src: Add fading label class

Co-Authored-By: Titouan Real <titouan.real@gmail.com> Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/657>
2026-02-03 17:11:21 -03:00
parent 32f44b160e
commit bd4d503080
7 changed files with 432 additions and 0 deletions
@@ -0,0 +1,71 @@
+/* GDK - The GIMP Drawing Kit
+ * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS
+ * file for a list of people on the GTK+ Team.  See the ChangeLog
+ * files for a list of changes.  These files are distributed with
+ * GTK+ at ftp://ftp.gtk.org/pub/gtk/..
+ */
+
+/* Bits taken from GTK 4.0.2 and tweaked to be used by libadwaita. */
+/* Copied from libadwaita 1.8 and adapted for use in gnome-calendar. */
+
+#include "gcal-bidi.h"
+
+#include <fribidi.h>
+
+static PangoDirection
+gcal_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;
+}
+
+PangoDirection
+gcal_find_base_dir (const gchar *text,
+                    gint         length)
+{
+  PangoDirection dir = PANGO_DIRECTION_NEUTRAL;
+  const char *p;
+
+  g_return_val_if_fail (text != NULL || length == 0, PANGO_DIRECTION_NEUTRAL);
+
+  p = text;
+  while ((length < 0 || p < text + length) && *p) {
+    gunichar wc = g_utf8_get_char (p);
+
+    dir = gcal_unichar_direction (wc);
+
+    if (dir != PANGO_DIRECTION_NEUTRAL)
+      break;
+
+    p = g_utf8_next_char (p);
+  }
+
+  return dir;
+}