qmldesigner: block local changes while initialization

 - emit after the initialization
 - emit only if found languages are differrent

Change-Id: I4f426b7bf055ef1d97e5db86bba075a032210303
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

2 files changed, 22 insertions, 17 deletions

diff --git a/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewactions.cpp b/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewactions.cpp
index 32d524f6909..c0da2f8b8c6 100644
--- a/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewactions.cpp
+++ b/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewactions.cpp
@@ -217,42 +217,46 @@ SwitchLanguageComboboxAction::SwitchLanguageComboboxAction(QObject *parent)
     connect(ProjectExplorer::SessionManager::instance(),
             &ProjectExplorer::SessionManager::startupProjectChanged,
             this,
-            &SwitchLanguageComboboxAction::refreshProjectLocales);
+            &SwitchLanguageComboboxAction::updateProjectLocales);
 }
 
 QWidget *SwitchLanguageComboboxAction::createWidget(QWidget *parent)
 {
     QPointer<QComboBox> comboBox = new QComboBox(parent);
     comboBox->setToolTip(tr("Switch the language used by preview."));
-    connect(comboBox, QOverload<int>::of(&QComboBox::currentIndexChanged), [this, comboBox](int index) {
-        if (index == 0)
-            emit currentLocaleChanged("");
-        else
-            emit currentLocaleChanged(comboBox->currentText());
-    });
+    comboBox->addItem(tr("Default"));
 
     auto refreshComboBoxFunction = [this, comboBox] (ProjectExplorer::Project *project) {
         if (comboBox) {
-            refreshProjectLocales(project);
-            comboBox->clear();
-            comboBox->addItem(tr("Default"));
-            comboBox->addItems(m_localeStrings);
+            if (updateProjectLocales(project)) {
+                comboBox->clear();
+                comboBox->addItem(tr("Default"));
+                comboBox->addItems(m_localeStrings);
+            }
         }
     };
-    connect(ProjectExplorer::SessionManager::instance(),
-            &ProjectExplorer::SessionManager::startupProjectChanged,
-            refreshComboBoxFunction);
+    connect(ProjectExplorer::SessionManager::instance(),  &ProjectExplorer::SessionManager::startupProjectChanged,
+        comboBox, refreshComboBoxFunction);
 
     if (auto project = SessionManager::startupProject())
         refreshComboBoxFunction(project);
 
+    // do this after refreshComboBoxFunction so we do not get currentLocaleChanged signals at initialization
+    connect(comboBox, QOverload<int>::of(&QComboBox::currentIndexChanged), [this, comboBox](int index) {
+        if (index == 0) // == Default
+            emit currentLocaleChanged("");
+        else
+            emit currentLocaleChanged(comboBox->currentText());
+    });
+
     return comboBox;
 }
 
-void SwitchLanguageComboboxAction::refreshProjectLocales(Project *project)
+bool SwitchLanguageComboboxAction::updateProjectLocales(Project *project)
 {
     if (!project)
-        return;
+        return false;
+    auto previousLocales = m_localeStrings;
     m_localeStrings.clear();
     const auto projectDirectory = project->rootProjectDirectory().toFileInfo().absoluteFilePath();
     const QDir languageDirectory(projectDirectory + "/i18n");
@@ -263,6 +267,7 @@ void SwitchLanguageComboboxAction::refreshProjectLocales(Project *project)
         const QString locale = qmFile.left(localeEndPosition).mid(localeStartPosition);
         return locale;
     });
+    return previousLocales != m_localeStrings;
 }
 
 SwitchLanguageAction::SwitchLanguageAction()
diff --git a/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewactions.h b/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewactions.h
index 8a71ee07c29..a23f125ca14 100644
--- a/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewactions.h
+++ b/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewactions.h
@@ -113,7 +113,7 @@ signals:
 protected:
     QWidget *createWidget(QWidget *parent) override;
 private:
-    void refreshProjectLocales(ProjectExplorer::Project *project);
+    bool updateProjectLocales(ProjectExplorer::Project *project);
     QStringList m_localeStrings;
 };