remoting/host/clipboard_win.cc

   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 #include "remoting/host/clipboard.h"
   6
   7 #include <windows.h>
   8
   9 #include "base/basictypes.h"
  10 #include "base/bind.h"
  11 #include "base/logging.h"
  12 #include "base/strings/string16.h"
  13 #include "base/strings/utf_string_conversions.h"
  14 #include "base/threading/platform_thread.h"
  15 #include "base/win/message_window.h"
  16 #include "base/win/scoped_hglobal.h"
  17 #include "base/win/windows_version.h"
  18 #include "remoting/base/constants.h"
  19 #include "remoting/base/util.h"
  20 #include "remoting/proto/event.pb.h"
  21 #include "remoting/protocol/clipboard_stub.h"
  22
  23 namespace {
  24
  25 // A scoper class that opens and closes the clipboard.
  26 // This class was adapted from the ScopedClipboard class in
  27 // ui/base/clipboard/clipboard_win.cc.
  28 class ScopedClipboard {
  29  public:
  30   ScopedClipboard() : opened_(false) {
  31   }
  32
  33   ~ScopedClipboard() {
  34     if (opened_) {
  35       ::CloseClipboard();
  36     }
  37   }
  38
  39   bool Init(HWND owner) {
  40     const int kMaxAttemptsToOpenClipboard = 5;
  41     const base::TimeDelta kSleepTimeBetweenAttempts =
  42         base::TimeDelta::FromMilliseconds(5);
  43
  44     if (opened_) {
  45       NOTREACHED();
  46       return true;
  47     }
  48
  49     // This code runs on the UI thread, so we can block only very briefly.
  50     for (int attempt = 0; attempt < kMaxAttemptsToOpenClipboard; ++attempt) {
  51       if (attempt > 0) {
  52         base::PlatformThread::Sleep(kSleepTimeBetweenAttempts);
  53       }
  54       if (::OpenClipboard(owner)) {
  55         opened_ = true;
  56         return true;
  57       }
  58     }
  59     return false;
  60   }
  61
  62   BOOL Empty() {
  63     if (!opened_) {
  64       NOTREACHED();
  65       return false;
  66     }
  67     return ::EmptyClipboard();
  68   }
  69
  70   void SetData(UINT uFormat, HANDLE hMem) {
  71     if (!opened_) {
  72       NOTREACHED();
  73       return;
  74     }
  75     // The caller must not close the handle that ::SetClipboardData returns.
  76     ::SetClipboardData(uFormat, hMem);
  77   }
  78
  79   // The caller must not free the handle. The caller should lock the handle,
  80   // copy the clipboard data, and unlock the handle. All this must be done
  81   // before this ScopedClipboard is destroyed.
  82   HANDLE GetData(UINT format) {
  83     if (!opened_) {
  84       NOTREACHED();
  85       return NULL;
  86     }
  87     return ::GetClipboardData(format);
  88   }
  89
  90  private:
  91   bool opened_;
  92 };
  93
  94 typedef BOOL (WINAPI AddClipboardFormatListenerFn)(HWND);
  95 typedef BOOL (WINAPI RemoveClipboardFormatListenerFn)(HWND);
  96
  97 }  // namespace
  98
  99 namespace remoting {
 100
 101 class ClipboardWin : public Clipboard {
 102  public:
 103   ClipboardWin();
 104
 105   virtual void Start(
 106       scoped_ptr<protocol::ClipboardStub> client_clipboard) OVERRIDE;
 107   virtual void InjectClipboardEvent(
 108       const protocol::ClipboardEvent& event) OVERRIDE;
 109   virtual void Stop() OVERRIDE;
 110
 111  private:
 112   void OnClipboardUpdate();
 113
 114   // Handles messages received by |window_|.
 115   bool HandleMessage(UINT message,
 116                      WPARAM wparam,
 117                      LPARAM lparam,
 118                      LRESULT* result);
 119
 120   scoped_ptr<protocol::ClipboardStub> client_clipboard_;
 121   AddClipboardFormatListenerFn* add_clipboard_format_listener_;
 122   RemoveClipboardFormatListenerFn* remove_clipboard_format_listener_;
 123
 124   // Used to subscribe to WM_CLIPBOARDUPDATE messages.
