ppapi/examples/scripting/post_message.cc

   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 #include <algorithm>
   6
   7 #include "ppapi/cpp/instance.h"
   8 #include "ppapi/cpp/module.h"
   9 #include "ppapi/cpp/var.h"
  10
  11 // When compiling natively on Windows, PostMessage can be #define-d to
  12 // something else.
  13 #ifdef PostMessage
  14 #undef PostMessage
  15 #endif
  16
  17 // This is a simple C++ Pepper plugin that demonstrates HandleMessage and
  18 // PostMessage.
  19
  20 // This object represents one time the page says <embed>.
  21 class MyInstance : public pp::Instance {
  22  public:
  23   explicit MyInstance(PP_Instance instance) : pp::Instance(instance) {}
  24   virtual ~MyInstance() {}
  25   virtual void HandleMessage(const pp::Var& message_data);
  26 };
  27
  28 // HandleMessage gets invoked when postMessage is called on the DOM element
  29 // associated with this plugin instance.
  30 // In this case, if we are given a string, we'll post a message back to
  31 // JavaScript indicating whether or not that string is a palindrome.
  32 void MyInstance::HandleMessage(const pp::Var& message_data) {
  33   if (message_data.is_string()) {
  34     std::string string_copy(message_data.AsString());
  35     std::reverse(string_copy.begin(), string_copy.end());
  36     bool is_palindrome(message_data.AsString() == string_copy);
  37
  38     PostMessage(pp::Var(is_palindrome));
  39   }
  40 }
  41
  42 // This object is the global object representing this plugin library as long
  43 // as it is loaded.
  44 class MyModule : public pp::Module {
  45  public:
  46   MyModule() : pp::Module() {}
  47   virtual ~MyModule() {}
  48
  49   // Override CreateInstance to create your customized Instance object.
  50   virtual pp::Instance* CreateInstance(PP_Instance instance) {
  51     return new MyInstance(instance);
  52   }
  53 };
  54
  55 namespace pp {
  56
  57 // Factory function for your specialization of the Module object.
  58 Module* CreateModule() {
  59   return new MyModule();
  60 }
  61
  62 }  // namespace pp
  63