Avoid conversions between OUString and OString in VCL

Standardize on OUString, which is the main internal string class.
Convert from/to OUString only when communicating with respective
external APIs.

Removes about 200 conversions from the code.

Change-Id: I96ecee7c6fd271bb76639220e96d69d2964bed26
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/149930
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

6 files changed, 263 insertions, 264 deletions

diff --git a/vcl/unx/generic/print/prtsetup.cxx b/vcl/unx/generic/print/prtsetup.cxx
index a13133d6017b..90ae49ec5179 100644
--- a/vcl/unx/generic/print/prtsetup.cxx
+++ b/vcl/unx/generic/print/prtsetup.cxx
@@ -90,7 +90,7 @@ RTSDialog::~RTSDialog()
 {
 }
 
-IMPL_LINK(RTSDialog, ActivatePage, const OString&, rPage, void)
+IMPL_LINK(RTSDialog, ActivatePage, const OUString&, rPage, void)
 {
     if (rPage == "paper")
         m_xPaperPage->update();
diff --git a/vcl/unx/generic/print/prtsetup.hxx b/vcl/unx/generic/print/prtsetup.hxx
index bcf86670d0b6..04b89d54e075 100644
--- a/vcl/unx/generic/print/prtsetup.hxx
+++ b/vcl/unx/generic/print/prtsetup.hxx
@@ -45,7 +45,7 @@ class RTSDialog : public weld::GenericDialogController
     std::unique_ptr<RTSPaperPage> m_xPaperPage;
     std::unique_ptr<RTSDevicePage> m_xDevicePage;
 
-    DECL_LINK(ActivatePage, const OString&, void);
+    DECL_LINK(ActivatePage, const OUString&, void);
     DECL_LINK(ClickButton, weld::Button&, void);
 
     // helper functions
diff --git a/vcl/unx/gtk3/gtkdata.cxx b/vcl/unx/gtk3/gtkdata.cxx
index cc8535ff2ad2..f595369f8b53 100644
--- a/vcl/unx/gtk3/gtkdata.cxx
+++ b/vcl/unx/gtk3/gtkdata.cxx
@@ -888,37 +888,37 @@ namespace {
 
 struct ButtonOrder
 {
-    std::string_view m_aType;
+    std::u16string_view m_aType;
     int m_nPriority;
 };
 
 }
 
-int getButtonPriority(std::string_view rType)
+int getButtonPriority(std::u16string_view rType)
 {
     static const size_t N_TYPES = 8;
     static const ButtonOrder aDiscardCancelSave[N_TYPES] =
     {
-        { "discard", 0 },
-        { "cancel", 1 },
-        { "close", 1 },
-        { "no", 2 },
-        { "open", 3 },
-        { "save", 3 },
-        { "yes", 3 },
-        { "ok", 3 }
+        { u"discard", 0 },
+        { u"cancel", 1 },
+        { u"close", 1 },
+        { u"no", 2 },
+        { u"open", 3 },
+        { u"save", 3 },
+        { u"yes", 3 },
+        { u"ok", 3 }
     };
 
     static const ButtonOrder aSaveDiscardCancel[N_TYPES] =
     {
-        { "open", 0 },
-        { "save", 0 },
-        { "yes", 0 },
-        { "ok", 0 },
-        { "discard", 1 },
-        { "no", 1 },
-        { "cancel", 2 },
-        { "close", 2 }
+        { u"open", 0 },
+        { u"save", 0 },
+        { u"yes", 0 },
+        { u"ok", 0 },
+        { u"discard", 1 },
+        { u"no", 1 },
+        { u"cancel", 2 },
+        { u"close", 2 }
     };
 
     const ButtonOrder* pOrder = &aDiscardCancelSave[0];
diff --git a/vcl/unx/gtk3/gtkinst.cxx b/vcl/unx/gtk3/gtkinst.cxx
index 6369aec3b1a3..30ff8681f630 100644
--- a/vcl/unx/gtk3/gtkinst.cxx
+++ b/vcl/unx/gtk3/gtkinst.cxx
@@ -2174,17 +2174,17 @@ namespace
 
 class GtkInstanceBuilder;
 
-    void set_help_id(const GtkWidget *pWidget, const OString& rHelpId)
+    void set_help_id(const GtkWidget *pWidget, std::u16string_view rHelpId)
     {
-        gchar *helpid = g_strdup(rHelpId.getStr());
+        gchar *helpid = g_strdup(OUStringToOString(rHelpId, RTL_TEXTENCODING_UTF8).getStr());
         g_object_set_data_full(G_OBJECT(pWidget), "g-lo-helpid", helpid, g_free);
     }
 
-    OString get_help_id(const GtkWidget *pWidget)
+    OUString get_help_id(const GtkWidget *pWidget)
     {
         void* pData = g_object_get_data(G_OBJECT(pWidget), "g-lo-helpid");
         const gchar* pStr = static_cast<const gchar*>(pData);
-        return OString(pStr, pStr ? strlen(pStr) : 0);
+        return OUString(pStr, pStr ? strlen(pStr) : 0, RTL_TEXTENCODING_UTF8);
     }
 
     KeyEvent CreateKeyEvent(guint keyval, guint16 hardware_keycode, guint state, guint8 group)
@@ -2522,23 +2522,23 @@ vcl::Font get_font(GtkWidget* pWidget)
 
 }
 
-OString get_buildable_id(GtkBuildable* pWidget)
+OUString get_buildable_id(GtkBuildable* pWidget)
 {
 #if GTK_CHECK_VERSION(4, 0, 0)
     const gchar* pStr = gtk_buildable_get_buildable_id(pWidget);
 #else
     const gchar* pStr = gtk_buildable_get_name(pWidget);
 #endif
-    return OString(pStr, pStr ? strlen(pStr) : 0);
+    return OUString(pStr, pStr ? strlen(pStr) : 0, RTL_TEXTENCODING_UTF8);
 }
 
-void set_buildable_id(GtkBuildable* pWidget, const OString& rId)
+void set_buildable_id(GtkBuildable* pWidget, const OUString& rId)
 {
 #if GTK_CHECK_VERSION(4, 0, 0)
     GtkBuildableIface *iface = GTK_BUILDABLE_GET_IFACE(pWidget);
-    (*iface->set_id)(pWidget, rId.getStr());
+    (*iface->set_id)(pWidget, OUStringToOString(rId, RTL_TEXTENCODING_UTF8).getStr());
 #else
-    gtk_buildable_set_name(pWidget, rId.getStr());
+    gtk_buildable_set_name(pWidget, OUStringToOString(rId, RTL_TEXTENCODING_UTF8).getStr());
 #endif
 }
 
@@ -3929,26 +3929,26 @@ public:
 
     virtual std::unique_ptr<weld::Container> weld_parent() const override;
 
-    virtual OString get_buildable_name() const override
+    virtual OUString get_buildable_name() const override
     {
         return ::get_buildable_id(GTK_BUILDABLE(m_pWidget));
     }
 
-    virtual void set_buildable_name(const OString& rId) override
+    virtual void set_buildable_name(const OUString& rId) override
     {
         ::set_buildable_id(GTK_BUILDABLE(m_pWidget), rId);
     }
 
-    virtual void set_help_id(const OString& rHelpId) override
+    virtual void set_help_id(const OUString& rHelpId) override
     {
         ::set_help_id(m_pWidget, rHelpId);
     }
 
-    virtual OString get_help_id() const override
+    virtual OUString get_help_id() const override
     {
-        OString sRet = ::get_help_id(m_pWidget);
+        OUString sRet = ::get_help_id(m_pWidget);
         if (sRet.isEmpty())
-            sRet = OString("null");
+            sRet = "null";
         return sRet;
     }
 
@@ -4426,7 +4426,7 @@ public:
         }
     }
 
-    virtual void help_hierarchy_foreach(const std::function<bool(const OString&)>& func) override;
+    virtual void help_hierarchy_foreach(const std::function<bool(const OUString&)>& func) override;
 
     virtual OUString strip_mnemonic(const OUString &rLabel) const override
     {
@@ -5232,13 +5232,13 @@ protected:
 #if !GTK_CHECK_VERSION(4, 0, 0)
     GtkMenu* m_pMenu;
 
-    std::map<OString, GtkMenuItem*> m_aMap;
+    std::map<OUString, GtkMenuItem*> m_aMap;
 #else
     GtkPopoverMenu* m_pMenu;
 
     o3tl::sorted_vector<OString> m_aInsertedActions; // must outlive m_aActionEntries
-    std::map<OString, OString> m_aIdToAction;
-    std::set<OString> m_aHiddenIds;
+    std::map<OUString, OString> m_aIdToAction;
+    std::set<OUString> m_aHiddenIds;
     std::vector<GActionEntry> m_aActionEntries;
     GActionGroup* m_pActionGroup;
     // move 'invisible' entries to m_pHiddenActionGroup
@@ -5247,7 +5247,7 @@ protected:
     bool m_bTakeOwnership;
 private:
 
-    virtual void signal_item_activate(const OString& rIdent) = 0;
+    virtual void signal_item_activate(const OUString& rIdent) = 0;
 
 #if !GTK_CHECK_VERSION(4, 0, 0)
     static void collect(GtkWidget* pItem, gpointer widget)
@@ -5266,15 +5266,15 @@ private:
         pThis->signal_item_activate(::get_buildable_id(GTK_BUILDABLE(pItem)));
     }
 #else
-    static std::pair<GMenuModel*, int> find_id(GMenuModel* pMenuModel, const OString& rId)
+    static std::pair<GMenuModel*, int> find_id(GMenuModel* pMenuModel, const OUString& rId)
     {
         for (int i = 0, nCount = g_menu_model_get_n_items(pMenuModel); i < nCount; ++i)
         {
-            OString sTarget;
+            OUString sTarget;
             char *id;
             if (g_menu_model_get_item_attribute(pMenuModel, i, "target", "s", &id))
             {
-                sTarget = OString(id);
+                sTarget = OStringToOUString(id, RTL_TEXTENCODING_UTF8);
                 g_free(id);
             }
 
