Refactor screen/monitor so that gfx::Screen returns monitor object.

ui/gfx/monitor.h

+// Copyright (c) 2012 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_GFX_MONITOR_H_
+#define UI_GFX_MONITOR_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "ui/base/ui_export.h"
+#include "ui/gfx/rect.h"
+
+namespace gfx {
+
+class UI_EXPORT Monitor {
+ public:
+  Monitor();
+  virtual ~Monitor();
+
+  // Returns the monitor's bounds in gfx::Screen's coordinates.
+  virtual Rect GetBounds() const = 0;
+
+  // Returns the monitor's work area in gfx::Screen's coordinates.
+  virtual Rect GetWorkArea() const = 0;
+
+  // Output device's pixel scale factor. This specifies how much the
+  // UI should be scaled when the actual output has more pixels than
+  // standard monitors (which is around 100~120dpi.) For aura, this
+  // value is either 1.0 or 2.0, but may return different values on
+  // other platforms.
+  virtual float GetDeviceScaleFactor() const = 0;
+
+  // Utility functions that just return the size of monitor and
+  // work area.
+  Size GetSize() const;
+  Size GetWorkAreaSize() const;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(Monitor);
+};
+
+// Simple monitor class that stores bounds and workarea.
+class UI_EXPORT SimpleMonitor : public Monitor {
+ public:
+  SimpleMonitor();
+  explicit SimpleMonitor(const gfx::Rect& bounds);
+  virtual ~SimpleMonitor();
+
+  void set_bounds(const Rect& bounds) { bounds_ = bounds; }
+  void set_work_area(const Rect& work_area) { work_area_ = work_area; }
+
+  // Monitor overrides:
+  virtual Rect GetBounds() const OVERRIDE;
+  virtual Rect GetWorkArea() const OVERRIDE;
+  virtual float GetDeviceScaleFactor() const OVERRIDE;
+
+ private:
+  Rect bounds_;
+  Rect work_area_;
+
+  DISALLOW_COPY_AND_ASSIGN(SimpleMonitor);
+};
+
+}  // namespace gfx
+
+#endif  // UI_GFX_MONITOR_H_