NativeMethods.cs

/////////////////////////////////////////////////////////////////////////
//
// Copyright © Microsoft Corporation.  All rights reserved.  
// This code is a “supplement” under the terms of the 
// Microsoft Kinect for Windows SDK (Beta) from Microsoft Research 
// License Agreement: http://research.microsoft.com/KinectSDK-ToU
// and is licensed under the terms of that license agreement. 
//
/////////////////////////////////////////////////////////////////////////

// get past MouseData not being initialized warning...it needs to be there for p/invoke
#pragma warning disable 0649

using System;
using System.ComponentModel;
using System.Runtime.InteropServices;

namespace Microsoft.Research.Kinect.Samples.CursorControl
{
	internal struct MouseInput
	{
		public int X;
		public int Y;
		public uint MouseData;
		public uint Flags;
		public uint Time;
		public IntPtr ExtraInfo;
	}

	internal struct Input
	{
		public int Type;
		public MouseInput MouseInput;
	}

	public static class NativeMethods
	{
		public const int InputMouse = 0;

		public const int MouseEventMove      = 0x01;
		public const int MouseEventLeftDown  = 0x02;
		public const int MouseEventLeftUp    = 0x04;
		public const int MouseEventRightDown = 0x08;
		public const int MouseEventRightUp   = 0x10;
		public const int MouseEventAbsolute  = 0x8000;

		private static bool lastLeftDown;

		[DllImport("user32.dll", SetLastError = true)]
		private static extern uint SendInput(uint numInputs, Input[] inputs, int size);

		public static void SendMouseInput(int positionX, int positionY, int maxX, int maxY, bool leftDown)
		{
			if(positionX > int.MaxValue)
				throw new ArgumentOutOfRangeException("positionX");
			if(positionY > int.MaxValue)
				throw new ArgumentOutOfRangeException("positionY");

			Input[] i = new Input[2];

			// move the mouse to the position specified
			i[0] = new Input();
			i[0].Type = InputMouse;
			i[0].MouseInput.X = (positionX * 65535) / maxX;
			i[0].MouseInput.Y = (positionY * 65535) / maxY;
			i[0].MouseInput.Flags = MouseEventAbsolute | MouseEventMove;

			// determine if we need to send a mouse down or mouse up event
			if(!lastLeftDown && leftDown)
			{
				i[1] = new Input();
				i[1].Type = InputMouse;
				i[1].MouseInput.Flags = MouseEventLeftDown;
			}
			else if(lastLeftDown && !leftDown)
			{
				i[1] = new Input();
				i[1].Type = InputMouse;
				i[1].MouseInput.Flags = MouseEventLeftUp;
			}

			lastLeftDown = leftDown;

			// send it off
			uint result = SendInput(2, i, Marshal.SizeOf(i[0]));
			if(result == 0)
				throw new Win32Exception(Marshal.GetLastWin32Error());
		}
	}
}