Views: Draw Textfield selected text in gray when top-level Widget loses focus.

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/strings/utf_string_conversions.h"
@@ skipping 222 matching lines @@
       read_only_(false),
       default_width_in_chars_(0),
       use_default_text_color_(true),
       use_default_background_color_(true),
       use_default_selection_text_color_(true),
       use_default_selection_background_color_(true),
       text_color_(SK_ColorBLACK),
       background_color_(SK_ColorWHITE),
       selection_text_color_(SK_ColorWHITE),
       selection_background_color_(SK_ColorBLUE),
+      focus_manager_(nullptr),
       placeholder_text_color_(kDefaultPlaceholderTextColor),
       invalid_(false),
       text_input_type_(ui::TEXT_INPUT_TYPE_TEXT),
       text_input_flags_(0),
       performing_user_action_(false),
       skip_input_method_cancel_composition_(false),
       drop_cursor_visible_(false),
       initiating_drag_(false),
       selection_controller_(this),
       drag_start_display_offset_(0),
@@ skipping 17 matching lines @@
   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));
 }
 
 Textfield::~Textfield() {
   if (GetInputMethod()) {
     // The textfield should have been blurred before destroy.
     DCHECK(this != GetInputMethod()->GetTextInputClient());
   }
+  DCHECK(!focus_manager_);
 }
 
 void Textfield::SetReadOnly(bool read_only) {
   // Update read-only without changing the focusable state (or active, etc.).
   read_only_ = read_only;
   if (GetInputMethod())
     GetInputMethod()->OnTextInputTypeChanged(this);
   SetColor(GetTextColor());
   UpdateBackgroundColor();
 }
@@ skipping 127 matching lines @@
 SkColor Textfield::GetSelectionBackgroundColor() const {
   return use_default_selection_background_color_ ?
       GetNativeTheme()->GetSystemColor(
           ui::NativeTheme::kColorId_TextfieldSelectionBackgroundFocused) :
       selection_background_color_;
 }
 
 void Textfield::SetSelectionBackgroundColor(SkColor color) {
   selection_background_color_ = color;
   use_default_selection_background_color_ = false;
-  GetRenderText()->set_selection_background_focused_color(
+  GetRenderText()->set_selection_background_color(
       GetSelectionBackgroundColor());
   SchedulePaint();
 }
 
 void Textfield::UseDefaultSelectionBackgroundColor() {
   use_default_selection_background_color_ = true;
-  GetRenderText()->set_selection_background_focused_color(
+  GetRenderText()->set_selection_background_color(
       GetSelectionBackgroundColor());
   SchedulePaint();
 }
 
+SkColor Textfield::GetUnfocusedSelectionBackgroundColor() const {

[msw, 2016/11/09 02:08:53]

Inline this or make a file-local function, it's not needed on Textfield.

+  return GetNativeTheme()->GetSystemColor(
+      ui::NativeTheme::kColorId_TextfieldSelectionBackgroundUnfocused);
+}
+
 bool Textfield::GetCursorEnabled() const {
   return GetRenderText()->cursor_enabled();
 }
 
 void Textfield::SetCursorEnabled(bool enabled) {
   GetRenderText()->SetCursorEnabled(enabled);
 }
 
 const gfx::FontList& Textfield::GetFontList() const {
   return GetRenderText()->font_list();
@@ skipping 485 matching lines @@
     touch_selection_controller_->SelectionChanged();
 }
 
 void Textfield::OnEnabledChanged() {
   View::OnEnabledChanged();
   if (GetInputMethod())
     GetInputMethod()->OnTextInputTypeChanged(this);
   SchedulePaint();
 }
 
+void Textfield::ViewHierarchyChanged(
+    const ViewHierarchyChangedDetails& details) {
+  if (details.parent->Contains(this) && details.move_view == nullptr)

[msw, 2016/11/09 02:08:53]

Can you explain what's happening here? Shouldn't this be something like:
if (details.child == this)
  ObserveWidgetFocusChanges(details.is_add);

+    ObserveWidgetFocusChanges(details.is_add);
+}
+
+void Textfield::NativeViewHierarchyChanged() {
+  ObserveWidgetFocusChanges(true);

[msw, 2016/11/09 02:08:53]

Add a comment explaining why this is necessary; The function comment says it's
useful for tracking the view's FocusManager, but it's not obvious...

