Add GtkAccel helper abstracting operations with GTK accelerators

This simple struct combines both the accelerator code and flags and is
simpler to work with than two different variables.

It will also allow reusing this functionality in the upcoming changes
more easily.

No real changes yet.

src/gtk/menu.cpp

@@ -36,8 +36,35 @@ extern int wxOpenModalDialogsCount;
 static const int wxGTK_TITLE_ID = -3;
 
 #if wxUSE_ACCEL
-static bool wxGetGtkAccel(const wxMenuItem*, guint*, GdkModifierType*);
-#endif
+namespace
+{
+
+// Simple struct encapsulating a GTK accelerator with wrappers for just the
+// operations that we need.
+class GtkAccel
+{
+public:
+    // Can be constructed from any menu item (must be valid, but doesn't have
+    // to be an accelerator).
+    explicit GtkAccel(const wxMenuItem* item);
+
+    // Default copy ctor, assignment operator and dtor are all OK.
+
+    bool IsOk() const { return m_key != 0; }
+
+    void Add(GtkWidget* widget, GtkAccelGroup* accelGroup, GtkAccelFlags accelFlags);
+    void Remove(GtkWidget* widget, GtkAccelGroup* accelGroup);
+
+private:
+    static wxString GetGtkHotKey(const wxMenuItem& item);
+
+    guint m_key;
+    GdkModifierType m_mods;
+};
+
+} // anonymous namespace
+
+#endif // wxUSE_ACCEL
 
 // Unity hack: under Ubuntu Unity the global menu bar is not affected by a
 // modal dialog being shown, so the user can select a menu item before hiding
@@ -642,12 +669,10 @@ void wxMenuItem::SetItemLabel( const wxString& str )
     if (m_menuItem)
     {
         // remove old accelerator
-        guint accel_key;
-        GdkModifierType accel_mods;
-        if ( wxGetGtkAccel(this, &accel_key, &accel_mods) )
+        GtkAccel gtkAccel(this);
+        if ( gtkAccel.IsOk() )
         {
-            gtk_widget_remove_accelerator(
-                m_menuItem, GetRootParentMenu(m_parentMenu)->m_accel, accel_key, accel_mods);
+            gtkAccel.Remove(m_menuItem, GetRootParentMenu(m_parentMenu)->m_accel);
         }
     }
 #endif // wxUSE_ACCEL
@@ -662,13 +687,11 @@ void wxMenuItem::SetGtkLabel()
     GtkLabel* label = GTK_LABEL(gtk_bin_get_child(GTK_BIN(m_menuItem)));
     gtk_label_set_text_with_mnemonic(label, wxGTK_CONV_SYS(text));
 #if wxUSE_ACCEL
-    guint accel_key;
-    GdkModifierType accel_mods;
-    if ( wxGetGtkAccel(this, &accel_key, &accel_mods) )
+    GtkAccel gtkAccel(this);
+    if ( gtkAccel.IsOk() )
     {
-        gtk_widget_add_accelerator(
-            m_menuItem, "activate", GetRootParentMenu(m_parentMenu)->m_accel,
-            accel_key, accel_mods, GTK_ACCEL_VISIBLE);
+        gtkAccel.Add(m_menuItem, GetRootParentMenu(m_parentMenu)->m_accel,
+                     GTK_ACCEL_VISIBLE);
     }
     else
     {
@@ -1038,7 +1061,8 @@ void wxMenu::Attach(wxMenuBarBase *menubar)
 
 #if wxUSE_ACCEL
 
-static wxString GetGtkHotKey( const wxMenuItem& item )
+/* static */
+wxString GtkAccel::GetGtkHotKey( const wxMenuItem& item )
 {
     wxString hotkey;
 
@@ -1320,26 +1344,33 @@ static wxString GetGtkHotKey( const wxMenuItem& item )
     return hotkey;
 }
 
-static bool
-wxGetGtkAccel(const wxMenuItem* item, guint* accel_key, GdkModifierType* accel_mods)
+GtkAccel::GtkAccel(const wxMenuItem* item)
 {
     const wxString string = GetGtkHotKey(*item);
     if (!string.empty())
     {
-        gtk_accelerator_parse(wxGTK_CONV_SYS(string), accel_key, accel_mods);
+        gtk_accelerator_parse(wxGTK_CONV_SYS(string), &m_key, &m_mods);
 
         // Normally, we detect all the keys considered invalid by GTK in
         // GetGtkHotKey(), but just in case GTK decides to add more invalid
         // keys in the future versions, recheck once again using its function.
-        if ( gtk_accelerator_valid(*accel_key, *accel_mods) )
-            return true;
-
+        if ( !gtk_accelerator_valid(m_key, m_mods) )
+        {
         wxLogDebug("\"%s\" is not a valid keyboard accelerator "
                    "for this GTK version",
                    string);
+            m_key = 0;
+        }
     }
-#ifndef __WXGTK4__
     else
+    {
+        // Key with this code can never be a valid accelerator, so we use
+        // it to indicate that it's invalid.
+        m_key = 0;
+    }
+
+#ifndef __WXGTK4__
+    if ( !IsOk() )
     {
         wxGCC_WARNING_SUPPRESS(deprecated-declarations)
 
@@ -1351,17 +1382,33 @@ wxGetGtkAccel(const wxMenuItem* item, guint* accel_key, GdkModifierType* accel_m
                 gtk_stock_lookup(stockid, &stock_item) &&
                     stock_item.keyval )
         {
-            *accel_key = stock_item.keyval;
-            *accel_mods = stock_item.modifier;
-
-            return true;
+            m_key = stock_item.keyval;
+            m_mods = stock_item.modifier;
         }
         wxGCC_WARNING_RESTORE()
     }
-#endif
-
-    return false;
+#endif // !__WXGTK4__
 }
+
+void
+GtkAccel::Add(GtkWidget* widget, GtkAccelGroup* accelGroup, GtkAccelFlags accelFlags)
+{
+    if ( IsOk() )
+    {
+        gtk_widget_add_accelerator(
+            widget, "activate", accelGroup,
+            m_key, m_mods, accelFlags);
+    }
+}
+
+void GtkAccel::Remove(GtkWidget* widget, GtkAccelGroup* accelGroup)
+{
+    if ( IsOk() )
+    {
+        gtk_widget_remove_accelerator(widget, accelGroup, m_key, m_mods);
+    }
+}
+
 #endif // wxUSE_ACCEL
 
 #ifndef __WXGTK4__