+                stateGroup->setState(stateName);
+            }
+            else
+                qWarning() << QString("Could not switch the state to %1").arg(stateName);
+        }
+    }
+
+    void sendStateChanged()
+    {
+        QString stateName;
+        if (QQuickStateGroup *stateGroup = qobject_cast<QQuickStateGroup*>(sender()))
+            stateName = stateGroup->state();
+        QVersionedPacket<QQmlDebugConnector> packet;
+        packet << Reply::StateChanged << stateName;
+        emit q->messageToClient(q->name(), packet.data());
+    }
+
+    void sendStateList()
+    {
+        QVersionedPacket<QQmlDebugConnector> packet;
+        packet << Reply::StateList;
+
+        QQuickItem *rootItem = currentQuickView->rootObject();
+        QQuickStateGroup *stateGroup = QQuickItemPrivate::get(rootItem)->_states();
+
+        QList<QQuickState *> states = stateGroup->states();
+        QVector<QmlState> qmlStates;
+
+        for (QQuickState *state : states) {
+            QmlState qmlState;
+            qmlState.name = state->name();
+            qmlStates.append(qmlState);
+        }
+
+        packet << qmlStates;
+        emit q->messageToClient(q->name(), packet.data());
+    }
+
+    void setWatchTextElides(bool s)
+    {
+        // TODO: for disabling we need to keep track which one were enabled
+        if (s == false)
+            qWarning() << "disable WatchTextElides is not implemented";
+        watchTextElides = s;
+        for (auto &&information : qAsConst(objectTranslationBindingMultiMap)) {
+            QObject *scopeObject = information.scopeObject;
+            int elideIndex = scopeObject->metaObject()->indexOfProperty("elide");
+            if (elideIndex >= 0) {
+                auto elideProperty = scopeObject->metaObject()->property(elideIndex);
+                elideProperty.write(scopeObject, Qt::ElideRight);
+            }
+        }
+    }
+
+    void sendTranslatableTextOccurrences()
+    {
+
+        QVersionedPacket<QQmlDebugConnector> packet;
+        packet << Reply::TranslatableTextOccurrences;
+
+        QVector<QmlElement> qmlElements;
+
+        for (auto &&information : qAsConst(objectTranslationBindingMultiMap)) {
+
+            QObject *scopeObject = information.scopeObject;
+            auto compilationUnit = information.compilationUnit;
+            auto binding = information.compiledBinding;
+            auto metaObject = scopeObject->metaObject();
+
+            const QString propertyName = compilationUnit->stringAt(binding->propertyNameIndex);
+
+            int textIndex = metaObject->indexOfProperty(propertyName.toLatin1());
+            if (textIndex >= 0) {
+
+                QmlElement qmlElement;
+
+                qmlElement.codeMarker = codeMarker(information);
+
+                auto textProperty = scopeObject->metaObject()->property(textIndex);
+                qmlElement.propertyName = textProperty.name();
+                qmlElement.translationId = compilationUnit->stringAt(
+                        compilationUnit->data->translations()[binding->value.translationDataIndex]
+                                .stringIndex);
+                qmlElement.translatedText = textProperty.read(scopeObject).toString();
+                qmlElement.elementId = qmlContext(scopeObject)->nameForObject(scopeObject);
+
+                QFont font = scopeObject->property("font").value<QFont>();
+                qmlElement.fontFamily = font.family();
+                qmlElement.fontPointSize = font.pointSize();
+                qmlElement.fontPixelSize = font.pixelSize();
+                qmlElement.fontStyleName = font.styleName();
+                qmlElement.horizontalAlignment =
+                        scopeObject->property("horizontalAlignment").toInt();
+                qmlElement.verticalAlignment = scopeObject->property("verticalAlignment").toInt();
+
+                QQmlType qmlType = QQmlMetaType::qmlType(metaObject);
+                qmlElement.elementType = qmlType.qmlTypeName() + "/" + qmlType.typeName();
+                qmlElements.append(qmlElement);
+
+            } else {
+                QString warningMessage = "(QQmlDebugTranslationService can not resolve %1 - %2:"\
+                                         " this should never happen)";
+                const QString id = qmlContext(scopeObject)->nameForObject(scopeObject);
+                qWarning().noquote() << warningMessage.arg(id, propertyName);
+            }
+        }
+        std::sort(qmlElements.begin(), qmlElements.end(), [](const auto &l1, const auto &l2){
+            return l1.codeMarker < l2.codeMarker;
+        });
+
+        packet << qmlElements;
+        emit q->messageToClient(q->name(), packet.data());
+    }
+
+    void sendLanguageChanged()
+    {
+        QVersionedPacket<QQmlDebugConnector> packet;
+        packet << Reply::LanguageChanged;
+        emit q->messageToClient(q->name(), packet.data());
+    }
+
+    void sendMissingTranslations()
+    {
+        QVersionedPacket<QQmlDebugConnector> packet;
+        packet << Reply::MissingTranslations;
+
+        QVector<TranslationIssue> issues;
+        for (auto &&information : qAsConst(objectTranslationBindingMultiMap)) {
+            if (!proxyTranslator->hasTranslation(information)) {
+                TranslationIssue issue;
+                issue.type = TranslationIssue::Type::Missing;
+                issue.codeMarker = codeMarker(information);
+                issue.language = proxyTranslator->currentUILanguages();
+                issues.append(issue);
+            }
+        }
+        std::sort(issues.begin(), issues.end(), [](const auto &l1, const auto &l2){
+            return l1.codeMarker < l2.codeMarker;
+        });
+        packet << issues;
+        emit q->messageToClient(q->name(), packet.data());
+    }
+
+    void sendElidedTextWarning(const TranslationBindingInformation &information)
+    {
+        QVersionedPacket<QQmlDebugConnector> packet;
+        packet << Reply::TextElided;
+
+        TranslationIssue issue;
+        issue.type = TranslationIssue::Type::Elided;
+        issue.codeMarker = codeMarker(information);
+        issue.language = proxyTranslator->currentUILanguages();
+
+        packet << issue;
+        emit q->messageToClient(q->name(), packet.data());
+    }
+
+    QQmlDebugTranslationServiceImpl *q;
+
+    bool watchTextElides = false;
+    QMultiMap<QObject*, TranslationBindingInformation> objectTranslationBindingMultiMap;
+    QHash<QObject*, QVector<QMetaObject::Connection>> elideConnections;
+    ProxyTranslator *proxyTranslator;
+
+    bool enableWatchTranslations = false;
+    QTimer translatableTextOccurrenceTimer;
+    QList<QPointer<QQuickItem>> translatableTextOccurrences;
+
+    QPointer<QQuickView> currentQuickView;
+private:
+    CodeMarker codeMarker(const TranslationBindingInformation &information)
+    {
+        CodeMarker c;
+        c.url = information.compilationUnit->url();
+        c.line = information.compiledBinding->valueLocation.line;
+        c.column = information.compiledBinding->valueLocation.column;
+        return c;
+    }
+};
+
+QQmlDebugTranslationServiceImpl::QQmlDebugTranslationServiceImpl(QObject *parent)
+    : QQmlDebugTranslationService(1, parent)
 {
+    d = new QQmlDebugTranslationServicePrivate(this);
+
+    connect(this, &QQmlDebugTranslationServiceImpl::watchTextElides,
+            d, &QQmlDebugTranslationServicePrivate::setWatchTextElides,
+            Qt::QueuedConnection);
+
+    connect(this, &QQmlDebugTranslationServiceImpl::language,
+            d->proxyTranslator, &ProxyTranslator::setLanguage,
+            Qt::QueuedConnection);
+
+    connect(this, &QQmlDebugTranslationServiceImpl::state,
+            d, &QQmlDebugTranslationServicePrivate::setState,
+            Qt::QueuedConnection);
+
+    connect(this, &QQmlDebugTranslationServiceImpl::stateList, d,
+            &QQmlDebugTranslationServicePrivate::sendStateList, Qt::QueuedConnection);
+
+    connect(d->proxyTranslator, &ProxyTranslator::languageChanged,
+            d, &QQmlDebugTranslationServicePrivate::sendLanguageChanged);
+
+    connect(this, &QQmlDebugTranslationServiceImpl::missingTranslations,
+            d, &QQmlDebugTranslationServicePrivate::sendMissingTranslations);
+
+    connect(this, &QQmlDebugTranslationServiceImpl::sendTranslatableTextOccurrences,
+            d, &QQmlDebugTranslationServicePrivate::sendTranslatableTextOccurrences,
+            Qt::QueuedConnection);
+}
+
+QQmlDebugTranslationServiceImpl::~QQmlDebugTranslationServiceImpl()
+{
+    delete d->proxyTranslator;
+    d->proxyTranslator = {};
 }
 
