fix know issues in RenderText

ui/gfx/render_text_win.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gfx/render_text_win.h"
 
 #include "base/i18n/break_iterator.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/string_util.h"
@@ skipping 173 matching lines @@
     bool leading = selection.caret_placement() == SelectionModel::LEADING;
     // Adjust the x value for right-side placement.
     if (run->script_analysis.fRTL == leading)
       rect.set_x(rect.right());
     rect.set_width(0);
   }
   rect.set_origin(ToViewPoint(rect.origin()));
   return rect;
 }
 
+size_t RenderTextWin::GetIndexOfNextGrapheme(size_t position) {
+  return IndexOfAdjacentGrapheme(position, true);
+}
+
 SelectionModel RenderTextWin::GetLeftSelectionModel(
     const SelectionModel& selection,
     BreakType break_type) {
   if (break_type == LINE_BREAK || text().empty())
     return LeftEndSelectionModel();
   if (break_type == CHARACTER_BREAK)
     return LeftSelectionModel(selection);
   // TODO(msw): Implement word breaking.
   return RenderText::GetLeftSelectionModel(selection, break_type);
 }
@@ skipping 84 matching lines @@
       if (!bounds.empty() && rect.SharesEdgeWith(bounds.back())) {
         rect = rect.Union(bounds.back());
         bounds.pop_back();
       }
       bounds.push_back(rect);
     }
   }
   return bounds;
 }
 
+bool RenderTextLinux::IsCursorablePosition(size_t position) {

[msw, 2011/09/14 02:43:48]

RenderText*Win*

[xji, 2011/09/15 23:38:13]

Done.

+  if (position == 0 || position == text().length())
+    return true;
+
+  size_t run_index = GetRunContainingPosition(position);
+  internal::TextRun* run = run_index < runs_.size() ? runs_[run_index] : NULL;
+  if (!run)

[msw, 2011/09/14 02:43:48]

This could just be "if (run_index >= runs_.size()) /n return false;" followed up
by "internal::TextRun* run = runs_[run_index];"

[xji, 2011/09/15 23:38:13]

Done.

+    return false;
+  if (position == run->range.start())
+    return true;
+  return run->logical_clusters[position] != run->logical_clusters[position -1];

[msw, 2011/09/14 02:43:48]

The logical clusters array is indexed by offsets from the run start.
This will crash unless you first subtract run->range.start() from position.
This needs a space at "[position -* *1]"

[xji, 2011/09/15 23:38:13]

Done.

+}
+
 void RenderTextWin::ItemizeLogicalText() {
   text_is_dirty_ = false;
   STLDeleteContainerPointers(runs_.begin(), runs_.end());
   runs_.clear();
   if (text().empty())
     return;
 
   const wchar_t* raw_text = text().c_str();
   const int text_length = text().length();
 
@@ skipping 329 matching lines @@
     Rect r(GetUpdatedCursorBounds());
     canvas->DrawRectInt(kCursorColor, r.x(), r.y(), r.width(), r.height());
   }
 }
 
 RenderText* RenderText::CreateRenderText() {
   return new RenderTextWin;
 }
 
 }  // namespace gfx