[evince] Expose links as AtkObject children of the page

[Joanmarie Diggs <joanied src gnome org>]

commit 004b19922ebc3a6e76024e6e24c80085dbef7b28
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Mon Jun 23 09:57:05 2014 -0400

    Expose links as AtkObject children of the page
    
    https://bugzilla.gnome.org/show_bug.cgi?id=728475

 libview/ev-link-accessible.c |  121 +++++++++++++++++++++++++++++++++++++++++-
 libview/ev-page-accessible.c |  104 ++++++++++++++++++++++++++++++++++++
 2 files changed, 224 insertions(+), 1 deletions(-)
---
diff --git a/libview/ev-link-accessible.c b/libview/ev-link-accessible.c
index 729ad35..ebb9485 100644
--- a/libview/ev-link-accessible.c
+++ b/libview/ev-link-accessible.c
@@ -32,6 +32,8 @@ struct _EvLinkAccessiblePrivate {
         EvRectangle       area;
 
         EvHyperlink      *hyperlink;
+
+        gchar      *name;
 };
 
 struct _EvHyperlink {
@@ -187,10 +189,71 @@ ev_hyperlink_init (EvHyperlink *link)
 
 static void ev_link_accessible_hyperlink_impl_iface_init (AtkHyperlinkImplIface *iface);
 static void ev_link_accessible_action_interface_init     (AtkActionIface        *iface);
+static void ev_link_accessible_component_iface_init      (AtkComponentIface     *iface);
 
 G_DEFINE_TYPE_WITH_CODE (EvLinkAccessible, ev_link_accessible, ATK_TYPE_OBJECT,
                         G_IMPLEMENT_INTERFACE (ATK_TYPE_HYPERLINK_IMPL, 
ev_link_accessible_hyperlink_impl_iface_init)
-                        G_IMPLEMENT_INTERFACE (ATK_TYPE_ACTION, ev_link_accessible_action_interface_init))
+                        G_IMPLEMENT_INTERFACE (ATK_TYPE_ACTION, ev_link_accessible_action_interface_init)
+                        G_IMPLEMENT_INTERFACE (ATK_TYPE_COMPONENT, ev_link_accessible_component_iface_init))
+
+static const gchar *
+ev_link_accessible_get_name (AtkObject *atk_object)
+{
+       EvLinkAccessiblePrivate *priv;
+       gint start_index;
+       gint end_index;
+
+       priv = EV_LINK_ACCESSIBLE (atk_object)->priv;
+       if (priv->name)
+               return priv->name;
+
+       start_index = ev_hyperlink_get_start_index (ATK_HYPERLINK (priv->hyperlink));
+       end_index = ev_hyperlink_get_end_index (ATK_HYPERLINK (priv->hyperlink));
+       priv->name = atk_text_get_text (ATK_TEXT (atk_object_get_parent (atk_object)), start_index, 
end_index);
+
+       return priv->name;
+}
+
+static AtkObject *
+ev_link_accessible_get_parent (AtkObject *atk_object)
+{
+       EvLinkAccessiblePrivate *priv = EV_LINK_ACCESSIBLE (atk_object)->priv;
+
+       return ATK_OBJECT (priv->page);
+}
+
+static AtkStateSet *
+ev_link_accessible_ref_state_set (AtkObject *atk_object)
+{
+       AtkStateSet *state_set;
+       AtkStateSet *copy_set;
+       AtkStateSet *page_accessible_state_set;
+       EvLinkAccessible *self;
+       EvViewAccessible *view_accessible;
+       EvView *view;
+       gint page;
+
+       self = EV_LINK_ACCESSIBLE (atk_object);
+       state_set = ATK_OBJECT_CLASS (ev_link_accessible_parent_class)->ref_state_set (atk_object);
+       atk_state_set_clear_states (state_set);
+
+       page_accessible_state_set = atk_object_ref_state_set (ATK_OBJECT (self->priv->page));
+       copy_set = atk_state_set_or_sets (state_set, page_accessible_state_set);
+
+       view_accessible = ev_page_accessible_get_view_accessible (self->priv->page);
+       page = ev_page_accessible_get_page (self->priv->page);
+       if (!ev_view_accessible_is_doc_rect_showing (view_accessible, page, &self->priv->area))
+               atk_state_set_remove_state (copy_set, ATK_STATE_SHOWING);
+
+       view = ev_page_accessible_get_view (self->priv->page);
+       if (!view->focused_element || view->focused_element->data != self->priv->link)
+               atk_state_set_remove_state (copy_set, ATK_STATE_FOCUSED);
+
+       g_object_unref (state_set);
+       g_object_unref (page_accessible_state_set);
+
+       return copy_set;
+}
 
 static void
 ev_link_accessible_finalize (GObject *object)
@@ -198,6 +261,7 @@ ev_link_accessible_finalize (GObject *object)
         EvLinkAccessible *link = EV_LINK_ACCESSIBLE (object);
 
         g_clear_object (&link->priv->hyperlink);
+        g_free (link->priv->name);
 
