Keep PangoFontmap derivable

This functionality is used in PackageKit.

1 files changed, 71 insertions, 0 deletions

diff --git a/pango/pango-fontmap.h b/pango/pango-fontmap.h
index 036de2df..b6206f1d 100644
--- a/pango/pango-fontmap.h
+++ b/pango/pango-fontmap.h
@@ -47,9 +47,80 @@ G_BEGIN_DECLS
 #define PANGO_TYPE_FONT_MAP              (pango_font_map_get_type ())
 #define PANGO_FONT_MAP(object)           (G_TYPE_CHECK_INSTANCE_CAST ((object), PANGO_TYPE_FONT_MAP, PangoFontMap))
 #define PANGO_IS_FONT_MAP(object)        (G_TYPE_CHECK_INSTANCE_TYPE ((object), PANGO_TYPE_FONT_MAP))
+#define PANGO_FONT_MAP_CLASS(klass)      (G_TYPE_CHECK_CLASS_CAST ((klass), PANGO_TYPE_FONT_MAP, PangoFontMapClass))
+#define PANGO_IS_FONT_MAP_CLASS(klass)   (G_TYPE_CHECK_CLASS_TYPE ((klass), PANGO_TYPE_FONT_MAP))
+#define PANGO_FONT_MAP_GET_CLASS(obj)    (G_TYPE_INSTANCE_GET_CLASS ((obj), PANGO_TYPE_FONT_MAP, PangoFontMapClass))
 
+typedef struct _PangoFontMapClass PangoFontMapClass;
 typedef struct _PangoContext PangoContext;
 
+/**
+ * PangoFontMap:
+ *
+ * The #PangoFontMap represents the set of fonts available for a
+ * particular rendering system. This is a virtual object with
+ * implementations being specific to particular rendering systems.  To
+ * create an implementation of a #PangoFontMap, the rendering-system
+ * specific code should allocate a larger structure that contains a nested
+ * #PangoFontMap, fill in the <structfield>klass</structfield> member of the nested #PangoFontMap with a
+ * pointer to a appropriate #PangoFontMapClass, then call
+ * pango_font_map_init() on the structure.
+ *
+ * The #PangoFontMap structure contains one member which the implementation
+ * fills in.
+ */
+struct _PangoFontMap
+{
+  GObject parent_instance;
+};
+
+/**
+ * PangoFontMapClass:
+ * @parent_class: parent #GObjectClass.
+ * @load_font: a function to load a font with a given description. See
+ * pango_font_map_load_font().
+ * @list_families: A function to list available font families. See
+ * pango_font_map_list_families().
+ * @load_fontset: a function to load a fontset with a given given description
+ * suitable for a particular language. See pango_font_map_load_fontset().
+ * @shape_engine_type: the type of rendering-system-dependent engines that
+ * can handle fonts of this fonts loaded with this fontmap.
+ * @get_serial: a function to get the serial number of the fontmap.
+ * See pango_font_map_get_serial().
+ * @changed: See pango_font_map_changed()
+ *
+ * The #PangoFontMapClass structure holds the virtual functions for
+ * a particular #PangoFontMap implementation.
+ */
+struct _PangoFontMapClass
+{
+  GObjectClass parent_class;
+
+  /*< public >*/
+
+  PangoFont *   (*load_font)     (PangoFontMap               *fontmap,
+                                  PangoContext               *context,
+                                  const PangoFontDescription *desc);
+  void          (*list_families) (PangoFontMap               *fontmap,
+                                  PangoFontFamily          ***families,
+                                  int                        *n_families);
+  PangoFontset *(*load_fontset)  (PangoFontMap               *fontmap,
+                                  PangoContext               *context,
+                                  const PangoFontDescription *desc,
+                                  PangoLanguage              *language);
+
+  const char     *shape_engine_type;
+
+  guint         (*get_serial)    (PangoFontMap               *fontmap);
+  void          (*changed)       (PangoFontMap               *fontmap);
+
+  /*< private >*/
+
+  /* Padding for future expansion */
+  void (*_pango_reserved1) (void);
+  void (*_pango_reserved2) (void);
+};
+
 PANGO_AVAILABLE_IN_ALL
 GType         pango_font_map_get_type       (void) G_GNUC_CONST;
 PANGO_AVAILABLE_IN_1_22