[gtk/matthiasc/a11y: 4/7] atspicontext: Implement GetRelationSet

[Matthias Clasen <matthiasc src gnome org>]

commit 184ac7e2e83e2affe36035e03860a4b2509f08a2
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Oct 10 10:43:59 2020 -0400

    atspicontext: Implement GetRelationSet
    
    This translates relations as far as the match.
    
    I'm not sure yet what we can do about the fact that
    atspi expects relations to be bidirectional (ie have
    label-for *and* labelled-by) while aria has only one
    direction.

 gtk/a11y/gtkatspicontext.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
---
diff --git a/gtk/a11y/gtkatspicontext.c b/gtk/a11y/gtkatspicontext.c
index 32b85ffabd..b7031a9a92 100644
--- a/gtk/a11y/gtkatspicontext.c
+++ b/gtk/a11y/gtkatspicontext.c
@@ -180,6 +180,50 @@ collect_states (GtkAtSpiContext    *self,
   g_variant_builder_add (builder, "u", (guint32) (state >> 32));
 }
 
+static void
+collect_relations (GtkAtSpiContext *self,
+                   GVariantBuilder *builder)
+{
+  GtkATContext *ctx = GTK_AT_CONTEXT (self);
+  struct {
+    GtkAccessibleRelation r;
+    AtspiRelationType s;
+  } map[] = {
+    { GTK_ACCESSIBLE_RELATION_LABELLED_BY, ATSPI_RELATION_LABELLED_BY },
+    { GTK_ACCESSIBLE_RELATION_CONTROLS, ATSPI_RELATION_CONTROLLER_FOR },
+    { GTK_ACCESSIBLE_RELATION_DESCRIBED_BY, ATSPI_RELATION_DESCRIBED_BY },
+    { GTK_ACCESSIBLE_RELATION_FLOW_TO, ATSPI_RELATION_FLOWS_TO},
+  };
+  GtkAccessibleValue *value;
+  GList *list, *l;
+  GtkATContext *target_ctx;
+  const char *unique_name;
+  int i;
+
+  unique_name = g_dbus_connection_get_unique_name (self->connection);
+
+  for (i = 0; i < G_N_ELEMENTS (map); i++)
+    {
+      if (!gtk_at_context_has_accessible_relation (ctx, map[i].r))
+        continue;
+
+      GVariantBuilder b = G_VARIANT_BUILDER_INIT (G_VARIANT_TYPE ("a(so)"));
+
+      value = gtk_at_context_get_accessible_relation (ctx, map[i].r);
+      list = gtk_reference_list_accessible_value_get (value);
+
+      for (l = list; l; l = l->next)
+        {
+          target_ctx = gtk_accessible_get_at_context (GTK_ACCESSIBLE (l->data));
+          g_variant_builder_add (&b, "(so)",
+                                 unique_name,
+                                 GTK_AT_SPI_CONTEXT (target_ctx)->context_path);
+        }
+
+      g_variant_builder_add (builder, "(ua(so))", map[i].s, &b);
+    }
+}
+
 static void
 handle_accessible_method (GDBusConnection       *connection,
                           const gchar           *sender,
@@ -324,6 +368,12 @@ handle_accessible_method (GDBusConnection       *connection,
 
       g_dbus_method_invocation_return_value (invocation, g_variant_new ("(i)", idx));
     }
+  else if (g_strcmp0 (method_name, "GetRelationSet") == 0)
+    {
+      GVariantBuilder builder = G_VARIANT_BUILDER_INIT (G_VARIANT_TYPE ("a(ua(so))"));
+       collect_relations (self, &builder);
+      g_dbus_method_invocation_return_value (invocation, g_variant_new ("(a(ua(so)))", &builder));
+    }
   else if (g_strcmp0 (method_name, "GetInterfaces") == 0)
     {
       GtkAccessible *accessible = gtk_at_context_get_accessible (GTK_AT_CONTEXT (self));