This is a reapply of

http://src.chromium.org/viewvc/chrome?view=rev&revision=102006

fix know issues in RenderText

1. add tests.
2. change SelectWord() to use BreakIterator, so it works for Chinese and Complex script.
3. DELETE/ReplaceChar delete/replace a whole grapheme. ReplaceTextInternal should only replace one grapheme when there is no selection.
4. pointing to position outside of text returns HOME/END position.
5. based on Chrome Linux omnibox and gedit, given 
"abc|   def", double click should select "   " instead of "abc". Change test expectation.

BUG=90426
TEST=compile with touchui=1 test omnibox. run views_unittests.NativeTextfieldViewsTest/TextfieldViewsModelTest
Review URL: http://codereview.chromium.org/7841056

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@102160 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 27 insertions, 0 deletions

diff --git a/base/i18n/break_iterator.cc b/base/i18n/break_iterator.cc
index afa1fd8..eae531c 100644
--- a/base/i18n/break_iterator.cc
+++ b/base/i18n/break_iterator.cc
@@ -92,6 +92,27 @@ bool BreakIterator::IsWord() const {
   return (break_type_ == BREAK_WORD && status != UBRK_WORD_NONE);
 }
 
+bool BreakIterator::IsEndOfWord(size_t position) const {
+  if (break_type_ != BREAK_WORD)
+    return false;
+
+  UBreakIterator* iter = static_cast<UBreakIterator*>(iter_);
+  UBool boundary = ubrk_isBoundary(iter, static_cast<int32_t>(position));
+  int32_t status = ubrk_getRuleStatus(iter);
+  return (!!boundary && status != UBRK_WORD_NONE);
+}
+
+bool BreakIterator::IsStartOfWord(size_t position) const {
+  if (break_type_ != BREAK_WORD)
+    return false;
+
+  UBreakIterator* iter = static_cast<UBreakIterator*>(iter_);
+  UBool boundary = ubrk_isBoundary(iter, static_cast<int32_t>(position));
+  ubrk_next(iter);
+  int32_t next_status = ubrk_getRuleStatus(iter);
+  return (!!boundary && next_status != UBRK_WORD_NONE);
+}
+
 string16 BreakIterator::GetString() const {
   DCHECK(prev_ != npos && pos_ != npos);
   return string_.substr(prev_, pos_ - prev_);
diff --git a/base/i18n/break_iterator.h b/base/i18n/break_iterator.h
index f375962..3207256 100644
--- a/base/i18n/break_iterator.h
+++ b/base/i18n/break_iterator.h
@@ -88,6 +88,12 @@ class BASE_I18N_EXPORT BreakIterator {
   // this distinction doesn't apply and it always retuns false.
   bool IsWord() const;
 
+  // Under BREAK_WORD mode, returns true if |position| is at the end of word or
+  // at the start of word. It always retuns false under BREAK_LINE and
+  // BREAK_NEWLINE modes.
+  bool IsEndOfWord(size_t position) const;
+  bool IsStartOfWord(size_t position) const;
+
   // Returns the string between prev() and pos().
   // Advance() must have been called successfully at least once for pos() to
   // have advanced to somewhere useful.