class/System.Design/System.Windows.Forms.Design/ScrollableControlDesigner.cs

   1 //
   2 // System.Windows.Forms.Design.ScrollableControlDesigner
   3 //
   4 // Authors:
   5 //        Ivan N. Zlatev (contact i-nZ.net)
   6 //
   7 // (C) 2006-2007 Ivan N. Zlatev
   8
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30
  31 using System;
  32 using System.ComponentModel;
  33 using System.ComponentModel.Design;
  34 using System.Windows.Forms;
  35 using System.Drawing;
  36 using System.Drawing.Design;
  37 using System.Collections;
  38
  39
  40
  41 namespace System.Windows.Forms.Design
  42 {
  43
  44         public class ScrollableControlDesigner : ParentControlDesigner
  45         {
  46
  47                 public ScrollableControlDesigner ()
  48                 {
  49                 }
  50
  51                 private const int HTHSCROLL = 6;
  52                 private const int HTVSCROLL = 7;
  53
  54                 protected override bool GetHitTest (Point point)
  55                 {
  56                         if (base.GetHitTest (point)) {
  57                                 return true;
  58                         }
  59
  60                         // Check if the user has clicked on the scroll bars and forward the message to
  61                         // the ScrollableControl. (Don't filter out the scrolling.). Keep in mind that scrollbars
  62                         // will be shown only if ScrollableControl.AutoScroll = true
  63                         //
  64                         if (this.Control is ScrollableControl && ((ScrollableControl)Control).AutoScroll) {
  65                                 int hitTestResult = (int) Native.SendMessage (this.Control.Handle,
  66                                                                                                                                          Native.Msg.WM_NCHITTEST,
  67                                                                                                                                          IntPtr.Zero,
  68                                                                                                                                         (IntPtr) Native.LParam (point.X, point.Y));
  69                                 if (hitTestResult == HTHSCROLL || hitTestResult == HTVSCROLL)
  70                                         return true;
  71                         }
  72                         return false;
  73                 }
  74
  75
  76                 protected override void WndProc (ref Message m)
  77                 {
  78                         base.WndProc (ref m);
  79                         if (m.Msg == (int)Native.Msg.WM_HSCROLL || m.Msg == (int)Native.Msg.WM_VSCROLL)
  80                                 this.DefWndProc (ref m);
  81                 }
  82         }
  83 }