DialogButtonBox: fix standard buttons not being translated

When calling QQmlEngine::retranslate() after component completion,
buttons in a DialogButtonBox were not being retranslated.

For now the only way to be notified of language change events
is by installing an event filter on the application, but in
the future we can use the solution to QTBUG-78141 instead.

Change-Id: Ibc435c3829945489adcbaa8a813013fe735a9c38
Fixes: QTBUG-75085
Reviewed-by: Andy Shaw <andy.shaw@qt.io>

6 files changed, 247 insertions, 1 deletions

diff --git a/src/quicktemplates2/qquickdialogbuttonbox.cpp b/src/quicktemplates2/qquickdialogbuttonbox.cpp
index 91fb41f2..10d80778 100644
--- a/src/quicktemplates2/qquickdialogbuttonbox.cpp
+++ b/src/quicktemplates2/qquickdialogbuttonbox.cpp
@@ -430,7 +430,8 @@ void QQuickDialogButtonBoxPrivate::removeStandardButtons()
     while (i >= 0) {
         QQuickAbstractButton *button = qobject_cast<QQuickAbstractButton *>(q->itemAt(i));
         if (button) {
-            QQuickDialogButtonBoxAttached *attached = qobject_cast<QQuickDialogButtonBoxAttached *>(qmlAttachedPropertiesObject<QQuickDialogButtonBox>(button, false));
+            QQuickDialogButtonBoxAttached *attached = qobject_cast<QQuickDialogButtonBoxAttached *>(
+                qmlAttachedPropertiesObject<QQuickDialogButtonBox>(button, false));
             if (attached) {
                 QQuickDialogButtonBoxAttachedPrivate *p = QQuickDialogButtonBoxAttachedPrivate::get(attached);
                 if (p->standardButton != QPlatformDialogHelper::NoButton) {
@@ -443,6 +444,24 @@ void QQuickDialogButtonBoxPrivate::removeStandardButtons()
     }
 }
 
+void QQuickDialogButtonBoxPrivate::updateLanguage()
+{
+    Q_Q(QQuickDialogButtonBox);
+    int i = q->count() - 1;
+    while (i >= 0) {
+        QQuickAbstractButton *button = qobject_cast<QQuickAbstractButton *>(itemAt(i));
+        if (button) {
+            QQuickDialogButtonBoxAttached *attached = qobject_cast<QQuickDialogButtonBoxAttached *>(
+                qmlAttachedPropertiesObject<QQuickDialogButtonBox>(button, true));
+            const auto boxAttachedPrivate = QQuickDialogButtonBoxAttachedPrivate::get(attached);
+            const QPlatformDialogHelper::StandardButton standardButton = boxAttachedPrivate->standardButton;
+            const QString buttonText = QGuiApplicationPrivate::platformTheme()->standardButtonText(standardButton);
+            button->setText(QPlatformTheme::removeMnemonics(buttonText));
+        }
+        --i;
+    }
+}
+
 QQuickDialogButtonBox::QQuickDialogButtonBox(QQuickItem *parent)
     : QQuickContainer(*(new QQuickDialogButtonBoxPrivate), parent)
 {
@@ -684,11 +703,34 @@ void QQuickDialogButtonBox::updatePolish()
     d->updateLayout();
 }
 
+class LanguageEventFilter : public QObject
+{
+public:
+    LanguageEventFilter(QQuickDialogButtonBoxPrivate *box)
+        : QObject(box->q_ptr)
+        , boxPrivate(box)
+    {
+    }
+
+protected:
+    bool eventFilter(QObject *, QEvent *event)
+    {
+        if (event->type() == QEvent::LanguageChange)
+            boxPrivate->updateLanguage();
+        return false;
+    }
+
+private:
+    QQuickDialogButtonBoxPrivate *boxPrivate;
+};
+
 void QQuickDialogButtonBox::componentComplete()
 {
     Q_D(QQuickDialogButtonBox);
     QQuickContainer::componentComplete();
     d->updateLayout();
+    // TODO: use the solution in QTBUG-78141 instead, when it's implemented.
+    qApp->installEventFilter(new LanguageEventFilter(d));
 }
 
 void QQuickDialogButtonBox::geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry)
diff --git a/src/quicktemplates2/qquickdialogbuttonbox_p_p.h b/src/quicktemplates2/qquickdialogbuttonbox_p_p.h
index 66386911..6f9c9033 100644
--- a/src/quicktemplates2/qquickdialogbuttonbox_p_p.h
+++ b/src/quicktemplates2/qquickdialogbuttonbox_p_p.h
@@ -78,6 +78,8 @@ public:
     QQuickAbstractButton *createStandardButton(QPlatformDialogHelper::StandardButton button);
     void removeStandardButtons();
 
