jingle/notifier/base/weak_xmpp_client.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4 //
   5 // A thin wrapper around buzz::XmppClient that exposes weak pointers
   6 // so that users know when the buzz::XmppClient becomes invalid to use
   7 // (not necessarily only at destruction time).
   8
   9 #ifndef JINGLE_NOTIFIER_BASE_WEAK_XMPP_CLIENT_H_
  10 #define JINGLE_NOTIFIER_BASE_WEAK_XMPP_CLIENT_H_
  11
  12 #include "base/basictypes.h"
  13 #include "base/compiler_specific.h"
  14 #include "base/memory/weak_ptr.h"
  15 #include "base/threading/non_thread_safe.h"
  16 #include "talk/xmpp/xmppclient.h"
  17
  18 namespace rtc {
  19 class TaskParent;
  20 }  // namespace
  21
  22 namespace notifier {
  23
  24 // buzz::XmppClient's destructor isn't marked virtual, but it inherits
  25 // from rtc::Task, whose destructor *is* marked virtual, so we
  26 // can safely inherit from it.
  27 class WeakXmppClient : public buzz::XmppClient, public base::NonThreadSafe {
  28  public:
  29   explicit WeakXmppClient(rtc::TaskParent* parent);
  30
  31   virtual ~WeakXmppClient();
  32
  33   // Returns a weak pointer that is invalidated when the XmppClient
  34   // becomes invalid to use.
  35   base::WeakPtr<WeakXmppClient> AsWeakPtr();
  36
  37   // Invalidates all weak pointers to this object.  (This method is
  38   // necessary as calling Abort() does not always lead to Stop() being
  39   // called, so it's not a reliable way to cause an invalidation.)
  40   void Invalidate();
  41
  42  protected:
  43   virtual void Stop() OVERRIDE;
  44
  45  private:
  46   // We use our own WeakPtrFactory instead of inheriting from
  47   // SupportsWeakPtr since we want to invalidate in other places
  48   // besides the destructor.
  49   base::WeakPtrFactory<WeakXmppClient> weak_ptr_factory_;
  50
  51   DISALLOW_COPY_AND_ASSIGN(WeakXmppClient);
  52 };
  53
  54 }  // namespace notifier
  55
  56 #endif  // JINGLE_NOTIFIER_BASE_WEAK_XMPP_CLIENT_H_