Remove PREVIOUS_GRAPHEME_TRAILING.

Remove const from GetIndexOfPreviousGrapheme() so the override function could
update local data.
Construct SelectionModel correctly in unittest.

BUG=90426
TEST=--use-pure-view.
Review URL: http://codereview.chromium.org/7607018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@97029 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 13 insertions, 8 deletions

diff --git a/ui/gfx/render_text.cc b/ui/gfx/render_text.cc
index 2855a07..498bb3b 100644
--- a/ui/gfx/render_text.cc
+++ b/ui/gfx/render_text.cc
@@ -87,11 +87,15 @@ StyleRange::StyleRange()
 }
 
 SelectionModel::SelectionModel() {
-  Init(0, 0, 0, PREVIOUS_GRAPHEME_TRAILING);
+  Init(0, 0, 0, LEADING);
 }
 
 SelectionModel::SelectionModel(size_t pos) {
-  Init(pos, pos, pos, PREVIOUS_GRAPHEME_TRAILING);
+  Init(pos, pos, pos, LEADING);
+}
+
+SelectionModel::SelectionModel(size_t start, size_t end) {
+  Init(start, end, end, LEADING);
 }
 
 SelectionModel::SelectionModel(size_t end,
@@ -266,6 +270,8 @@ 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();
@@ -305,7 +311,8 @@ void RenderText::SelectWord() {
   SelectionModel sel(selection_model());
   sel.set_selection_start(selection_start);
   sel.set_selection_end(cursor_position);
-  sel.set_caret_placement(SelectionModel::PREVIOUS_GRAPHEME_TRAILING);
+  sel.set_caret_pos(GetIndexOfPreviousGrapheme(cursor_position));
+  sel.set_caret_placement(SelectionModel::TRAILING);
   SetSelectionModel(sel);
 }
 
@@ -542,7 +549,7 @@ SelectionModel RenderText::GetRightSelectionModel(const SelectionModel& current,
   return SelectionModel(pos, pos, SelectionModel::LEADING);
 }
 
-size_t RenderText::GetIndexOfPreviousGrapheme(size_t position) const {
+size_t RenderText::GetIndexOfPreviousGrapheme(size_t position) {
   // TODO(msw): Handle complex script.
   return std::max(static_cast<int>(position - 1), static_cast<int>(0));
 }
diff --git a/ui/gfx/render_text.h b/ui/gfx/render_text.h
index c3f9104..cc4f4e5 100644
--- a/ui/gfx/render_text.h
+++ b/ui/gfx/render_text.h
@@ -90,15 +90,13 @@ enum BreakType {
 class UI_EXPORT SelectionModel {
  public:
   enum CaretPlacement {
-    // PREVIOUS_GRAPHEME_TRAILING means cursor is visually attached to the
-    // trailing edge of previous grapheme.
-    PREVIOUS_GRAPHEME_TRAILING,
     LEADING,
     TRAILING,
   };
 
   SelectionModel();
   explicit SelectionModel(size_t pos);
+  SelectionModel(size_t start, size_t end);
   SelectionModel(size_t end, size_t pos, CaretPlacement status);
   SelectionModel(size_t start, size_t end, size_t pos, CaretPlacement status);
 
@@ -277,7 +275,7 @@ class UI_EXPORT RenderText {
                                                 BreakType break_type);
 
   // Get the logical index of the grapheme preceeding the argument |position|.
-  virtual size_t GetIndexOfPreviousGrapheme(size_t position) const;
+  virtual size_t GetIndexOfPreviousGrapheme(size_t position);
 
   // Apply composition style (underline) to composition range and selection
   // style (foreground) to selection range.