clutter: Avoid string translation to find text direction

Use Pango and Harfbuzz for the task, getting the default language,
then its scripts, then their directions. We pick the first valid
horizontal direction, resorting to LTR as a fallback.

Related: https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/5385
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2780>

4 files changed, 26 insertions, 15 deletions

diff --git a/clutter/clutter/clutter-main.c b/clutter/clutter/clutter-main.c
index be9f74441..e758e170a 100644
--- a/clutter/clutter/clutter-main.c
+++ b/clutter/clutter/clutter-main.c
@@ -51,6 +51,7 @@
 
 #include <stdlib.h>
 #include <glib/gi18n-lib.h>
+#include <hb-glib.h>
 
 #include "clutter-actor-private.h"
 #include "clutter-backend-private.h"
@@ -221,20 +222,28 @@ clutter_get_text_direction (void)
     }
   else
     {
-      /*
-       * Translate to default:RTL if you want your widgets
-       * to be RTL, otherwise translate to default:LTR.
-       * Do *not* translate it to "predefinito:LTR", if it
-       * it isn't default:LTR or default:RTL it will not work
-       */
-      const char *e = _("default:LTR");
-
-      if (strcmp (e, "default:RTL") == 0)
-        dir = CLUTTER_TEXT_DIRECTION_RTL;
-      else if (strcmp (e, "default:LTR") == 0)
-        dir = CLUTTER_TEXT_DIRECTION_LTR;
-      else
-        g_warning ("Whoever translated default:LTR did so wrongly.");
+      PangoLanguage *language;
+      const PangoScript *scripts;
+      int n_scripts, i;
+
+      language = pango_language_get_default ();
+      scripts = pango_language_get_scripts (language, &n_scripts);
+
+      for (i = 0; i < n_scripts; i++)
+        {
+          hb_script_t script;
+          hb_direction_t text_dir;
+
+          script = hb_glib_script_to_script ((GUnicodeScript) scripts[i]);
+          text_dir = hb_script_get_horizontal_direction (script);
+
+          if (text_dir == HB_DIRECTION_LTR)
+            dir = CLUTTER_TEXT_DIRECTION_LTR;
+          else if (text_dir == HB_DIRECTION_RTL)
+            dir = CLUTTER_TEXT_DIRECTION_RTL;
+          else
+            continue;
+        }
     }
 
   CLUTTER_NOTE (MISC, "Text direction: %s",
diff --git a/clutter/meson.build b/clutter/meson.build
index ac6db2fd2..918153ee4 100644
--- a/clutter/meson.build
+++ b/clutter/meson.build
@@ -36,6 +36,7 @@ clutter_pkg_deps = [
   gio_dep,
   json_glib_dep,
   pango_dep,
+  harfbuzz_dep,
 ]
 
 clutter_pkg_private_deps = [
diff --git a/meson.build b/meson.build
index af716b750..227725c94 100644
--- a/meson.build
+++ b/meson.build
@@ -38,6 +38,7 @@ libstartup_notification_req = '>= 0.7'
 libcanberra_req = '>= 0.26'
 libwacom_req = '>= 0.13'
 atk_req = '>= 2.5.3'
+harfbuzz_req = '>= 2.6'
 
 # optional version requirements
 udev_req = '>= 228'
@@ -128,6 +129,7 @@ atk_dep = dependency('atk', version: atk_req)
 dbus_dep = dependency('dbus-1')
 colord_dep = dependency('colord', version: colord_req)
 lcms2_dep = dependency('lcms2', version: lcms2_req)
+harfbuzz_dep = dependency('harfbuzz', version: harfbuzz_req)
 
 have_wayland = get_option('wayland')
 # For now always require X11 support
diff --git a/po/POTFILES.in b/po/POTFILES.in
index d671ba4ab..ebafa966e 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -11,7 +11,6 @@ src/backends/meta-input-settings.c
 src/backends/meta-monitor.c
 src/backends/meta-monitor-manager.c
 src/backends/x11/meta-clutter-backend-x11.c
-src/clutter/clutter/clutter-main.c
 src/compositor/compositor.c
 src/compositor/meta-background.c
 src/core/bell.c