Sync ui/events to chromium @ https://codereview.chromium.org/1210203002

ui/gfx/screen.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_SCREEN_H_
+#define UI_GFX_SCREEN_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "ui/gfx/display.h"
+#include "ui/gfx/geometry/point.h"
+#include "ui/gfx/gfx_export.h"
+#include "ui/gfx/native_widget_types.h"
+#include "ui/gfx/screen_type_delegate.h"
+
+namespace gfx {
+class DisplayObserver;
+class Rect;
+
+// A utility class for getting various info about screen size, displays,
+// cursor position, etc.
+//
+// Note that this class does not represent an individual display connected to a
+// computer -- see the Display class for that. A single Screen object exists on
+// most operating systems regardless of the number of connected displays. On
+// Windows 8, two Screens exist: one for Metro UI and another for the desktop.
+class GFX_EXPORT Screen {
+ public:
+  // Retrieves the Screen that the specified NativeView belongs to. A value of
+  // NULL is treated as |SCREEN_TYPE_NATIVE|.
+  static Screen* GetScreenFor(NativeView view);
+
+  // Returns the SCREEN_TYPE_NATIVE Screen. This should be used with caution,
+  // as it is likely to be incorrect for code that runs on Windows.
+  static Screen* GetNativeScreen();
+
+  // Sets the global screen for a particular screen type. Only the _NATIVE
+  // ScreenType must be provided.
+  // NOTE: this does not take ownership of |screen|. Tests must be sure to
+  // reset any state they install.
+  static void SetScreenInstance(ScreenType type, Screen* instance);
+
+  // Returns the global screen for a particular type. Types other than _NATIVE
+  // may be NULL.
+  static Screen* GetScreenByType(ScreenType type);
+
+  // Sets the global ScreenTypeDelegate. May be left unset if the platform
+  // uses only the _NATIVE ScreenType.
+  // NOTE: this does not take ownership of |delegate|. Tests must be sure to
+  // reset any state they install.
+  static void SetScreenTypeDelegate(ScreenTypeDelegate* delegate);
+
+  Screen();
+  virtual ~Screen();
+
+  // Returns the current absolute position of the mouse pointer.
+  virtual gfx::Point GetCursorScreenPoint() = 0;
+
+  // Returns the window under the cursor.
+  virtual gfx::NativeWindow GetWindowUnderCursor() = 0;
+
+  // Returns the window at the given screen coordinate |point|.
+  virtual gfx::NativeWindow GetWindowAtScreenPoint(const gfx::Point& point) = 0;
+
+  // Returns the number of displays.
+  // Mirrored displays are excluded; this method is intended to return the
+  // number of distinct, usable displays.
+  virtual int GetNumDisplays() const = 0;
+
+  // Returns the list of displays that are currently available.
+  virtual std::vector<gfx::Display> GetAllDisplays() const = 0;
+
+  // Returns the display nearest the specified window.
+  // If the window is NULL or the window is not rooted to a display this will
+  // return the primary display.
+  virtual gfx::Display GetDisplayNearestWindow(NativeView view) const = 0;
+
+  // Returns the display nearest the specified point. |point| should be in DIPs.
+  virtual gfx::Display GetDisplayNearestPoint(
+      const gfx::Point& point) const = 0;
+
+  // Returns the display that most closely intersects the provided bounds.
+  virtual gfx::Display GetDisplayMatching(
+      const gfx::Rect& match_rect) const = 0;
+
+  // Returns the primary display.
+  virtual gfx::Display GetPrimaryDisplay() const = 0;
+
+  // Adds/Removes display observers.
+  virtual void AddObserver(DisplayObserver* observer) = 0;
+  virtual void RemoveObserver(DisplayObserver* observer) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(Screen);
+};
+
+Screen* CreateNativeScreen();
+
+}  // namespace gfx
+
+#endif  // UI_GFX_SCREEN_H_