context: // Permission is hereby granted, free of charge, to any person obtaining
  // a copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to
  // permit persons to whom the Software is furnished to do so, subject to
  // the following conditions:
  // 
  // The above copyright notice and this permission notice shall be
  // included in all copies or substantial portions of the Software.
  // 
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  //
  // Copyright (c) 2007 Novell, Inc.
  //
  // Authors:
  //	Geoff Norton  <gnorton@novell.com>
  //
  //
  
  using System;
  using System.Runtime.InteropServices;
  
  namespace System.Windows.Forms.CarbonInternal {
  	internal class MouseHandler : EventHandlerBase, IEventHandler {
  		internal const uint kEventMouseDown = 1;
  		internal const uint kEventMouseUp = 2;
  		internal const uint kEventMouseMoved = 5;
  		internal const uint kEventMouseDragged = 6;
  		internal const uint kEventMouseEntered = 8;
  		internal const uint kEventMouseExited = 9;
  		internal const uint kEventMouseWheelMoved = 10;
  		internal const uint kEventMouseScroll = 11;
  
  		internal const uint kEventParamMouseLocation = 1835822947;
  		internal const uint kEventParamMouseButton = 1835168878;
  		internal const uint kEventParamMouseWheelAxis = 1836540280;
  		internal const uint kEventParamMouseWheelDelta = 1836541036;
  		internal const uint typeLongInteger = 1819242087;
  		internal const uint typeMouseWheelAxis = 1836540280;
  		internal const uint typeMouseButton = 1835168878;
  		internal const uint typeQDPoint = 1363439732;
  
  		internal const uint kEventMouseWheelAxisX = 0;
  		internal const uint kEventMouseWheelAxisY = 1;
  
  		internal const uint DoubleClickInterval = 7500000;
  		internal static ClickStruct ClickPending;
  		
  		internal MouseHandler (XplatUICarbon driver) : base (driver) {}
  
  		public bool ProcessEvent (IntPtr callref, IntPtr eventref, IntPtr handle, uint kind, ref MSG msg) {
  			QDPoint qdpoint = new QDPoint ();
  			CGPoint point = new CGPoint ();
  			Rect window_bounds = new Rect ();
  			IntPtr view_handle = IntPtr.Zero;
  			IntPtr window_handle = IntPtr.Zero;
  			bool client = true;
  			ushort button = 0;
  			Hwnd hwnd;
  
  			GetEventParameter (eventref, kEventParamMouseLocation, typeQDPoint, IntPtr.Zero, (uint)Marshal.SizeOf (typeof (QDPoint)), IntPtr.Zero, ref qdpoint);
  			GetEventParameter (eventref, kEventParamMouseButton, typeMouseButton, IntPtr.Zero, (uint)Marshal.SizeOf (typeof (ushort)), IntPtr.Zero, ref button);
  			
  			if (button == 1 && ((Driver.ModifierKeys & Keys.Control) != 0))
  				button = 2;
  
  			point.x = qdpoint.x;
  			point.y = qdpoint.y;
  
  			if (FindWindow (qdpoint, ref window_handle) == 5)
  				return true;
  
  			GetWindowBounds (handle, 33, ref window_bounds);
  			HIViewFindByID (HIViewGetRoot (handle), new HIViewID (EventHandler.kEventClassWindow, 1), ref window_handle);
  
  			point.x -= window_bounds.left;
  			point.y -= window_bounds.top;
  
  			HIViewGetSubviewHit (window_handle, ref point, true, ref view_handle);
  			HIViewConvertPoint (ref point, window_handle, view_handle);
  
  			hwnd = Hwnd.ObjectFromHandle (view_handle);
  
  			if (hwnd != null)
  				client = (hwnd.ClientWindow == view_handle ? true : false);
  
  			if (XplatUICarbon.Grab.Hwnd != IntPtr.Zero) {
  				hwnd = Hwnd.ObjectFromHandle (XplatUICarbon.Grab.Hwnd); 
  				client = true;
  			}
  			if (hwnd == null)
  				return true;
  			
  			if (client) {
  				qdpoint.x = (short) point.x;
  				qdpoint.y = (short) point.y;
  
