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

ui/views/controls/textfield/textfield.h

Index: ui/views/controls/textfield/textfield.h
diff --git a/ui/views/controls/textfield/textfield.h b/ui/views/controls/textfield/textfield.h
index 0d77946328f05a0b58694fd2c288787389ca8b69..c5ef6bb71bab69d15ada0626b6b516aa5fe21dd5 100644
--- a/ui/views/controls/textfield/textfield.h
+++ b/ui/views/controls/textfield/textfield.h
@@ -29,6 +29,7 @@
 #include "ui/views/context_menu_controller.h"
 #include "ui/views/controls/textfield/textfield_model.h"
 #include "ui/views/drag_controller.h"
+#include "ui/views/focus/focus_manager.h"
 #include "ui/views/selection_controller.h"
 #include "ui/views/selection_controller_delegate.h"
 #include "ui/views/view.h"
@@ -45,6 +46,7 @@ class VIEWS_EXPORT Textfield : public View,
                                public TextfieldModel::Delegate,
                                public ContextMenuController,
                                public DragController,
+                               public FocusChangeListener,

[msw, 2016/11/09 02:14:54]

Would it make sense (and/or be easier to manage) to make Textfield a
WidgetObserver and handle OnWidgetActivationChanged and check for the focus
state (instead of being a FocusChangeListener)

[Patti Lor, 2016/11/10 07:29:09]

Ah, I hadn't considered using OnWidgetActivationChanged. From first glance, I
think the code might be quite similar - the hard part is probably just when to
add the Textfield as a observer, which will probably just go into
(Native)ViewHierarchyChanged() like now. It might make more sense though (and we
could get rid of the |focus_manager_| pointer, I think). I'll try it and see if
anything weird breaks.

                                public WordLookupClient,
                                public SelectionControllerDelegate,
                                public ui::TouchEditable,
@@ -140,6 +142,10 @@ class VIEWS_EXPORT Textfield : public View,
   void SetSelectionBackgroundColor(SkColor color);
   void UseDefaultSelectionBackgroundColor();
 
+  // Gets the selection background color for use when the Textfield was the last
+  // to be focused in a widget.
+  SkColor GetUnfocusedSelectionBackgroundColor() const;
+
   // Set drop shadows underneath the text.
   void SetShadows(const gfx::ShadowValues& shadows);
 
@@ -244,6 +250,9 @@ class VIEWS_EXPORT Textfield : public View,
   bool GetNeedsNotificationWhenVisibleBoundsChange() const override;
   void OnVisibleBoundsChanged() override;
   void OnEnabledChanged() override;
+  void ViewHierarchyChanged(
+      const ViewHierarchyChangedDetails& details) override;
+  void NativeViewHierarchyChanged() override;
   void OnPaint(gfx::Canvas* canvas) override;
   void OnFocus() override;
   void OnBlur() override;
@@ -267,6 +276,10 @@ class VIEWS_EXPORT Textfield : public View,
                            const gfx::Point& press_pt,
                            const gfx::Point& p) override;
 
+  // FocusChangeListener overrides:
+  void OnWillChangeFocus(View* focused_before, View* focused_now) override;
+  void OnDidChangeFocus(View* focused_before, View* focused_now) override;
+
   // WordLookupClient overrides:
   bool GetDecoratedWordAtPoint(const gfx::Point& point,
                                gfx::DecoratedText* decorated_word,
@@ -364,6 +377,11 @@ class VIEWS_EXPORT Textfield : public View,
   bool PasteSelectionClipboard() override;
   void UpdateSelectionClipboard() override;
 
+  // Adds this Textfield as a FocusChangeListener based on |add_as_listener|.
+  // Always removes this Textfield as a listener of the previously listened-to
+  // focus manager (if it exists) before this happens.
+  void ObserveWidgetFocusChanges(bool add_as_listener);
+
   // Updates the painted background color.
   void UpdateBackgroundColor();
 
@@ -465,6 +483,12 @@ class VIEWS_EXPORT Textfield : public View,
   SkColor selection_text_color_;
   SkColor selection_background_color_;
 
+  // In cases where the Widget is deleted before the Textfield, there is no
+  // longer a way to retrieve the FocusManager. It's still needed to remove this
+  // Textfield as an observer, so keep a reference to the FocusManager this
+  // Textfield is listening to, if any.
+  FocusManager* focus_manager_;
+
   // Text to display when empty.
   base::string16 placeholder_text_;