gtk_paint_box
     (
-        button->style,
+        gtk_widget_get_style(button),
         gdk_window,
         state,
         GTK_SHADOW_OUT,
     if (win->GetLayoutDirection() == wxLayout_RightToLeft)
         x_diff = rect.width;
 
-    // VZ: I don't know how to get the size of the expander so as to centre it
-    //     in the given rectangle, +2/3 below is just what looks good here...
+    // x and y parameters specify the center of the expander
     gtk_paint_expander
     (
-        tree->style,
+        gtk_widget_get_style(tree),
         gdk_window,
         state,
         NULL,
         tree,
         "treeview",
-        dc.LogicalToDeviceX(rect.x) + 6 - x_diff,
-        dc.LogicalToDeviceY(rect.y) + 3,
+        dc.LogicalToDeviceX(rect.x) + rect.width / 2 - x_diff,
+        dc.LogicalToDeviceY(rect.y) + rect.height / 2,
         flags & wxCONTROL_EXPANDED ? GTK_EXPANDER_EXPANDED
                                    : GTK_EXPANDER_COLLAPSED
     );
                                 wxOrientation orient,
                                 int flags)
 {
-    if ( !win->m_wxwindow->window )
+    if (gtk_widget_get_window(win->m_wxwindow) == NULL)
     {
         // window not realized yet
         return;
 
     gtk_paint_handle
     (
-        win->m_wxwindow->style,
+        gtk_widget_get_style(win->m_wxwindow),
         gdk_window,
         flags & wxCONTROL_CURRENT ? GTK_STATE_PRELIGHT : GTK_STATE_NORMAL,
         GTK_SHADOW_NONE,
     // draw arrow on button
     gtk_paint_arrow
     (
-        button->style,
+        gtk_widget_get_style(button),
         gdk_window,
         state,
         flags & wxCONTROL_PRESSED ? GTK_SHADOW_IN : GTK_SHADOW_OUT,
 
     gtk_paint_check
     (
-        button->style,
+        gtk_widget_get_style(button),
         gdk_window,
         state,
         shadow_type,
 
     gtk_paint_box
     (
-        button->style,
+        gtk_widget_get_style(button),
         gdk_window,
         state,
         flags & wxCONTROL_PRESSED ? GTK_SHADOW_IN : GTK_SHADOW_OUT,
 
         // the wxCONTROL_FOCUSED state is deduced
         // directly from the m_wxwindow by GTK+
-        gtk_paint_flat_box(wxGTKPrivate::GetTreeWidget()->style,
+        gtk_paint_flat_box(gtk_widget_get_style(wxGTKPrivate::GetTreeWidget()),
                         gdk_window,
                         GTK_STATE_SELECTED,
                         GTK_SHADOW_NONE,
     else
         state = GTK_STATE_NORMAL;
 
-    gtk_paint_focus( win->m_widget->style,
+    gtk_paint_focus( gtk_widget_get_style(win->m_widget),
                      gdk_window,
                      state,
                      NULL,
     if ( flags & wxCONTROL_DISABLED )
         state = GTK_STATE_INSENSITIVE;
 
-    if (flags & wxCONTROL_CURRENT )
-        GTK_WIDGET_SET_FLAGS( entry, GTK_HAS_FOCUS );
-    else
-        GTK_WIDGET_UNSET_FLAGS( entry, GTK_HAS_FOCUS );
+    gtk_widget_set_can_focus(entry, (flags & wxCONTROL_CURRENT) != 0);
 
     gtk_paint_shadow
     (
-        entry->style,
+        gtk_widget_get_style(entry),
         gdk_window,
         state,
         GTK_SHADOW_OUT,
     if ( flags & wxCONTROL_DISABLED )
        state = GTK_STATE_INSENSITIVE;
 
-    if (flags & wxCONTROL_CURRENT )
-        GTK_WIDGET_SET_FLAGS( combo, GTK_HAS_FOCUS );
-    else
-        GTK_WIDGET_UNSET_FLAGS( combo, GTK_HAS_FOCUS );
+    gtk_widget_set_can_focus(combo, (flags & wxCONTROL_CURRENT) != 0);
 
     gtk_paint_shadow
     (
-        combo->style,
+        gtk_widget_get_style(combo),
         gdk_window,
         state,
         GTK_SHADOW_OUT,
 
     gtk_paint_arrow
     (
-        combo->style,
+        gtk_widget_get_style(combo),
         gdk_window,
         state,
         GTK_SHADOW_OUT,
 
     gtk_paint_box
     (
-        combo->style,
+        gtk_widget_get_style(combo),
         gdk_window,
         state,
         GTK_SHADOW_ETCHED_OUT,
 
     gtk_paint_option
     (
-        button->style,
+        gtk_widget_get_style(button),
         gdk_window,
         state,
         shadow_type,