1 files changed, 97 insertions, 0 deletions
diff --git a/chromium/ui/views/interaction/element_tracker_views.h b/chromium/ui/views/interaction/element_tracker_views.h
new file mode 100644
index 00000000000..7da7fad8d16
--- /dev/null
+++ b/chromium/ui/views/interaction/element_tracker_views.h
@@ -0,0 +1,97 @@
+// Copyright 2021 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_INTERACTION_ELEMENT_TRACKER_VIEWS_H_
+#define UI_VIEWS_INTERACTION_ELEMENT_TRACKER_VIEWS_H_
+
+#include <map>
+#include <memory>
+#include <vector>
+
+#include "base/scoped_multi_source_observation.h"
+#include "ui/base/interaction/element_identifier.h"
+#include "ui/base/interaction/element_tracker.h"
+#include "ui/views/views_export.h"
+#include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_observer.h"
+
+namespace views {
+
+class View;
+
+// Wraps a View in an ui::TrackedElement.
+class VIEWS_EXPORT TrackedElementViews : public ui::TrackedElement {
+ public:
+  TrackedElementViews(View* view,
+                      ui::ElementIdentifier identifier,
+                      ui::ElementContext context);
+  ~TrackedElementViews() override;
+
+  View* view() { return view_; }
+  const View* view() const { return view_; }
+
+  DECLARE_ELEMENT_TRACKER_METADATA()
+
+ private:
+  View* const view_;
+};
+
+// Manages TrackedElements associated with View objects.
+class VIEWS_EXPORT ElementTrackerViews : private WidgetObserver {
+ public:
+  using ViewList = std::vector<View*>;
+
+  // Gets the global instance of the tracker for Views.
+  static ElementTrackerViews* GetInstance();
+
+  // Returns the context associated with a particular View. The context will be
+  // the same across all Views associated with a root Widget (such as an
+  // application window).
+  static ui::ElementContext GetContextForView(View* view);
+
+  // Returns the corresponding TrackedElementViews for the given view, or
+  // null if none exists. Note that views which are not visible or not added to
+  // a Widget may not have associated elements, and that the returned object
+  // may be transient.
+  TrackedElementViews* GetElementForView(View* view);
+  const TrackedElementViews* GetElementForView(const View* view) const;
+
+  // Called by View after the kUniqueElementKey property is set.
+  void RegisterView(ui::ElementIdentifier element_id, View* view);
+
+  // Called by View if the kUniqueElementKey property is changed from a non-null
+  // value.
+  void UnregisterView(ui::ElementIdentifier element_id, View* view);
+
+  // Called by a View when the user activates it (clicks a button, selects a
+  // menu item, etc.)
+  void NotifyViewActivated(ui::ElementIdentifier element_id, View* view);
+
+ private:
+  friend class base::NoDestructor<ElementTrackerViews>;
+  class ElementDataViews;
+
+  ElementTrackerViews();
+  ~ElementTrackerViews() override;
+
+  // WidgetObserver:
+  void OnWidgetVisibilityChanged(Widget* widget, bool visible) override;
+  void OnWidgetDestroying(Widget* widget) override;
+
+  // We do not get notified at the View level if a view's widget has not yet
+  // been shown. We need this notification to know when the view is actually
+  // visible to the user. So if a view is added to the trakcer or is added to
+  // a widget, and its widget is not visible, we watch it until it is (or it is
+  // destroyed).
+  void MaybeObserveWidget(Widget* widget);
+
+  std::map<ui::ElementIdentifier, std::unique_ptr<ElementDataViews>>
+      element_data_;
+  base::ScopedMultiSourceObservation<Widget, WidgetObserver> widget_observer_{
+      this};
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_INTERACTION_ELEMENT_TRACKER_VIEWS_H_