[pango/wip/kill-shape-engine-win32: 1/25] Add api to get a hb_font_t

[Chun-wei Fan <fanchunwei src gnome org>]

commit 887056d931bb9fd71173793d496c18ba17751341
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Jul 12 23:59:44 2019 -0400

    Add api to get a hb_font_t
    
    Add pango_font_get_hb_font, which will make it easier
    access harfbuzz features.

 docs/pango-sections.txt    |  1 +
 pango/fonts.c              | 50 +++++++++++++++++++++++++++++++++++++++++++++-
 pango/pango-font-private.h |  6 +-----
 pango/pango-font.h         |  3 +++
 4 files changed, 54 insertions(+), 6 deletions(-)
---
diff --git a/docs/pango-sections.txt b/docs/pango-sections.txt
index 496db41a..9d08d0b2 100644
--- a/docs/pango-sections.txt
+++ b/docs/pango-sections.txt
@@ -262,6 +262,7 @@ pango_font_get_glyph_extents
 pango_font_get_metrics
 pango_font_get_font_map
 pango_font_get_features
+pango_font_get_hb_font
 <SUBSECTION>
 PangoFontFamily
 PANGO_TYPE_FONT_FAMILY
diff --git a/pango/fonts.c b/pango/fonts.c
index fafd6a2d..9e965a6f 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 +1856,36 @@ 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);
+
+  if (G_UNLIKELY (!font))
+    return NULL;
+
+  if (priv->hb_font)
+    return priv->hb_font;
+  else if (PANGO_FONT_GET_CLASS (font)->create_hb_font)
+    {
+      priv->hb_font = PANGO_FONT_GET_CLASS (font)->create_hb_font (font);
+      return priv->hb_font;
+    }
+
+  return NULL;
+}
+
 G_DEFINE_BOXED_TYPE (PangoFontMetrics, pango_font_metrics,
                      pango_font_metrics_ref,
                      pango_font_metrics_unref);
diff --git a/pango/pango-font-private.h b/pango/pango-font-private.h
index be399d7d..029bef99 100644
--- a/pango/pango-font-private.h
+++ b/pango/pango-font-private.h
@@ -179,11 +179,7 @@ struct _PangoFontClass
                                                hb_feature_t   *features,
                                                guint           len,
                                                guint          *num_features);
-
-  /*< private >*/
-
-  /* Padding for future expansion */
-  void (*_pango_reserved1) (void);
+  hb_font_t *           (*create_hb_font)     (PangoFont      *font);
 };
 
 /* used for very rare and miserable situtations that we cannot even
diff --git a/pango/pango-font.h b/pango/pango-font.h
index 5e49d266..cec7efc6 100644
--- a/pango/pango-font.h
+++ b/pango/pango-font.h
@@ -26,6 +26,7 @@
 #include <pango/pango-types.h>
 
 #include <glib-object.h>
+#include <hb.h>
 
 G_BEGIN_DECLS
 
@@ -492,6 +493,8 @@ void                  pango_font_get_features      (PangoFont        *font,
                                                     hb_feature_t     *features,
                                                     guint             len,
                                                     guint            *num_features);
+PANGO_AVAILABLE_IN_1_44
+hb_font_t *           pango_font_get_hb_font       (PangoFont        *font);
 
 
 /**