[gnome-font-viewer/wip/cdavis/fix-pango-deprecation] sushi-font-widget: Copy deprecated pango direction API

[Christopher Davis <christopherdavis src gnome org>]

commit 78f36e377d321f00f2132d1033dc37098d561fcd
Author: Christopher Davis <christopherdavis gnome org>
Date:   Fri Sep 2 13:17:05 2022 -0400

    sushi-font-widget: Copy deprecated pango direction API
    
    These APIs are still useful for us, so we want to continue
    to use them. Since pango intends to remove them in the future,
    we can simply copy them in-tree.

 meson.build             |  1 +
 src/meson.build         | 12 ++++++++-
 src/sushi-font-widget.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 76 insertions(+), 2 deletions(-)
---
diff --git a/meson.build b/meson.build
index a0a88f0..8f9d254 100644
--- a/meson.build
+++ b/meson.build
@@ -34,6 +34,7 @@ harfbuzz_dep = dependency('harfbuzz', version: harfbuzz_req_version)
 fontconfig_dep = dependency('fontconfig')
 freetype2_dep = dependency('freetype2')
 gnomedesktop_dep = dependency('gnome-desktop-4')
+fribidi_dep = dependency('fribidi')
 mathlib_dep = cc.find_library('m')
 
 if get_option('profile') == 'development'
diff --git a/src/meson.build b/src/meson.build
index 396c8b2..a6c1f4b 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -31,7 +31,17 @@ executable('gnome-thumbnail-font', thumbnail_sources,
 
 executable('gnome-font-viewer', viewer_sources + resources,
   include_directories: [ root_inc, include_directories('.') ],
-  dependencies: [ mathlib_dep, glib_dep, gtk_dep, libadwaita_dep, harfbuzz_dep, fontconfig_dep, 
freetype2_dep, gnomedesktop_dep ],
+  dependencies: [
+    mathlib_dep,
+    glib_dep,
+    gtk_dep,
+    libadwaita_dep,
+    harfbuzz_dep,
+    fontconfig_dep,
+    freetype2_dep,
+    gnomedesktop_dep,
+    fribidi_dep,
+  ],
   install: true)
 
 desktop_file = 'org.gnome.font-viewer.desktop'
diff --git a/src/sushi-font-widget.c b/src/sushi-font-widget.c
index bb6a4b3..863902b 100644
--- a/src/sushi-font-widget.c
+++ b/src/sushi-font-widget.c
@@ -30,6 +30,7 @@
 #include <graphene.h>
 #include <hb-glib.h>
 #include <math.h>
+#include <fribidi.h>
 
 enum {
   PROP_URI = 1,
@@ -75,6 +76,68 @@ static const gchar lowercase_text_stock[] = "abcdefghijklmnopqrstuvwxyz";
 static const gchar uppercase_text_stock[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 static const gchar punctuation_text_stock[] = "0123456789.:,;(*!?')";
 
+/*
+ * Copied from 
https://gitlab.gnome.org/GNOME/pango/-/blob/eb973b9bdfd11467f63f1626f16d5d4005eb82a7/pango/pango-bidi-type.c#L259-274
+ *
+ * This function is needed for `fonts_find_base_dir()`, but Pango
+ * has deprecated this function and scheduled it for removal.
+ *
+ * (C) 2004 Red Hat, Owen Taylor <otaylor redhat com>
+ *
+ * License: LGPL-2.0-or-later
+ */
+static PangoDirection
+fonts_unichar_direction (gunichar ch)
+{
+  FriBidiCharType fribidi_ch_type;
+
+  G_STATIC_ASSERT (sizeof (FriBidiChar) == sizeof (gunichar));
+
+  fribidi_ch_type = fribidi_get_bidi_type (ch);
+
+  if (!FRIBIDI_IS_STRONG (fribidi_ch_type))
+    return PANGO_DIRECTION_NEUTRAL;
+  else if (FRIBIDI_IS_RTL (fribidi_ch_type))
+    return PANGO_DIRECTION_RTL;
+  else
+    return PANGO_DIRECTION_LTR;
+}
+
+/*
+ * Copied from 
https://gitlab.gnome.org/GNOME/pango/-/blob/eb973b9bdfd11467f63f1626f16d5d4005eb82a7/pango/pango-utils.c#L866-889
+ *
+ * This function is needed for our `text_to_glyphs ()` function, but Pango
+ * has deprecated this function and scheduled it for removal.
+ *
+ * (C) 2004 Red Hat, Owen Taylor <otaylor redhat com>
+ *
+ * License: LGPL-2.0-or-later
+ */
+static PangoDirection
+fonts_find_base_dir (const gchar *text,
+                     gint         length)
+{
+  PangoDirection dir = PANGO_DIRECTION_NEUTRAL;
+  const gchar *p;
+
+  g_return_val_if_fail (text != NULL || length == 0, dir);
+
+  p = text;
+  while ((length < 0 || p < text + length) && *p)
+    {
+      gunichar wc = g_utf8_get_char (p);
+
+      dir = fonts_unichar_direction (wc);
+
+      if (dir != PANGO_DIRECTION_NEUTRAL)
+        break;
+
+      p = g_utf8_next_char (p);
+    }
+
+  return dir;
+}
+
 static void
 text_to_glyphs (cairo_t *cr,
                 const gchar *text,
@@ -96,7 +159,7 @@ text_to_glyphs (cairo_t *cr,
   *num_glyphs = 0;
   *glyphs = NULL;
 
-  base_dir = pango_find_base_dir (text, -1);
+  base_dir = fonts_find_base_dir (text, -1);
 
   cairo_scaled_font_t *cr_font = cairo_get_scaled_font (cr);
   ft_face = cairo_ft_scaled_font_lock_face (cr_font);