Re-land: NativeTextfieldViews: Show the drop cursor when dragging text

ui/gfx/render_text.cc

 // Copyright (c) 2012 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.h"
 
 #include <algorithm>
 
 #include "base/i18n/break_iterator.h"
 #include "base/logging.h"
@@ skipping 593 matching lines @@
     Rect clip_rect(display_rect());
     clip_rect.Inset(ShadowValue::GetMargin(text_shadows_));
 
     canvas->Save();
     canvas->ClipRect(clip_rect);
   }
 
   if (!text().empty())
     DrawSelection(canvas);
 
-  DrawCursor(canvas);
+  if (cursor_enabled() && cursor_visible() && focused())
+    DrawCursor(canvas, selection_model_);
 
   if (!text().empty())
     DrawVisualText(canvas);
 
   if (clip_to_display_rect())
     canvas->Restore();
 }
 
+void RenderText::DrawCursor(Canvas* canvas, const SelectionModel& position) {
+  // Paint cursor. Replace cursor is drawn as rectangle for now.
+  // TODO(msw): Draw a better cursor with a better indication of association.
+  canvas->FillRect(GetCursorBounds(position, true), cursor_color_);
+}
+
 void RenderText::DrawSelectedText(Canvas* canvas) {
   EnsureLayout();
   const std::vector<Rect> sel = GetSubstringBounds(selection());
   for (size_t i = 0; i < sel.size(); ++i) {
     canvas->Save();
     canvas->ClipRect(sel[i]);
     DrawVisualText(canvas);
     canvas->Restore();
   }
 }
 
 Rect RenderText::GetCursorBounds(const SelectionModel& caret,
                                  bool insert_mode) {
   EnsureLayout();
 
   size_t caret_pos = caret.caret_pos();
+  DCHECK(IsCursorablePosition(caret_pos));
   // In overtype mode, ignore the affinity and always indicate that we will
   // overtype the next character.
   LogicalCursorDirection caret_affinity =
       insert_mode ? caret.caret_affinity() : CURSOR_FORWARD;
   int x = 0, width = 1, height = 0;
   if (caret_pos == (caret_affinity == CURSOR_BACKWARD ? 0 : text().length())) {
     // The caret is attached to the boundary. Always return a 1-dip width caret,
     // since there is nothing to overtype.
     Size size = GetStringSize();
     if ((GetTextDirection() == base::i18n::RIGHT_TO_LEFT) == (caret_pos == 0))
@@ skipping 307 matching lines @@
 }
 
 void RenderText::DrawSelection(Canvas* canvas) {
   const SkColor color = focused() ? selection_background_focused_color_ :
                                     selection_background_unfocused_color_;
   const std::vector<Rect> sel = GetSubstringBounds(selection());
   for (std::vector<Rect>::const_iterator i = sel.begin(); i < sel.end(); ++i)
     canvas->FillRect(*i, color);
 }
 
-void RenderText::DrawCursor(Canvas* canvas) {
-  // Paint cursor. Replace cursor is drawn as rectangle for now.
-  // TODO(msw): Draw a better cursor with a better indication of association.
-  if (cursor_enabled() && cursor_visible() && focused()) {
-    canvas->FillRect(GetUpdatedCursorBounds(),
-        insert_mode_ ? cursor_color_ : selection_background_unfocused_color_);
-  }
-}
-
 }  // namespace gfx