content/public/browser/browser_child_process_host_iterator.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 #ifndef CONTENT_PUBLIC_BROWSER_BROWSER_CHILD_PROCESS_HOST_ITERATOR_H_
   6 #define CONTENT_PUBLIC_BROWSER_BROWSER_CHILD_PROCESS_HOST_ITERATOR_H_
   7
   8 #include <list>
   9
  10 #include "content/common/content_export.h"
  11
  12 namespace IPC {
  13 class Message;
  14 }
  15
  16 namespace content {
  17 class BrowserChildProcessHostDelegate;
  18 class BrowserChildProcessHostImpl;
  19 struct ChildProcessData;
  20
  21 // This class allows iteration through either all child processes, or ones of a
  22 // specific type, depending on which constructor is used.  Note that this should
  23 // be done from the IO thread and that the iterator should not be kept around as
  24 // it may be invalidated on subsequent event processing in the event loop.
  25 class CONTENT_EXPORT BrowserChildProcessHostIterator {
  26  public:
  27   BrowserChildProcessHostIterator();
  28   explicit BrowserChildProcessHostIterator(int type);
  29
  30   // These methods work on the current iterator object. Only call them if
  31   // Done() returns false.
  32   bool operator++();
  33   bool Done();
  34   const ChildProcessData& GetData();
  35   bool Send(IPC::Message* message);
  36   BrowserChildProcessHostDelegate* GetDelegate();
  37
  38  private:
  39   bool all_;
  40   int process_type_;
  41   std::list<BrowserChildProcessHostImpl*>::iterator iterator_;
  42 };
  43
  44 // Helper class so that subclasses of BrowserChildProcessHostDelegate can be
  45 // iterated with no casting needing. Note that because of the components build,
  46 // this class can only be used by BCPHD implementations that live in content,
  47 // otherwise link errors will result.
  48 template <class T>
  49 class CONTENT_EXPORT BrowserChildProcessHostTypeIterator
  50     : public BrowserChildProcessHostIterator {
  51  public:
  52   explicit BrowserChildProcessHostTypeIterator(int process_type)
  53       : BrowserChildProcessHostIterator(process_type) {}
  54   T* operator->() {
  55     return static_cast<T*>(GetDelegate());
  56   }
  57   T* operator*() {
  58     return static_cast<T*>(GetDelegate());
  59   }
  60 };
  61
  62 };  // namespace content
  63
  64 #endif  // CONTENT_PUBLIC_BROWSER_BROWSER_CHILD_PROCESS_HOST_ITERATOR_H_