         G_OBJECT_CLASS (ev_link_accessible_parent_class)->finalize (object);
 }
@@ -206,15 +270,21 @@ static void
 ev_link_accessible_class_init (EvLinkAccessibleClass *klass)
 {
         GObjectClass *object_class = G_OBJECT_CLASS (klass);
+        AtkObjectClass *atk_class = ATK_OBJECT_CLASS (klass);
 
         object_class->finalize = ev_link_accessible_finalize;
 
         g_type_class_add_private (klass, sizeof (EvLinkAccessiblePrivate));
+
+        atk_class->get_parent = ev_link_accessible_get_parent;
+        atk_class->get_name = ev_link_accessible_get_name;
+        atk_class->ref_state_set = ev_link_accessible_ref_state_set;
 }
 
 static void
 ev_link_accessible_init (EvLinkAccessible *link)
 {
+        atk_object_set_role (ATK_OBJECT (link), ATK_ROLE_LINK);
         link->priv = G_TYPE_INSTANCE_GET_PRIVATE (link, EV_TYPE_LINK_ACCESSIBLE, EvLinkAccessiblePrivate);
 }
 
@@ -286,6 +356,55 @@ ev_link_accessible_action_interface_init (AtkActionIface *iface)
        iface->get_name = ev_link_accessible_action_get_name;
 }
 
+static void
+ev_link_accessible_get_extents (AtkComponent *atk_component,
+                               gint         *x,
+                               gint         *y,
+                               gint         *width,
+                               gint         *height,
+                               AtkCoordType coord_type)
+{
+       EvLinkAccessible *self;
+       EvViewAccessible *view_accessible;
+       gint page;
+       EvRectangle atk_rect;
+
+       self = EV_LINK_ACCESSIBLE (atk_component);
+       view_accessible = ev_page_accessible_get_view_accessible (self->priv->page);
+       page = ev_page_accessible_get_page (self->priv->page);
+       _transform_doc_rect_to_atk_rect (view_accessible, page, &self->priv->area, &atk_rect, coord_type);
+       *x = atk_rect.x1;
+       *y = atk_rect.y1;
+       *width = atk_rect.x2 - atk_rect.x1;
+       *height = atk_rect.y2 - atk_rect.y1;
+}
+
+static gboolean
+ev_link_accessible_grab_focus (AtkComponent *atk_component)
+{
+       EvLinkAccessible *self;
+       EvView *view;
+       EvMappingList *link_mapping;
+       EvMapping *mapping;
+       gint page;
+
+       self = EV_LINK_ACCESSIBLE (atk_component);
+       view = ev_page_accessible_get_view (self->priv->page);
+       page = ev_page_accessible_get_page (self->priv->page);
+       link_mapping = ev_page_cache_get_link_mapping (view->page_cache, page);
+       mapping = ev_mapping_list_find (link_mapping, self->priv->link);
+       _ev_view_set_focused_element (view, mapping, page);
+
+       return TRUE;
+}
+
+static void
+ev_link_accessible_component_iface_init (AtkComponentIface *iface)
+{
+       iface->get_extents = ev_link_accessible_get_extents;
+       iface->grab_focus = ev_link_accessible_grab_focus;
+}
+
 EvLinkAccessible *
 ev_link_accessible_new (EvPageAccessible *page,
                         EvLink           *link,
diff --git a/libview/ev-page-accessible.c b/libview/ev-page-accessible.c
index b6e4278..1bb0aca 100644
--- a/libview/ev-page-accessible.c
+++ b/libview/ev-page-accessible.c
@@ -31,6 +31,8 @@ struct _EvPageAccessiblePrivate {
         EvViewAccessible *view_accessible;
        gint              page;
        GHashTable       *links;
+       GPtrArray        *children;
+       gboolean          children_initialized;
 };
 
 
@@ -77,12 +79,87 @@ ev_page_accessible_get_parent (AtkObject *obj)
        return ATK_OBJECT (self->priv->view_accessible);
 }
 