@@ -5314,7 +5314,7 @@ private:
     {
         gsize nLength(0);
         const gchar* pStr = g_variant_get_string(pParameter, &nLength);
-        OString aStr(pStr, nLength);
+        OUString aStr(pStr, nLength, RTL_TEXTENCODING_UTF8);
         MenuHelper* pThis = static_cast<MenuHelper*>(widget);
         SolarMutexGuard aGuard;
         pThis->signal_item_activate(aStr);
@@ -5343,14 +5343,14 @@ public:
 #if !GTK_CHECK_VERSION(4, 0, 0)
     void add_to_map(GtkMenuItem* pMenuItem)
     {
-        OString id = ::get_buildable_id(GTK_BUILDABLE(pMenuItem));
+        OUString id = ::get_buildable_id(GTK_BUILDABLE(pMenuItem));
         m_aMap[id] = pMenuItem;
         g_signal_connect(pMenuItem, "activate", G_CALLBACK(signalActivate), this);
     }
 
     void remove_from_map(GtkMenuItem* pMenuItem)
     {
-        OString id = ::get_buildable_id(GTK_BUILDABLE(pMenuItem));
+        OUString id = ::get_buildable_id(GTK_BUILDABLE(pMenuItem));
         auto iter = m_aMap.find(id);
         g_signal_handlers_disconnect_by_data(pMenuItem, this);
         m_aMap.erase(iter);
@@ -5427,7 +5427,8 @@ public:
     {
         for (int i = 0, nCount = g_menu_model_get_n_items(pMenuModel); i < nCount; ++i)
         {
-            OString sAction, sTarget;
+            OString sAction;
+            OUString sTarget;
             char *id;
             if (g_menu_model_get_item_attribute(pMenuModel, i, "action", "s", &id))
             {
@@ -5451,7 +5452,7 @@ public:
 
             if (g_menu_model_get_item_attribute(pMenuModel, i, "target", "s", &id))
             {
-                sTarget = OString(id);
+                sTarget = OStringToOUString(id, RTL_TEXTENCODING_UTF8);
                 g_free(id);
             }
 
@@ -5517,7 +5518,7 @@ public:
         if (eCheckRadioFalse == TRISTATE_FALSE)
             gtk_check_menu_item_set_draw_as_radio(GTK_CHECK_MENU_ITEM(pItem), true);
 
-        ::set_buildable_id(GTK_BUILDABLE(pItem), OUStringToOString(rId, RTL_TEXTENCODING_UTF8));
+        ::set_buildable_id(GTK_BUILDABLE(pItem), rId);
         gtk_menu_shell_append(GTK_MENU_SHELL(m_pMenu), pItem);
         gtk_widget_show(pItem);
         add_to_map(GTK_MENU_ITEM(pItem));
@@ -5551,7 +5552,7 @@ public:
     {
 #if !GTK_CHECK_VERSION(4, 0, 0)
         GtkWidget* pItem = gtk_separator_menu_item_new();
-        ::set_buildable_id(GTK_BUILDABLE(pItem), OUStringToOString(rId, RTL_TEXTENCODING_UTF8));
+        ::set_buildable_id(GTK_BUILDABLE(pItem), rId);
         gtk_menu_shell_append(GTK_MENU_SHELL(m_pMenu), pItem);
         gtk_widget_show(pItem);
         add_to_map(GTK_MENU_ITEM(pItem));
@@ -5590,7 +5591,7 @@ public:
 #endif
     }
 
-    void remove_item(const OString& rIdent)
+    void remove_item(const OUString& rIdent)
     {
 #if !GTK_CHECK_VERSION(4, 0, 0)
         GtkMenuItem* pMenuItem = m_aMap[rIdent];
@@ -5607,7 +5608,7 @@ public:
 #endif
     }
 
-    void set_item_sensitive(const OString& rIdent, bool bSensitive)
+    void set_item_sensitive(const OUString& rIdent, bool bSensitive)
     {
 #if GTK_CHECK_VERSION(4, 0, 0)
         GActionGroup* pActionGroup = m_aHiddenIds.find(rIdent) == m_aHiddenIds.end() ? m_pActionGroup : m_pHiddenActionGroup;
@@ -5618,7 +5619,7 @@ public:
 #endif
     }
 
-    bool get_item_sensitive(const OString& rIdent) const
+    bool get_item_sensitive(const OUString& rIdent) const
     {
 #if GTK_CHECK_VERSION(4, 0, 0)
         GActionGroup* pActionGroup = m_aHiddenIds.find(rIdent) == m_aHiddenIds.end() ? m_pActionGroup : m_pHiddenActionGroup;
@@ -5629,7 +5630,7 @@ public:
 #endif
     }
 
-    void set_item_active(const OString& rIdent, bool bActive)
+    void set_item_active(const OUString& rIdent, bool bActive)
     {
 #if !GTK_CHECK_VERSION(4, 0, 0)
         disable_item_notify_events();
@@ -5638,11 +5639,11 @@ public:
 #else
         GActionGroup* pActionGroup = m_aHiddenIds.find(rIdent) == m_aHiddenIds.end() ? m_pActionGroup : m_pHiddenActionGroup;
         g_action_group_change_action_state(pActionGroup, m_aIdToAction[rIdent].getStr(),
-                                           g_variant_new_string(bActive ? rIdent.getStr() : "'none'"));
+                                           g_variant_new_string(bActive ? OUStringToOString(rIdent, RTL_TEXTENCODING_UTF8).getStr() : "'none'"));
 #endif
     }
 
-    bool get_item_active(const OString& rIdent) const
+    bool get_item_active(const OUString& rIdent) const
     {
 #if !GTK_CHECK_VERSION(4, 0, 0)
         return gtk_check_menu_item_get_active(GTK_CHECK_MENU_ITEM(m_aMap.find(rIdent)->second));
@@ -5658,7 +5659,7 @@ public:
 #endif
     }
 
-    void set_item_label(const OString& rIdent, const OUString& rText)
+    void set_item_label(const OUString& rIdent, const OUString& rText)
     {
 #if !GTK_CHECK_VERSION(4, 0, 0)
         gtk_menu_item_set_label(m_aMap[rIdent], MapToGtkAccelerator(rText).getStr());
@@ -5679,7 +5680,7 @@ public:
 #endif
     }
 
-    OUString get_item_label(const OString& rIdent) const
+    OUString get_item_label(const OUString& rIdent) const
     {
 #if !GTK_CHECK_VERSION(4, 0, 0)
         const gchar* pText = gtk_menu_item_get_label(m_aMap.find(rIdent)->second);
@@ -5704,7 +5705,7 @@ public:
 #endif
     }
 
-    void set_item_visible(const OString& rIdent, bool bShow)
+    void set_item_visible(const OUString& rIdent, bool bShow)
     {
 #if !GTK_CHECK_VERSION(4, 0, 0)
         GtkWidget* pWidget = GTK_WIDGET(m_aMap[rIdent]);
@@ -5734,23 +5735,23 @@ public:
 #endif
     }
 
-    OString get_item_id(int pos) const
+    OUString get_item_id(int pos) const
     {
 #if !GTK_CHECK_VERSION(4, 0, 0)
         GList* pChildren = gtk_container_get_children(GTK_CONTAINER(m_pMenu));
         gpointer pMenuItem = g_list_nth_data(pChildren, pos);
-        OString id = ::get_buildable_id(GTK_BUILDABLE(pMenuItem));
+        OUString id = ::get_buildable_id(GTK_BUILDABLE(pMenuItem));
         g_list_free(pChildren);
         return id;
 #else
-        OString sTarget;
+        OUString sTarget;
         if (GMenuModel* pMenuModel = m_pMenu ? gtk_popover_menu_get_menu_model(m_pMenu) : nullptr)
         {
             auto aSectionAndPos = get_section_and_pos_for(pMenuModel, pos);
             char *id;
             if (g_menu_model_get_item_attribute(aSectionAndPos.first, aSectionAndPos.second, "target", "s", &id))
             {
-                sTarget = OString(id);
+                sTarget = OStringToOUString(id, RTL_TEXTENCODING_UTF8);
                 g_free(id);
             }
         }
@@ -6468,7 +6469,7 @@ public:
 #endif
     }
 
-    virtual void set_window_state(const OString& rStr) override
+    virtual void set_window_state(const OUString& rStr) override
     {
         const vcl::WindowData aData(rStr);
         const auto nMask = aData.mask();
@@ -6494,7 +6495,7 @@ public:
 #endif
     }
 
-    virtual OString get_window_state(vcl::WindowDataMask nMask) const override
+    virtual OUString get_window_state(vcl::WindowDataMask nMask) const override
     {
         bool bPositioningAllowed = isPositioningAllowed();
 
@@ -7142,7 +7143,7 @@ public:
 
     virtual void response(int nResponse) override;
 
-    virtual void add_button(const OUString& rText, int nResponse, const OString& rHelpId) override
+    virtual void add_button(const OUString& rText, int nResponse, const OUString& rHelpId) override
     {
         GtkWidget* pWidget = gtk_dialog_add_button(GTK_DIALOG(m_pDialog), MapToGtkAccelerator(rText).getStr(), VclToGtk(nResponse));
         if (!rHelpId.isEmpty())
@@ -7386,15 +7387,15 @@ private:
     GtkButton* m_pCancel;
     gulong m_nButtonPressSignalId;
     std::vector<std::unique_ptr<GtkInstanceContainer>> m_aPages;
-    std::map<OString, bool> m_aNotClickable;
+    std::map<OUString, bool> m_aNotClickable;
 