 void QQmlDebugTranslationServiceImpl::messageReceived(const QByteArray &message)
 {
-    Q_UNUSED(message);
+    QVersionedPacket<QQmlDebugConnector> packet(message);
+    QQmlDebugTranslation::Request command;
+
+    packet >> command;
+    switch (command) {
+        case QQmlDebugTranslation::Request::ChangeLanguage: {
+            QUrl context;
+            QString locale;
+            packet >> context >> locale;
+            emit language(context, QLocale(locale));
+            break;
+        }
+        case QQmlDebugTranslation::Request::ChangeState: {
+            QString stateName;
+            packet >> stateName;
+            emit state(stateName);
+            break;
+        }
+        case QQmlDebugTranslation::Request::StateList: {
+            emit stateList();
+            break;
+        }
+        case QQmlDebugTranslation::Request::MissingTranslations: {
+            emit missingTranslations();
+            break;
+        }
+        case QQmlDebugTranslation::Request::TranslatableTextOccurrences: {
+            emit sendTranslatableTextOccurrences();
+            break;
+        }
+        case QQmlDebugTranslation::Request::WatchTextElides: {
+            emit watchTextElides(true);
+            break;
+        }
+        case QQmlDebugTranslation::Request::DisableWatchTextElides: {
+            emit watchTextElides(false);
+            break;
+        }
+        default: {
+            qWarning() << "DebugTranslationService: received unknown command: " << static_cast<int>(command);
+            break;
+        }
+    } // switch (command)
+}
+
+void QQmlDebugTranslationServiceImpl::engineAboutToBeAdded(QJSEngine *engine)
+{
+    if (QQmlEngine *qmlEngine = qobject_cast<QQmlEngine *>(engine))
+        d->proxyTranslator->addEngine(qmlEngine);
+
+    if (engine->parent())
+        d->currentQuickView = qobject_cast<QQuickView*>(engine->parent());
+
+    emit attachedToEngine(engine);
+}
+
+void QQmlDebugTranslationServiceImpl::engineAboutToBeRemoved(QJSEngine *engine)
+{
+    if (QQmlEngine *qmlEngine = qobject_cast<QQmlEngine *>(engine))
+        d->proxyTranslator->removeEngine(qmlEngine);
+    emit detachedFromEngine(engine);
 }
 
