From 95ceb4977055a3659369551364088340321c1224 Mon Sep 17 00:00:00 2001
From: Emmanuele Bassi <ebassi@gnome.org>
Date: Thu, 21 Jan 2021 16:39:22 +0000
Subject: [PATCH] a11y: Make GtkATContext realization lazier

We only realize the ATContext on the top level, which will create an
GtkAtSpiRoot object and the corresponding GtkAtSpiCache object. Whenever
an AT connects to the accessibility bus, and asks for the various
objects, all the ATContext will be realized on demand.
---
 gtk/gtkwidget.c        | 26 +++++++++++++-------------
 gtk/gtkwidgetprivate.h |  3 +++
 gtk/gtkwindow.c        |  4 ++++
 3 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 5ac8b9ac84..217293cd23 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -2374,7 +2374,7 @@ gtk_widget_init (GTypeInstance *instance, gpointer g_class)
   priv->at_context = gtk_accessible_get_at_context (GTK_ACCESSIBLE (widget));
 }
 
-static void
+void
 gtk_widget_realize_at_context (GtkWidget *self)
 {
   GtkWidgetPrivate *priv = gtk_widget_get_instance_private (self);
@@ -2383,10 +2383,6 @@ gtk_widget_realize_at_context (GtkWidget *self)
   if (priv->at_context == NULL || gtk_at_context_is_realized (priv->at_context))
     return;
 
-  /* Realize the root ATContext first */
-  if (!GTK_IS_ROOT (self))
-    gtk_widget_realize_at_context (GTK_WIDGET (priv->root));
-
   /* Reset the accessible role to its current value */
   if (role == GTK_ACCESSIBLE_ROLE_WIDGET)
     {
@@ -2400,6 +2396,18 @@ gtk_widget_realize_at_context (GtkWidget *self)
   gtk_at_context_realize (priv->at_context);
 }
 
+void
+gtk_widget_unrealize_at_context (GtkWidget *widget)
+{
+  GtkWidgetPrivate *priv = gtk_widget_get_instance_private (widget);
+
+  if (priv->at_context != NULL)
+    {
+      gtk_at_context_set_display (priv->at_context, gdk_display_get_default ());
+      gtk_at_context_unrealize (priv->at_context);
+    }
+}
+
 void
 gtk_widget_root (GtkWidget *widget)
 {
@@ -2428,8 +2436,6 @@ gtk_widget_root (GtkWidget *widget)
   if (priv->layout_manager)
     gtk_layout_manager_set_root (priv->layout_manager, priv->root);
 
-  gtk_widget_realize_at_context (widget);
-
   GTK_WIDGET_GET_CLASS (widget)->root (widget);
 
   if (!GTK_IS_ROOT (widget))
@@ -2454,12 +2460,6 @@ gtk_widget_unroot (GtkWidget *widget)
 
   GTK_WIDGET_GET_CLASS (widget)->unroot (widget);
 
-  if (priv->at_context != NULL)
-    {
-      gtk_at_context_set_display (priv->at_context, gdk_display_get_default ());
-      gtk_at_context_unrealize (priv->at_context);
-    }
-
   if (priv->context)
     gtk_style_context_set_display (priv->context, gdk_display_get_default ());
 
diff --git a/gtk/gtkwidgetprivate.h b/gtk/gtkwidgetprivate.h
index eb6959fe7c..9848d4038f 100644
--- a/gtk/gtkwidgetprivate.h
+++ b/gtk/gtkwidgetprivate.h
@@ -373,6 +373,9 @@ gboolean gtk_widget_focus_self       (GtkWidget        *widget,
 void    gtk_widget_update_orientation   (GtkWidget      *widget,
                                          GtkOrientation  orientation);
 
+void    gtk_widget_realize_at_context   (GtkWidget *widget);
+void    gtk_widget_unrealize_at_context (GtkWidget *widget);
+
 /* inline getters */
 
 static inline GtkWidget *
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index d704f497b1..06835dc99c 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -3806,6 +3806,8 @@ gtk_window_map (GtkWidget *widget)
 
   if (priv->application)
     gtk_application_handle_window_map (priv->application, window);
+
+  gtk_widget_realize_at_context (widget);
 }
 
 static void
@@ -3818,6 +3820,8 @@ gtk_window_unmap (GtkWidget *widget)
   GTK_WIDGET_CLASS (gtk_window_parent_class)->unmap (widget);
   gdk_surface_hide (priv->surface);
 
+  gtk_widget_unrealize_at_context (widget);
+
   if (priv->title_box != NULL)
     gtk_widget_unmap (priv->title_box);
 
-- 
2.30.2