1 files changed, 82 insertions, 0 deletions
diff --git a/intl/lwbrk/LineBreaker.h b/intl/lwbrk/LineBreaker.h
new file mode 100644
index 0000000000..a2d7377474
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+++ b/intl/lwbrk/LineBreaker.h
@@ -0,0 +1,82 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef mozilla_intl_LineBreaker_h__
+#define mozilla_intl_LineBreaker_h__
+
+#include <cstdint>
+
+#define NS_LINEBREAKER_NEED_MORE_TEXT -1
+
+namespace mozilla {
+namespace intl {
+enum class LineBreakRule : uint8_t;
+enum class WordBreakRule : uint8_t;
+
+class LineBreaker final {
+ public:
+  // LineBreaker is a utility class with only static methods. No need to
+  // instantiate it.
+  LineBreaker() = delete;
+  ~LineBreaker() = delete;
+
+  // Find the next line break opportunity starting from aPos + 1. It can return
+  // aLen if there's no break opportunity between [aPos + 1, aLen - 1].
+  //
+  // If aPos is already at the end of aText or beyond, i.e. aPos >= aLen, return
+  // NS_LINEBREAKER_NEED_MORE_TEXT.
+  //
+  // DEPRECATED: Use LineBreakIteratorUtf16 instead.
+  static int32_t Next(const char16_t* aText, uint32_t aLen, uint32_t aPos);
+
+  // Call this on a word with whitespace at either end. We will apply JISx4051
+  // rules to find breaks inside the word. aBreakBefore is set to the break-
+  // before status of each character; aBreakBefore[0] will always be false
+  // because we never return a break before the first character.
+  // aLength is the length of the aText array and also the length of the
+  // aBreakBefore output array.
+  static void ComputeBreakPositions(const char16_t* aText, uint32_t aLength,
+                                    WordBreakRule aWordBreak,
+                                    LineBreakRule aLevel,
+                                    bool aIsChineseOrJapanese,
+                                    uint8_t* aBreakBefore);
+  static void ComputeBreakPositions(const uint8_t* aText, uint32_t aLength,
+                                    WordBreakRule aWordBreak,
+                                    LineBreakRule aLevel,
+                                    bool aIsChineseOrJapanese,
+                                    uint8_t* aBreakBefore);
+};
+
+static inline bool NS_IsSpace(char16_t u) {
+  return u == 0x0020 ||                   // SPACE
+         u == 0x0009 ||                   // CHARACTER TABULATION
+         u == 0x000D ||                   // CARRIAGE RETURN
+         (0x2000 <= u && u <= 0x2006) ||  // EN QUAD, EM QUAD, EN SPACE,
+                                          // EM SPACE, THREE-PER-EM SPACE,
+                                          // FOUR-PER-SPACE, SIX-PER-EM SPACE,
+         (0x2008 <= u && u <= 0x200B) ||  // PUNCTUATION SPACE, THIN SPACE,
+                                          // HAIR SPACE, ZERO WIDTH SPACE
+         u == 0x1361 ||                   // ETHIOPIC WORDSPACE
+         u == 0x1680 ||                   // OGHAM SPACE MARK
+         u == 0x205F;                     // MEDIUM MATHEMATICAL SPACE
+}
+
+static inline bool NS_NeedsPlatformNativeHandling(char16_t aChar) {
+  return
+#if ANDROID || XP_WIN  // Bug 1647377/1736393: no "platform native" support for
+                       // Tibetan; better to just use our class-based breaker.
+      (0x0e01 <= aChar && aChar <= 0x0eff) ||  // Thai, Lao
+#else
+      // Routing Tibetan to the platform-native breaker currently results in
+      // WPT failures in a few css3-text-line-break-opclns-* testcases that mix
+      // a Tibetan character with other-script context.
+      (0x0e01 <= aChar && aChar <= 0x0fff) ||  // Thai, Lao, Tibetan
+#endif
+      (0x1780 <= aChar && aChar <= 0x17ff);  // Khmer
+}
+
+}  // namespace intl
+}  // namespace mozilla
+
+#endif /* mozilla_intl_LineBreaker_h__ */