ScrollableControlDesigner.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Designer / WinForms / System / WinForms / Design / ScrollableControlDesigner.cs / 1 / ScrollableControlDesigner.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

/* 
 */ 
namespace System.Windows.Forms.Design {
    using System.Design; 
    using System.Runtime.Serialization.Formatters;
    using System.ComponentModel;
    using System.Diagnostics;
    using System; 
    using System.ComponentModel.Design;
    using System.Windows.Forms; 
    using System.Windows.Forms.Design.Behavior; 
    using System.Drawing;
    using Microsoft.Win32; 

    /// 
    /// 
    ///     The ScrollableControlDesigner class builds on the ParentControlDesigner, and adds the implementation 
    ///     of IWinFormsDesigner so that the designer can be hosted as a document.
    ///  
    public class ScrollableControlDesigner : ParentControlDesigner { 

        private SelectionManager selManager; 

        /// 
        /// 
        ///     Overrides the base class's GetHitTest method to determine regions of the 
        ///     control that should always be UI-Active.  For a form, if it has autoscroll
        ///     set the scroll bars are always UI active. 
        ///  
        protected override bool GetHitTest(Point pt) {
            if (base.GetHitTest(pt)) { 
                return true;
            }

            // The scroll bars on a form are "live" 
            //
            ScrollableControl f = (ScrollableControl)Control; 
            if (f.IsHandleCreated && f.AutoScroll) { 
                int hitTest = (int)NativeMethods.SendMessage(f.Handle, NativeMethods.WM_NCHITTEST, (IntPtr)0, (IntPtr)NativeMethods.Util.MAKELPARAM(pt.X, pt.Y));
                if (hitTest == NativeMethods.HTVSCROLL || hitTest == NativeMethods.HTHSCROLL) { 
                    return true;
                }
            }
            return false; 
        }
 
        ///  
        /// 
        ///     We override our base class's WndProc to monitor certain messages. 
        /// 
        protected override void WndProc(ref Message m) {

            base.WndProc(ref m); 

            switch(m.Msg) { 
                case NativeMethods.WM_HSCROLL: 
                case NativeMethods.WM_VSCROLL:
 
                    // When we scroll, we reposition a control without causing a
                    // property change event.  Therefore, we must tell the
                    // SelectionManager to refresh its glyphs.
                    if (selManager == null) { 
                        selManager = GetService(typeof(SelectionManager)) as SelectionManager;
                    } 
 
                    if (selManager != null) {
                        selManager.Refresh(); 
                    }

                    // Now we must paint our adornments, since the scroll does not
                    // trigger a paint event 
                    //
                    Control.Invalidate(); 
                    Control.Update(); 
                    break;
            } 
        }
    }
}
 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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