[gtk/matthiasc/a11y] Simplify GetInterfaces handling

[Matthias Clasen <matthiasc src gnome org>]

commit 4b212f9e04de7a57a2938cdd98810462d4653c86
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun Oct 11 11:06:29 2020 -0400

    Simplify GetInterfaces handling
    
    It is error prone to keep the same conditions in sync
    in two places. Instead, just assemble the list of interfaces
    as we register objects, and use when GetInterfaces is called.

 gtk/a11y/gtkatspicontext.c | 32 ++++++++++++++------------------
 1 file changed, 14 insertions(+), 18 deletions(-)
---
diff --git a/gtk/a11y/gtkatspicontext.c b/gtk/a11y/gtkatspicontext.c
index e67485960f..ba21a2d509 100644
--- a/gtk/a11y/gtkatspicontext.c
+++ b/gtk/a11y/gtkatspicontext.c
@@ -79,6 +79,12 @@ struct _GtkAtSpiContext
    * associated to the GtkATContext
    */
   GDBusConnection *connection;
+
+  /* Accerciser refuses to work unless we implement a GetInterface
+   * call that returns a list of all implemented interfaces. We
+   * collect the answer here.
+   */
+  GVariant *interfaces;
 };
 
 enum
@@ -429,24 +435,7 @@ handle_accessible_method (GDBusConnection       *connection,
     }
   else if (g_strcmp0 (method_name, "GetInterfaces") == 0)
     {
-      GtkAccessible *accessible = gtk_at_context_get_accessible (GTK_AT_CONTEXT (self));
-      GVariantBuilder builder = G_VARIANT_BUILDER_INIT (G_VARIANT_TYPE ("as"));
-
-      g_variant_builder_add (&builder, "s", "org.a11y.atspi.Accessible");
-      if (GTK_IS_LABEL (accessible) ||
-          GTK_IS_TEXT (accessible) ||
-          GTK_IS_TEXT_VIEW (accessible))
-        g_variant_builder_add (&builder, "s", "org.a11y.atspi.Text");
-
-      if (GTK_IS_LEVEL_BAR (accessible) ||
-          GTK_IS_PANED (accessible) ||
-          GTK_IS_PROGRESS_BAR (accessible) ||
-          GTK_IS_RANGE (accessible) ||
-          GTK_IS_SCALE_BUTTON (accessible) ||
-          GTK_IS_SPIN_BUTTON (accessible))
-        g_variant_builder_add (&builder, "s", "org.a11y.atspi.Value");
-
-      g_dbus_method_invocation_return_value (invocation, g_variant_new ("(as)", &builder));
+      g_dbus_method_invocation_return_value (invocation, g_variant_new ("(@as)", self->interfaces));
     }
 
 }
@@ -1279,7 +1268,9 @@ static void
 gtk_at_spi_context_register_object (GtkAtSpiContext *self)
 {
   GtkWidget *widget = GTK_WIDGET (gtk_at_context_get_accessible (GTK_AT_CONTEXT (self)));
+  GVariantBuilder interfaces = G_VARIANT_BUILDER_INIT (G_VARIANT_TYPE_STRING_ARRAY);
 
+  g_variant_builder_add (&interfaces, "s", "org.a11y.atspi.Accessible");
   g_dbus_connection_register_object (self->connection,
                                      self->context_path,
                                      (GDBusInterfaceInfo *) &atspi_accessible_interface,
@@ -1292,6 +1283,7 @@ gtk_at_spi_context_register_object (GtkAtSpiContext *self)
       GTK_IS_TEXT (widget) ||
       GTK_IS_TEXT_VIEW (widget))
     {
+      g_variant_builder_add (&interfaces, "s", "org.a11y.atspi.Text");
       g_dbus_connection_register_object (self->connection,
                                          self->context_path,
                                          (GDBusInterfaceInfo *) &atspi_text_interface,
@@ -1308,6 +1300,7 @@ gtk_at_spi_context_register_object (GtkAtSpiContext *self)
       GTK_IS_SCALE_BUTTON (widget) ||
       GTK_IS_SPIN_BUTTON (widget))
     {
+      g_variant_builder_add (&interfaces, "s", "org.a11y.atspi.Value");
       g_dbus_connection_register_object (self->connection,
                                          self->context_path,
                                          (GDBusInterfaceInfo *) &atspi_value_interface,
@@ -1316,6 +1309,8 @@ gtk_at_spi_context_register_object (GtkAtSpiContext *self)
                                          NULL,
                                          NULL);
     }
+
+  self->interfaces = g_variant_ref_sink (g_variant_builder_end (&interfaces));
 }
 
 static void
@@ -1336,6 +1331,7 @@ gtk_at_spi_context_finalize (GObject *gobject)
 
   g_free (self->bus_address);
   g_free (self->context_path);
+  g_clear_pointer (&self->interfaces, g_variant_unref);
 
   G_OBJECT_CLASS (gtk_at_spi_context_parent_class)->finalize (gobject);
 }