Add api to get a hb_font_t

Add pango_font_get_hb_font, which will make it easier
access harfbuzz features.

1 files changed, 45 insertions, 1 deletions

diff --git a/pango/fonts.c b/pango/fonts.c
index fafd6a2d..4ba9d3fe 100644
--- a/pango/fonts.c
+++ b/pango/fonts.c
@@ -1617,11 +1617,29 @@ pango_parse_stretch (const char   *str,
  * PangoFont
  */
 
-G_DEFINE_ABSTRACT_TYPE (PangoFont, pango_font, G_TYPE_OBJECT)
+typedef struct {
+  hb_font_t *hb_font;
+} PangoFontPrivate;
+
+G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (PangoFont, pango_font, G_TYPE_OBJECT)
+
+static void
+pango_font_finalize (GObject *object)
+{
+  PangoFont *font = PANGO_FONT (object);
+  PangoFontPrivate *priv = pango_font_get_instance_private (font);
+
+  hb_font_destroy (priv->hb_font);
+
+  G_OBJECT_CLASS (pango_font_parent_class)->finalize (object);
+}
 
 static void
 pango_font_class_init (PangoFontClass *class G_GNUC_UNUSED)
 {
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+
+  object_class->finalize = pango_font_finalize;
 }
 
 static void
@@ -1838,6 +1856,32 @@ pango_font_get_font_map (PangoFont *font)
     return NULL;
 }
 
+/**
+ * pango_font_get_hb_font:
+ * @font: a #PangoFont
+ *
+ * Get a hb_font_t object backing this font.
+ *
+ * Returns: (transfer none) (nullable): the hb_font_t object backing the
+ *          font, or %NULL if the font does not have one
+ *
+ * Since: 1.44
+ */
+hb_font_t *
+pango_font_get_hb_font (PangoFont *font)
+{
+  PangoFontPrivate *priv = pango_font_get_instance_private (font);
+
+  g_return_val_if_fail (PANGO_IS_FONT (font), NULL);
+
+  if (priv->hb_font)
+    return priv->hb_font;
+
+  priv->hb_font = PANGO_FONT_GET_CLASS (font)->create_hb_font (font);
+
+  return priv->hb_font;
+}
+
 G_DEFINE_BOXED_TYPE (PangoFontMetrics, pango_font_metrics,
                      pango_font_metrics_ref,
                      pango_font_metrics_unref);