Add data files and routines for emoji itemization

Ported from Chromium.

Not hooked yet.

1 files changed, 266 insertions, 0 deletions

diff --git a/pango/pango-emoji.c b/pango/pango-emoji.c
new file mode 100644
index 00000000..630a0e7f
--- /dev/null
+++ b/pango/pango-emoji.c
@@ -0,0 +1,266 @@
+/* Pango
+ * pango-emoji.c: Emoji handling
+ *
+ * Copyright (C) 2017 Google, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Implementation of pango_emoji_iter is derived from Chromium:
+ *
+ * https://cs.chromium.org/chromium/src/third_party/WebKit/Source/platform/fonts/FontFallbackPriority.h
+ * https://cs.chromium.org/chromium/src/third_party/WebKit/Source/platform/text/CharacterEmoji.cpp
+ * https://cs.chromium.org/chromium/src/third_party/WebKit/Source/platform/fonts/SymbolsIterator.cpp
+ *
+ * // Copyright 2015 The Chromium Authors. All rights reserved.
+ * // Use of this source code is governed by a BSD-style license that can be
+ * // found in the LICENSE file.
+ */
+
+#include "config.h"
+#include <stdlib.h>
+#include <string.h>
+
+#include "pango-emoji-private.h"
+#include "pango-emoji-table.h"
+
+
+static int
+interval_compare (const void *key, const void *elt)
+{
+  gunichar c = GPOINTER_TO_UINT (key);
+  struct Interval *interval = (struct Interval *)elt;
+
+  if (c < interval->start)
+    return -1;
+  if (c > interval->end)
+    return +1;
+
+  return 0;
+}
+
+#define DEFINE_pango_Is_(name) \
+static gboolean \
+_pango_Is_##name (gunichar ch) \
+{ \
+  /* bsearch() is declared attribute(nonnull(1)) so we can't validly search \
+   * for a NULL key */ \
+  /* \
+  if (G_UNLIKELY (ch == 0)) \
+    return FALSE; \
+   */ \
+ \
+  if (bsearch (GUINT_TO_POINTER (ch), \
+               _pango_##name##_table, \
+               G_N_ELEMENTS (_pango_##name##_table), \
+               sizeof _pango_##name##_table[0], \
+	       interval_compare)) \
+    return TRUE; \
+ \
+  return FALSE; \
+}
+
+DEFINE_pango_Is_(Emoji)
+DEFINE_pango_Is_(Emoji_Presentation)
+DEFINE_pango_Is_(Emoji_Modifier)
+DEFINE_pango_Is_(Emoji_Modifier_Base)
+
+
+static gboolean
+_pango_Is_Emoji_Text_Default (gunichar ch)
+{
+  return _pango_Is_Emoji (ch) && !_pango_Is_Emoji_Presentation (ch);
+}
+
+static gboolean
+_pango_Is_Emoji_Emoji_Default (gunichar ch)
+{
+  return _pango_Is_Emoji_Presentation (ch);
+}
+
+static gboolean
+_pango_Is_Emoji_Keycap_Base (gunichar ch)
+{
+  return (ch >= '0' && ch <= '9') || ch == '#' || ch == '*';
+}
+
+static gboolean
+_pango_Is_Regional_Indicator (gunichar ch)
+{
+  return (ch >= 0x1F1E6 && ch <= 0x1F1FF);
+}
+
+
+const gunichar kCombiningEnclosingCircleBackslashCharacter = 0x20E0;
+const gunichar kCombiningEnclosingKeycapCharacter = 0x20E3;
+const gunichar kEyeCharacter = 0x1F441;
+const gunichar kFemaleSignCharacter = 0x2640;
+const gunichar kLeftSpeechBubbleCharacter = 0x1F5E8;
+const gunichar kMaleSignCharacter = 0x2642;
+const gunichar kRainbowCharacter = 0x1F308;
+const gunichar kStaffOfAesculapiusCharacter = 0x2695;
+const gunichar kVariationSelector15Character = 0xFE0E;
+const gunichar kVariationSelector16Character = 0xFE0F;
+const gunichar kWavingWhiteFlagCharacter = 0x1F3F3;
+const gunichar kZeroWidthJoinerCharacter = 0x200D;
+
+
+typedef enum {
+  PANGO_EMOJI_TYPE_INVALID,
+  PANGO_EMOJI_TYPE_TEXT, /* For regular non-symbols text */
+  PANGO_EMOJI_TYPE_EMOJI_TEXT, /* For emoji in text presentaiton */
+  PANGO_EMOJI_TYPE_EMOJI_EMOJI /* For emoji in emoji presentation */
+} PangoEmojiType;
+
+static PangoEmojiType
+_pango_get_emoji_type (gunichar codepoint)
+{
+  /* Those should only be Emoji presentation as combinations of two. */
+  if (_pango_Is_Emoji_Keycap_Base (codepoint) ||
+      _pango_Is_Regional_Indicator (codepoint))
+    return PANGO_EMOJI_TYPE_TEXT;
+
+  if (codepoint == kCombiningEnclosingKeycapCharacter)
+    return PANGO_EMOJI_TYPE_EMOJI_EMOJI;
+
+  if (_pango_Is_Emoji_Emoji_Default (codepoint) ||
