append screen source files

include/nana/gui/screen.hpp

@@ -0,0 +1,52 @@
+/*
+*	Screen Informations
+*	Nana C++ Library(http://www.nanapro.org)
+*	Copyright(C) 2003-2015 Jinhao(cnjinhao@hotmail.com)
+*
+*	Distributed under the Boost Software License, Version 1.0.
+*	(See accompanying file LICENSE_1_0.txt or copy at
+*	http://www.boost.org/LICENSE_1_0.txt)
+*
+*	@file: nana/gui/screen.hpp
+*/
+
+#ifndef NANA_GUI_SCREEN_HPP
+#define NANA_GUI_SCREEN_HPP
+#include "basis.hpp"
+#include <functional>
+#include <memory>
+
+namespace nana
+{
+	/// The monitor display metrics
+	class display
+	{
+	public:
+		virtual ~display() = default;
+
+		/// The index of monitor.
+		virtual std::size_t index() const = 0;
+
+		/// Returns the positional coordinates and size of the display device in reference to the desktop area
+		virtual const ::nana::rectangle& area() const = 0;
+	};
+
+	class screen
+	{
+	public:
+		static ::nana::size desktop_size();
+		static ::nana::size primary_monitor_size();
+		static std::shared_ptr<display>	from_point(const point&);
+		static std::shared_ptr<display> from_window(window);
+
+		/// Returns the number of display monitors
+		std::size_t count() const;
+
+		std::shared_ptr<display> get_display(std::size_t index) const;
+		std::shared_ptr<display> get_primary() const;
+
+		void for_each(std::function<void(display&)>) const;
+	};
+}//end namespace nana
+
+#endif