-    int find_page(std::string_view ident) const
+    int find_page(std::u16string_view ident) const
     {
         int nPages = gtk_assistant_get_n_pages(m_pAssistant);
         for (int i = 0; i < nPages; ++i)
         {
             GtkWidget* pPage = gtk_assistant_get_nth_page(m_pAssistant, i);
-            OString sBuildableName = ::get_buildable_id(GTK_BUILDABLE(pPage));
+            OUString sBuildableName = ::get_buildable_id(GTK_BUILDABLE(pPage));
             if (sBuildableName == ident)
                 return i;
         }
@@ -7413,7 +7414,7 @@ private:
 
     static void find_sidebar(GtkWidget *pWidget, gpointer user_data)
     {
-        OString sBuildableName = ::get_buildable_id(GTK_BUILDABLE(pWidget));
+        OUString sBuildableName = ::get_buildable_id(GTK_BUILDABLE(pWidget));
         if (sBuildableName == "sidebar")
         {
             GtkWidget **ppSidebar = static_cast<GtkWidget**>(user_data);
@@ -7506,7 +7507,7 @@ private:
 
         if (nNewCurrentPage != -1 && nNewCurrentPage != get_current_page())
         {
-            OString sIdent = get_page_ident(nNewCurrentPage);
+            OUString sIdent = get_page_ident(nNewCurrentPage);
             if (!m_aNotClickable[sIdent] && !signal_jump_page(sIdent))
                 set_current_page(nNewCurrentPage);
         }
@@ -7655,13 +7656,13 @@ public:
         return gtk_assistant_get_n_pages(m_pAssistant);
     }
 
-    virtual OString get_page_ident(int nPage) const override
+    virtual OUString get_page_ident(int nPage) const override
     {
         const GtkWidget* pWidget = gtk_assistant_get_nth_page(m_pAssistant, nPage);
         return ::get_buildable_id(GTK_BUILDABLE(pWidget));
     }
 
-    virtual OString get_current_page_ident() const override
+    virtual OUString get_current_page_ident() const override
     {
         return get_page_ident(get_current_page());
     }
@@ -7679,7 +7680,7 @@ public:
             gtk_window_set_title(GTK_WINDOW(m_pAssistant), sDialogTitle.getStr());
     }
 
-    virtual void set_current_page(const OString& rIdent) override
+    virtual void set_current_page(const OUString& rIdent) override
     {
         int nPage = find_page(rIdent);
         if (nPage == -1)
@@ -7687,7 +7688,7 @@ public:
         set_current_page(nPage);
     }
 
-    virtual void set_page_title(const OString& rIdent, const OUString& rTitle) override
+    virtual void set_page_title(const OUString& rIdent, const OUString& rTitle) override
     {
         int nIndex = find_page(rIdent);
         if (nIndex == -1)
@@ -7700,7 +7701,7 @@ public:
 #endif
     }
 
-    virtual OUString get_page_title(const OString& rIdent) const override
+    virtual OUString get_page_title(const OUString& rIdent) const override
     {
         int nIndex = find_page(rIdent);
         if (nIndex == -1)
@@ -7710,12 +7711,12 @@ public:
         return OUString(pStr, pStr ? strlen(pStr) : 0, RTL_TEXTENCODING_UTF8);
     }
 
-    virtual void set_page_sensitive(const OString& rIdent, bool bSensitive) override
+    virtual void set_page_sensitive(const OUString& rIdent, bool bSensitive) override
     {
         m_aNotClickable[rIdent] = !bSensitive;
     }
 
-    virtual void set_page_index(const OString& rIdent, int nNewIndex) override
+    virtual void set_page_index(const OUString& rIdent, int nNewIndex) override
     {
         int nOldIndex = find_page(rIdent);
         if (nOldIndex == -1)
@@ -7741,7 +7742,7 @@ public:
         g_object_unref(pPage);
     }
 
-    virtual weld::Container* append_page(const OString& rIdent) override
+    virtual weld::Container* append_page(const OUString& rIdent) override
     {
         disable_notify_events();
 
@@ -7762,7 +7763,7 @@ public:
         return m_aPages.back().get();
     }
 
-    virtual void set_page_side_help_id(const OString& rHelpId) override
+    virtual void set_page_side_help_id(const OUString& rHelpId) override
     {
         if (!m_pSidebar)
             return;
@@ -8814,7 +8815,7 @@ private:
         }
         if (m_bOverFlowBoxActive)
             gtk_notebook_set_current_page(m_pOverFlowNotebook, gtk_notebook_get_n_pages(m_pOverFlowNotebook) - 1);
-        OString sNewIdent(get_page_ident(nNewPage));
+        OUString sNewIdent(get_page_ident(nNewPage));
         if (!m_bInternalPageChange)
             m_aEnterPageHdl.Call(sNewIdent);
     }
@@ -8831,7 +8832,7 @@ private:
         int i = nMainPages;
         while (nOverFlowPages)
         {
-            OString sIdent(get_page_ident(m_pOverFlowNotebook, 0));
+            OUString sIdent(get_page_ident(m_pOverFlowNotebook, 0));
             OUString sLabel(get_tab_label_text(m_pOverFlowNotebook, 0));
             remove_page(m_pOverFlowNotebook, sIdent);
 
@@ -8847,7 +8848,7 @@ private:
         }
 
         // remove the dangling placeholder tab page
-        remove_page(m_pOverFlowNotebook, "useless");
+        remove_page(m_pOverFlowNotebook, u"useless");
     }
 
     // a tab has been selected on the overflow notebook
@@ -8881,30 +8882,30 @@ private:
         enable_notify_events();
 
         // trigger main notebook switch-page callback
-        OString sNewIdent(get_page_ident(m_pNotebook, nNewPage));
+        OUString sNewIdent(get_page_ident(m_pNotebook, nNewPage));
         m_aEnterPageHdl.Call(sNewIdent);
     }
 
-    static OString get_page_ident(GtkNotebook *pNotebook, guint nPage)
+    static OUString get_page_ident(GtkNotebook *pNotebook, guint nPage)
     {
         const GtkWidget* pTabWidget = gtk_notebook_get_tab_label(pNotebook, gtk_notebook_get_nth_page(pNotebook, nPage));
         return ::get_buildable_id(GTK_BUILDABLE(pTabWidget));
     }
 
-    static gint get_page_number(GtkNotebook *pNotebook, std::string_view ident)
+    static gint get_page_number(GtkNotebook *pNotebook, std::u16string_view ident)
     {
         gint nPages = gtk_notebook_get_n_pages(pNotebook);
         for (gint i = 0; i < nPages; ++i)
         {
             const GtkWidget* pTabWidget = gtk_notebook_get_tab_label(pNotebook, gtk_notebook_get_nth_page(pNotebook, i));
-            OString sBuildableName = ::get_buildable_id(GTK_BUILDABLE(pTabWidget));
+            OUString sBuildableName = ::get_buildable_id(GTK_BUILDABLE(pTabWidget));
             if (sBuildableName == ident)
                 return i;
         }
         return -1;
     }
 
-    int remove_page(GtkNotebook *pNotebook, std::string_view ident)
+    int remove_page(GtkNotebook *pNotebook, std::u16string_view ident)
     {
         disable_notify_events();
         int nPageNumber = get_page_number(pNotebook, ident);
@@ -8954,7 +8955,7 @@ private:
         enable_notify_events();
     }
 
-    void insert_page(GtkNotebook *pNotebook, const OString& rIdent, const OUString& rLabel, GtkWidget *pChild, int nPos)
+    void insert_page(GtkNotebook *pNotebook, const OUString& rIdent, const OUString& rLabel, GtkWidget *pChild, int nPos)
     {
         disable_notify_events();
 
@@ -9058,7 +9059,7 @@ private:
         int nOverFlowPages = m_nStartTabCount;
         while (nOverFlowPages)
         {
-            OString sIdent(get_page_ident(m_pNotebook, 0));
+            OUString sIdent(get_page_ident(m_pNotebook, 0));
             OUString sLabel(get_tab_label_text(m_pNotebook, 0));
             remove_page(m_pNotebook, sIdent);
             insert_page(m_pOverFlowNotebook, sIdent, sLabel, gtk_grid_new(), -1);
@@ -9095,7 +9096,7 @@ private:
         gtk_widget_set_size_request(GTK_WIDGET(m_pOverFlowNotebook), nWidth, -1);
 
         // remove it once we've measured it
-        remove_page(m_pNotebook, "useless");
+        remove_page(m_pNotebook, u"useless");
 
 #if !GTK_CHECK_VERSION(4, 0, 0)
         gtk_widget_thaw_child_notify(GTK_WIDGET(m_pOverFlowNotebook));
@@ -9266,7 +9267,7 @@ public:
         return nPage;
     }
 
-    virtual OString get_page_ident(int nPage) const override
+    virtual OUString get_page_ident(int nPage) const override
     {
         auto nMainLen = gtk_notebook_get_n_pages(m_pNotebook);
         auto nOverFlowLen = m_bOverFlowBoxActive ? gtk_notebook_get_n_pages(m_pOverFlowNotebook) - 1 : 0;
@@ -9286,13 +9287,13 @@ public:
         }
     }
 
-    virtual OString get_current_page_ident() const override
+    virtual OUString get_current_page_ident() const override
     {
         const int nPage = get_current_page();
-        return nPage != -1 ? get_page_ident(nPage) : OString();
+        return nPage != -1 ? get_page_ident(nPage) : OUString();
     }
 
-    virtual int get_page_index(const OString& rIdent) const override
+    virtual int get_page_index(const OUString& rIdent) const override
     {
         auto nMainIndex = get_page_number(m_pNotebook, rIdent);
         auto nOverFlowIndex = get_page_number(m_pOverFlowNotebook, rIdent);
@@ -9322,7 +9323,7 @@ public:
         }
     }
 
-    virtual weld::Container* get_page(const OString& rIdent) const override
+    virtual weld::Container* get_page(const OUString& rIdent) const override
     {
         int nPage = get_page_index(rIdent);
         if (nPage < 0)
@@ -9400,7 +9401,7 @@ public:
         m_bInternalPageChange = bInternalPageChange;
     }
 
