/* *
 * Daniel Moth - http://www.danielmoth.com/Blog/
 * Credit for the trick goes to Alex Feinman [http://www.alexfeinman.com/download.asp?doc=IMSwitch.zip]
 * Minor modifications made for non-PPC devices, wrapping in its own class
 * */
using System;
using System.Drawing;
using System.Runtime.InteropServices;

namespace Microsoft.WindowsCE.Forms {
	/// <summary>
	/// InputPanel replacement for showing SIP in numeric mode for *WindowsCE devices only*
	/// For PocketPCs see the original implementation or reverse the changes as described
	/// here: 
	/// </summary>
	public class InputPanelEx : InputPanel {

		private const int X = 2;
		private const int Y = 77;

		public InputPanelEx():base(){}


		public void Show(bool isNumeric){

			// Show panel if it is not shown yet
			if ( !this.Enabled ) {
				this.Enabled = true;
				System.Windows.Forms.Application.DoEvents();
			}

			// Ensure that keyboard and not some of the other IMs is active
			//			Guid clsidKbdIM = new Guid("{42429667-ae04-11d0-a4f8-00aa00a749b9}");
			//			SipSetCurrentIM(clsidKbdIM.ToByteArray());

			// Find the SIP window
			IntPtr hWnd = FindWindow("SipWndClass", null);
			// Go one level below as the actual SIP window is a child
			hWnd = GetWindow(hWnd, GW_CHILD);
			//	hWnd = GetWindow(hWnd, GW_HWNDPREV);
			// Obtain its context and get a color sample
			// The premise here is that the numeric mode is controlled by a virtual button in the top left corner
			// Whenever the numeric mode is active, the button background will be of COLOR_WINDOW_TEXT
			IntPtr hDC = GetDC(hWnd);
			int pixel = GetPixel(hDC, X, Y);
			// Notice that we cannot simply compare the color to the system color as the system color is 24 bit (or palette)
			// and the real color is dithered to 15-16 bits for most devices, so white (0xff, 0xff, 0xff) becomes
			// almost white (oxf8, 0xfc, 0xf8)
			int clrText = (SystemColors.Window.R) | (SystemColors.Window.G << 8) | (SystemColors.Window.B << 16);
			SetPixel(hDC, X, Y, clrText);
			int pixelNew = GetPixel(hDC, X, Y);
			// Restore the original pixel
			SetPixel(hDC, X, Y, pixel);

			if ( ( pixel == pixelNew && isNumeric ) || (pixel==0 && !isNumeric) ){
				// Simulate stylus click
				Message msg = Message.Create(hWnd, WM_LBUTTONDOWN, new IntPtr(1), new IntPtr(0x00490009));
				MessageWindow.SendMessage(ref msg);
				msg = Message.Create(hWnd, WM_LBUTTONUP, new IntPtr(0), new IntPtr(0x00490009));
				MessageWindow.SendMessage(ref msg);
			}
			// Free resources
			ReleaseDC(hWnd, hDC);
		}


		#region pinvokes
		[DllImport("coredll")]
		extern static IntPtr FindWindow(string wndClass, string caption);

		[DllImport("coredll")]
		extern static IntPtr GetWindow(IntPtr hWnd, int nType);

		[DllImport("coredll")]
		extern static int GetPixel(IntPtr hdc, int nXPos, 	int nYPos ); 
		
		[DllImport("coredll")]
		extern static void SetPixel(IntPtr hdc, int nXPos, 	int nYPos, int clr); 
		
		[DllImport("coredll")]
		extern static IntPtr GetDC(IntPtr hWnd); 

		[DllImport("coredll")]
		extern static void ReleaseDC(IntPtr hWnd, IntPtr hDC); 
		const int WM_LBUTTONDOWN                  = 0x0201;
		const int WM_LBUTTONUP                    = 0x0202;
		const int GW_CHILD						  = 5;
		#endregion
	}
}