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      1 // Copyright (c) 2011 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 CHROME_BROWSER_EXTENSIONS_EXTENSION_TEST_MESSAGE_LISTENER_H_
      6 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_TEST_MESSAGE_LISTENER_H_
      7 #pragma once
      8 
      9 #include <string>
     10 
     11 #include "content/common/notification_observer.h"
     12 #include "content/common/notification_registrar.h"
     13 
     14 class ExtensionTestSendMessageFunction;
     15 
     16 // This class helps us wait for incoming messages sent from javascript via
     17 // chrome.test.sendMessage(). A sample usage would be:
     18 //
     19 //   ExtensionTestMessageListener listener("foo");
     20 //   ... do some work
     21 //   ASSERT_TRUE(listener.WaitUntilSatisfied());
     22 //
     23 // It is also possible to have the extension wait for our reply. This is
     24 // useful for coordinating multiple pages/processes and having them wait on
     25 // each other. Example:
     26 //
     27 //   ExtensionTestMessageListener listener1("foo1");
     28 //   ExtensionTestMessageListener listener2("foo2");
     29 //   ASSERT_TRUE(listener1.WaitUntilSatisfied());
     30 //   ASSERT_TRUE(listener2.WaitUntilSatisfied());
     31 //   ... do some work
     32 //   listener1.Reply("foo2 is ready");
     33 //   listener2.Reply("foo1 is ready");
     34 //
     35 // TODO(asargent) - In the future we may want to add the ability to listen for
     36 // multiple messages, and/or to wait for "any" message and then retrieve the
     37 // contents of that message. We may also want to specify an extension id as
     38 // satisfaction criteria in addition to message content.
     39 //
     40 // Note that when using it in browser tests, you need to make sure it gets
     41 // destructed *before* the browser gets torn down. Two common patterns are to
     42 // either make it a local variable inside your test body, or if it's a member
     43 // variable of a ExtensionBrowserTest subclass, override the
     44 // InProcessBrowserTest::CleanUpOnMainThread() method and clean it up there.
     45 class ExtensionTestMessageListener : public NotificationObserver {
     46  public:
     47   // We immediately start listening for |expected_message|.
     48   ExtensionTestMessageListener(const std::string& expected_message,
     49                                bool will_reply);
     50   ~ExtensionTestMessageListener();
     51 
     52   // This returns true immediately if we've already gotten the expected
     53   // message, or waits until it arrives. Returns false if the wait is
     54   // interrupted and we still haven't gotten the message.
     55   bool WaitUntilSatisfied();
     56 
     57   // Send the given message as a reply. It is only valid to call this after
     58   // WaitUntilSatisfied has returned true, and if will_reply is true.
     59   void Reply(const std::string& message);
     60 
     61   // Implements the NotificationObserver interface.
     62   virtual void Observe(NotificationType type,
     63                        const NotificationSource& source,
     64                        const NotificationDetails& details);
     65 
     66   bool was_satisfied() const { return satisfied_; }
     67 
     68  private:
     69   NotificationRegistrar registrar_;
     70 
     71   // The message we're expecting.
     72   std::string expected_message_;
     73 
     74   // Whether we've seen expected_message_ yet.
     75   bool satisfied_;
     76 
     77   // If we're waiting, then we want to post a quit task when the expected
     78   // message arrives.
     79   bool waiting_;
     80 
     81   // If true, we expect the calling code to manually send a reply. Otherwise,
     82   // we send an automatic empty reply to the extension.
     83   bool will_reply_;
     84 
     85   // The function we need to reply to.
     86   ExtensionTestSendMessageFunction* function_;
     87 };
     88 
     89 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_TEST_MESSAGE_LISTENER_H_
     90