Extending the Views-on-Mac experiment: whole app list grid.

ui/views_core/bridged_view_mac.h

+// Copyright 2013 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_CORE_BRIDGED_VIEW_MAC_H_
+#define UI_VIEWS_CORE_BRIDGED_VIEW_MAC_H_
+
+#include <stddef.h>
+
+#include "base/mac/scoped_nsobject.h"
+#include "ui/views/views_export.h"
+
+@class BridgedViewImpl;
+@class NSView;
+
+namespace views {
+
+class View;
+
+// Represents a toolkit-view that has been bridged so that it can be painted
+// using an NSView. This is the non-templatized base.
+class VIEWS_EXPORT BridgedViewBase {
+  typedef base::scoped_nsobject<BridgedViewImpl> BridgedViewBase::*Testable;
+
+ public:
+  // Allow bool-conversion, returning the private pointer-to-member trick to
+  // avoid returning something that easily converts to int.
+  operator Testable() const {
+    return bridged_view_.get() ? &BridgedViewBase::bridged_view_ : NULL;
+  }
+
+  // Returns the NSView side of the bridge, or nil.
+  NSView* GetNSView();
+
+  // Returns the views::View side of the bridge, or NULL.
+  View* GetView();
+
+ protected:
+  BridgedViewBase();
+  explicit BridgedViewBase(View* view);
+  ~BridgedViewBase();
+
+  void ResetView(View* view);
+
+ private:
+  base::scoped_nsobject<BridgedViewImpl> bridged_view_;
+};
+
+// Templatized scoped_ptr-style class for representing a bridged views::View.
+// Members of the views::View subtype are accessed via the strongly typed
+// operator->(). When a BridgedView goes out of scope, the owned |view| is
+// removed from the hosting NSView superview and immediately destroyed. The
+// NSView is released, but it is reference counted so could still hang around
+// for a while.
+template <class T>
+class BridgedView : public BridgedViewBase {
+ public:
+  // Construct with an initially NULL bridge.
+  BridgedView() : BridgedViewBase() {}
+
+  // Takes ownership of |view|.
+  explicit BridgedView(T* view) : BridgedViewBase(view) {}
+
+  // Takes ownership of |view|.
+  void reset(T* view = NULL) { ResetView(view); }
+
+  T* get() { return static_cast<T*>(GetView()); }
+  const T* get() const { return static_cast<const T*>(GetView()); }
+  T* operator->() { return get(); }
+  const T* operator->() const { return get(); }
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_CORE_BRIDGED_VIEW_MAC_H_