-    virtual void set_current_page(const OString& rIdent) override
+    virtual void set_current_page(const OUString& rIdent) override
     {
         gint nPage = get_page_index(rIdent);
         set_current_page(nPage);
@@ -9414,7 +9415,7 @@ public:
         return nLen;
     }
 
-    virtual OUString get_tab_label_text(const OString& rIdent) const override
+    virtual OUString get_tab_label_text(const OUString& rIdent) const override
     {
         gint nPageNum = get_page_number(m_pNotebook, rIdent);
         if (nPageNum != -1)
@@ -9425,7 +9426,7 @@ public:
         return OUString();
     }
 
-    virtual void set_tab_label_text(const OString& rIdent, const OUString& rText) override
+    virtual void set_tab_label_text(const OUString& rIdent, const OUString& rText) override
     {
         gint nPageNum = get_page_number(m_pNotebook, rIdent);
         if (nPageNum != -1)
@@ -9491,7 +9492,7 @@ public:
         m_nEndTabCount = 0;
     }
 
-    virtual void remove_page(const OString& rIdent) override
+    virtual void remove_page(const OUString& rIdent) override
     {
         if (m_bOverFlowBoxActive)
         {
@@ -9504,7 +9505,7 @@ public:
             m_aPages.erase(m_aPages.begin() + nPageIndex);
     }
 
-    virtual void insert_page(const OString& rIdent, const OUString& rLabel, int nPos) override
+    virtual void insert_page(const OUString& rIdent, const OUString& rLabel, int nPos) override
     {
         if (m_bOverFlowBoxActive)
         {
@@ -10846,7 +10847,7 @@ public:
         MenuHelper::insert_separator(pos, rId);
     }
 
-    virtual void remove_item(const OString& rId) override
+    virtual void remove_item(const OUString& rId) override
     {
         MenuHelper::remove_item(rId);
     }
@@ -10856,32 +10857,32 @@ public:
         MenuHelper::clear_items();
     }
 
-    virtual void set_item_active(const OString& rIdent, bool bActive) override
+    virtual void set_item_active(const OUString& rIdent, bool bActive) override
     {
         MenuHelper::set_item_active(rIdent, bActive);
     }
 
-    virtual void set_item_sensitive(const OString& rIdent, bool bSensitive) override
+    virtual void set_item_sensitive(const OUString& rIdent, bool bSensitive) override
     {
         MenuHelper::set_item_sensitive(rIdent, bSensitive);
     }
 
-    virtual void set_item_label(const OString& rIdent, const OUString& rLabel) override
+    virtual void set_item_label(const OUString& rIdent, const OUString& rLabel) override
     {
         MenuHelper::set_item_label(rIdent, rLabel);
     }
 
-    virtual OUString get_item_label(const OString& rIdent) const override
+    virtual OUString get_item_label(const OUString& rIdent) const override
     {
         return MenuHelper::get_item_label(rIdent);
     }
 
-    virtual void set_item_visible(const OString& rIdent, bool bVisible) override
+    virtual void set_item_visible(const OUString& rIdent, bool bVisible) override
     {
         MenuHelper::set_item_visible(rIdent, bVisible);
     }
 
-    virtual void signal_item_activate(const OString& rIdent) override
+    virtual void signal_item_activate(const OUString& rIdent) override
     {
         signal_selected(rIdent);
     }
@@ -11275,7 +11276,7 @@ public:
         MenuHelper::insert_separator(pos, rId);
     }
 
-    virtual void remove_item(const OString& rId) override
+    virtual void remove_item(const OUString& rId) override
     {
         MenuHelper::remove_item(rId);
     }
@@ -11285,32 +11286,32 @@ public:
         MenuHelper::clear_items();
     }
 
-    virtual void set_item_active(const OString& rIdent, bool bActive) override
+    virtual void set_item_active(const OUString& rIdent, bool bActive) override
     {
         MenuHelper::set_item_active(rIdent, bActive);
     }
 
-    virtual void set_item_sensitive(const OString& rIdent, bool bSensitive) override
+    virtual void set_item_sensitive(const OUString& rIdent, bool bSensitive) override
     {
         MenuHelper::set_item_sensitive(rIdent, bSensitive);
     }
 
-    virtual void set_item_label(const OString& rIdent, const OUString& rLabel) override
+    virtual void set_item_label(const OUString& rIdent, const OUString& rLabel) override
     {
         MenuHelper::set_item_label(rIdent, rLabel);
     }
 
-    virtual OUString get_item_label(const OString& rIdent) const override
+    virtual OUString get_item_label(const OUString& rIdent) const override
     {
         return MenuHelper::get_item_label(rIdent);
     }
 
-    virtual void set_item_visible(const OString& rIdent, bool bVisible) override
+    virtual void set_item_visible(const OUString& rIdent, bool bVisible) override
     {
         MenuHelper::set_item_visible(rIdent, bVisible);
     }
 
-    virtual void signal_item_activate(const OString& rIdent) override
+    virtual void signal_item_activate(const OUString& rIdent) override
     {
         signal_selected(rIdent);
     }
@@ -11327,13 +11328,13 @@ protected:
 #if !GTK_CHECK_VERSION(4, 0, 0)
     std::vector<GtkMenuItem*> m_aExtraItems;
 #endif
-    OString m_sActivated;
+    OUString m_sActivated;
 #if !GTK_CHECK_VERSION(4, 0, 0)
     MenuHelper* m_pTopLevelMenuHelper;
 #endif
 
 private:
-    virtual void signal_item_activate(const OString& rIdent) override
+    virtual void signal_item_activate(const OUString& rIdent) override
     {
         m_sActivated = rIdent;
         weld::Menu::signal_activate(m_sActivated);
@@ -11401,7 +11402,7 @@ public:
 #endif
     }
 
-    virtual OString popup_at_rect(weld::Widget* pParent, const tools::Rectangle& rRect, weld::Placement ePlace) override
+    virtual OUString popup_at_rect(weld::Widget* pParent, const tools::Rectangle& rRect, weld::Placement ePlace) override
     {
         m_sActivated.clear();
 
@@ -11526,37 +11527,37 @@ public:
         return m_sActivated;
     }
 
-    virtual void set_sensitive(const OString& rIdent, bool bSensitive) override
+    virtual void set_sensitive(const OUString& rIdent, bool bSensitive) override
     {
         set_item_sensitive(rIdent, bSensitive);
     }
 
-    virtual bool get_sensitive(const OString& rIdent) const override
+    virtual bool get_sensitive(const OUString& rIdent) const override
     {
         return get_item_sensitive(rIdent);
     }
 
-    virtual void set_active(const OString& rIdent, bool bActive) override
+    virtual void set_active(const OUString& rIdent, bool bActive) override
     {
         set_item_active(rIdent, bActive);
     }
 
-    virtual bool get_active(const OString& rIdent) const override
+    virtual bool get_active(const OUString& rIdent) const override
     {
         return get_item_active(rIdent);
     }
 
-    virtual void set_visible(const OString& rIdent, bool bShow) override
+    virtual void set_visible(const OUString& rIdent, bool bShow) override
     {
         set_item_visible(rIdent, bShow);
     }
 
-    virtual void set_label(const OString& rIdent, const OUString& rLabel) override
+    virtual void set_label(const OUString& rIdent, const OUString& rLabel) override
     {
         set_item_label(rIdent, rLabel);
     }
 
-    virtual OUString get_label(const OString& rIdent) const override
+    virtual OUString get_label(const OUString& rIdent) const override
     {
         return get_item_label(rIdent);
     }
@@ -11613,7 +11614,7 @@ public:
         if (eCheckRadioFalse == TRISTATE_FALSE)
             gtk_check_menu_item_set_draw_as_radio(GTK_CHECK_MENU_ITEM(pItem), true);
 
-        ::set_buildable_id(GTK_BUILDABLE(pItem), OUStringToOString(rId, RTL_TEXTENCODING_UTF8));
+        ::set_buildable_id(GTK_BUILDABLE(pItem), rId);
         gtk_menu_shell_append(GTK_MENU_SHELL(m_pMenu), pItem);
         gtk_widget_show(pItem);
         GtkMenuItem* pMenuItem = GTK_MENU_ITEM(pItem);
@@ -11651,7 +11652,7 @@ public:
 #endif
     }
 
-    virtual OString get_id(int pos) const override
+    virtual OUString get_id(int pos) const override
     {
         return get_item_id(pos);
     }
@@ -11661,7 +11662,7 @@ public:
         return get_n_children();
     }
 
-    void remove(const OString& rIdent) override
+    void remove(const OUString& rIdent) override
     {
 #if !GTK_CHECK_VERSION(4, 0, 0)
         if (!m_aExtraItems.empty())
@@ -11819,9 +11820,9 @@ private:
 #endif
     GtkCssProvider *m_pMenuButtonProvider;
 
-    std::map<OString, GtkWidget*> m_aMap;
-    std::map<OString, std::unique_ptr<GtkInstanceMenuButton>> m_aMenuButtonMap;
-    std::map<OString, bool> m_aMirroredMap;
+    std::map<OUString, GtkWidget*> m_aMap;
+    std::map<OUString, std::unique_ptr<GtkInstanceMenuButton>> m_aMenuButtonMap;
+    std::map<OUString, bool> m_aMirroredMap;
 
 #if !GTK_CHECK_VERSION(4, 0, 0)
     // at the time of writing there is no gtk_menu_tool_button_set_popover available
@@ -11872,7 +11873,7 @@ private:
 
     void add_to_map(GtkWidget* pToolItem, GtkMenuButton* pMenuButton)
     {
-        OString id = ::get_buildable_id(GTK_BUILDABLE(pToolItem));
+        OUString id = ::get_buildable_id(GTK_BUILDABLE(pToolItem));
         m_aMap[id] = pToolItem;
         if (pMenuButton)
         {
@@ -12089,36 +12090,36 @@ public:
         }
     }
 
