Implement OzonePlatform

ui/ozone/ozone_platform.h

+// Copyright (c) 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_OZONE_OZONE_PLATFORM_H_
+#define UI_OZONE_OZONE_PLATFORM_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "ui/events/ozone/event_factory_ozone.h"
+#include "ui/gfx/ozone/surface_factory_ozone.h"
+#include "ui/ozone/ozone_export.h"
+
+namespace ui {
+
+// Base class for Ozone platform implementations.
+//
+// Ozone platforms must override this class and implement the virtual
+// GetFooFactoryOzone() methods to provide implementations of the
+// various ozone interfaces.
+//
+// The OzonePlatform subclass can own any state needed by the
+// implementation that is shared between the various ozone interfaces,
+// such as a connection to the windowing system.
+//
+// A platform is free to use different implementations of each
+// interface depending on the context. You can, for example, create
+// different objects depending on the underlying hardware, command
+// line flags, or whatever is appropriate for the platform.
+class OZONE_EXPORT OzonePlatform {
+ public:
+  OzonePlatform();
+  virtual ~OzonePlatform();
+
+  // Initialize the platform. Once complete, SurfaceFactoryOzone &
+  // EventFactoryOzone will be set.
+  static void Initialize();
+
+  // Factory getters to override in subclasses. The returned objects will be
+  // injected into the appropriate layer at startup. Subclasses should not
+  // inject these objects themselves. Ownership is retained by OzonePlatform.
+  virtual gfx::SurfaceFactoryOzone* GetSurfaceFactoryOzone() = 0;
+  virtual ui::EventFactoryOzone* GetEventFactoryOzone() = 0;
+
+ private:
+  static OzonePlatform* instance_;
+
+  DISALLOW_COPY_AND_ASSIGN(OzonePlatform);
+};
+
+// Hook to be provided by the built-in default implementation.
+OzonePlatform* CreateDefaultOzonePlatform();
+
+}  // namespace ui
+
+#endif  // UI_OZONE_OZONE_PLATFORM_H_