Load preferred language from settings

src/control/Control.cpp

@@ -88,6 +88,8 @@ Control::Control(GladeSearchpath* gladeSearchPath) {
     this->settings = new Settings(std::move(name));
     this->settings->load();
 
+    this->applyPreferredLanguage();
+
     TextView::setDpi(settings->getDisplayDpi());
 
     this->pageTypes = new PageTypeHandler(gladeSearchPath);
@@ -2458,6 +2460,8 @@ void Control::closeDocument() {
     this->undoRedoChanged();
 }
 
+void Control::applyPreferredLanguage() { setenv("LANGUAGE", this->settings->getPreferredLocale().c_str(), 1); }
+
 auto Control::askToReplace(fs::path const& filepath) const -> bool {
     if (fs::exists(filepath)) {
         string msg = FS(FORMAT_STR("The file {1} already exists! Do you want to replace it?") %

src/control/Control.h

@@ -326,6 +326,11 @@ private:
      */
     void closeDocument();
 
+    /**
+     * Applies the preferred language to the UI
+     */
+    void applyPreferredLanguage();
+
     RecentManager* recent;
     UndoRedoHandler* undoRedo;
     ZoomControl* zoom;

src/control/settings/Settings.cpp

@@ -845,6 +845,8 @@ void Settings::save() {
     WRITE_BOOL_PROP(inputSystemTPCButton);
     WRITE_BOOL_PROP(inputSystemDrawOutsideWindow);
 
+    WRITE_STRING_PROP(preferredLocale);
+
     WRITE_BOOL_PROP(latexSettings.autoCheckDependencies);
     // Inline WRITE_STRING_PROP(latexSettings.globalTemplatePath) since it
     // breaks on Windows due to the native character representation being

src/control/settings/Settings.h

@@ -431,7 +431,6 @@ public:
      */
     bool getTrySelectOnStrokeFiltered() const;
 
-
     /**
      * Set snap recognized shapes enabled
      */
@@ -452,6 +451,16 @@ public:
      */
     bool getRestoreLineWidthEnabled() const;
 
+    /**
+     * Set the preferred locale
+     */
+    void setPreferredLocale(std::string const& locale) const;
+
+    /**
+     * Get the preferred locale
+     */
+    std::string getPreferredLocale() const {
+        return "de_DE.UTF-8"; }
 
 public:
     // Custom settings
@@ -882,4 +891,9 @@ private:
      * "Transaction" running, do not save until the end is reached
      */
     bool inTransaction{};
+
+    /** The preferred locale as its language code
+     * e.g. "en_US"
+     */
+    std::string preferredLocale;
 };