content/child/scheduler/cancelable_closure_holder.h

   1 // Copyright 2014 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 #ifndef CONTENT_CHILD_SCHEDULER_CANCELABLE_CLOSURE_HOLDER_H_
   6 #define CONTENT_CHILD_SCHEDULER_CANCELABLE_CLOSURE_HOLDER_H_
   7
   8 #include "base/cancelable_callback.h"
   9
  10 namespace content {
  11
  12 // A CancelableClosureHolder is a CancelableCallback which resets its wrapped
  13 // callback with a cached closure whenever it is canceled.
  14 class CancelableClosureHolder {
  15  public:
  16   CancelableClosureHolder();
  17   ~CancelableClosureHolder();
  18
  19   // Resets the closure to be wrapped by the cancelable callback.  Cancels any
  20   // outstanding callbacks.
  21   void Reset(const base::Closure& callback);
  22
  23   // Cancels any outstanding closures returned by callback().
  24   void Cancel();
  25
  26   // Returns a callback that will be disabled by calling Cancel(). Callback
  27   // must have been set using Reset() before calling this function.
  28   const base::Closure& callback() const;
  29
  30  private:
  31   base::Closure callback_;
  32   base::CancelableClosure cancelable_callback_;
  33
  34   DISALLOW_COPY_AND_ASSIGN(CancelableClosureHolder);
  35 };
  36
  37 }  // namespace content
  38
  39 #endif  // CONTENT_CHILD_SCHEDULER_CANCELABLE_CLOSURE_HOLDER_H_