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/trace_event/trace_event.h"
@@ skipping 220 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 164 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 {
+  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 473 matching lines @@
     touch_selection_controller_->SelectionChanged();
 }
 
 void Textfield::OnEnabledChanged() {
   View::OnEnabledChanged();
   if (GetInputMethod())
     GetInputMethod()->OnTextInputTypeChanged(this);
   SchedulePaint();
 }
 
+void Textfield::ViewHierarchyChanged(
+    const ViewHierarchyChangedDetails& details) {
+  // Textfields only care about focus changes if the entire Widget has lost
+  // focus, so don't bother listening if there is no Widget.
+  if (!GetWidget()) {
+    focus_manager_ = nullptr;

[tapted, 2016/10/31 00:30:25]

Ah, so this doesn't look right without the other code fragment. 

Is there a reason not to use the simpler code fragment? Since, it seems like we
also need handling in NativeViewHierarchyChanged (or a modification to view.cc).
E.g. probably both ViewHierarchyChanged and NativeViewHierarchyChanged should
call a helper method like UpdateFocusChangeListener() which won't have access to
ViewHierarchyChangedDetails.

(the reason it doesn't look right is that RemoveFocusChangeListener() isn't
invoked. I think that's required before ~FocusManager, so instead of
`focus_manager_ = nullptr;` it looks like `DCHECK(!focus_manager_)` should work
on this line, but I'm less sure about whether that's valid :/. Anyway, that
simpler code fragment should deal with these concerns).

[Patti Lor, 2016/11/02 03:19:48]

Oops, sorry for the misunderstanding - I thought you meant "use the other code
fragment if switching to NativeViewHierarchyChanged() instead of
ViewHierarchyChanged()."

In any case, using this code snippet doesn't work - on Mac, the FocusManager is
destroyed after the Textfield, so GetFocusManager() still returns a valid
FocusManager and it never removes itself. On Linux, GetWidget() returns null
when ViewHierarchyChanged is called on the remove case and it sets
focus_manager_ to null and never removes itself there either. (On Linux, this
only happened with the Omnibox - maybe it only affects top-level Widgets? Didn't
investigate further.)

I've left this code kind of as is minus the focus_manager = null plus also
calling it in NativeViewHierarchyChanged(), but if we wanted to use the code you
posted, we could alternatively re-add that OnFocusManagerDestroying()
notification, this time, passing in the FocusManager as an argument, so this
means we can also get rid of |focus_manager_|. Not sure what you would prefer.

[tapted, 2016/11/02 03:45:06]

This looks OK. It might be nice to have GetWidget()  (and GetFocusManager())
return null during Widget Close, but that would affect a lot of things.

+    return;
+  }
+
+  if (details.parent->Contains(this) && details.move_view == nullptr) {
+    if (details.is_add) {
+      FocusManager* focus_manager = GetFocusManager();
+      // There should never be two different FocusManagers for the same Widget
+      // at the same time.
+      DCHECK(!focus_manager_ && focus_manager);
+      focus_manager_ = focus_manager;
+      focus_manager_->AddFocusChangeListener(this);
+    } else {
+      DCHECK(focus_manager_);
+      focus_manager_->RemoveFocusChangeListener(this);
+      focus_manager_ = nullptr;
+    }
+  }
+}
+
 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()) {
+    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) {
+  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);
+}
+
+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 970 matching lines @@
 }
 
 void Textfield::OnCursorBlinkTimerFired() {
   DCHECK(ShouldBlinkCursor());
   gfx::RenderText* render_text = GetRenderText();
   render_text->set_cursor_visible(!render_text->cursor_visible());
   RepaintCursor();
 }
 
 }  // namespace views