Paint text cursor in LAYER_SOLID_COLOR

ui/views/controls/textfield/textfield.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/views/controls/textfield/textfield.h"
 
 #include <string>
 #include <utility>
 
 #include "base/memory/ptr_util.h"
@@ skipping 256 matching lines @@
       skip_input_method_cancel_composition_(false),
       drop_cursor_visible_(false),
       initiating_drag_(false),
       selection_controller_(this),
       drag_start_display_offset_(0),
       touch_handles_hidden_due_to_scroll_(false),
       use_focus_ring_(ui::MaterialDesignController::IsSecondaryUiMaterial()),
       weak_ptr_factory_(this) {
   set_context_menu_controller(this);
   set_drag_controller(this);
+  cursor_view_.SetPaintToLayer(ui::LAYER_SOLID_COLOR);
+  cursor_view_.layer()->SetColor(GetTextColor());

[msw, 2017/02/16 20:44:24]

You'll need to change the cursor_view_ member to a raw pointer, so that it may
be owned by the views hierarchy:

In textfield.h (with optional comment):
  View* cursor_view_;  // Owned by the views hierarchy.
Above this, in textfield.cc's initializer list:
  cursor_view_(new View),
  weak_ptr_fact...
And then just change use here to reflect that.

+  AddChildView(&cursor_view_);
   GetRenderText()->SetFontList(GetDefaultFontList());
   View::SetBorder(std::unique_ptr<Border>(new FocusableBorder()));
   SetFocusBehavior(FocusBehavior::ALWAYS);
 
   // These allow BrowserView to pass edit commands from the Chrome menu to us
   // when we're focused by simply asking the FocusManager to
   // ProcessAccelerator() with the relevant accelerators.
   AddAccelerator(ui::Accelerator(ui::VKEY_X, ui::EF_CONTROL_DOWN));
   AddAccelerator(ui::Accelerator(ui::VKEY_C, ui::EF_CONTROL_DOWN));
   AddAccelerator(ui::Accelerator(ui::VKEY_V, ui::EF_CONTROL_DOWN));
@@ skipping 681 matching lines @@
 }
 
 void Textfield::OnPaint(gfx::Canvas* canvas) {
   OnPaintBackground(canvas);
   PaintTextAndCursor(canvas);
   OnPaintBorder(canvas);
 }
 
 void Textfield::OnFocus() {
   GetRenderText()->set_focused(true);
-  if (ShouldShowCursor())
-    GetRenderText()->set_cursor_visible(true);
+  if (ShouldShowCursor()) {
+    UpdateCursorView();
+    cursor_view_.SetVisible(true);
+  }
   if (GetInputMethod())
     GetInputMethod()->SetFocusedTextInputClient(this);
   OnCaretBoundsChanged();
   if (ShouldBlinkCursor())
     StartBlinkingCursor();
   if (use_focus_ring_) {
     FocusRing::Install(this, invalid_
                                  ? ui::NativeTheme::kColorId_AlertSeverityHigh
                                  : ui::NativeTheme::kColorId_NumColors);
   }
   SchedulePaint();
   View::OnFocus();
 }
 
 void Textfield::OnBlur() {
   gfx::RenderText* render_text = GetRenderText();
   render_text->set_focused(false);
   if (GetInputMethod())
     GetInputMethod()->DetachTextInputClient(this);
   StopBlinkingCursor();
-  if (render_text->cursor_visible()) {
-    render_text->set_cursor_visible(false);
-    RepaintCursor();
-  }
+  cursor_view_.SetVisible(false);
 
