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

ui/views/selection_controller_delegate.h

 // Copyright 2016 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.
 
 #ifndef UI_VIEWS_SELECTION_CONTROLLER_DELEGATE_H_
 #define UI_VIEWS_SELECTION_CONTROLLER_DELEGATE_H_
 
+#include "third_party/skia/include/core/SkColor.h"
+#include "ui/views/focus/focus_manager.h"
 #include "ui/views/views_export.h"
 
+namespace gfx {
+class RenderText;
+}
+
 namespace ui {
 class MouseEvent;
 }
 
 namespace views {
 
+// For cosmetic use only. TODO(patricialor): Probably this can be removed.
+enum class TextSelectionDrawState {
+  // The control has focus, the selection text color and selection background
+  // color are used.
+  kDrawAsFocused,
+  // The control doesn't have focus, but it was last to be focused before
+  // changing to a different views::Widget or application. The selection text
+  // color and selection background unfocused color are used.
+  kDrawAsLastFocused,
+  // In all other cases, the selection is not drawn at all.
+  kDrawAsUnfocused
+};
+
 // An interface implemented/managed by a view which uses the
 // SelectionController.
-class VIEWS_EXPORT SelectionControllerDelegate {
+class VIEWS_EXPORT SelectionControllerDelegate
+    : virtual public FocusChangeListener {
  public:
   // Returns the associated RenderText instance to be used for selection.
   virtual gfx::RenderText* GetRenderTextForSelectionController() = 0;
 
   // Methods related to properties of the associated view.
 
   // Returns true if the associated text view is read only.
   virtual bool IsReadOnly() const = 0;
   // Returns whether the associated view supports drag-and-drop.
   virtual bool SupportsDrag() const = 0;
@@ skipping 25 matching lines @@
   // Pastes the text from the selection clipboard at the current cursor
   // position. Always called within a pointer action for a non-readonly view.
   // Returns true if some text was pasted.
   virtual bool PasteSelectionClipboard() = 0;
   // Updates the selection clipboard with the currently selected text. Should
   // empty the selection clipboard if no text is currently selected.
   // NO-OP if the associated text view is obscured. Since this does not modify
   // the render text instance, it may be called outside of a pointer action.
   virtual void UpdateSelectionClipboard() = 0;
 
+  // These methods are used for drawing the selected text while also considering
+  // its focused state. See TextSelectionDrawState.
+  virtual SkColor GetSelectionTextColor() const = 0;
+  virtual SkColor GetSelectionBackgroundColor() const = 0;
+  virtual SkColor GetSelectionBackgroundUnfocusedColor() const = 0;
+  TextSelectionDrawState UpdateTextSelectionDrawState(
+      const View* this_view,
+      const View* focused_before,
+      const View* focused_now);
+
+  // Set the FocusManager observed for focus change events. The
+  // SelectionControllerDelegate implementation must call this in order for
+  // selection drawing to reflect changes in focus.
+  virtual void ObserveWidgetFocusChanges(FocusManager* new_focus_manager,
+                                         bool add_as_listener);
+
+  // FocusChangeListener overrides:
+  // Subclasses must pass the call below to UpdateTextSelectionDrawState().
+  void OnWillChangeFocus(View* focused_before, View* focused_now) override = 0;
+  void OnDidChangeFocus(View* focused_before, View* focused_now) override;
+
  protected:
-  virtual ~SelectionControllerDelegate() {}
+  ~SelectionControllerDelegate() override;
+
+  FocusManager* focus_manager_ = nullptr;
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_SELECTION_CONTROLLER_DELEGATE_H_