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

ui/gfx/monitor.h

Index: ui/gfx/monitor.h
diff --git a/ui/gfx/monitor.h b/ui/gfx/monitor.h
new file mode 100644
index 0000000000000000000000000000000000000000..3110acd31e97bc8c62b30aaf5d321c19f231c0ef
--- /dev/null
+++ b/ui/gfx/monitor.h
@@ -0,0 +1,76 @@
+// 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 {
+
+// Note: The screen and monitor currently uses pixel coordinate
+// system.  ENABLE_DIP macro (which is enabled with enable_dip=1 gyp
+// flag) will make this inconsistent with views' coordinate system
+// because views will use DIP coordinate system, which uses
+// (1.0/device_scale_factor) scale of the pixel coordinate system.
+// TODO(oshima): Change aura/screen to DIP coordinate system and
+// update this comment.
+class UI_EXPORT Monitor {
+ public:
+  // Creates a monitor with invalid id(-1) as default.
+  Monitor();
+  explicit Monitor(int id);
+  Monitor(int id, const Rect& bounds);
+  ~Monitor();
+
+  // Sets/Gets unique identifier associated with the monitor.
+  int id() const { return id_; }
+  void set_id(int id) { id_ = id; }
+
+  // Gets/Sets the monitor's bounds in gfx::Screen's coordinates.
+  // -1 means invalid monitor and it doesn't not exit.
+  const Rect& bounds() const { return bounds_; }
+  void set_bounds(const Rect& bounds) { bounds_ = bounds; }
+
+  // Gets/Sets the monitor's work area in gfx::Screen's coordinates.
+  const Rect& work_area() const { return work_area_; }
+  void set_work_area(const Rect& work_area) { work_area_ = work_area; }
+
+  // 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.) The potential return
+  // values depend on each platforms.
+  float device_scale_factor() const { return device_scale_factor_; }
+  void set_device_scale_factor(float scale) { device_scale_factor_ = scale; }
+
+  // Utility functions that just return the size of monitor and
+  // work area.
+  const Size& size() const { return bounds_.size(); }
+  const Size& work_area_size() const { return work_area_.size(); }
+
+  // Sets the monitor bounds and updates the work are using the same insets
+  // between old bounds and work area.
+  void SetBoundsAndUpdateWorkArea(const gfx::Rect& bounds);
+
+  // Sets the monitor size and updates the work are using the same insets
+  // between old bounds and work area.
+  void SetSizeAndUpdateWorkArea(const gfx::Size& size);
+
+  // Computes and updates the monitor's work are using insets and the bounds.
+  void UpdateWorkAreaWithInsets(const gfx::Insets& work_area_insets);
+
+ private:
+  int id_;
+  Rect bounds_;
+  Rect work_area_;
+  float device_scale_factor_;
+};
+
+}  // namespace gfx
+
+#endif  // UI_GFX_MONITOR_H_