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   ~BrowserChildProcessHostIterator();
  30
  31   // These methods work on the current iterator object. Only call them if
  32   // Done() returns false.
  33   bool operator++();
  34   bool Done();
  35   const ChildProcessData& GetData();
  36   bool Send(IPC::Message* message);
  37   BrowserChildProcessHostDelegate* GetDelegate();
  38
  39  private:
  40   bool all_;
  41   int process_type_;
  42   std::list<BrowserChildProcessHostImpl*>::iterator iterator_;
  43 };
  44
  45 // Helper class so that subclasses of BrowserChildProcessHostDelegate can be
  46 // iterated with no casting needing. Note that because of the components build,
  47 // this class can only be used by BCPHD implementations that live in content,
  48 // otherwise link errors will result.
  49 template <class T>
  50 class CONTENT_EXPORT BrowserChildProcessHostTypeIterator
  51     : public BrowserChildProcessHostIterator {
  52  public:
  53   explicit BrowserChildProcessHostTypeIterator(int process_type)
  54       : BrowserChildProcessHostIterator(process_type) {}
  55   T* operator->() {
  56     return static_cast<T*>(GetDelegate());
  57   }
  58   T* operator*() {
  59     return static_cast<T*>(GetDelegate());
  60   }
  61 };
  62
  63 };  // namespace content
  64
  65 #endif  // CONTENT_PUBLIC_BROWSER_BROWSER_CHILD_PROCESS_HOST_ITERATOR_H_