[gtk/backport-font-feature-pango-hb: 3/5] Font features demo: Port to newer Pango

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

commit 48ced32a4e6b9fea36a545075218f448155bac22
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Thu Nov 25 18:08:22 2021 +0800

    Font features demo: Port to newer Pango
    
    ...if Pango 1.44.0+ and HarfBuzz 2.2.0+ are available, otherwise we
    stick on to the current code path.
    
    This way, we can have people build and run the demo even without
    PangoFT2 if Pango 1.44.0 or later and HarfBuzz 2.2.0 or later is
    installed.

 demos/gtk-demo/font_features.c | 67 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 56 insertions(+), 11 deletions(-)
---
diff --git a/demos/gtk-demo/font_features.c b/demos/gtk-demo/font_features.c
index 761bf8f38f..ab9ae0d66c 100644
--- a/demos/gtk-demo/font_features.c
+++ b/demos/gtk-demo/font_features.c
@@ -9,10 +9,19 @@
  */
 
 #include <gtk/gtk.h>
+
+#if !(PANGO_VERSION_CHECK(1,44,0) && HB_VERSION_ATLEAST(2,2,0))
+#define FONT_FEATURES_USE_PANGOFT2 1
+#endif
+
+#ifdef FONT_FEATURES_USE_PANGOFT2
 #include <pango/pangofc-font.h>
 #include <hb.h>
 #include <hb-ot.h>
 #include <hb-ft.h>
+#else
+#include <hb-ot.h>
+#endif
 
 static GtkWidget *label;
 static GtkWidget *settings;
@@ -205,19 +214,32 @@ static void
 update_script_combo (void)
 {
   GtkListStore *store;
-  hb_font_t *hb_font;
+  hb_font_t *hb_font = NULL;
   gint i, j, k, l;
-  FT_Face ft_face;
   PangoFont *pango_font;
   GHashTable *tags;
   GHashTableIter iter;
   TagPair *pair;
+  gboolean cleanup_hb_face = FALSE;
+
+#ifdef FONT_FEATURES_USE_PANGOFT2
+  FT_Face ft_face;
+#endif
 
   store = gtk_list_store_new (4, G_TYPE_STRING, G_TYPE_UINT, G_TYPE_UINT, G_TYPE_UINT);
 
   pango_font = get_pango_font ();
-  ft_face = pango_fc_font_lock_face (PANGO_FC_FONT (pango_font)),
-  hb_font = hb_ft_font_create (ft_face, NULL);
+
+#ifdef FONT_FEATURES_USE_PANGOFT2
+  if (PANGO_IS_FC_FONT (pango_font)
+    {
+      ft_face = pango_fc_font_lock_face (PANGO_FC_FONT (pango_font)),
+      hb_font = hb_ft_font_create (ft_face, NULL);
+      cleanup_hb_face = TRUE;
+    }
+#else
+  hb_font = pango_font_get_hb_font (pango_font);
+#endif
 
   tags = g_hash_table_new_full (tag_pair_hash, tag_pair_equal, g_free, NULL);
 
@@ -264,10 +286,15 @@ update_script_combo (void)
             }
         }
 
-      hb_face_destroy (hb_face);
+      if (cleanup_hb_face)
+        hb_face_destroy (hb_face);
     }
 
-  pango_fc_font_unlock_face (PANGO_FC_FONT (pango_font));
+#ifdef FONT_FEATURES_USE_PANGOFT2
+  if (PANGO_IS_FC_FONT (pango_font)
+    pango_fc_font_unlock_face (PANGO_FC_FONT (pango_font));
+#endif
+
   g_object_unref (pango_font);
 
   g_hash_table_iter_init (&iter, tags);
@@ -346,8 +373,12 @@ update_features (void)
   GtkTreeIter iter;
   guint script_index, lang_index;
   PangoFont *pango_font;
+  hb_font_t *hb_font = NULL;
+  gboolean cleanup_hb_face = FALSE;
+
+#ifdef FONT_FEATURES_USE_PANGOFT2
   FT_Face ft_face;
-  hb_font_t *hb_font;
+#endif
 
   for (i = 0; i < num_features; i++)
     gtk_widget_set_opacity (icon[i], 0);
@@ -364,8 +395,17 @@ update_features (void)
                       -1);
 
   pango_font = get_pango_font ();
-  ft_face = pango_fc_font_lock_face (PANGO_FC_FONT (pango_font)),
-  hb_font = hb_ft_font_create (ft_face, NULL);
+
+#ifdef FONT_FEATURES_USE_PANGOFT2
+  if (PANGO_IS_FC_FONT (pango_font)
+    {
+      ft_face = pango_fc_font_lock_face (PANGO_FC_FONT (pango_font)),
+      hb_font = hb_ft_font_create (ft_face, NULL);
+      cleanup_hb_face = TRUE;
+    }
+#else
+  hb_font = pango_font_get_hb_font (pango_font);
+#endif
 
   if (hb_font)
     {
@@ -397,10 +437,15 @@ update_features (void)
             }
         }
 
-      hb_face_destroy (hb_face);
+      if (cleanup_hb_face)
+        hb_face_destroy (hb_face);
     }
 
-  pango_fc_font_unlock_face (PANGO_FC_FONT (pango_font));
+#ifdef FONT_FEATURES_USE_PANGOFT2
+  if (PANGO_IS_FC_FONT (pango_font)
+    pango_fc_font_unlock_face (PANGO_FC_FONT (pango_font));
+#endif
+
   g_object_unref (pango_font);
 }