[gtk: 1/5] Set correct accessible relations for GtkMenuButton

[Matthias Clasen <matthiasc src gnome org>]

commit b664b2d1fd6779cc10b4759bc797f04da41a1146
Author: Lukáš Tyrychtr <lukastyrychtr gmail com>
Date:   Tue Sep 14 14:26:18 2021 +0200

    Set correct accessible relations for GtkMenuButton
    
    Up until now, as the focus was moved to the inner button, it was not possible for
    assistive technologies to determine the correct labels and descriptions
    because developers could set them only for the parent widget.
    Now, the proper relations are added so the labels should be picked up properly.
    
    Fixes #4254

 gtk/gtkmenubutton.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
---
diff --git a/gtk/gtkmenubutton.c b/gtk/gtkmenubutton.c
index 02eb13b4a0..6552165824 100644
--- a/gtk/gtkmenubutton.c
+++ b/gtk/gtkmenubutton.c
@@ -669,6 +669,10 @@ gtk_menu_button_init (GtkMenuButton *self)
   gtk_widget_set_sensitive (self->button, FALSE);
 
   gtk_widget_add_css_class (GTK_WIDGET (self), "popup");
+
+  gtk_accessible_update_relation (GTK_ACCESSIBLE (self->button), GTK_ACCESSIBLE_RELATION_LABELLED_BY, self, 
NULL,
+  GTK_ACCESSIBLE_RELATION_DESCRIBED_BY, self, NULL,
+                                  -1);
 }
 
 static GtkBuildableIface *parent_buildable_iface;
@@ -1017,6 +1021,9 @@ gtk_menu_button_set_icon_name (GtkMenuButton *menu_button,
   box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
   gtk_widget_set_halign (box, GTK_ALIGN_CENTER);
 
+  // Because we are setting only an icon, let the inner button be labeled by us, so the accessible label can 
be overridden
+  gtk_accessible_update_relation (GTK_ACCESSIBLE (menu_button->button), GTK_ACCESSIBLE_RELATION_LABELLED_BY, 
menu_button, NULL, -1);
+
   image_widget = g_object_new (GTK_TYPE_IMAGE,
                                "accessible-role", GTK_ACCESSIBLE_ROLE_PRESENTATION,
                                "icon-name", icon_name,
@@ -1149,6 +1156,9 @@ gtk_menu_button_set_label (GtkMenuButton *menu_button,
   gtk_button_set_child (GTK_BUTTON (menu_button->button), box);
   menu_button->label_widget = label_widget;
 
+  // When the user explicitly set a label assume that it should be announced by assistive technologies as 
well
+  gtk_accessible_update_relation (GTK_ACCESSIBLE (menu_button->button), GTK_ACCESSIBLE_RELATION_LABELLED_BY, 
menu_button->label_widget, NULL, -1);
+
   menu_button->image_widget = NULL;
   menu_button->child = NULL;