 QString QQmlDebugTranslationServiceImpl::foundElidedText(QObject *textObject, const QString &layoutText, const QString &elideText)
 {
-    Q_UNUSED(textObject);
-    Q_UNUSED(layoutText);
-    return elideText;
+    Q_UNUSED(layoutText)
+    QString elidedTextResult = elideText;
+    // do the check only for text objects which have translation bindings
+    auto it = d->objectTranslationBindingMultiMap.find(textObject);
+    if (it != d->objectTranslationBindingMultiMap.end()) {
+        if (QQuickItem* quickItem = qobject_cast<QQuickItem*>(textObject)) {
+            //const QColor originColor = quickItem->color();
+            const TranslationBindingInformation information = d->objectTranslationBindingMultiMap.value(quickItem);
+            if (d->watchTextElides && d->proxyTranslator->hasTranslation(information)) {
+                d->sendElidedTextWarning(information);
+            }
+            if (!d->elideConnections.contains(quickItem)) {
+                // add "refresh" elide state connections which remove themself
+                auto clearElideInformation = [=]() {
+                    //quickItem->setColor(originColor);
+                    for (QMetaObject::Connection connection : d->elideConnections.value(quickItem))
+                        quickItem->disconnect(connection);
+                    d->elideConnections.remove(quickItem);
+                };
+
+                auto connectWithChangedWidthThreshold = [=] () {
+                    return connect(quickItem, &QQuickItem::widthChanged, [=]() {
+                        if (quickItem->implicitWidth() <= quickItem->width())
+                            clearElideInformation();
+                    });
+                };
+                auto connectImplicitWidthChangedThreshold = [=] () {
+                    return connect(quickItem, &QQuickItem::implicitWidthChanged, [=]() {
+                        if (quickItem->implicitWidth() <= quickItem->width())
+                            clearElideInformation();
+                    });
+                };
+
+                d->elideConnections.insert(quickItem,
+                                          {connectWithChangedWidthThreshold(),
+                                           connectImplicitWidthChangedThreshold()});
+            }
+        }
+    }
+    return elidedTextResult;
 }
 