  				Driver.ScreenToClient (hwnd.Handle, ref qdpoint);
  			} else {
  				point.x = qdpoint.x;
  				point.y = qdpoint.y;
  			}
  
  			msg.hwnd = hwnd.Handle;
  			msg.lParam = (IntPtr) ((ushort) point.y << 16 | (ushort) point.x);
  
  			switch (kind) {
  				case kEventMouseDown:
  					UpdateMouseState (button, true);
  					msg.message = (client ? Msg.WM_MOUSEMOVE : Msg.WM_NCMOUSEMOVE) + ((button - 1) * 3) + 1;
  					msg.wParam = Driver.GetMousewParam (0);
  					if (ClickPending.Pending && (((DateTime.Now.Ticks - ClickPending.Time) < DoubleClickInterval) && (msg.hwnd == ClickPending.Hwnd) && (msg.wParam == ClickPending.wParam) && (msg.lParam == ClickPending.lParam) && (msg.message == ClickPending.Message))) {
  						msg.message = (client ? Msg.WM_MOUSEMOVE : Msg.WM_NCMOUSEMOVE) + ((button - 1) * 3) + 3;
  						ClickPending.Pending = false;
  					} else {
  						ClickPending.Pending = true;
  						ClickPending.Hwnd = msg.hwnd;
  						ClickPending.Message = msg.message;
  						ClickPending.wParam = msg.wParam;
  						ClickPending.lParam = msg.lParam;
  						ClickPending.Time = DateTime.Now.Ticks;
  					}
  					break;
  				case kEventMouseUp:
  					UpdateMouseState (button, false);
  					msg.message = (client ? Msg.WM_MOUSEMOVE : Msg.WM_NCMOUSEMOVE) + ((button - 1) * 3) + 2;
  					msg.wParam = Driver.GetMousewParam (0);
  					break;
  				case kEventMouseDragged:
  				case kEventMouseMoved:
  					if (XplatUICarbon.Grab.Hwnd == IntPtr.Zero) {
  						IntPtr ht = IntPtr.Zero;
  						if (client) {
  							ht = (IntPtr) HitTest.HTCLIENT;
  							NativeWindow.WndProc(msg.hwnd, Msg.WM_SETCURSOR, msg.hwnd, (IntPtr)HitTest.HTCLIENT);
  						} else {
  	                                                ht = (IntPtr) NativeWindow.WndProc (hwnd.client_window, Msg.WM_NCHITTEST, IntPtr.Zero, msg.lParam).ToInt32 ();
  							NativeWindow.WndProc(hwnd.client_window, Msg.WM_SETCURSOR, msg.hwnd, ht);
  						}
  					}
  					msg.message = (client ? Msg.WM_MOUSEMOVE : Msg.WM_NCMOUSEMOVE);
  					msg.wParam = Driver.GetMousewParam (0);
  					break;
  				case kEventMouseWheelMoved:
  				case kEventMouseScroll:
  					UInt16 axis = 0;
  					Int32 delta = 0;
  
  					GetEventParameter (eventref, kEventParamMouseWheelAxis, typeMouseWheelAxis, IntPtr.Zero, (uint)Marshal.SizeOf (typeof (UInt16)), IntPtr.Zero, ref axis);
  					GetEventParameter (eventref, kEventParamMouseWheelDelta, typeLongInteger, IntPtr.Zero, (uint)Marshal.SizeOf (typeof (Int32)), IntPtr.Zero, ref delta);
  
  					if (axis == kEventMouseWheelAxisY) {
  						msg.hwnd = XplatUICarbon.FocusWindow;
  						msg.message = Msg.WM_MOUSEWHEEL;
  						msg.wParam = Driver.GetMousewParam (delta*40);
  						return true;
  					}
  					break;
  				default:
  					return false;
  			}
  			Driver.mouse_position.X = (int) point.x;
  			Driver.mouse_position.Y = (int) point.y;
  			return true;
  		}
  		