-    virtual void set_item_sensitive(const OString& rIdent, bool bSensitive) override
+    virtual void set_item_sensitive(const OUString& rIdent, bool bSensitive) override
     {
         disable_item_notify_events();
         gtk_widget_set_sensitive(GTK_WIDGET(m_aMap[rIdent]), bSensitive);
         enable_item_notify_events();
     }
 
-    virtual bool get_item_sensitive(const OString& rIdent) const override
+    virtual bool get_item_sensitive(const OUString& rIdent) const override
     {
         return gtk_widget_get_sensitive(GTK_WIDGET(m_aMap.find(rIdent)->second));
     }
 
-    virtual void set_item_visible(const OString& rIdent, bool bVisible) override
+    virtual void set_item_visible(const OUString& rIdent, bool bVisible) override
     {
         disable_item_notify_events();
         gtk_widget_set_visible(GTK_WIDGET(m_aMap[rIdent]), bVisible);
         enable_item_notify_events();
     }
 
-    virtual void set_item_help_id(const OString& rIdent, const OString& rHelpId) override
+    virtual void set_item_help_id(const OUString& rIdent, const OUString& rHelpId) override
     {
         ::set_help_id(GTK_WIDGET(m_aMap[rIdent]), rHelpId);
     }
 
-    virtual bool get_item_visible(const OString& rIdent) const override
+    virtual bool get_item_visible(const OUString& rIdent) const override
     {
         return gtk_widget_get_visible(GTK_WIDGET(m_aMap.find(rIdent)->second));
     }
 
-    virtual void set_item_active(const OString& rIdent, bool bActive) override
+    virtual void set_item_active(const OUString& rIdent, bool bActive) override
     {
         disable_item_notify_events();
 
@@ -12159,7 +12160,7 @@ public:
         enable_item_notify_events();
     }
 
-    virtual bool get_item_active(const OString& rIdent) const override
+    virtual bool get_item_active(const OUString& rIdent) const override
     {
         GtkWidget* pToolButton = m_aMap.find(rIdent)->second;
 
@@ -12192,7 +12193,7 @@ public:
         return false;
     }
 
-    virtual void set_menu_item_active(const OString& rIdent, bool bActive) override
+    virtual void set_menu_item_active(const OUString& rIdent, bool bActive) override
     {
         disable_item_notify_events();
 
@@ -12203,7 +12204,7 @@ public:
         enable_item_notify_events();
     }
 
-    virtual bool get_menu_item_active(const OString& rIdent) const override
+    virtual bool get_menu_item_active(const OUString& rIdent) const override
     {
         auto aFind = m_aMenuButtonMap.find(rIdent);
         assert (aFind != m_aMenuButtonMap.end());
@@ -12212,13 +12213,12 @@ public:
 
     virtual void insert_item(int pos, const OUString& rId) override
     {
-        OString sId = OUStringToOString(rId, RTL_TEXTENCODING_UTF8);
 #if !GTK_CHECK_VERSION(4, 0, 0)
-        GtkToolItem* pItem = gtk_tool_button_new(nullptr, sId.getStr());
+        GtkToolItem* pItem = gtk_tool_button_new(nullptr, OUStringToOString(rId, RTL_TEXTENCODING_UTF8).getStr());
 #else
         GtkWidget* pItem = gtk_button_new();
 #endif
-        ::set_buildable_id(GTK_BUILDABLE(pItem), sId);
+        ::set_buildable_id(GTK_BUILDABLE(pItem), rId);
 #if !GTK_CHECK_VERSION(4, 0, 0)
         gtk_toolbar_insert(m_pToolbar, pItem, pos);
 #else
@@ -12230,13 +12230,12 @@ public:
 
     virtual void insert_separator(int pos, const OUString& rId) override
     {
-        OString sId = OUStringToOString(rId, RTL_TEXTENCODING_UTF8);
 #if !GTK_CHECK_VERSION(4, 0, 0)
         GtkToolItem* pItem = gtk_separator_tool_item_new();
 #else
         GtkWidget* pItem = gtk_separator_new(GTK_ORIENTATION_VERTICAL);
 #endif
-        ::set_buildable_id(GTK_BUILDABLE(pItem), sId);
+        ::set_buildable_id(GTK_BUILDABLE(pItem), rId);
 #if !GTK_CHECK_VERSION(4, 0, 0)
         gtk_toolbar_insert(m_pToolbar, pItem, pos);
 #else
@@ -12245,12 +12244,12 @@ public:
         gtk_widget_show(GTK_WIDGET(pItem));
     }
 
-    virtual void set_item_popover(const OString& rIdent, weld::Widget* pPopover) override
+    virtual void set_item_popover(const OUString& rIdent, weld::Widget* pPopover) override
     {
         m_aMenuButtonMap[rIdent]->set_popover(pPopover);
     }
 
-    virtual void set_item_menu(const OString& rIdent, weld::Menu* pMenu) override
+    virtual void set_item_menu(const OUString& rIdent, weld::Menu* pMenu) override
     {
         m_aMenuButtonMap[rIdent]->set_menu(pMenu);
     }
@@ -12270,15 +12269,15 @@ public:
 #endif
     }
 
-    virtual OString get_item_ident(int nIndex) const override
+    virtual OUString get_item_ident(int nIndex) const override
     {
         auto* pItem = toolbar_get_nth_item(nIndex);
         return ::get_buildable_id(GTK_BUILDABLE(pItem));
     }
 
-    virtual void set_item_ident(int nIndex, const OString& rIdent) override
+    virtual void set_item_ident(int nIndex, const OUString& rIdent) override
     {
-        OString sOldIdent(get_item_ident(nIndex));
+        OUString sOldIdent(get_item_ident(nIndex));
         m_aMap.erase(m_aMap.find(sOldIdent));
 
         auto* pItem = toolbar_get_nth_item(nIndex);
@@ -12311,7 +12310,7 @@ public:
 #endif
     }
 
-    virtual void set_item_label(const OString& rIdent, const OUString& rLabel) override
+    virtual void set_item_label(const OUString& rIdent, const OUString& rLabel) override
     {
         GtkWidget* pItem = m_aMap[rIdent];
 #if !GTK_CHECK_VERSION(4, 0, 0)
@@ -12325,7 +12324,7 @@ public:
 #endif
     }
 
-    OUString get_item_label(const OString& rIdent) const override
+    OUString get_item_label(const OUString& rIdent) const override
     {
 #if !GTK_CHECK_VERSION(4, 0, 0)
         const gchar* pText = gtk_tool_button_get_label(GTK_TOOL_BUTTON(m_aMap.find(rIdent)->second));
@@ -12335,7 +12334,7 @@ public:
         return OUString(pText, pText ? strlen(pText) : 0, RTL_TEXTENCODING_UTF8);
     }
 
-    virtual void set_item_icon_name(const OString& rIdent, const OUString& rIconName) override
+    virtual void set_item_icon_name(const OUString& rIdent, const OUString& rIconName) override
     {
         GtkWidget* pItem = m_aMap[rIdent];
 #if !GTK_CHECK_VERSION(4, 0, 0)
@@ -12359,12 +12358,12 @@ public:
 #endif
     }
 
-    virtual void set_item_image_mirrored(const OString& rIdent, bool bMirrored) override
+    virtual void set_item_image_mirrored(const OUString& rIdent, bool bMirrored) override
     {
         m_aMirroredMap[rIdent] = bMirrored;
     }
 
-    virtual void set_item_image(const OString& rIdent, const css::uno::Reference<css::graphic::XGraphic>& rIcon) override
+    virtual void set_item_image(const OUString& rIdent, const css::uno::Reference<css::graphic::XGraphic>& rIcon) override
     {
         GtkWidget* pItem = m_aMap[rIdent];
         auto it = m_aMirroredMap.find(rIdent);
@@ -12380,7 +12379,7 @@ public:
 #endif
     }
 
-    virtual void set_item_image(const OString& rIdent, VirtualDevice* pDevice) override
+    virtual void set_item_image(const OUString& rIdent, VirtualDevice* pDevice) override
     {
         GtkWidget* pItem = m_aMap[rIdent];
 #if !GTK_CHECK_VERSION(4, 0, 0)
@@ -12412,13 +12411,13 @@ public:
         gtk_widget_set_tooltip_text(GTK_WIDGET(pItem), OUStringToOString(rTip, RTL_TEXTENCODING_UTF8).getStr());
     }
 
-    virtual void set_item_tooltip_text(const OString& rIdent, const OUString& rTip) override
+    virtual void set_item_tooltip_text(const OUString& rIdent, const OUString& rTip) override
     {
         GtkWidget* pItem = GTK_WIDGET(m_aMap[rIdent]);
         gtk_widget_set_tooltip_text(pItem, OUStringToOString(rTip, RTL_TEXTENCODING_UTF8).getStr());
     }
 
-    virtual OUString get_item_tooltip_text(const OString& rIdent) const override
+    virtual OUString get_item_tooltip_text(const OUString& rIdent) const override
     {
         GtkWidget* pItem = GTK_WIDGET(m_aMap.find(rIdent)->second);
         const gchar* pStr = gtk_widget_get_tooltip_text(pItem);
@@ -19036,7 +19035,7 @@ public:
         , m_pComboBox(pComboBox)
     {
     }
-    virtual void signal_item_activate(const OString& /*rIdent*/) override
+    virtual void signal_item_activate(const OUString& /*rIdent*/) override
     {
         gtk_toggle_button_set_active(m_pComboBox, false);
     }
@@ -19062,11 +19061,11 @@ gboolean signalTooltipQuery(GtkWidget* pWidget, gint /*x*/, gint /*y*/,
 #endif
 
         // fallback to the mechanism which needs help installed
-        OString sHelpId = ::get_help_id(pWidget);
+        OUString sHelpId = ::get_help_id(pWidget);
         Help* pHelp = !sHelpId.isEmpty() ? Application::GetHelp() : nullptr;
         if (pHelp)
         {
-            OUString sHelpText = pHelp->GetHelpText(OStringToOUString(sHelpId, RTL_TEXTENCODING_UTF8), static_cast<weld::Widget*>(nullptr));
+            OUString sHelpText = pHelp->GetHelpText(sHelpId, static_cast<weld::Widget*>(nullptr));
             if (!sHelpText.isEmpty())
             {
                 gtk_tooltip_set_text(tooltip, OUStringToOString(sHelpText, RTL_TEXTENCODING_UTF8).getStr());
@@ -20756,7 +20755,7 @@ public:
         return create_virtual_device();
     }
 