-void QQmlDebugTranslationServiceImpl::foundTranslationBinding(
-        QQmlTranslationBinding *binding, QObject *scopeObject,
-        const QQmlRefPointer<QQmlContextData> &contextData)
+void QQmlDebugTranslationServiceImpl::foundTranslationBinding(const TranslationBindingInformation &translationBindingInformation)
 {
-    Q_UNUSED(binding);
-    Q_UNUSED(scopeObject);
-    Q_UNUSED(contextData);
+    QObject *scopeObject = translationBindingInformation.scopeObject;
+    connect(scopeObject, &QObject::destroyed, [this, scopeObject] () {
+        this->d->objectTranslationBindingMultiMap.remove(scopeObject);
+    });
+    d->objectTranslationBindingMultiMap.insert(scopeObject, translationBindingInformation);
 }
 
 QT_END_NAMESPACE
+
+#include <qqmldebugtranslationservice.moc>
diff --git a/src/plugins/qmltooling/qmldbg_preview/qqmldebugtranslationservice.h b/src/plugins/qmltooling/qmldbg_preview/qqmldebugtranslationservice.h
index 802f21ecce..72e70f4b29 100644
--- a/src/plugins/qmltooling/qmldbg_preview/qqmldebugtranslationservice.h
+++ b/src/plugins/qmltooling/qmldbg_preview/qqmldebugtranslationservice.h
@@ -36,9 +36,8 @@
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
-
-#ifndef QDEBUGMESSAGESERVICE_H
-#define QDEBUGMESSAGESERVICE_H
+#ifndef QQMLDEBUGTRANSLATIONSERVICE_H
+#define QQMLDEBUGTRANSLATIONSERVICE_H
 
 //
 //  W A R N I N G
@@ -50,39 +49,44 @@
 //
 // We mean it.
 //
+#include <QtCore/qglobal.h>
 
 #include <private/qqmldebugserviceinterfaces_p.h>
 
-#include <QtCore/qlogging.h>
-#include <QtCore/qmutex.h>
-#include <QtCore/qelapsedtimer.h>
+#include <QtCore/qbytearray.h>
+#include <QtCore/qstring.h>
+#include <QtCore/qurl.h>
+#include <QtGui/qcolor.h>
 
 QT_BEGIN_NAMESPACE
 
 class QQmlDebugTranslationServicePrivate;
-
 class QQmlDebugTranslationServiceImpl : public QQmlDebugTranslationService
 {
     Q_OBJECT
 public:
-    //needs to be in sync with QQmlDebugTranslationClient in qqmldebugtranslationclient_p.h
-    enum Command {
-        ChangeLanguage,
-        ChangeWarningColor,
-        ChangeElidedTextWarningString,
-        SetDebugTranslationServiceLogFile,
-        EnableElidedTextWarning,
-        DisableElidedTextWarning,
-        TestAllLanguages
-    };
     QQmlDebugTranslationServiceImpl(QObject *parent = 0);
+    ~QQmlDebugTranslationServiceImpl();
 
     QString foundElidedText(QObject *textObject, const QString &layoutText, const QString &elideText) override;
-    void foundTranslationBinding(QQmlTranslationBinding *binding, QObject *scopeObject,
-                                 const QQmlRefPointer<QQmlContextData> &contextData) override;
+    void foundTranslationBinding(const TranslationBindingInformation &translationBindingInformation) override;
+
     void messageReceived(const QByteArray &message) override;
+    void engineAboutToBeAdded(QJSEngine *engine) override;
+    void engineAboutToBeRemoved(QJSEngine *engine) override;
+
+signals:
+    void language(const QUrl &context, const QLocale &locale);
+    void state(const QString &stateName);
+    void stateList();
+    void watchTextElides(bool);
+    void missingTranslations();
+    void sendTranslatableTextOccurrences();
+
+private:
+    QQmlDebugTranslationServicePrivate *d;
 };
 
