remoting/host/win/message_window.cc

   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 #include "remoting/host/win/message_window.h"
   6
   7 #include "base/logging.h"
   8 #include "base/process_util.h"
   9 #include "base/stringprintf.h"
  10 #include "base/utf_string_conversions.h"
  11 #include "base/win/wrapped_window_proc.h"
  12
  13 const char kClassNameFormat[] = "Chromoting_MessageWindow_%p";
  14
  15 namespace remoting {
  16 namespace win {
  17
  18 MessageWindow::MessageWindow()
  19     : atom_(0),
  20       instance_(NULL),
  21       window_(NULL) {
  22   class_name_ = base::StringPrintf(kClassNameFormat, this);
  23   instance_ = base::GetModuleFromAddress(static_cast<WNDPROC>(
  24       &base::win::WrappedWindowProc<WindowProc>));
  25 }
  26
  27 MessageWindow::MessageWindow(const std::string& class_name, HINSTANCE instance)
  28     : atom_(0),
  29       class_name_(class_name),
  30       instance_(instance),
  31       window_(NULL) {
  32 }
  33
  34 MessageWindow::~MessageWindow() {
  35   DCHECK(CalledOnValidThread());
  36
  37   if (window_ != NULL) {
  38     DestroyWindow(window_);
  39     window_ = NULL;
  40   }
  41
  42   if (atom_ != 0) {
  43     UnregisterClass(MAKEINTATOM(atom_), instance_);
  44     atom_ = 0;
  45   }
  46 }
  47
  48 bool MessageWindow::Create(Delegate* delegate) {
  49   DCHECK(CalledOnValidThread());
  50   DCHECK(!atom_);
  51   DCHECK(!window_);
  52
  53   // Register a separate window class for each instance of |MessageWindow|.
  54   string16 class_name = UTF8ToUTF16(class_name_);
  55   WNDCLASSEX window_class;
  56   window_class.cbSize = sizeof(window_class);
  57   window_class.style = 0;
  58   window_class.lpfnWndProc = &base::win::WrappedWindowProc<WindowProc>;
  59   window_class.cbClsExtra = 0;
  60   window_class.cbWndExtra = 0;
  61   window_class.hInstance = instance_;
  62   window_class.hIcon = NULL;
  63   window_class.hCursor = NULL;
  64   window_class.hbrBackground = NULL;
  65   window_class.lpszMenuName = NULL;
  66   window_class.lpszClassName = class_name.c_str();
  67   window_class.hIconSm = NULL;
  68   atom_ = RegisterClassEx(&window_class);
  69   if (atom_ == 0) {
  70     LOG_GETLASTERROR(ERROR)
  71         << "Failed to register the window class '" << class_name_ << "'";
  72     return false;
  73   }
  74
  75   window_ = CreateWindow(MAKEINTATOM(atom_), 0, 0, 0, 0, 0, 0, HWND_MESSAGE, 0,
  76                          instance_, delegate);
  77   if (!window_) {
  78     LOG_GETLASTERROR(ERROR) << "Failed to create a message-only window";
  79     return false;
  80   }
  81
  82   return true;
  83 }
  84
  85 // static
  86 LRESULT CALLBACK MessageWindow::WindowProc(HWND hwnd,
  87                                            UINT message,
  88                                            WPARAM wparam,
  89                                            LPARAM lparam) {
  90   Delegate* delegate = NULL;
  91
  92   // Set up the delegate before handling WM_CREATE.
  93   if (message == WM_CREATE) {
  94     CREATESTRUCT* cs = reinterpret_cast<CREATESTRUCT*>(lparam);
  95     delegate = reinterpret_cast<Delegate*>(cs->lpCreateParams);
  96
  97     // Store pointer to the delegate to the window's user data.
  98     SetLastError(ERROR_SUCCESS);
  99     LONG_PTR result = SetWindowLongPtr(
 100         hwnd, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(delegate));
 101     CHECK(result != 0 || GetLastError() == ERROR_SUCCESS);
 102   } else {
 103     delegate = reinterpret_cast<Delegate*>(GetWindowLongPtr(hwnd,
 104                                                             GWLP_USERDATA));
 105   }
 106
 107   // Handle the message.
 108   if (delegate) {
 109     LRESULT message_result;
 110     if (delegate->HandleMessage(hwnd, message, wparam, lparam, &message_result))
 111       return message_result;
 112   }
 113
 114   return DefWindowProc(hwnd, message, wparam, lparam);
 115 }
 116
 117 }  // namespace win
 118 }  // namespace remoting