-    virtual void set_item_menu(const OString& rIdent, weld::Menu* pMenu) override
+    virtual void set_item_menu(const OUString& rIdent, weld::Menu* pMenu) override
     {
 #if 0
         m_xCustomMenuButtonHelper.reset();
@@ -20767,7 +20766,7 @@ public:
         gtk_widget_queue_resize_no_redraw(GTK_WIDGET(m_pOverlayButton)); // force location recalc
         if (pMenuWidget)
             m_xCustomMenuButtonHelper.reset(new CustomRenderMenuButtonHelper(GTK_MENU(pMenuWidget), GTK_TOGGLE_BUTTON(m_pToggleButton)));
-        m_sMenuButtonRow = OUString::fromUtf8(rIdent);
+        m_sMenuButtonRow = rIdent;
 #else
         (void)rIdent; (void)pMenu;
 #endif
@@ -22565,7 +22564,7 @@ public:
         return create_virtual_device();
     }
 
-    virtual void set_item_menu(const OString& rIdent, weld::Menu* pMenu) override
+    virtual void set_item_menu(const OUString& rIdent, weld::Menu* pMenu) override
     {
         m_xCustomMenuButtonHelper.reset();
         GtkInstanceMenu* pPopoverWidget = dynamic_cast<GtkInstanceMenu*>(pMenu);
@@ -22575,7 +22574,7 @@ public:
         gtk_widget_queue_resize_no_redraw(GTK_WIDGET(m_pOverlayButton)); // force location recalc
         if (pMenuWidget)
             m_xCustomMenuButtonHelper.reset(new CustomRenderMenuButtonHelper(GTK_MENU(pMenuWidget), GTK_TOGGLE_BUTTON(m_pToggleButton)));
-        m_sMenuButtonRow = OUString::fromUtf8(rIdent);
+        m_sMenuButtonRow = rIdent;
     }
 
     OUString get_mru_entries() const override
@@ -23004,7 +23003,7 @@ public:
         assert(false && "not implemented");
     }
 
-    virtual void set_item_menu(const OString&, weld::Menu*) override
+    virtual void set_item_menu(const OUString&, weld::Menu*) override
     {
         assert(false && "not implemented");
     }
@@ -23559,7 +23558,7 @@ class GtkInstanceBuilder : public weld::Builder
 {
 private:
     ResHookProc m_pStringReplace;
-    OString m_aUtf8HelpRoot;
+    OUString m_aHelpRoot;
     OUString m_aIconTheme;
     OUString m_aUILang;
     GtkBuilder* m_pBuilder;
@@ -23683,10 +23682,10 @@ private:
 #endif
 
         //set helpids
-        OString sBuildableName = ::get_buildable_id(GTK_BUILDABLE(pWidget));
+        OUString sBuildableName = ::get_buildable_id(GTK_BUILDABLE(pWidget));
         if (!sBuildableName.isEmpty())
         {
-            OString sHelpId = m_aUtf8HelpRoot + sBuildableName;
+            OUString sHelpId = m_aHelpRoot + sBuildableName;
             set_help_id(pWidget, sHelpId);
             //hook up for extended help
             const ImplSVHelpData& aHelpData = ImplGetSVHelpData();
@@ -23891,7 +23890,7 @@ public:
         if (nIdx != -1)
             sHelpRoot = sHelpRoot.copy(0, nIdx);
         sHelpRoot += "/";
-        m_aUtf8HelpRoot = OUStringToOString(sHelpRoot, RTL_TEXTENCODING_UTF8);
+        m_aHelpRoot = sHelpRoot;
         m_aIconTheme = Application::GetSettings().GetStyleSettings().DetermineIconTheme();
         m_aUILang = Application::GetSettings().GetUILanguageTag().getBcp47();
 
@@ -23966,9 +23965,9 @@ public:
         m_aMnemonicButtons.clear();
     }
 
-    OString get_current_page_help_id()
+    OUString get_current_page_help_id()
     {
-        OString sPageHelpId;
+        OUString sPageHelpId;
         // check to see if there is a notebook called tabcontrol and get the
         // helpid for the current page of that
         std::unique_ptr<weld::Notebook> xNotebook(weld_notebook("tabcontrol"));
@@ -24014,18 +24013,18 @@ public:
 #endif
     }
 
-    virtual std::unique_ptr<weld::MessageDialog> weld_message_dialog(const OString &id) override
+    virtual std::unique_ptr<weld::MessageDialog> weld_message_dialog(const OUString &id) override
     {
-        GtkMessageDialog* pMessageDialog = GTK_MESSAGE_DIALOG(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkMessageDialog* pMessageDialog = GTK_MESSAGE_DIALOG(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pMessageDialog)
             return nullptr;
         gtk_window_set_transient_for(GTK_WINDOW(pMessageDialog), GTK_WINDOW(widget_get_toplevel(m_pParentWidget)));
         return std::make_unique<GtkInstanceMessageDialog>(pMessageDialog, this, true);
     }
 
-    virtual std::unique_ptr<weld::Assistant> weld_assistant(const OString &id) override
+    virtual std::unique_ptr<weld::Assistant> weld_assistant(const OUString &id) override
     {
-        GtkAssistant* pAssistant = GTK_ASSISTANT(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkAssistant* pAssistant = GTK_ASSISTANT(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pAssistant)
             return nullptr;
         if (m_pParentWidget)
@@ -24033,9 +24032,9 @@ public:
         return std::make_unique<GtkInstanceAssistant>(pAssistant, this, true);
     }
 
-    virtual std::unique_ptr<weld::Dialog> weld_dialog(const OString &id) override
+    virtual std::unique_ptr<weld::Dialog> weld_dialog(const OUString &id) override
     {
-        GtkWindow* pDialog = GTK_WINDOW(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkWindow* pDialog = GTK_WINDOW(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pDialog)
             return nullptr;
         if (m_pParentWidget)
@@ -24086,21 +24085,21 @@ public:
         return std::make_unique<GtkInstanceDialog>(pDialog, this, true);
     }
 
-    virtual std::unique_ptr<weld::Widget> weld_widget(const OString &id) override
+    virtual std::unique_ptr<weld::Widget> weld_widget(const OUString &id) override
     {
-        GtkWidget* pWidget = GTK_WIDGET(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkWidget* pWidget = GTK_WIDGET(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pWidget)
             return nullptr;
         auto_add_parentless_widgets_to_container(pWidget);
         return std::make_unique<GtkInstanceWidget>(pWidget, this, false);
     }
 
-    virtual std::unique_ptr<weld::Container> weld_container(const OString &id) override
+    virtual std::unique_ptr<weld::Container> weld_container(const OUString &id) override
     {
 #if !GTK_CHECK_VERSION(4, 0, 0)
-        GtkContainer* pContainer = GTK_CONTAINER(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkContainer* pContainer = GTK_CONTAINER(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
 #else
-        GtkWidget* pContainer = GTK_WIDGET(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkWidget* pContainer = GTK_WIDGET(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
 #endif
         if (!pContainer)
             return nullptr;
@@ -24108,72 +24107,72 @@ public:
         return std::make_unique<GtkInstanceContainer>(pContainer, this, false);
     }
 
-    virtual std::unique_ptr<weld::Box> weld_box(const OString &id) override
+    virtual std::unique_ptr<weld::Box> weld_box(const OUString &id) override
     {
-        GtkBox* pBox = GTK_BOX(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkBox* pBox = GTK_BOX(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pBox)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pBox));
         return std::make_unique<GtkInstanceBox>(pBox, this, false);
     }
 
-    virtual std::unique_ptr<weld::Paned> weld_paned(const OString &id) override
+    virtual std::unique_ptr<weld::Paned> weld_paned(const OUString &id) override
     {
-        GtkPaned* pPaned = GTK_PANED(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkPaned* pPaned = GTK_PANED(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pPaned)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pPaned));
         return std::make_unique<GtkInstancePaned>(pPaned, this, false);
     }
 
-    virtual std::unique_ptr<weld::Frame> weld_frame(const OString &id) override
+    virtual std::unique_ptr<weld::Frame> weld_frame(const OUString &id) override
     {
-        GtkFrame* pFrame = GTK_FRAME(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkFrame* pFrame = GTK_FRAME(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pFrame)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pFrame));
         return std::make_unique<GtkInstanceFrame>(pFrame, this, false);
     }
 
-    virtual std::unique_ptr<weld::ScrolledWindow> weld_scrolled_window(const OString &id, bool bUserManagedScrolling = false) override
+    virtual std::unique_ptr<weld::ScrolledWindow> weld_scrolled_window(const OUString &id, bool bUserManagedScrolling = false) override
     {
-        GtkScrolledWindow* pScrolledWindow = GTK_SCROLLED_WINDOW(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkScrolledWindow* pScrolledWindow = GTK_SCROLLED_WINDOW(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pScrolledWindow)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pScrolledWindow));
         return std::make_unique<GtkInstanceScrolledWindow>(pScrolledWindow, this, false, bUserManagedScrolling);
     }
 
-    virtual std::unique_ptr<weld::Notebook> weld_notebook(const OString &id) override
+    virtual std::unique_ptr<weld::Notebook> weld_notebook(const OUString &id) override
     {
-        GtkNotebook* pNotebook = GTK_NOTEBOOK(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkNotebook* pNotebook = GTK_NOTEBOOK(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pNotebook)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pNotebook));
         return std::make_unique<GtkInstanceNotebook>(pNotebook, this, false);
     }
 