 QT_END_NAMESPACE
 
-#endif // QDEBUGMESSAGESERVICE_H
+#endif // QQMLDEBUGTRANSLATIONSERVICE_H
diff --git a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewhandler.cpp b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewhandler.cpp
index c9317edb44..b8453128d8 100644
--- a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewhandler.cpp
+++ b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewhandler.cpp
@@ -42,7 +42,6 @@
 #include <QtCore/qtimer.h>
 #include <QtCore/qsettings.h>
 #include <QtCore/qlibraryinfo.h>
-#include <QtCore/qtranslator.h>
 
 #include <QtGui/qwindow.h>
 #include <QtGui/qguiapplication.h>
@@ -93,9 +92,6 @@ QQmlPreviewHandler::QQmlPreviewHandler(QObject *parent) : QObject(parent)
 
 QQmlPreviewHandler::~QQmlPreviewHandler()
 {
-#if QT_CONFIG(translation)
-    removeTranslators();
-#endif
     clear();
 }
 
@@ -225,41 +221,6 @@ void QQmlPreviewHandler::doZoom()
     m_lastPosition.initLastSavedWindowPosition(m_currentWindow);
 }
 
-#if QT_CONFIG(translation)
-void QQmlPreviewHandler::removeTranslators()
-{
-    if (!m_qtTranslator.isNull()) {
-        QCoreApplication::removeTranslator(m_qtTranslator.get());
-        m_qtTranslator.reset();
-    }
-
-    if (m_qmlTranslator.isNull()) {
-        QCoreApplication::removeTranslator(m_qmlTranslator.get());
-        m_qmlTranslator.reset();
-    }
-}
-
-void QQmlPreviewHandler::language(const QUrl &context, const QLocale &locale)
-{
-    removeTranslators();
-
-    m_qtTranslator.reset(new QTranslator(this));
-    if (m_qtTranslator->load(locale, QLatin1String("qt"), QLatin1String("_"),
-                           QLibraryInfo::path(QLibraryInfo::TranslationsPath))) {
-        QCoreApplication::installTranslator(m_qtTranslator.get());
-    }
-
-    m_qmlTranslator.reset(new QTranslator(this));
-    if (m_qmlTranslator->load(locale, QLatin1String("qml"), QLatin1String("_"),
-                              context.toLocalFile() + QLatin1String("/i18n"))) {
-        QCoreApplication::installTranslator(m_qmlTranslator.get());
-    }
-
-    for (QQmlEngine *engine : qAsConst(m_engines))
-        engine->retranslate();
-}
-#endif
-
 void QQmlPreviewHandler::clear()
 {
     qDeleteAll(m_createdObjects);
diff --git a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewhandler.h b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewhandler.h
index 5dc867b763..b7ee8fa09b 100644
--- a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewhandler.h
+++ b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewhandler.h
@@ -66,7 +66,6 @@ class QQmlEngine;
 class QQuickItem;
 class QQmlPreviewUrlInterceptor;
 class QQuickWindow;
-class QTranslator;
 
 class QQmlPreviewHandler : public QObject
 {
@@ -81,9 +80,6 @@ public:
     void loadUrl(const QUrl &url);
     void rerun();
     void zoom(qreal newFactor);
-#if QT_CONFIG(translation)
-    void language(const QUrl &context, const QLocale &locale);
-#endif
 
     void clear();
 
@@ -117,9 +113,6 @@ private:
     void frameSwapped();
 
     void fpsTimerHit();
-#if QT_CONFIG(translation)
-    void removeTranslators();
-#endif
 
     QScopedPointer<QQuickItem> m_dummyItem;
     QList<QQmlEngine *> m_engines;
@@ -148,11 +141,6 @@ private:
 