+}
+
 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);
@@ skipping 33 matching lines @@
 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());
+  if (HasFocus()) {

[msw, 2016/11/09 02:08:53]

optional nit: use an inlined ternary or something like line 1102:
SkColor selection_bg_color = HasFocus()
                                 ? GetSelectionBackgroundColor()
                                 : GetUnfocusedSelectionBackgroundColor();

+    render_text->set_selection_background_color(GetSelectionBackgroundColor());
+  } else {
+    render_text->set_selection_background_color(
+        GetUnfocusedSelectionBackgroundColor());
+  }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Textfield, TextfieldModel::Delegate overrides:
 
 void Textfield::OnCompositionTextConfirmedOrCleared() {
   if (!skip_input_method_cancel_composition_)
     GetInputMethod()->CancelComposition(this);
 }
 
@@ skipping 56 matching lines @@
   return drag_operations;
 }
 
 bool Textfield::CanStartDragForView(View* sender,
                                     const gfx::Point& press_pt,
                                     const gfx::Point& p) {
   return initiating_drag_ && GetRenderText()->IsPointInSelection(press_pt);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// Textfield, FocusChangeListener overrides:
+
+void Textfield::OnWillChangeFocus(View* focus_before, View* focus_after) {

[msw, 2016/11/09 02:08:53]

It's really unfortunate that we can't do this via OnFocus/OnBlur... Why was it
determined that we shouldn't paint unfocused selections when the focus is
transferred to another view in the widget?

[tapted, 2016/11/11 00:10:39]

I think this would be inconsistent with the WebContents. Also the "Graphite"
option is a popular theme on Mac, which gives an (almost?) identical gray color
to unfocused selections (i.e. instead of Aqua/blue). This would make it almost
impossible to tell what textfield has focus based on the selection highlight.

+  if (focus_before != this && focus_after != this)
+    return;
+
+  SkColor selection_bg_color = focus_after
+                                   ? GetSelectionBackgroundColor()
+                                   : GetUnfocusedSelectionBackgroundColor();
+
+  // Selection is drawn if |this| has focus, or the Widget loses activation, but
+  // not if another View in this Widget is gaining focus.
+  GetRenderText()->set_draw_text_selection(focus_after == this || !focus_after);
+  GetRenderText()->set_selection_background_color(selection_bg_color);

[msw, 2016/11/09 02:08:53]

Should we SchedulePaint after this, just in case this happens after
Textfield::OnFocus or Textfield::OnBlur (in which case this might change the
appearance without scheduling a paint)

+}
+
+void Textfield::OnDidChangeFocus(View* focused_before, View* focused_now) {}
+
+////////////////////////////////////////////////////////////////////////////////
 // Textfield, WordLookupClient overrides:
 
 bool Textfield::GetDecoratedWordAtPoint(const gfx::Point& point,
                                         gfx::DecoratedText* decorated_word,
                                         gfx::Point* baseline_point) {
   return GetRenderText()->GetDecoratedWordAtPoint(point, decorated_word,
                                                   baseline_point);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ skipping 746 matching lines @@
 #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
   if (text_input_type_ != ui::TEXT_INPUT_TYPE_PASSWORD) {
     ui::ScopedClipboardWriter(ui::CLIPBOARD_TYPE_SELECTION)
         .WriteText(GetSelectedText());
     if (controller_)
       controller_->OnAfterCutOrCopy(ui::CLIPBOARD_TYPE_SELECTION);
   }
 #endif
 }
 
+void Textfield::ObserveWidgetFocusChanges(bool add_as_listener) {
+  if (focus_manager_) {
+    focus_manager_->RemoveFocusChangeListener(this);
+    focus_manager_ = nullptr;
+  }
+
+  if (add_as_listener) {
+    focus_manager_ = GetFocusManager();

[msw, 2016/11/09 02:08:53]

Should this early-return up top if |focus_manager_ == GetFocusManager() &&
add_as_listener|?

+    if (!focus_manager_) {
+      // |focus_manager_| will be null if GetWidget() is null (not currently in
+      // a Widget), or if the Widget's FocusManager is null and there is no
+      // parent Widget yet (e.g. TYPE_CONTROL Widgets). In the latter case, a
+      // call to NativeViewHierarchyChanged() should follow.
+      return;
+    }
+    focus_manager_->AddFocusChangeListener(this);
+  }
+}
+
 void Textfield::UpdateBackgroundColor() {
   const SkColor color = GetBackgroundColor();
   if (ui::MaterialDesignController::IsSecondaryUiMaterial()) {
     set_background(Background::CreateBackgroundPainter(
         true, Painter::CreateSolidRoundRectPainter(
                   color, FocusableBorder::kCornerRadiusDp)));
   } else {
     set_background(Background::CreateSolidBackground(color));
   }
   // Disable subpixel rendering when the background color is transparent
@@ skipping 197 matching lines @@
 }
 
 void Textfield::OnCursorBlinkTimerFired() {
   DCHECK(ShouldBlinkCursor());
   gfx::RenderText* render_text = GetRenderText();
   render_text->set_cursor_visible(!render_text->cursor_visible());
   RepaintCursor();
 }
 
 }  // namespace views