3 * @brief Common LibVLC objects marshalling utilities
7 /**********************************************************************
8 * Copyright (C) 2007-2009 RĂ©mi Denis-Courmont. *
9 * This program is free software; you can redistribute and/or modify *
10 * it under the terms of the GNU General Public License as published *
11 * by the Free Software Foundation; version 2 of the license, or (at *
12 * your option) any later version. *
14 * This program is distributed in the hope that it will be useful, *
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. *
17 * See the GNU General Public License for more details. *
19 * You should have received a copy of the GNU General Public License *
20 * along with this program; if not, you can get it from: *
21 * http://www.gnu.org/copyleft/gpl.html *
22 **********************************************************************/
25 using System.Collections;
26 using System.Collections.Generic;
27 using System.Runtime.InteropServices;
29 namespace VideoLAN.LibVLC
32 * @brief NonNullHandle: abstract safe handle class for non-NULL pointers
34 * Microsoft.* namespace has a similar class. However we want to use the
35 * System.* namespace only.
37 internal abstract class NonNullHandle : SafeHandle
39 protected NonNullHandle ()
40 : base (IntPtr.Zero, true)
45 * System.Runtime.InteropServices.SafeHandle::IsInvalid.
47 public override bool IsInvalid
51 return handle == IntPtr.Zero;
56 * Destroys an handle. Cannot fail.
58 protected abstract void Destroy ();
61 * System.Runtime.InteropServices.SafeHandle::ReleaseHandle.
63 protected override bool ReleaseHandle ()
71 * @brief BaseObject: generic wrapper around a safe LibVLC handle.
74 * This is the baseline for all managed LibVLC objects. It wraps:
75 * - an unmanaged LibVLC pointer,
76 * - a native exception structure.
78 public class BaseObject : IDisposable
80 internal NativeException ex; /**< buffer for LibVLC exceptions */
81 internal SafeHandle handle; /**< wrapped safe handle */
83 internal BaseObject ()
85 ex = new NativeException ();
90 * Checks if the LibVLC run-time raised an exception
91 * If so, raises a CIL exception.
93 internal void Raise ()
99 * IDisposable::Dispose.
101 public void Dispose ()
104 GC.SuppressFinalize (this);
108 * Releases unmanaged resources associated with the object.
109 * @param disposing true if the disposing the object explicitly,
110 * false if finalizing the object inside the GC.
112 protected virtual void Dispose (bool disposing)
125 internal class EventManagerHandle : NonNullHandle
127 protected override void Destroy ()
134 * @brief EventingObject: wrapper around an eventing LibVLC handle.
137 * This is the base class for all managed LibVLC objects which do have an
140 public abstract class EventingObject : BaseObject
143 * @brief Managed to unmanaged event handler mapping
146 * The CLR cannot do reference counting for unmanaged callbacks.
147 * We keep track of handled events here instead.
151 public EventCallback managed;
152 public IntPtr unmanaged;
154 public Event (EventCallback managed, IntPtr unmanaged)
156 this.managed = managed;
157 this.unmanaged = unmanaged;
160 private Dictionary<EventType, Event> events;
161 /**< references to our unmanaged function pointers */
163 internal EventingObject () : base ()
165 events = new Dictionary<EventType, Event> ();
169 * Releases unmanaged resources associated with the object.
170 * @param disposing true if the disposing the object explicitly,
171 * false if finalizing the object inside the GC.
173 protected override void Dispose (bool disposing)
176 base.Dispose (disposing);
180 * @return the unmanaged event manager for this object
182 internal abstract EventManagerHandle GetManager ();
185 * Registers an event handler.
186 * @param type event type to register to
187 * @param callback callback to invoke when the event occurs
190 * For simplicity, we only allow one handler per type.
191 * Multicasting can be implemented higher up with managed code.
193 internal void Attach (EventType type, EventCallback callback)
195 EventManagerHandle manager;
196 IntPtr cb = Marshal.GetFunctionPointerForDelegate (callback);
197 Event ev = new Event (callback, cb);
200 if (events.ContainsKey (type))
201 throw new ArgumentException ("Duplicate event");
205 handle.DangerousAddRef (ref unref);
206 manager = GetManager ();
207 LibVLC.EventAttach (manager, type, cb, IntPtr.Zero, ex);
212 handle.DangerousRelease ();
215 events.Add (type, ev);
218 private void Detach (EventType type, IntPtr callback)
220 EventManagerHandle manager;
225 handle.DangerousAddRef (ref unref);
226 manager = GetManager ();
227 LibVLC.EventDetach (manager, type, callback, IntPtr.Zero, ex);
232 handle.DangerousRelease ();
235 events.Remove (type);
238 internal void Detach (EventType type)
240 Detach(type, events[type].unmanaged);