+    void updateLanguage();
+
     Qt::Alignment alignment = 0;
     QQuickDialogButtonBox::Position position = QQuickDialogButtonBox::Footer;
     QPlatformDialogHelper::StandardButtons standardButtons = QPlatformDialogHelper::NoButton;
diff --git a/tests/auto/translation/data/dialogButtonBox.qml b/tests/auto/translation/data/dialogButtonBox.qml
new file mode 100644
index 00000000..03a3ae0e
--- /dev/null
+++ b/tests/auto/translation/data/dialogButtonBox.qml
@@ -0,0 +1,61 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.13
+import QtQuick.Controls 2.13
+
+Item {
+    property Dialog dialog: Dialog {
+        width: 300
+        height: 300
+        visible: true
+        standardButtons: DialogButtonBox.Save | DialogButtonBox.Discard
+    }
+}
diff --git a/tests/auto/translation/qtbase_fr.ts b/tests/auto/translation/qtbase_fr.ts
new file mode 100644
index 00000000..a2a05a07
--- /dev/null
+++ b/tests/auto/translation/qtbase_fr.ts
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE TS>
+<TS version="2.1" language="fr_FR">
+<context>
+    <name>QPlatformTheme</name>
+    <message>
+        <source>Save</source>
+        <translation>Enregistrer</translation>
+    </message>
+    <message>
+        <source>Discard</source>
+        <translation>Ne pas tenir compte</translation>
+    </message>
+</context>
+<context>
+    <name>QGnomeTheme</name>
+    <message>
+        <source>&amp;Save</source>
+        <translation>&amp;Enregistrer</translation>
+    </message>
+</context>
+</TS>
diff --git a/tests/auto/translation/translation.pro b/tests/auto/translation/translation.pro
new file mode 100644
index 00000000..d2d9d6ee
--- /dev/null
+++ b/tests/auto/translation/translation.pro
@@ -0,0 +1,19 @@
+CONFIG += testcase
+TARGET = tst_translation
+SOURCES += tst_translation.cpp
+
+macos:CONFIG -= app_bundle
+
+QT += testlib gui-private quicktemplates2-private
+
+include (../shared/util.pri)
+
+TESTDATA = data/*
+
+OTHER_FILES += \
+    data/*.qml
+
+# We only want to run lrelease, which is why we use EXTRA_TRANSLATIONS.
+EXTRA_TRANSLATIONS = qtbase_fr.ts
+# Embed the translations in a qrc file.
+CONFIG += lrelease embed_translations
diff --git a/tests/auto/translation/tst_translation.cpp b/tests/auto/translation/tst_translation.cpp
new file mode 100644
index 00000000..9cbca915
--- /dev/null
+++ b/tests/auto/translation/tst_translation.cpp
@@ -0,0 +1,100 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://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.LGPLv3 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.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 later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtTest/qtest.h>
+#include "../shared/visualtestutil.h"
+
+#include <QtCore/qtranslator.h>
+#include <QtGui/private/qguiapplication_p.h>
+#include <QtGui/qpa/qplatformtheme.h>
+#include <QtQuick/qquickview.h>
+#include <QtQuickTemplates2/private/qquickabstractbutton_p.h>
+#include <QtQuickTemplates2/private/qquickdialog_p.h>
+#include <QtQuickTemplates2/private/qquickdialogbuttonbox_p.h>
+
+using namespace QQuickVisualTestUtil;
+
+class tst_translation : public QQmlDataTest
+{
+    Q_OBJECT
+
+private slots:
+    void dialogButtonBox();
+};
+
+void tst_translation::dialogButtonBox()
+{
+    QQuickView view(testFileUrl("dialogButtonBox.qml"));
+    if (view.status() != QQuickView::Ready)
+        QFAIL("Failed to load QML file");
+    view.show();
+    QVERIFY(QTest::qWaitForWindowActive(&view));
+
+    QQuickDialog *dialog = view.rootObject()->property("dialog").value<QQuickDialog*>();
+    QVERIFY(dialog);
+
+    QQuickDialogButtonBox *dialogButtonBox = qobject_cast<QQuickDialogButtonBox*>(dialog->footer());
+    QVERIFY(dialogButtonBox);
+
+    QQuickAbstractButton *saveButton = dialogButtonBox->standardButton(QPlatformDialogHelper::Save);
+    QVERIFY(saveButton);
+    QString defaultSaveText = QGuiApplicationPrivate::platformTheme()->standardButtonText(QPlatformDialogHelper::Save);
+    defaultSaveText = QPlatformTheme::removeMnemonics(defaultSaveText);
+    QCOMPARE(saveButton->text(), defaultSaveText);
+
+    QQuickAbstractButton *discardButton = dialogButtonBox->standardButton(QPlatformDialogHelper::Discard);
+    QVERIFY(discardButton);
+    QString defaultDiscardText = QGuiApplicationPrivate::platformTheme()->standardButtonText(QPlatformDialogHelper::Discard);
+    defaultDiscardText = QPlatformTheme::removeMnemonics(defaultDiscardText);
+    QCOMPARE(discardButton->text(), defaultDiscardText);
+
+    QTranslator translator;
+    QVERIFY(translator.load(":/i18n/qtbase_fr.qm"));
+    QVERIFY(qApp->installTranslator(&translator));
+    view.engine()->retranslate();
+
+    QString translatedSaveText = QGuiApplicationPrivate::platformTheme()->standardButtonText(QPlatformDialogHelper::Save);
+    translatedSaveText = QPlatformTheme::removeMnemonics(translatedSaveText);
+    QCOMPARE(saveButton->text(), translatedSaveText);
+
+    QString translatedDiscardText = QGuiApplicationPrivate::platformTheme()->standardButtonText(QPlatformDialogHelper::Discard);
+    translatedDiscardText = QPlatformTheme::removeMnemonics(translatedDiscardText);
+    QCOMPARE(discardButton->text(), translatedDiscardText);
+}
+
+QTEST_MAIN(tst_translation)
+
+#include "tst_translation.moc"