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 50 matching lines @@
   if (sel.is_empty())
     return selection_model_;
   return SelectionModel(sel.start(),
                         sel.is_reversed() ? CURSOR_BACKWARD : CURSOR_FORWARD);
 }
 
 void RenderText::SetTextShadows(const ShadowValues& shadows) {
   text_shadows_ = shadows;
 }
 
+// static
+bool RenderText::RangeContainsCaret(const ui::Range& range,
+                                    size_t caret_pos,
+                                    LogicalCursorDirection caret_affinity) {
+  // NB: exploits unsigned wraparound (WG14/N1124 section 6.2.5 paragraph 9).
+  size_t adjacent = (caret_affinity == CURSOR_BACKWARD) ?
+      caret_pos - 1 : caret_pos + 1;
+  return range.Contains(ui::Range(caret_pos, adjacent));
+}
+
 RenderText::RenderText()
     : horizontal_alignment_(base::i18n::IsRTL() ? ALIGN_RIGHT : ALIGN_LEFT),
       directionality_mode_(DIRECTIONALITY_FROM_TEXT),
       text_direction_(base::i18n::UNKNOWN_DIRECTION),
       cursor_enabled_(true),
       cursor_visible_(false),
       insert_mode_(true),
       cursor_color_(kDefaultColor),
       selection_color_(kDefaultColor),
       selection_background_focused_color_(kDefaultSelectionBackgroundColor),
@@ skipping 154 matching lines @@
       text_rect, left_part, right_part, colors_.breaks().front().second);
   if (shader)
     renderer->SetShader(shader.get(), display_rect());
 }
 
 void RenderText::ApplyTextShadows(internal::SkiaTextRenderer* renderer) {
   skia::RefPtr<SkDrawLooper> looper = CreateShadowDrawLooper(text_shadows_);
   renderer->SetDrawLooper(looper.get());
 }
 
-// static
-bool RenderText::RangeContainsCaret(const ui::Range& range,
-                                    size_t caret_pos,
-                                    LogicalCursorDirection caret_affinity) {
-  // NB: exploits unsigned wraparound (WG14/N1124 section 6.2.5 paragraph 9).
-  size_t adjacent = (caret_affinity == CURSOR_BACKWARD) ?
-      caret_pos - 1 : caret_pos + 1;
-  return range.Contains(ui::Range(caret_pos, adjacent));
-}
-
 void RenderText::MoveCursorTo(size_t position, bool select) {
   size_t cursor = std::min(position, text().length());
   if (IsCursorablePosition(cursor))
     SetSelectionModel(SelectionModel(
         ui::Range(select ? selection().start() : cursor, cursor),
         (cursor == 0) ? CURSOR_FORWARD : CURSOR_BACKWARD));
 }
 
 void RenderText::UpdateObscuredText() {
   if (!obscured_)
@@ skipping 53 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