     FrameTime m_rendering;
     FrameTime m_synchronizing;
-
-#if QT_CONFIG(translation)
-    QScopedPointer<QTranslator> m_qtTranslator;
-    QScopedPointer<QTranslator> m_qmlTranslator;
-#endif
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservice.cpp b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservice.cpp
index 2e6aaa5858..b6d6a7a220 100644
--- a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservice.cpp
+++ b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservice.cpp
@@ -64,9 +64,6 @@ QQmlPreviewServiceImpl::QQmlPreviewServiceImpl(QObject *parent) :
     connect(this, &QQmlPreviewServiceImpl::load, &m_handler, &QQmlPreviewHandler::loadUrl);
     connect(this, &QQmlPreviewServiceImpl::rerun, &m_handler, &QQmlPreviewHandler::rerun);
     connect(this, &QQmlPreviewServiceImpl::zoom, &m_handler, &QQmlPreviewHandler::zoom);
-#if QT_CONFIG(translation)
-    connect(this, &QQmlPreviewServiceImpl::language, &m_handler, &QQmlPreviewHandler::language);
-#endif
     connect(&m_handler, &QQmlPreviewHandler::error, this, &QQmlPreviewServiceImpl::forwardError,
             Qt::DirectConnection);
     connect(&m_handler, &QQmlPreviewHandler::fps, this, &QQmlPreviewServiceImpl::forwardFps,
@@ -137,16 +134,6 @@ void QQmlPreviewServiceImpl::messageReceived(const QByteArray &data)
         emit zoom(static_cast<qreal>(factor));
         break;
     }
-#if QT_CONFIG(translation)
-    case Language: {
-        QUrl context;
-        QString locale;
-        packet >> context >> locale;
-        emit language(context.isEmpty() ? m_currentUrl : context,
-                      locale.isEmpty() ? QLocale() : QLocale(locale));
-        break;
-    }
-#endif
     default:
         forwardError(QString::fromLatin1("Invalid command: %1").arg(command));
         break;
diff --git a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservice.h b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservice.h
index de50e6fc61..56deb7f092 100644
--- a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservice.h
+++ b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservice.h
@@ -73,8 +73,7 @@ public:
         Directory,
         ClearCache,
         Zoom,
-        Fps,
-        Language
+        Fps
     };
 
     static const QString s_key;
@@ -99,9 +98,6 @@ signals:
     void rerun();
     void clearCache();
     void zoom(qreal factor);
-#if QT_CONFIG(translation)
-    void language(const QUrl &context, const QLocale &locale);
-#endif
 
 private:
     QScopedPointer<QQmlPreviewFileEngineHandler> m_fileEngine;
diff --git a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservicefactory.cpp b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservicefactory.cpp
index 6ff9805bbe..23329dbcf2 100644
--- a/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservicefactory.cpp
+++ b/src/plugins/qmltooling/qmldbg_preview/qqmlpreviewservicefactory.cpp
@@ -39,7 +39,9 @@
 
 #include "qqmlpreviewservicefactory.h"
 #include "qqmlpreviewservice.h"
+#if QT_CONFIG(translation)
 #include "qqmldebugtranslationservice.h"
+#endif
 
 QT_BEGIN_NAMESPACE
 
@@ -47,9 +49,10 @@ QQmlDebugService *QQmlPreviewServiceFactory::create(const QString &key)
 {
     if (key == QQmlPreviewServiceImpl::s_key)
         return new QQmlPreviewServiceImpl(this);
+#if QT_CONFIG(translation)
     if (key == QQmlDebugTranslationServiceImpl::s_key)
         return new QQmlDebugTranslationServiceImpl(this);
-
+#endif
     return nullptr;
 }
 
diff --git a/src/plugins/qmltooling/qmldbg_server/qqmldebugserver.cpp b/src/plugins/qmltooling/qmldbg_server/qqmldebugserver.cpp
index 13d5292eb2..0e4c90f987 100644
--- a/src/plugins/qmltooling/qmldbg_server/qqmldebugserver.cpp
+++ b/src/plugins/qmltooling/qmldbg_server/qqmldebugserver.cpp
@@ -422,11 +422,13 @@ void QQmlDebugServerImpl::parseArguments()
             << tr("Sends qDebug() and similar messages over the QML debug\n"
                "\t\t  connection. QtCreator uses this for showing debug\n"
                "\t\t  messages in the debugger console.") << '\n'
+#if QT_CONFIG(translation)
             << '\n' << QQmlDebugTranslationService::s_key << "\t- "
             //: Please preserve the line breaks and formatting
             << tr("helps to see if a translated text\n"
                "\t\t  will result in an elided text\n"
                "\t\t  in QML elements.") << '\n'
+#endif //QT_CONFIG(translation)
            << tr("Other services offered by qmltooling plugins that implement "
                  "QQmlDebugServiceFactory and which can be found in the standard plugin "
                  "paths will also be available and can be specified. If no \"services\" "