From e7b290debbca685220a0c96ddc8c5aab13138f4f Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Sat, 24 Oct 2020 13:13:07 -0400
Subject: [PATCH] a11y: Improve child notification for toplevels

We need to translate the list model position into
an accessible tree position, since hidden toplevels
will be skipped.

While we are at it, add an api for this notification
that will be used in the next commit.
---
 gtk/a11y/gtkatspiroot.c        | 78 +++++++++++++++++++++++++---------
 gtk/a11y/gtkatspirootprivate.h |  6 +++
 2 files changed, 65 insertions(+), 19 deletions(-)

diff --git a/gtk/a11y/gtkatspiroot.c b/gtk/a11y/gtkatspiroot.c
index 8c35fb6a29..21beb2eab3 100644
--- a/gtk/a11y/gtkatspiroot.c
+++ b/gtk/a11y/gtkatspiroot.c
@@ -412,8 +412,59 @@ root_toplevels__items_changed (GtkAtSpiRoot *self,
                                guint         added,
                                GListModel   *toplevels)
 {
-  GtkWidget *window = g_list_model_get_item (self->toplevels, position);
-  GVariant *window_ref = NULL;
+  if (added == 1 && removed == 0)
+    {
+      GtkWidget *window;
+
+      window = GTK_WIDGET (g_list_model_get_item (self->toplevels, position));
+      gtk_at_spi_root_child_changed (self,
+                                     GTK_ACCESSIBLE_CHILD_STATE_ADDED,
+                                     G_MAXUINT,
+                                     window);
+      g_object_unref (window);
+    }
+  else if (added == 0 && removed == 1)
+    {
+      gtk_at_spi_root_child_changed (self,
+                                     GTK_ACCESSIBLE_CHILD_STATE_REMOVED,
+                                     position,
+                                     NULL);
+    }
+  else
+    {
+      g_assert_not_reached ();
+    }
+}
+
+void
+gtk_at_spi_root_child_changed (GtkAtSpiRoot             *self,
+                               GtkAccessibleChildState   state,
+                               guint                     position,
+                               GtkWidget                *window)
+{
+  guint n, i;
+  int idx = 0;
+  GVariant *window_ref;
+
+  /* We can be called either with a valid position and window == NULL
+   * or with position == G_MAXUINT and a valid window. In both cases,
+   * we need to determine the index of where the removed object would
+   * have been in the accessible tree.
+   */
+  for (i = 0, n = g_list_model_get_n_items (self->toplevels); i < n; i++)
+    {
+      GtkAccessible *item = g_list_model_get_item (self->toplevels, i);
+
+      g_object_unref (item);
+
+      if (i == position || item == GTK_ACCESSIBLE (window))
+        break;
+
+      if (!gtk_accessible_should_present (item))
+        continue;
+
+      idx++;
+    }
 
   if (window == NULL)
     {
@@ -426,23 +477,12 @@ root_toplevels__items_changed (GtkAtSpiRoot *self,
       window_ref = gtk_at_spi_context_to_ref (GTK_AT_SPI_CONTEXT (context));
     }
 
-  if (added == 1 && removed == 0)
-    gtk_at_spi_emit_children_changed (self->connection,
-                                      self->root_path,
-                                      GTK_ACCESSIBLE_CHILD_STATE_ADDED,
-                                      position,
-                                      gtk_at_spi_root_to_ref (self),
-                                      window_ref);
-  else if (removed == 1 && added == 0)
-    gtk_at_spi_emit_children_changed (self->connection,
-                                      self->root_path,
-                                      GTK_ACCESSIBLE_CHILD_STATE_REMOVED,
-                                      position,
-                                      gtk_at_spi_root_to_ref (self),
-                                      window_ref);
-
-  if (window != NULL)
-    g_object_unref (window);
+  gtk_at_spi_emit_children_changed (self->connection,
+                                    self->root_path,
+                                    state,
+                                    idx,
+                                    gtk_at_spi_root_to_ref (self),
+                                    window_ref);
 }
 
 static void
diff --git a/gtk/a11y/gtkatspirootprivate.h b/gtk/a11y/gtkatspirootprivate.h
index 0ce5e6b693..12cba41085 100644
--- a/gtk/a11y/gtkatspirootprivate.h
+++ b/gtk/a11y/gtkatspirootprivate.h
@@ -42,4 +42,10 @@ gtk_at_spi_root_get_cache (GtkAtSpiRoot *self);
 GVariant *
 gtk_at_spi_root_to_ref (GtkAtSpiRoot *self);
 
+void
+gtk_at_spi_root_child_changed (GtkAtSpiRoot             *self,
+                               GtkAccessibleChildState   state,
+                               guint                     position,
+                               GtkWidget                *window);
+
 G_END_DECLS
-- 
2.30.2