  		internal bool TranslateMessage (ref MSG msg) {
  			if (msg.message == Msg.WM_MOUSEMOVE || msg.message == Msg.WM_NCMOUSEMOVE) {
  				Hwnd hwnd = Hwnd.ObjectFromHandle (msg.hwnd);
  				if (XplatUICarbon.MouseHwnd == null) { 
  					Driver.PostMessage (hwnd.Handle, Msg.WM_MOUSE_ENTER, IntPtr.Zero, IntPtr.Zero);
  					Cursor.SetCursor (hwnd.Cursor);
  				} else if (XplatUICarbon.MouseHwnd.Handle != hwnd.Handle) {
  					Driver.PostMessage (XplatUICarbon.MouseHwnd.Handle, Msg.WM_MOUSELEAVE, IntPtr.Zero, IntPtr.Zero);
  					Driver.PostMessage (hwnd.Handle, Msg.WM_MOUSE_ENTER, IntPtr.Zero, IntPtr.Zero);
  					Cursor.SetCursor (hwnd.Cursor);
  				}
  				XplatUICarbon.MouseHwnd = hwnd;
  			}
  			
  			return false;
  		}
  
  		private void UpdateMouseState (int button, bool down) {
  			switch (button) {
  				case 1:
  					if (down) XplatUICarbon.MouseState |= MouseButtons.Left; else XplatUICarbon.MouseState &= ~MouseButtons.Left;
  					break;
  				case 2:
  					if (down) XplatUICarbon.MouseState |= MouseButtons.Right; else XplatUICarbon.MouseState &= ~MouseButtons.Right;
  					break;
  				case 3:
  					if (down) XplatUICarbon.MouseState |= MouseButtons.Middle; else XplatUICarbon.MouseState &= ~MouseButtons.Middle;
  					break;
  			}
  		}
  
  		[DllImport ("/System/Library/Frameworks/Carbon.framework/Versions/Current/Carbon")]
  		static extern int GetEventParameter (IntPtr eventref, uint name, uint type, IntPtr outtype, uint size, IntPtr outsize, ref QDPoint data);
  		[DllImport ("/System/Library/Frameworks/Carbon.framework/Versions/Current/Carbon")]
  		static extern int GetEventParameter (IntPtr eventref, uint name, uint type, IntPtr outtype, uint size, IntPtr outsize, ref Int32 data);
  		[DllImport ("/System/Library/Frameworks/Carbon.framework/Versions/Current/Carbon")]
  		static extern int GetEventParameter (IntPtr eventref, uint name, uint type, IntPtr outtype, uint size, IntPtr outsize, ref ushort data);
  
  		[DllImport("/System/Library/Frameworks/Carbon.framework/Versions/Current/Carbon")]
  		internal static extern short FindWindow (QDPoint point, ref IntPtr handle);
  		[DllImport("/System/Library/Frameworks/Carbon.framework/Versions/Current/Carbon")]
  		internal static extern int GetWindowBounds (IntPtr handle, uint region, ref Rect bounds);
  		[DllImport("/System/Library/Frameworks/Carbon.framework/Versions/Current/Carbon")]
  		internal static extern int HIViewConvertPoint (ref CGPoint point, IntPtr source_view, IntPtr target_view);
  		[DllImport("/System/Library/Frameworks/Carbon.framework/Versions/Current/Carbon")]
  		internal static extern IntPtr HIViewGetRoot (IntPtr handle);
  		[DllImport("/System/Library/Frameworks/Carbon.framework/Versions/Current/Carbon")]
  		internal static extern int HIViewGetSubviewHit (IntPtr content_view, ref CGPoint point, bool tval, ref IntPtr hit_view);
  		[DllImport("/System/Library/Frameworks/Carbon.framework/Versions/Current/Carbon")]
  		internal static extern int HIViewFindByID (IntPtr root_window, HIViewID id, ref IntPtr view_handle);
  		
  		[DllImport("/System/Library/Frameworks/Carbon.framework/Versions/Current/Carbon")]
  
gt: 		internal static extern int GetCurrentEventButtonState ();