+static gint
+compare_mappings (EvMapping *a, EvMapping *b)
+{
+       gdouble dx, dy;
+
+       /* Very rough heuristic for simple, non-tagged PDFs. */
+
+       dy = a->area.y1 - b->area.y1;
+       dx = a->area.x1 - b->area.x1;
+
+       return ABS (dy) > 10 ? dy : dx;
+}
+
+static void
+ev_page_accessible_initialize_children (EvPageAccessible *self)
+{
+       EvView *view;
+       EvMappingList *links;
+       GList *children = NULL;
+       GList *list;
+
+       if (self->priv->children_initialized)
+               return;
+
+       view = ev_page_accessible_get_view (self);
+       if (!ev_page_cache_is_page_cached (view->page_cache, self->priv->page))
+               return;
+
+       self->priv->children_initialized = TRUE;
+
+       links = ev_page_cache_get_link_mapping (view->page_cache, self->priv->page);
+       if (!links)
+               return;
+
+       children = g_list_copy (ev_mapping_list_get_list (links));
+
+       children = g_list_sort (children, (GCompareFunc) compare_mappings);
+       self->priv->children = g_ptr_array_new_full (g_list_length (children), (GDestroyNotify) 
g_object_unref);
+
+       for (list = children; list && list->data; list = list->next) {
+               EvMapping *mapping = list->data;
+               AtkObject *child = NULL;
+
+               if (links && ev_mapping_list_find (links, mapping->data)) {
+                       EvLinkAccessible *link = ev_link_accessible_new (self, EV_LINK (mapping->data), 
&mapping->area);
+                       AtkHyperlink *atk_link = atk_hyperlink_impl_get_hyperlink (ATK_HYPERLINK_IMPL (link));
+
+                       child = atk_hyperlink_get_object (atk_link, 0);
+               }
+
+               if (child)
+                       g_ptr_array_add (self->priv->children, child);
+       }
+
+       g_list_free (children);
+}
+
+static void
+clear_children (EvPageAccessible *self)
+{
+       gint i;
+       AtkObject *child;
+
+       if (!self->priv->children)
+               return;
+
+       for (i = 0; i < self->priv->children->len; i++) {
+               child = g_ptr_array_index (self->priv->children, i);
+               atk_object_notify_state_change (child, ATK_STATE_DEFUNCT, TRUE);
+       }
+
+       g_clear_pointer (&self->priv->children, g_ptr_array_unref);
+}
+
 static void
 ev_page_accessible_finalize (GObject *object)
 {
        EvPageAccessiblePrivate *priv = EV_PAGE_ACCESSIBLE (object)->priv;
 
        g_clear_pointer (&priv->links, (GDestroyNotify)g_hash_table_destroy);
+       clear_children (EV_PAGE_ACCESSIBLE (object));
 
        G_OBJECT_CLASS (ev_page_accessible_parent_class)->finalize (object);
 }
@@ -230,6 +307,31 @@ ev_page_accessible_ref_state_set (AtkObject *accessible)
        return copy_set;
 }
 
+static gint
+ev_page_accessible_get_n_children (AtkObject *accessible)
+{
+       EvPageAccessible *self;
+
+       self = EV_PAGE_ACCESSIBLE (accessible);
+       ev_page_accessible_initialize_children (self);
+
+       return self->priv->children == NULL ? 0 : self->priv->children->len;
+}
+
+static AtkObject *
+ev_page_accessible_ref_child (AtkObject *accessible,
+                             gint       i)
+{
+       EvPageAccessible *self;
+
+       self = EV_PAGE_ACCESSIBLE (accessible);
+       ev_page_accessible_initialize_children (self);
+
+       g_return_val_if_fail (i >= 0 || i < self->priv->children->len, NULL);
+
+       return g_object_ref (g_ptr_array_index (self->priv->children, i));
+}
+
 static void
 ev_page_accessible_class_init (EvPageAccessibleClass *klass)
 {
@@ -241,6 +343,8 @@ ev_page_accessible_class_init (EvPageAccessibleClass *klass)
        atk_class->get_parent  = ev_page_accessible_get_parent;
        atk_class->ref_relation_set = ev_page_accessible_ref_relation_set;
        atk_class->ref_state_set = ev_page_accessible_ref_state_set;
+       atk_class->get_n_children = ev_page_accessible_get_n_children;
+       atk_class->ref_child = ev_page_accessible_ref_child;
 
        g_object_class->get_property = ev_page_accessible_get_property;
        g_object_class->set_property = ev_page_accessible_set_property;