+      _pango_Is_Emoji_Modifier_Base (codepoint) ||
+      _pango_Is_Emoji_Modifier (codepoint))
+    return PANGO_EMOJI_TYPE_EMOJI_EMOJI;
+
+  if (_pango_Is_Emoji_Text_Default (codepoint))
+    return PANGO_EMOJI_TYPE_EMOJI_TEXT;
+
+  return PANGO_EMOJI_TYPE_TEXT;
+}
+
+
+PangoEmojiIter *
+_pango_emoji_iter_init (PangoEmojiIter *iter,
+			const char     *text,
+			int             length)
+{
+  iter->text_start = text;
+  if (length >= 0)
+    iter->text_end = text + length;
+  else
+    iter->text_end = text + strlen (text);
+
+  iter->start = text;
+  iter->end = text;
+  iter->is_emoji = FALSE;
+
+  _pango_emoji_iter_next (iter);
+
+  return iter;
+}
+
+void
+_pango_emoji_iter_fini (PangoEmojiIter *iter)
+{
+}
+
+#define PANGO_EMOJI_TYPE_IS_EMOJI(typ) ((typ) == PANGO_EMOJI_TYPE_EMOJI_EMOJI)
+
+gboolean
+_pango_emoji_iter_next (PangoEmojiIter *iter)
+{
+  PangoEmojiType current_emoji_type = PANGO_EMOJI_TYPE_INVALID;
+
+  if (iter->end == iter->text_end)
+    return FALSE;
+
+  iter->start = iter->end;
+
+  for (; iter->end < iter->text_end; iter->end = g_utf8_next_char (iter->end))
+    {
+      gunichar ch = g_utf8_get_char (iter->end);
+
+    /* Except at the beginning, ZWJ just carries over the emoji or neutral
+     * text type, VS15 & VS16 we just carry over as well, since we already
+     * resolved those through lookahead. Also, don't downgrade to text
+     * presentation for emoji that are part of a ZWJ sequence, example
+     * U+1F441 U+200D U+1F5E8, eye (text presentation) + ZWJ + left speech
+     * bubble, see below. */
+    if ((!(ch == kZeroWidthJoinerCharacter && iter->is_emoji) &&
+	 ch != kVariationSelector15Character &&
+	 ch != kVariationSelector16Character &&
+	 ch != kCombiningEnclosingCircleBackslashCharacter &&
+	 !_pango_Is_Regional_Indicator(ch) &&
+	 !((ch == kLeftSpeechBubbleCharacter ||
+	    ch == kRainbowCharacter ||
+	    ch == kMaleSignCharacter ||
+	    ch == kFemaleSignCharacter ||
+	    ch == kStaffOfAesculapiusCharacter) &&
+	   iter->is_emoji)) ||
+	current_emoji_type == PANGO_EMOJI_TYPE_INVALID) {
+      current_emoji_type = _pango_get_emoji_type (ch);
+    }
+
+    if (iter->end < iter->text_end)
+    {
+      gunichar peek_char = g_utf8_get_char (iter->end);
+
+      /* Variation Selectors */
+      if (current_emoji_type ==
+	      PANGO_EMOJI_TYPE_EMOJI_EMOJI &&
+	  peek_char == kVariationSelector15Character) {
+	current_emoji_type = PANGO_EMOJI_TYPE_EMOJI_TEXT;
+      }
+
+      if ((current_emoji_type ==
+	       PANGO_EMOJI_TYPE_EMOJI_TEXT ||
+	   _pango_Is_Emoji_Keycap_Base(ch)) &&
+	  peek_char == kVariationSelector16Character) {
+	current_emoji_type = PANGO_EMOJI_TYPE_EMOJI_EMOJI;
+      }
+
+      /* Combining characters Keycap... */
+      if (_pango_Is_Emoji_Keycap_Base(ch) &&
+	  peek_char == kCombiningEnclosingKeycapCharacter) {
+	current_emoji_type = PANGO_EMOJI_TYPE_EMOJI_EMOJI;
+      };
+
+      /* Regional indicators */
+      if (_pango_Is_Regional_Indicator(ch) &&
+	  _pango_Is_Regional_Indicator(peek_char)) {
+	current_emoji_type = PANGO_EMOJI_TYPE_EMOJI_EMOJI;
+      }
+
+      /* Upgrade text presentation emoji to emoji presentation when followed by
+       * ZWJ, Example U+1F441 U+200D U+1F5E8, eye + ZWJ + left speech bubble. */
+      if ((ch == kEyeCharacter ||
+	   ch == kWavingWhiteFlagCharacter) &&
+	  peek_char == kZeroWidthJoinerCharacter) {
+	current_emoji_type = PANGO_EMOJI_TYPE_EMOJI_EMOJI;
+      }
+    }
+
+    if (iter->is_emoji != PANGO_EMOJI_TYPE_IS_EMOJI (current_emoji_type) && iter->start != iter->text_start)
+    {
+      iter->is_emoji = PANGO_EMOJI_TYPE_IS_EMOJI (current_emoji_type);
+      return TRUE;
+    }
+  }
+
+  iter->is_emoji = PANGO_EMOJI_TYPE_IS_EMOJI (current_emoji_type);
+
+  return TRUE;
+}
+
+
+/**********************************************************
+ * End of code from Chromium
+ **********************************************************/