Implement Uniscribe RenderText for Windows.

ui/gfx/render_text.cc

Index: ui/gfx/render_text.cc
diff --git a/ui/gfx/render_text.cc b/ui/gfx/render_text.cc
index 498bb3b42a3ad552208fee366dc42ec7de434b44..d3f567342257308048c13fbd77752705e85ce77c 100644
--- a/ui/gfx/render_text.cc
+++ b/ui/gfx/render_text.cc
@@ -175,6 +175,11 @@ void RenderText::SetSelectionModel(const SelectionModel& sel) {
   cached_bounds_and_offset_valid_ = false;
 }
 
+void RenderText::ToggleInsertMode() {
+  insert_mode_ = !insert_mode_;
+  cached_bounds_and_offset_valid_ = false;
+}
+
 void RenderText::SetDisplayRect(const Rect& r) {
   display_rect_ = r;
   cached_bounds_and_offset_valid_ = false;
@@ -184,13 +189,8 @@ size_t RenderText::GetCursorPosition() const {
   return selection_model_.selection_end();
 }
 
-void RenderText::SetCursorPosition(const size_t position) {
-  SelectionModel sel(selection_model());
-  sel.set_selection_start(position);
-  sel.set_selection_end(position);
-  sel.set_caret_pos(GetIndexOfPreviousGrapheme(position));
-  sel.set_caret_placement(SelectionModel::TRAILING);
-  SetSelectionModel(sel);
+void RenderText::SetCursorPosition(size_t position) {
+  MoveCursorTo(position, false);
 }
 
 void RenderText::MoveCursorLeft(BreakType break_type, bool select) {
@@ -251,6 +251,8 @@ bool RenderText::MoveCursorTo(const Point& point, bool select) {
 }
 
 bool RenderText::IsPointInSelection(const Point& point) {
+  if (EmptySelection())
+    return false;
   // TODO(xji): should this check whether the point is inside the visual
   // selection bounds? In case of "abcFED", if "ED" is selected, |point| points
   // to the right half of 'c', is the point in selection?
@@ -308,12 +310,8 @@ void RenderText::SelectWord() {
       break;
   }
 
-  SelectionModel sel(selection_model());
-  sel.set_selection_start(selection_start);
-  sel.set_selection_end(cursor_position);
-  sel.set_caret_pos(GetIndexOfPreviousGrapheme(cursor_position));
-  sel.set_caret_placement(SelectionModel::TRAILING);
-  SetSelectionModel(sel);
+  MoveCursorTo(selection_start, false);
+  MoveCursorTo(cursor_position, true);
 }
 
 const ui::Range& RenderText::GetCompositionRange() const {
@@ -576,6 +574,15 @@ void RenderText::ApplyCompositionAndSelectionStyles(
   }
 }
 
+void RenderText::MoveCursorTo(size_t position, bool select) {
+  size_t caret_pos = GetIndexOfPreviousGrapheme(position);
+  SelectionModel::CaretPlacement placement = (caret_pos == position) ?
+      SelectionModel::LEADING : SelectionModel::TRAILING;
+  size_t selection_start = select ? GetSelectionStart() : position;
+  SelectionModel sel(selection_start, position, 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]));
@@ -589,7 +596,6 @@ void RenderText::UpdateCachedBoundsAndOffset() {
   // function will set |cursor_bounds_| and |display_offset_| to correct values.
   cached_bounds_and_offset_valid_ = true;
   cursor_bounds_ = GetCursorBounds(selection_model_, insert_mode_);
-  cursor_bounds_.set_width(std::max(cursor_bounds_.width(), 1));
   // Update |display_offset_| to ensure the current cursor is visible.
   int display_width = display_rect_.width();
   int string_width = GetStringWidth();