-    virtual std::unique_ptr<weld::Button> weld_button(const OString &id) override
+    virtual std::unique_ptr<weld::Button> weld_button(const OUString &id) override
     {
-        GtkButton* pButton = GTK_BUTTON(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkButton* pButton = GTK_BUTTON(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pButton)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pButton));
         return std::make_unique<GtkInstanceButton>(pButton, this, false);
     }
 
-    virtual std::unique_ptr<weld::MenuButton> weld_menu_button(const OString &id) override
+    virtual std::unique_ptr<weld::MenuButton> weld_menu_button(const OUString &id) override
     {
-        GtkMenuButton* pButton = GTK_MENU_BUTTON(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkMenuButton* pButton = GTK_MENU_BUTTON(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pButton)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pButton));
         return std::make_unique<GtkInstanceMenuButton>(pButton, nullptr, this, false);
     }
 
-    virtual std::unique_ptr<weld::MenuToggleButton> weld_menu_toggle_button(const OString &id) override
+    virtual std::unique_ptr<weld::MenuToggleButton> weld_menu_toggle_button(const OUString &id) override
     {
-        GtkMenuButton* pButton = GTK_MENU_BUTTON(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkMenuButton* pButton = GTK_MENU_BUTTON(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pButton)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pButton));
@@ -24182,30 +24181,30 @@ public:
         return std::make_unique<GtkInstanceMenuToggleButton>(pMenuToggleButton, pButton, this, false);
     }
 
-    virtual std::unique_ptr<weld::LinkButton> weld_link_button(const OString &id) override
+    virtual std::unique_ptr<weld::LinkButton> weld_link_button(const OUString &id) override
     {
-        GtkLinkButton* pButton = GTK_LINK_BUTTON(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkLinkButton* pButton = GTK_LINK_BUTTON(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pButton)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pButton));
         return std::make_unique<GtkInstanceLinkButton>(pButton, this, false);
     }
 
-    virtual std::unique_ptr<weld::ToggleButton> weld_toggle_button(const OString &id) override
+    virtual std::unique_ptr<weld::ToggleButton> weld_toggle_button(const OUString &id) override
     {
-        GtkToggleButton* pToggleButton = GTK_TOGGLE_BUTTON(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkToggleButton* pToggleButton = GTK_TOGGLE_BUTTON(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pToggleButton)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pToggleButton));
         return std::make_unique<GtkInstanceToggleButton>(pToggleButton, this, false);
     }
 
-    virtual std::unique_ptr<weld::RadioButton> weld_radio_button(const OString &id) override
+    virtual std::unique_ptr<weld::RadioButton> weld_radio_button(const OUString &id) override
     {
 #if GTK_CHECK_VERSION(4, 0, 0)
-        GtkCheckButton* pRadioButton = GTK_CHECK_BUTTON(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkCheckButton* pRadioButton = GTK_CHECK_BUTTON(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
 #else
-        GtkRadioButton* pRadioButton = GTK_RADIO_BUTTON(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkRadioButton* pRadioButton = GTK_RADIO_BUTTON(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
 #endif
         if (!pRadioButton)
             return nullptr;
@@ -24213,45 +24212,45 @@ public:
         return std::make_unique<GtkInstanceRadioButton>(pRadioButton, this, false);
     }
 
-    virtual std::unique_ptr<weld::CheckButton> weld_check_button(const OString &id) override
+    virtual std::unique_ptr<weld::CheckButton> weld_check_button(const OUString &id) override
     {
-        GtkCheckButton* pCheckButton = GTK_CHECK_BUTTON(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkCheckButton* pCheckButton = GTK_CHECK_BUTTON(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pCheckButton)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pCheckButton));
         return std::make_unique<GtkInstanceCheckButton>(pCheckButton, this, false);
     }
 
-    virtual std::unique_ptr<weld::Scale> weld_scale(const OString &id) override
+    virtual std::unique_ptr<weld::Scale> weld_scale(const OUString &id) override
     {
-        GtkScale* pScale = GTK_SCALE(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkScale* pScale = GTK_SCALE(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pScale)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pScale));
         return std::make_unique<GtkInstanceScale>(pScale, this, false);
     }
 
-    virtual std::unique_ptr<weld::ProgressBar> weld_progress_bar(const OString &id) override
+    virtual std::unique_ptr<weld::ProgressBar> weld_progress_bar(const OUString &id) override
     {
-        GtkProgressBar* pProgressBar = GTK_PROGRESS_BAR(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkProgressBar* pProgressBar = GTK_PROGRESS_BAR(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pProgressBar)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pProgressBar));
         return std::make_unique<GtkInstanceProgressBar>(pProgressBar, this, false);
     }
 
-    virtual std::unique_ptr<weld::Spinner> weld_spinner(const OString &id) override
+    virtual std::unique_ptr<weld::Spinner> weld_spinner(const OUString &id) override
     {
-        GtkSpinner* pSpinner = GTK_SPINNER(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkSpinner* pSpinner = GTK_SPINNER(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pSpinner)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pSpinner));
         return std::make_unique<GtkInstanceSpinner>(pSpinner, this, false);
     }
 
-    virtual std::unique_ptr<weld::Image> weld_image(const OString &id) override
+    virtual std::unique_ptr<weld::Image> weld_image(const OUString &id) override
     {
-        GtkWidget* pWidget = GTK_WIDGET(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkWidget* pWidget = GTK_WIDGET(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pWidget)
             return nullptr;
         if (GTK_IS_IMAGE(pWidget))
@@ -24269,50 +24268,50 @@ public:
         return nullptr;
     }
 
-    virtual std::unique_ptr<weld::Calendar> weld_calendar(const OString &id) override
+    virtual std::unique_ptr<weld::Calendar> weld_calendar(const OUString &id) override
     {
-        GtkCalendar* pCalendar = GTK_CALENDAR(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkCalendar* pCalendar = GTK_CALENDAR(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pCalendar)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pCalendar));
         return std::make_unique<GtkInstanceCalendar>(pCalendar, this, false);
     }
 
-    virtual std::unique_ptr<weld::Entry> weld_entry(const OString &id) override
+    virtual std::unique_ptr<weld::Entry> weld_entry(const OUString &id) override
     {
-        GtkEntry* pEntry = GTK_ENTRY(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkEntry* pEntry = GTK_ENTRY(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pEntry)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pEntry));
         return std::make_unique<GtkInstanceEntry>(pEntry, this, false);
     }
 
-    virtual std::unique_ptr<weld::SpinButton> weld_spin_button(const OString &id) override
+    virtual std::unique_ptr<weld::SpinButton> weld_spin_button(const OUString &id) override
     {
-        GtkSpinButton* pSpinButton = GTK_SPIN_BUTTON(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkSpinButton* pSpinButton = GTK_SPIN_BUTTON(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pSpinButton)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pSpinButton));
         return std::make_unique<GtkInstanceSpinButton>(pSpinButton, this, false);
     }
 
-    virtual std::unique_ptr<weld::MetricSpinButton> weld_metric_spin_button(const OString& id, FieldUnit eUnit) override
+    virtual std::unique_ptr<weld::MetricSpinButton> weld_metric_spin_button(const OUString& id, FieldUnit eUnit) override
     {
         return std::make_unique<weld::MetricSpinButton>(weld_spin_button(id), eUnit);
     }
 
-    virtual std::unique_ptr<weld::FormattedSpinButton> weld_formatted_spin_button(const OString &id) override
+    virtual std::unique_ptr<weld::FormattedSpinButton> weld_formatted_spin_button(const OUString &id) override
     {
-        GtkSpinButton* pSpinButton = GTK_SPIN_BUTTON(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkSpinButton* pSpinButton = GTK_SPIN_BUTTON(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pSpinButton)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pSpinButton));
         return std::make_unique<GtkInstanceFormattedSpinButton>(pSpinButton, this, false);
     }
 
-    virtual std::unique_ptr<weld::ComboBox> weld_combo_box(const OString &id) override
+    virtual std::unique_ptr<weld::ComboBox> weld_combo_box(const OUString &id) override
     {
-        GtkComboBox* pComboBox = GTK_COMBO_BOX(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkComboBox* pComboBox = GTK_COMBO_BOX(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pComboBox)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pComboBox));
@@ -24352,30 +24351,30 @@ public:
 #endif
     }
 
-    virtual std::unique_ptr<weld::TreeView> weld_tree_view(const OString &id) override
+    virtual std::unique_ptr<weld::TreeView> weld_tree_view(const OUString &id) override
     {
-        GtkTreeView* pTreeView = GTK_TREE_VIEW(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkTreeView* pTreeView = GTK_TREE_VIEW(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pTreeView)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pTreeView));
         return std::make_unique<GtkInstanceTreeView>(pTreeView, this, false);
     }
 
-    virtual std::unique_ptr<weld::IconView> weld_icon_view(const OString &id) override
+    virtual std::unique_ptr<weld::IconView> weld_icon_view(const OUString &id) override
     {
-        GtkIconView* pIconView = GTK_ICON_VIEW(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkIconView* pIconView = GTK_ICON_VIEW(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pIconView)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pIconView));
         return std::make_unique<GtkInstanceIconView>(pIconView, this, false);
     }
 
-    virtual std::unique_ptr<weld::EntryTreeView> weld_entry_tree_view(const OString& containerid, const OString& entryid, const OString& treeviewid) override
+    virtual std::unique_ptr<weld::EntryTreeView> weld_entry_tree_view(const OUString& containerid, const OUString& entryid, const OUString& treeviewid) override
     {
 #if GTK_CHECK_VERSION(4, 0, 0)
-        GtkWidget* pContainer = GTK_WIDGET(gtk_builder_get_object(m_pBuilder, containerid.getStr()));
+        GtkWidget* pContainer = GTK_WIDGET(gtk_builder_get_object(m_pBuilder, OUStringToOString(containerid, RTL_TEXTENCODING_UTF8).getStr()));
 #else
-        GtkContainer* pContainer = GTK_CONTAINER(gtk_builder_get_object(m_pBuilder, containerid.getStr()));
+        GtkContainer* pContainer = GTK_CONTAINER(gtk_builder_get_object(m_pBuilder, OUStringToOString(containerid, RTL_TEXTENCODING_UTF8).getStr()));
 #endif
         if (!pContainer)
             return nullptr;
@@ -24385,58 +24384,58 @@ public:
                                                           weld_tree_view(treeviewid));
     }
 
