greenshot/GreenshotPlugin/UnmanagedHelpers/DWM.cs

/*
 * Greenshot - a free and open source screenshot tool
 * Copyright (C) 2007-2016 Thomas Braun, Jens Klingen, Robin Krom
 * 
 * For more information see: http://getgreenshot.org/
 * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 1 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
using System;
using System.Runtime.InteropServices;
using Microsoft.Win32;
using System.Drawing;

namespace GreenshotPlugin.UnmanagedHelpers {

	// See: http://msdn.microsoft.com/en-us/library/aa969502(v=vs.85).aspx
	[StructLayout(LayoutKind.Sequential)]
	public struct DWM_THUMBNAIL_PROPERTIES {
		// A bitwise combination of DWM thumbnail constant values that indicates which members of this structure are set.
		public int dwFlags;
		// The area in the destination window where the thumbnail will be rendered.
		public RECT rcDestination;
		// The region of the source window to use as the thumbnail. By default, the entire window is used as the thumbnail.
		public RECT rcSource;
		// The opacity with which to render the thumbnail. 0 is fully transparent while 255 is fully opaque. The default value is 255.
		public byte opacity;
		// TRUE to make the thumbnail visible; otherwise, FALSE. The default is FALSE.
		public bool fVisible;
		// TRUE to use only the thumbnail source's client area; otherwise, FALSE. The default is FALSE.
		public bool fSourceClientAreaOnly;
		public RECT Destination {
			set {
				dwFlags |= DWM_TNP_RECTDESTINATION;
				rcDestination = value;
			}
		}
		public RECT Source {
			set {
				dwFlags |= DWM_TNP_RECTSOURCE;
				rcSource = value;
			}
		}
		public byte Opacity {
			set {
				dwFlags |= DWM_TNP_OPACITY;
				opacity = value;
			}
		}
		public bool Visible {
			set {
				dwFlags |= DWM_TNP_VISIBLE;
				fVisible = value;
			}
		}
		public bool SourceClientAreaOnly {
			set {
				dwFlags |= DWM_TNP_SOURCECLIENTAREAONLY;
				fSourceClientAreaOnly = value;
			}
		}
		// A value for the rcDestination member has been specified.
		public const int DWM_TNP_RECTDESTINATION = 0x00000001;
		// A value for the rcSource member has been specified.
		public const int DWM_TNP_RECTSOURCE = 0x00000002;
		// A value for the opacity member has been specified.
		public const int DWM_TNP_OPACITY = 0x00000004;
		// A value for the fVisible member has been specified.
		public const int DWM_TNP_VISIBLE = 0x00000008;
		// A value for the fSourceClientAreaOnly member has been specified.
		public const int DWM_TNP_SOURCECLIENTAREAONLY = 0x00000010;
	}
	
	[StructLayout(LayoutKind.Sequential)]
	public struct DWM_BLURBEHIND {
		public DWM_BB dwFlags;
		public bool fEnable;
		public IntPtr hRgnBlur;
		public bool fTransitionOnMaximized;
	}
	/// <summary>
	/// Description of DWM.
	/// </summary>
	public class DWM {
		public static readonly uint DWM_EC_DISABLECOMPOSITION = 0;
		public static readonly uint DWM_EC_ENABLECOMPOSITION = 1;

		// DWM
		[DllImport("dwmapi", SetLastError = true)]
		public static extern int DwmRegisterThumbnail(IntPtr dest, IntPtr src, out IntPtr thumb);
		[DllImport("dwmapi", SetLastError = true)]
		public static extern int DwmUnregisterThumbnail(IntPtr thumb);
		[DllImport("dwmapi", SetLastError = true)]
		public static extern int DwmQueryThumbnailSourceSize(IntPtr thumb, out SIZE size);
		[DllImport("dwmapi", SetLastError = true)]
		public static extern int DwmUpdateThumbnailProperties(IntPtr hThumb, ref DWM_THUMBNAIL_PROPERTIES props);

		// Deprecated as of Windows 8 Release Preview
		[DllImport("dwmapi", SetLastError = true)]
		public static extern int DwmIsCompositionEnabled(out bool enabled);
		[DllImport("dwmapi", SetLastError = true)]
		public static extern int DwmGetWindowAttribute(IntPtr hwnd, int dwAttribute, out RECT lpRect, int size);
		[DllImport("dwmapi", SetLastError = true)] 
		public static extern int DwmEnableBlurBehindWindow(IntPtr hwnd, ref DWM_BLURBEHIND blurBehind);
		[DllImport("dwmapi", SetLastError = true)]
		public static extern uint DwmEnableComposition(uint uCompositionAction);

		public static void EnableComposition() {
			DwmEnableComposition(DWM_EC_ENABLECOMPOSITION);
		}
		public static void DisableComposition() {
			DwmEnableComposition(DWM_EC_DISABLECOMPOSITION);
		}

		// Key to ColorizationColor for DWM
		private const string COLORIZATION_COLOR_KEY = @"SOFTWARE\Microsoft\Windows\DWM";

		/// <summary>
		/// Helper method for an easy DWM check
		/// </summary>
		/// <returns>bool true if DWM is available AND active</returns>
		public static bool IsDwmEnabled() {
			// According to: http://technet.microsoft.com/en-us/subscriptions/aa969538%28v=vs.85%29.aspx
			// And: http://msdn.microsoft.com/en-us/library/windows/desktop/aa969510%28v=vs.85%29.aspx
			// DMW is always enabled on Windows 8! So return true and save a check! ;-)
			if (Environment.OSVersion.Version.Major == 6 && Environment.OSVersion.Version.Minor == 2) {
				return true;
			}
			if (Environment.OSVersion.Version.Major >= 6) {
				bool dwmEnabled;
				DwmIsCompositionEnabled(out dwmEnabled);
				return dwmEnabled;
			}
			return false;
		}

		public static Color ColorizationColor {
			get {
				using (RegistryKey key = Registry.CurrentUser.OpenSubKey(COLORIZATION_COLOR_KEY, false)) {
					object dwordValue = key?.GetValue("ColorizationColor");
					if (dwordValue != null) {
						return Color.FromArgb((int)dwordValue);
					}
				}
				return Color.White;
			}
		}
	}
}