content/shell/renderer/test_runner/WebTask.h

   1 // Copyright 2013 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_SHELL_RENDERER_TEST_RUNNER_WEBTASK_H_
   6 #define CONTENT_SHELL_RENDERER_TEST_RUNNER_WEBTASK_H_
   7
   8 #include <vector>
   9
  10 namespace WebTestRunner {
  11
  12 class WebTaskList;
  13
  14 // WebTask represents a task which can run by WebTestDelegate::postTask() or
  15 // WebTestDelegate::postDelayedTask().
  16 class WebTask {
  17 public:
  18     explicit WebTask(WebTaskList*);
  19     virtual ~WebTask();
  20
  21     // The main code of this task.
  22     // An implementation of run() should return immediately if cancel() was called.
  23     virtual void run() = 0;
  24     virtual void cancel() = 0;
  25
  26 protected:
  27     WebTaskList* m_taskList;
  28 };
  29
  30 class WebTaskList {
  31 public:
  32     WebTaskList();
  33     ~WebTaskList();
  34     void registerTask(WebTask*);
  35     void unregisterTask(WebTask*);
  36     void revokeAll();
  37
  38 private:
  39     std::vector<WebTask*> m_tasks;
  40 };
  41
  42 // A task containing an object pointer of class T. Derived classes should
  43 // override runIfValid() which in turn can safely invoke methods on the
  44 // m_object. The Class T must have "WebTaskList* taskList()".
  45 template<class T>
  46 class WebMethodTask : public WebTask {
  47 public:
  48     explicit WebMethodTask(T* object)
  49         : WebTask(object->taskList())
  50         , m_object(object)
  51     {
  52     }
  53
  54     virtual ~WebMethodTask() { }
  55
  56     virtual void run()
  57     {
  58         if (m_object)
  59             runIfValid();
  60     }
  61
  62     virtual void cancel()
  63     {
  64         m_object = 0;
  65         m_taskList->unregisterTask(this);
  66         m_taskList = 0;
  67     }
  68
  69     virtual void runIfValid() = 0;
  70
  71 protected:
  72     T* m_object;
  73 };
  74
  75 }
  76
  77 #endif  // CONTENT_SHELL_RENDERER_TEST_RUNNER_WEBTASK_H_