Partial workaround for stale styling information with GTK3

We can trigger size events when we know the style cache has been updated.
See #16088

(backport of 101c43d0aa)

src/gtk/toplevel.cpp

@@ -53,6 +53,7 @@
 #endif // wxUSE_LIBHILDON2
 
 #ifdef __WXGTK3__
+extern GList* wx_sizeEventList;
 void wxGTKSizeRevalidate(wxWindow*);
 #endif
 
@@ -1049,9 +1050,7 @@ bool wxTopLevelWindowGTK::Show( bool show )
         // size_allocate signals occur in reverse order (bottom to top).
         // Things work better if the initial wxSizeEvents are sent (from the
         // top down), before the initial size_allocate signals occur.
-        wxSizeEvent event(GetSize(), GetId());
+        SendSizeEvent();
-        event.SetEventObject(this);
-        HandleWindowEvent(event);
 
 #ifdef __WXGTK3__
         wxGTKSizeRevalidate(this);
@@ -1060,6 +1059,14 @@ bool wxTopLevelWindowGTK::Show( bool show )
 
     bool change = base_type::Show(show);
 
+#ifdef __WXGTK3__
+    if (GList* p = g_list_find(wx_sizeEventList, this))
+    {
+        wx_sizeEventList = g_list_delete_link(wx_sizeEventList, p);
+        SendSizeEvent();
+    }
+#endif
+
     if (change && !show)
     {
         // make sure window has a non-default position, so when it is shown
@@ -1366,15 +1373,20 @@ void wxTopLevelWindowGTK::GTKUpdateDecorSize(const DecorSize& decorSize)
         // gtk_widget_show() was deferred, do it now
         m_deferShow = false;
         DoGetClientSize(&m_clientWidth, &m_clientHeight);
-        wxSizeEvent sizeEvent(GetSize(), GetId());
+        SendSizeEvent();
-        sizeEvent.SetEventObject(this);
-        HandleWindowEvent(sizeEvent);
 
 #ifdef __WXGTK3__
         wxGTKSizeRevalidate(this);
 #endif
         gtk_widget_show(m_widget);
 
+#ifdef __WXGTK3__
+        if (GList* p = g_list_find(wx_sizeEventList, this))
+        {
+            wx_sizeEventList = g_list_delete_link(wx_sizeEventList, p);
+            SendSizeEvent();
+        }
+#endif
         wxShowEvent showEvent(GetId(), true);
         showEvent.SetEventObject(this);
         HandleWindowEvent(showEvent);

src/gtk/window.cpp

@@ -222,6 +222,7 @@ int          g_lastButtonNumber = 0;
 #ifdef __WXGTK3__
 static GList* gs_sizeRevalidateList;
 static GSList* gs_queueResizeList;
+GList* wx_sizeEventList;
 static bool gs_inSizeAllocate;
 void wxGTKSizeRevalidate(wxWindow*);
 #endif
@@ -2583,7 +2584,8 @@ wxWindowGTK::~wxWindowGTK()
     if (m_styleProvider)
         g_object_unref(m_styleProvider);
 
-    gs_sizeRevalidateList = g_list_remove(gs_sizeRevalidateList, this);
+    gs_sizeRevalidateList = g_list_remove_all(gs_sizeRevalidateList, this);
+    wx_sizeEventList = g_list_remove(wx_sizeEventList, this);
 #endif
 
     gs_needCursorResetMap.erase(this);
@@ -2924,11 +2926,18 @@ void wxWindowGTK::DoSetSize( int x, int y, int width, int height, int sizeFlags
     if (height == -1)
         height = m_height;
 
-    const bool sizeChange = m_width != width || m_height != height;
+    bool sizeChange = m_width != width || m_height != height;
 
     if (sizeChange)
         m_useCachedClientSize = false;
 
+#ifdef __WXGTK3__
+    if (GList* p = g_list_find(wx_sizeEventList, this))
+    {
+        sizeChange = true;
+        wx_sizeEventList = g_list_delete_link(wx_sizeEventList, p);
+    }
+#endif
     if (sizeChange || m_x != x || m_y != y)
     {
         m_x = x;
@@ -4738,6 +4747,15 @@ void wxGTKSizeRevalidate(wxWindow* tlw)
         {
             win->InvalidateBestSize();
             gs_sizeRevalidateList = g_list_delete_link(gs_sizeRevalidateList, p);
+            for (;;)
+            {
+                win = win->GetParent();
+                if (win == NULL || g_list_find(wx_sizeEventList, win))
+                    break;
+                wx_sizeEventList = g_list_prepend(wx_sizeEventList, win);
+                if (win->IsTopLevel())
+                    break;
+            }
         }
     }
 }
@@ -4772,14 +4790,14 @@ bool wxWindowGTK::SetFont( const wxFont &font )
     // invalidate the best size right before the style cache is updated, so any
     // subsequent best size requests use the correct font.
     if (gtk_check_version(3,8,0) == NULL)
-        gs_sizeRevalidateList = g_list_append(gs_sizeRevalidateList, this);
+        gs_sizeRevalidateList = g_list_prepend(gs_sizeRevalidateList, this);
     else if (gtk_check_version(3,6,0) == NULL)
     {
         wxWindow* tlw = wxGetTopLevelParent(static_cast<wxWindow*>(this));
         if (tlw->m_widget && gtk_widget_get_visible(tlw->m_widget))
             g_idle_add_full(GTK_PRIORITY_RESIZE - 1, before_resize, this, NULL);
         else
-            gs_sizeRevalidateList = g_list_append(gs_sizeRevalidateList, this);
+            gs_sizeRevalidateList = g_list_prepend(gs_sizeRevalidateList, this);
     }
 #endif