/*
 * libjingle
 * Copyright 2004--2006, Google Inc.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice, 
 *     this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products 
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef TALK_BASE_TASKPARENT_H__
#define TALK_BASE_TASKPARENT_H__

#include <set>

#include "talk/base/basictypes.h"
#include "talk/base/scoped_ptr.h"

namespace talk_base {

class Task;
class TaskRunner;

class TaskParent {
 public:
  TaskParent(Task *derived_instance, TaskParent *parent);
  explicit TaskParent(TaskRunner *derived_instance);
  virtual ~TaskParent() { }

  TaskParent *GetParent() { return parent_; }
  TaskRunner *GetRunner() { return runner_; }

  // Retrieves a parent that corresponds to the given "code".  The code
  // should be defined in a unique manner for the given subtree.  This
  // method will crash (when the parent_ is NULL) if there is no corresponding
  // parent.
  // 
  // Example use:
  //  XmppClient* client =
  //      static_cast<XmppClient*>(parent->GetParent(XMPP_CLIENT_TASK_CODE));
  virtual TaskParent *GetParent(int code) { return parent_->GetParent(code); }

  bool AllChildrenDone();
  bool AnyChildError();
#ifdef _DEBUG
  bool IsChildTask(Task *task);
#endif

 protected:
  void OnStopped(Task *task);
  void AbortAllChildren();
  TaskParent *parent() {
    return parent_;
  }

 private:
  void Initialize();
  void OnChildStopped(Task *child);
  void AddChild(Task *child);

  TaskParent *parent_;
  TaskRunner *runner_;
  bool child_error_;
  typedef std::set<Task *> ChildSet;
  scoped_ptr<ChildSet> children_;
  DISALLOW_EVIL_CONSTRUCTORS(TaskParent);
};


} // namespace talk_base

#endif  // TALK_BASE_TASKPARENT_H__