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

1 files changed, 31 insertions, 38 deletions

diff --git a/ui/gfx/render_text.cc b/ui/gfx/render_text.cc
index 1111842..6d15e5c 100644
--- a/ui/gfx/render_text.cc
+++ b/ui/gfx/render_text.cc
@@ -247,6 +247,12 @@ bool RenderText::MoveCursorTo(const SelectionModel& selection_model) {
     sel.set_caret_pos(end.caret_pos());
     sel.set_caret_placement(end.caret_placement());
   }
+
+  if (!IsCursorablePosition(sel.selection_start()) ||
+      !IsCursorablePosition(sel.selection_end()) ||
+      !IsCursorablePosition(sel.caret_pos()))
+    return false;
+
   bool changed = !sel.Equals(selection_model_);
   SetSelectionModel(sel);
   return changed;
@@ -281,41 +287,28 @@ void RenderText::SelectAll() {
   SetSelectionModel(sel);
 }
 
-// TODO(xji): it does not work for languages do not use space as word breaker,
-// such as Chinese. Should use BreakIterator.
 void RenderText::SelectWord() {
-  size_t selection_start = GetSelectionStart();
   size_t cursor_position = GetCursorPosition();
-  // First we setup selection_start_ and selection_end_. There are so many cases
-  // because we try to emulate what select-word looks like in a gtk textfield.
-  // See associated testcase for different cases.
-  if (cursor_position > 0 && cursor_position < text().length()) {
-    if (u_isalnum(text()[cursor_position])) {
-      selection_start = cursor_position;
-      cursor_position++;
-    } else
-      selection_start = cursor_position - 1;
-  } else if (cursor_position == 0) {
-    selection_start = cursor_position;
-    if (text().length() > 0)
-      cursor_position++;
-  } else {
-    selection_start = cursor_position - 1;
-  }
 
-  // Now we move selection_start_ to beginning of selection. Selection boundary
-  // is defined as the position where we have alpha-num character on one side
-  // and non-alpha-num char on the other side.
-  for (; selection_start > 0; selection_start--) {
-    if (IsPositionAtWordSelectionBoundary(selection_start))
+  base::i18n::BreakIterator iter(text(), base::i18n::BreakIterator::BREAK_WORD);
+  bool success = iter.Init();
+  DCHECK(success);
+  if (!success)
+    return;
+
+  size_t selection_start = cursor_position;
+  for (; selection_start != 0; --selection_start) {
+    if (iter.IsStartOfWord(selection_start) ||
+        iter.IsEndOfWord(selection_start))
       break;
   }
 
-  // Now we move selection_end_ to end of selection. Selection boundary
-  // is defined as the position where we have alpha-num character on one side
-  // and non-alpha-num char on the other side.
-  for (; cursor_position < text().length(); cursor_position++) {
-    if (IsPositionAtWordSelectionBoundary(cursor_position))
+  if (selection_start == cursor_position)
+    ++cursor_position;
+
+  for (; cursor_position < text().length(); ++cursor_position) {
+    if (iter.IsEndOfWord(cursor_position) ||
+        iter.IsStartOfWord(cursor_position))
       break;
   }
 
@@ -462,6 +455,10 @@ const Rect& RenderText::GetUpdatedCursorBounds() {
   return cursor_bounds_;
 }
 
+size_t RenderText::GetIndexOfNextGrapheme(size_t position) {
+  return IndexOfAdjacentGrapheme(position, true);
+}
+
 RenderText::RenderText()
     : text_(),
       selection_model_(),
@@ -557,8 +554,7 @@ SelectionModel RenderText::RightEndSelectionModel() {
 }
 
 size_t RenderText::GetIndexOfPreviousGrapheme(size_t position) {
-  // TODO(msw): Handle complex script.
-  return std::max(static_cast<long>(position - 1), static_cast<long>(0));
+  return IndexOfAdjacentGrapheme(position, false);
 }
 
 std::vector<Rect> RenderText::GetSubstringBounds(size_t from, size_t to) {
@@ -632,13 +628,10 @@ void RenderText::MoveCursorTo(size_t position, bool select) {
   SelectionModel::CaretPlacement placement = (caret_pos == cursor) ?
       SelectionModel::LEADING : SelectionModel::TRAILING;
   size_t selection_start = select ? GetSelectionStart() : cursor;
-  SelectionModel sel(selection_start, cursor, caret_pos, placement);
-  SetSelectionModel(sel);
-}
-
-bool RenderText::IsPositionAtWordSelectionBoundary(size_t pos) {
-  return pos == 0 || (u_isalnum(text()[pos - 1]) && !u_isalnum(text()[pos])) ||
-      (!u_isalnum(text()[pos - 1]) && u_isalnum(text()[pos]));
+  if (IsCursorablePosition(cursor)) {
+    SelectionModel sel(selection_start, cursor, caret_pos, placement);
+    SetSelectionModel(sel);
+  }
 }
 
 void RenderText::UpdateCachedBoundsAndOffset() {