[pango/font-list] pangofc: Add list model implementations

[Matthias Clasen <matthiasc src gnome org>]

commit c40f0f530671a6682091e91b443a519b041af041
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Dec 4 23:04:09 2019 -0500

    pangofc: Add list model implementations
    
    Reimplement GListModel in the fontconfig backend.
    This implementation avoids memory copies.

 pango/pangofc-fontmap.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 86 insertions(+), 5 deletions(-)
---
diff --git a/pango/pangofc-fontmap.c b/pango/pangofc-fontmap.c
index 03d508dd..626fd1eb 100644
--- a/pango/pangofc-fontmap.c
+++ b/pango/pangofc-fontmap.c
@@ -45,6 +45,8 @@
 #include "config.h"
 #include <math.h>
 
+#include <gio/gio.h>
+
 #include "pango-context.h"
 #include "pango-font-private.h"
 #include "pangofc-fontmap-private.h"
@@ -1119,8 +1121,49 @@ pango_fc_fontset_foreach (PangoFontset           *fontset,
  * PangoFcFontMap
  */
 
+static GType
+pango_fc_font_map_get_item_type (GListModel *list)
+{
+  return PANGO_TYPE_FONT_FAMILY;
+}
+
+static void ensure_families (PangoFcFontMap *fcfontmap);
+
+static guint
+pango_fc_font_map_get_n_items (GListModel *list)
+{
+  PangoFcFontMap *fcfontmap = PANGO_FC_FONT_MAP (list);
+
+  ensure_families (fcfontmap);
+
+  return fcfontmap->priv->n_families;
+}
+
+static gpointer
+pango_fc_font_map_get_item (GListModel *list,
+                            guint       position)
+{
+  PangoFcFontMap *fcfontmap = PANGO_FC_FONT_MAP (list);
+
+  ensure_families (fcfontmap);
+
+  if (position < fcfontmap->priv->n_families)
+    return g_object_ref (fcfontmap->priv->families[position]);
+
+  return NULL;
+}
+
+static void
+pango_fc_font_map_list_model_init (GListModelInterface *iface)
+{
+  iface->get_item_type = pango_fc_font_map_get_item_type;
+  iface->get_n_items = pango_fc_font_map_get_n_items;
+  iface->get_item = pango_fc_font_map_get_item;
+}
+
 G_DEFINE_ABSTRACT_TYPE_WITH_CODE (PangoFcFontMap, pango_fc_font_map, PANGO_TYPE_FONT_MAP,
-                                  G_ADD_PRIVATE (PangoFcFontMap))
+                                  G_ADD_PRIVATE (PangoFcFontMap)
+                                  G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL, 
pango_fc_font_map_list_model_init))
 
 static void
 pango_fc_font_map_init (PangoFcFontMap *fcfontmap)
@@ -2596,7 +2639,48 @@ pango_fc_face_class_init (PangoFcFaceClass *class)
 
 typedef PangoFontFamilyClass PangoFcFamilyClass;
 
-G_DEFINE_TYPE (PangoFcFamily, pango_fc_family, PANGO_TYPE_FONT_FAMILY)
+static GType
+pango_fc_family_get_item_type (GListModel *list)
+{
+  return PANGO_TYPE_FONT_FACE;
+}
+
+static void ensure_faces (PangoFcFamily *family);
+
+static guint
+pango_fc_family_get_n_items (GListModel *list)
+{
+  PangoFcFamily *fcfamily = PANGO_FC_FAMILY (list);
+
+  ensure_faces (fcfamily);
+
+  return (guint)fcfamily->n_faces;
+}
+
+static gpointer
+pango_fc_family_get_item (GListModel *list,
+                          guint       position)
+{
+  PangoFcFamily *fcfamily = PANGO_FC_FAMILY (list);
+
+  ensure_faces (fcfamily);
+
+  if (position < fcfamily->n_faces)
+    return g_object_ref (fcfamily->faces[position]);
+
+  return NULL;
+}
+
+static void
+pango_fc_family_list_model_init (GListModelInterface *iface)
+{
+  iface->get_item_type = pango_fc_family_get_item_type;
+  iface->get_n_items = pango_fc_family_get_n_items;
+  iface->get_item = pango_fc_family_get_item;
+}
+
+G_DEFINE_TYPE_WITH_CODE (PangoFcFamily, pango_fc_family, PANGO_TYPE_FONT_FAMILY,
+                         G_IMPLEMENT_INTERFACE (G_TYPE_LIST_MODEL, pango_fc_family_list_model_init))
 
 static PangoFcFace *
 create_face (PangoFcFamily *fcfamily,
@@ -2737,9 +2821,6 @@ pango_fc_family_list_faces (PangoFontFamily  *family,
 {
   PangoFcFamily *fcfamily = PANGO_FC_FAMILY (family);
 
-  *faces = NULL;
-  *n_faces = 0;
-
   if (G_UNLIKELY (!fcfamily->fontmap))
     return;