-    virtual std::unique_ptr<weld::Label> weld_label(const OString &id) override
+    virtual std::unique_ptr<weld::Label> weld_label(const OUString &id) override
     {
-        GtkLabel* pLabel = GTK_LABEL(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkLabel* pLabel = GTK_LABEL(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pLabel)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pLabel));
         return std::make_unique<GtkInstanceLabel>(pLabel, this, false);
     }
 
-    virtual std::unique_ptr<weld::TextView> weld_text_view(const OString &id) override
+    virtual std::unique_ptr<weld::TextView> weld_text_view(const OUString &id) override
     {
-        GtkTextView* pTextView = GTK_TEXT_VIEW(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkTextView* pTextView = GTK_TEXT_VIEW(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pTextView)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pTextView));
         return std::make_unique<GtkInstanceTextView>(pTextView, this, false);
     }
 
-    virtual std::unique_ptr<weld::Expander> weld_expander(const OString &id) override
+    virtual std::unique_ptr<weld::Expander> weld_expander(const OUString &id) override
     {
-        GtkExpander* pExpander = GTK_EXPANDER(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkExpander* pExpander = GTK_EXPANDER(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pExpander)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pExpander));
         return std::make_unique<GtkInstanceExpander>(pExpander, this, false);
     }
 
-    virtual std::unique_ptr<weld::DrawingArea> weld_drawing_area(const OString &id, const a11yref& rA11y,
+    virtual std::unique_ptr<weld::DrawingArea> weld_drawing_area(const OUString &id, const a11yref& rA11y,
             FactoryFunction /*pUITestFactoryFunction*/, void* /*pUserData*/) override
     {
-        GtkDrawingArea* pDrawingArea = GTK_DRAWING_AREA(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkDrawingArea* pDrawingArea = GTK_DRAWING_AREA(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pDrawingArea)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pDrawingArea));
         return std::make_unique<GtkInstanceDrawingArea>(pDrawingArea, this, rA11y, false);
     }
 
-    virtual std::unique_ptr<weld::Menu> weld_menu(const OString &id) override
+    virtual std::unique_ptr<weld::Menu> weld_menu(const OUString &id) override
     {
 #if GTK_CHECK_VERSION(4, 0, 0)
-        GtkPopoverMenu* pMenu = GTK_POPOVER_MENU(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkPopoverMenu* pMenu = GTK_POPOVER_MENU(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
 #else
-        GtkMenu* pMenu = GTK_MENU(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkMenu* pMenu = GTK_MENU(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
 #endif
         if (!pMenu)
             return nullptr;
         return std::make_unique<GtkInstanceMenu>(pMenu, true);
     }
 
-    virtual std::unique_ptr<weld::Popover> weld_popover(const OString &id) override
+    virtual std::unique_ptr<weld::Popover> weld_popover(const OUString &id) override
     {
-        GtkPopover* pPopover = GTK_POPOVER(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkPopover* pPopover = GTK_POPOVER(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pPopover)
             return nullptr;
 #if GTK_CHECK_VERSION(4, 0, 0)
@@ -24446,12 +24445,12 @@ public:
 #endif
     }
 
-    virtual std::unique_ptr<weld::Toolbar> weld_toolbar(const OString &id) override
+    virtual std::unique_ptr<weld::Toolbar> weld_toolbar(const OUString &id) override
     {
 #if GTK_CHECK_VERSION(4, 0, 0)
-        GtkBox* pToolbar = GTK_BOX(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkBox* pToolbar = GTK_BOX(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
 #else
-        GtkToolbar* pToolbar = GTK_TOOLBAR(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkToolbar* pToolbar = GTK_TOOLBAR(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
 #endif
         if (!pToolbar)
             return nullptr;
@@ -24459,9 +24458,9 @@ public:
         return std::make_unique<GtkInstanceToolbar>(pToolbar, this, false);
     }
 
-    virtual std::unique_ptr<weld::Scrollbar> weld_scrollbar(const OString &id) override
+    virtual std::unique_ptr<weld::Scrollbar> weld_scrollbar(const OUString &id) override
     {
-        GtkScrollbar* pScrollbar = GTK_SCROLLBAR(gtk_builder_get_object(m_pBuilder, id.getStr()));
+        GtkScrollbar* pScrollbar = GTK_SCROLLBAR(gtk_builder_get_object(m_pBuilder, OUStringToOString(id, RTL_TEXTENCODING_UTF8).getStr()));
         if (!pScrollbar)
             return nullptr;
         auto_add_parentless_widgets_to_container(GTK_WIDGET(pScrollbar));
@@ -24482,7 +24481,7 @@ void GtkInstanceWindow::help()
     GtkWidget* pWidget = gtk_window_get_focus(m_pWindow);
     if (!pWidget)
         pWidget = GTK_WIDGET(m_pWindow);
-    OString sHelpId = ::get_help_id(pWidget);
+    OUString sHelpId = ::get_help_id(pWidget);
     while (sHelpId.isEmpty())
     {
         pWidget = gtk_widget_get_parent(pWidget);
@@ -24507,7 +24506,7 @@ void GtkInstanceWindow::help()
     // was the original id
     if (m_pBuilder && sHelpId.endsWith("/help"))
     {
-        OString sPageId = m_pBuilder->get_current_page_help_id();
+        OUString sPageId = m_pBuilder->get_current_page_help_id();
         if (!sPageId.isEmpty())
             sHelpId = sPageId;
         else
@@ -24531,12 +24530,12 @@ void GtkInstanceWindow::help()
         }
     }
 #endif
-    pHelp->Start(OStringToOUString(sHelpId, RTL_TEXTENCODING_UTF8), pSource);
+    pHelp->Start(sHelpId, pSource);
 }
 
 //iterate upwards through the hierarchy from this widgets through its parents
 //calling func with their helpid until func returns true or we run out of parents
-void GtkInstanceWidget::help_hierarchy_foreach(const std::function<bool(const OString&)>& func)
+void GtkInstanceWidget::help_hierarchy_foreach(const std::function<bool(const OUString&)>& func)
 {
     GtkWidget* pParent = m_pWidget;
     while ((pParent = gtk_widget_get_parent(pParent)))
@@ -24570,7 +24569,7 @@ gboolean GtkSalFrame::NativeWidgetHelpPressed(GtkAccelGroup*, GObject*, guint, G
     GtkWidget* pWidget = gtk_window_get_focus(pWindow);
     if (!pWidget)
         pWidget = GTK_WIDGET(pWindow);
-    OString sHelpId = ::get_help_id(pWidget);
+    OUString sHelpId = ::get_help_id(pWidget);
     while (sHelpId.isEmpty())
     {
         pWidget = gtk_widget_get_parent(pWidget);
@@ -24596,14 +24595,14 @@ gboolean GtkSalFrame::NativeWidgetHelpPressed(GtkAccelGroup*, GObject*, guint, G
         }
         if (!pChildWindow)
             return true;
-        pHelp->Start(OStringToOUString(sHelpId, RTL_TEXTENCODING_UTF8), pChildWindow);
+        pHelp->Start(sHelpId, pChildWindow);
         return true;
     }
 
     if (!pWidget)
         return true;
     std::unique_ptr<weld::Widget> xTemp(new GtkInstanceWidget(pWidget, nullptr, false));
-    pHelp->Start(OStringToOUString(sHelpId, RTL_TEXTENCODING_UTF8), xTemp.get());
+    pHelp->Start(sHelpId, xTemp.get());
     return true;
 }
 #endif
diff --git a/vcl/unx/gtk3/gtksalmenu.cxx b/vcl/unx/gtk3/gtksalmenu.cxx
index b03db5fa6cf6..a85bffa79c6e 100644
--- a/vcl/unx/gtk3/gtksalmenu.cxx
+++ b/vcl/unx/gtk3/gtksalmenu.cxx
@@ -797,7 +797,7 @@ namespace
 
 static void MenuButtonClicked(GtkWidget* pWidget, gpointer pMenu)
 {
-    OString aId(get_buildable_id(GTK_BUILDABLE(pWidget)));
+    OUString aId(get_buildable_id(GTK_BUILDABLE(pWidget)));
     static_cast<MenuBar*>(pMenu)->HandleMenuButtonEvent(aId.toUInt32());
 }
 
@@ -835,7 +835,7 @@ bool GtkSalMenu::AddMenuBarButton(const SalMenuButtonItem& rNewItem)
 
     maExtraButtons.emplace_back(rNewItem.mnId, pButton);
 
-    set_buildable_id(GTK_BUILDABLE(pButton), OString::number(rNewItem.mnId).getStr());
+    set_buildable_id(GTK_BUILDABLE(pButton), OUString::number(rNewItem.mnId));
 
     gtk_widget_set_tooltip_text(pButton, rNewItem.maToolTipText.toUtf8().getStr());
 
diff --git a/vcl/unx/gtk4/convert3to4.cxx b/vcl/unx/gtk4/convert3to4.cxx
index 272df9a5f74c..16c7403bb261 100644
--- a/vcl/unx/gtk4/convert3to4.cxx
+++ b/vcl/unx/gtk4/convert3to4.cxx
@@ -24,8 +24,8 @@ typedef std::pair<css::uno::Reference<css::xml::dom::XNode>, OUString> named_nod
 
 bool sortButtonNodes(const named_node& rA, const named_node& rB)
 {
-    OString sA(rA.second.toUtf8());
-    OString sB(rB.second.toUtf8());
+    OUString sA(rA.second);
+    OUString sB(rB.second);
     //order within groups according to platform rules
     return getButtonPriority(sA) < getButtonPriority(sB);
 }