   DestroyTouchSelection();
 
   if (use_focus_ring_)
     FocusRing::Uninstall(this);
   SchedulePaint();
   View::OnBlur();
 }
 
 gfx::Point Textfield::GetKeyboardContextMenuLocation() {
   return GetCaretBounds().bottom_right();
 }
 
 void Textfield::OnNativeThemeChanged(const ui::NativeTheme* theme) {
   gfx::RenderText* render_text = GetRenderText();
   render_text->SetColor(GetTextColor());
   UpdateBackgroundColor();
-  render_text->set_cursor_color(GetTextColor());
   render_text->set_selection_color(GetSelectionTextColor());
   render_text->set_selection_background_focused_color(
       GetSelectionBackgroundColor());
+  cursor_view_.layer()->SetColor(GetTextColor());
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Textfield, TextfieldModel::Delegate overrides:
 
 void Textfield::OnCompositionTextConfirmedOrCleared() {
   if (!skip_input_method_cancel_composition_)
     GetInputMethod()->CancelComposition(this);
 }
 
@@ skipping 863 matching lines @@
   View::SetBorder(std::move(border));
 }
 
 void Textfield::UpdateAfterChange(bool text_changed, bool cursor_changed) {
   if (text_changed) {
     if (controller_)
       controller_->ContentsChanged(this, text());
     NotifyAccessibilityEvent(ui::AX_EVENT_TEXT_CHANGED, true);
   }
   if (cursor_changed) {
-    GetRenderText()->set_cursor_visible(ShouldShowCursor());
-    RepaintCursor();
+    cursor_view_.SetVisible(ShouldShowCursor());
+    UpdateCursorView();
     if (ShouldBlinkCursor())
       StartBlinkingCursor();
     else
       StopBlinkingCursor();
     NotifyAccessibilityEvent(ui::AX_EVENT_TEXT_SELECTION_CHANGED, true);
   }
   if (text_changed || cursor_changed) {
     OnCaretBoundsChanged();
     SchedulePaint();
   }
 }
 
-void Textfield::RepaintCursor() {
-  gfx::Rect r(GetRenderText()->GetUpdatedCursorBounds());
-  r.Inset(-1, -1, -1, -1);
-  SchedulePaintInRect(r);
+void Textfield::UpdateCursorView() {
+  cursor_view_.SetBoundsRect(GetRenderText()->GetUpdatedCursorBounds());
 }
 
 void Textfield::PaintTextAndCursor(gfx::Canvas* canvas) {
   TRACE_EVENT0("views", "Textfield::PaintTextAndCursor");
   canvas->Save();
 
   // Draw placeholder text if needed.
   gfx::RenderText* render_text = GetRenderText();
   if (text().empty() && !GetPlaceholderText().empty()) {
     canvas->DrawStringRect(GetPlaceholderText(), GetFontList(),
                            ui::MaterialDesignController::IsSecondaryUiMaterial()
                                ? SkColorSetA(GetTextColor(), 0x83)
                                : placeholder_text_color_,
                            render_text->display_rect());
   }
 
   render_text->Draw(canvas);
 
   // Draw the detached drop cursor that marks where the text will be dropped.
-  if (drop_cursor_visible_)
-    render_text->DrawCursor(canvas, drop_cursor_position_);
+  if (drop_cursor_visible_) {
+    canvas->FillRect(render_text->GetCursorBounds(drop_cursor_position_, true),
+                     GetTextColor());
+  }
 
   canvas->Restore();
 }
 
 void Textfield::MoveCursorTo(const gfx::Point& point, bool select) {
   if (model_->MoveCursorTo(point, select))
     UpdateAfterChange(false, true);
 }
 
 void Textfield::OnCaretBoundsChanged() {
@@ skipping 117 matching lines @@
                                            Textfield::GetCaretBlinkMs()),
                             this, &Textfield::OnCursorBlinkTimerFired);
 }
 
 void Textfield::StopBlinkingCursor() {
   cursor_blink_timer_.Stop();
 }
 
 void Textfield::OnCursorBlinkTimerFired() {
   DCHECK(ShouldBlinkCursor());
-  gfx::RenderText* render_text = GetRenderText();
-  render_text->set_cursor_visible(!render_text->cursor_visible());
-  RepaintCursor();
+  cursor_view_.SetVisible(!cursor_view_.visible());
+  UpdateCursorView();
 }
 
 }  // namespace views