Add LazyLineBreakIterator::Next/PreviousBreakOpportunity()

third_party/WebKit/Source/platform/text/TextBreakIterator.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2007-2009 Torch Mobile, Inc.
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * 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
@@ skipping 232 matching lines @@
   }
   return false;
 }
 
 inline bool NeedsLineBreakIterator(UChar ch) {
   return ch > kAsciiLineBreakTableLastChar && ch != kNoBreakSpaceCharacter;
 }
 
 template <typename CharacterType, LineBreakType lineBreakType>
 static inline int NextBreakablePosition(
-    LazyLineBreakIterator& lazy_break_iterator,
+    const LazyLineBreakIterator& lazy_break_iterator,
     const CharacterType* str,
     unsigned length,
     int pos) {
   int len = static_cast<int>(length);
   int next_break = -1;
 
   UChar last_last_ch =
       pos > 1 ? str[pos - 2] : lazy_break_iterator.SecondToLastCharacter();
   UChar last_ch = pos > 0 ? str[pos - 1] : lazy_break_iterator.LastCharacter();
   ULineBreak last_line_break;
@@ skipping 43 matching lines @@
 
 static inline bool ShouldKeepAfter(UChar last_ch, UChar ch, UChar next_ch) {
   UChar pre_ch = U_MASK(u_charType(ch)) & U_GC_M_MASK ? last_ch : ch;
   return U_MASK(u_charType(pre_ch)) & (U_GC_L_MASK | U_GC_N_MASK) &&
          !WTF::Unicode::HasLineBreakingPropertyComplexContext(pre_ch) &&
          U_MASK(u_charType(next_ch)) & (U_GC_L_MASK | U_GC_N_MASK) &&
          !WTF::Unicode::HasLineBreakingPropertyComplexContext(next_ch);
 }
 
 static inline int NextBreakablePositionKeepAllInternal(
-    LazyLineBreakIterator& lazy_break_iterator,
+    const LazyLineBreakIterator& lazy_break_iterator,
     const UChar* str,
     unsigned length,
     int pos) {
   int len = static_cast<int>(length);
   int next_break = -1;
 
   UChar last_last_ch =
       pos > 1 ? str[pos - 2]
               : static_cast<UChar>(lazy_break_iterator.SecondToLastCharacter());
   UChar last_ch = pos > 0
@@ skipping 29 matching lines @@
 
     last_last_ch = last_ch;
     last_ch = ch;
   }
 
   return len;
 }
 
 template <LineBreakType lineBreakType>
 static inline int NextBreakablePosition(
-    LazyLineBreakIterator& lazy_break_iterator,
+    const LazyLineBreakIterator& lazy_break_iterator,
     const String& string,
     int pos) {
   if (string.Is8Bit())
     return NextBreakablePosition<LChar, lineBreakType>(
         lazy_break_iterator, string.Characters8(), string.length(), pos);
   return NextBreakablePosition<UChar, lineBreakType>(
       lazy_break_iterator, string.Characters16(), string.length(), pos);
 }
 
-int LazyLineBreakIterator::NextBreakablePositionIgnoringNBSP(int pos) {
+int LazyLineBreakIterator::NextBreakablePositionIgnoringNBSP(int pos) const {
   return NextBreakablePosition<LineBreakType::kNormal>(*this, string_, pos);
 }
 
-int LazyLineBreakIterator::NextBreakablePositionBreakAll(int pos) {
+int LazyLineBreakIterator::NextBreakablePositionBreakAll(int pos) const {
   return NextBreakablePosition<LineBreakType::kBreakAll>(*this, string_, pos);
 }
 
-int LazyLineBreakIterator::NextBreakablePositionKeepAll(int pos) {
+int LazyLineBreakIterator::NextBreakablePositionKeepAll(int pos) const {
   if (string_.Is8Bit())
     return NextBreakablePosition<LChar, LineBreakType::kNormal>(
         *this, string_.Characters8(), string_.length(), pos);
   return NextBreakablePositionKeepAllInternal(*this, string_.Characters16(),
                                               string_.length(), pos);
 }
 
+unsigned LazyLineBreakIterator::NextBreakOpportunity(unsigned offset) const {
+  int next_break = 0;
+  IsBreakable(offset, next_break);
+  return next_break;
+}
+
+unsigned LazyLineBreakIterator::PreviousBreakOpportunity(unsigned offset,
+                                                         unsigned min) const {
+  unsigned pos = std::min(offset, string_.length());
+  for (; pos > min; pos--) {
+    int next_break = 0;
+    if (IsBreakable(pos, next_break))
+      return pos;
+  }
+  return min;
+}
+
 }  // namespace blink