/src/StylusReader/StylusReader.cs

/////////////////////////////////////////////////////////////////////////////////

// Paint.NET                                                                   //

// Copyright (C) dotPDN LLC, Rick Brewster, Tom Jackson, and contributors.     //

// Portions Copyright (C) Microsoft Corporation. All Rights Reserved.          //

// See src/Resources/Files/License.txt for full licensing and attribution      //

// details.                                                                    //

// .                                                                           //

/////////////////////////////////////////////////////////////////////////////////



using Microsoft.Ink;

using Microsoft.StylusInput;

using System;

using System.Collections;

using System.Collections.Generic;

using System.Windows.Forms;



namespace PaintDotNet

{

    public static class StylusReader 

    {

        // If we don't keep the styluses, they get garbagecollected.

        private static readonly Hashtable HookedControls = Hashtable.Synchronized(new Hashtable());



        public static void HookStylus(IStylusReaderHooks subject, Control control)

        {

            if (HookedControls.Contains(control))

            {

                throw new ApplicationException("control is already hooked");

            }



            var stylus = new RealTimeStylus(control, true);

            var stylusReader = new StylusAsyncPlugin(subject, control);

            

            stylus.AsyncPluginCollection.Add(stylusReader);

            stylus.SetDesiredPacketDescription(new[] { PacketProperty.X, 

                                                            PacketProperty.Y, 

                                                            PacketProperty.NormalPressure, 

                                                            PacketProperty.PacketStatus});

            stylus.Enabled = true;



            control.Disposed += ControlDisposed;



            var weakRef = new WeakReference(control);

            HookedControls.Add(weakRef, stylus);

        }



        public static void UnhookStylus(Control control)

        {

            lock (HookedControls.SyncRoot)

            {

                var deleteUs = new List<WeakReference>();



                foreach (WeakReference weakRef in HookedControls.Keys)

                {

                    object target = weakRef.Target;



                    if (target == null)

                    {

                        deleteUs.Add(weakRef);

                    }

                    else

                    {

                        var control2 = (Control)target;



                        if (ReferenceEquals(control, control2))

                        {

                            deleteUs.Add(weakRef);

                        }

                    }

                }



                foreach (WeakReference weakRef in deleteUs)

                {

                    var stylus = (RealTimeStylus)HookedControls[weakRef];

                    stylus.Enabled = false;

                    stylus.AsyncPluginCollection.Clear();

                    HookedControls.Remove(weakRef);

                }

            }

        }



        private static void ControlDisposed(object sender, EventArgs e)

        {

            var asControl = (Control)sender;

            asControl.Disposed -= ControlDisposed;

            UnhookStylus(asControl);

        }

    }

}