 125   scoped_ptr<base::win::MessageWindow> window_;
 126
 127   DISALLOW_COPY_AND_ASSIGN(ClipboardWin);
 128 };
 129
 130 ClipboardWin::ClipboardWin()
 131     : add_clipboard_format_listener_(NULL),
 132       remove_clipboard_format_listener_(NULL) {
 133 }
 134
 135 void ClipboardWin::Start(
 136     scoped_ptr<protocol::ClipboardStub> client_clipboard) {
 137   DCHECK(!add_clipboard_format_listener_);
 138   DCHECK(!remove_clipboard_format_listener_);
 139   DCHECK(!window_);
 140
 141   client_clipboard_.swap(client_clipboard);
 142
 143   // user32.dll is statically linked.
 144   HMODULE user32 = GetModuleHandle(L"user32.dll");
 145   CHECK(user32);
 146
 147   add_clipboard_format_listener_ =
 148       reinterpret_cast<AddClipboardFormatListenerFn*>(
 149           GetProcAddress(user32, "AddClipboardFormatListener"));
 150   if (add_clipboard_format_listener_) {
 151     remove_clipboard_format_listener_ =
 152         reinterpret_cast<RemoveClipboardFormatListenerFn*>(
 153             GetProcAddress(user32, "RemoveClipboardFormatListener"));
 154     // If AddClipboardFormatListener() present, RemoveClipboardFormatListener()
 155     // should be available too.
 156     CHECK(remove_clipboard_format_listener_);
 157   } else {
 158     LOG(WARNING) << "AddClipboardFormatListener() is not available.";
 159   }
 160
 161   window_.reset(new base::win::MessageWindow());
 162   if (!window_->Create(base::Bind(&ClipboardWin::HandleMessage,
 163                                   base::Unretained(this)))) {
 164     LOG(ERROR) << "Couldn't create clipboard window.";
 165     window_.reset();
 166     return;
 167   }
 168
 169   if (add_clipboard_format_listener_) {
 170     if (!(*add_clipboard_format_listener_)(window_->hwnd())) {
 171       LOG(WARNING) << "AddClipboardFormatListener() failed: " << GetLastError();
 172     }
 173   }
 174 }
 175
 176 void ClipboardWin::Stop() {
 177   client_clipboard_.reset();
 178
 179   if (window_ && remove_clipboard_format_listener_)
 180     (*remove_clipboard_format_listener_)(window_->hwnd());
 181
 182   window_.reset();
 183 }
 184
 185 void ClipboardWin::InjectClipboardEvent(
 186     const protocol::ClipboardEvent& event) {
 187   if (!window_)
 188     return;
 189
 190   // Currently we only handle UTF-8 text.
 191   if (event.mime_type().compare(kMimeTypeTextUtf8) != 0)
 192     return;
 193   if (!StringIsUtf8(event.data().c_str(), event.data().length())) {
 194     LOG(ERROR) << "ClipboardEvent: data is not UTF-8 encoded.";
 195     return;
 196   }
 197
 198   base::string16 text = base::UTF8ToUTF16(ReplaceLfByCrLf(event.data()));
 199
 200   ScopedClipboard clipboard;
 201   if (!clipboard.Init(window_->hwnd())) {
 202     LOG(WARNING) << "Couldn't open the clipboard.";
 203     return;
 204   }
 205
 206   clipboard.Empty();
 207
 208   HGLOBAL text_global =
 209       ::GlobalAlloc(GMEM_MOVEABLE, (text.size() + 1) * sizeof(WCHAR));
 210   if (!text_global) {
 211     LOG(WARNING) << "Couldn't allocate global memory.";
 212     return;
 213   }
 214
 215   LPWSTR text_global_locked =
 216       reinterpret_cast<LPWSTR>(::GlobalLock(text_global));
 217   memcpy(text_global_locked, text.data(), text.size() * sizeof(WCHAR));
 218   text_global_locked[text.size()] = (WCHAR)0;
 219   ::GlobalUnlock(text_global);
 220
 221   clipboard.SetData(CF_UNICODETEXT, text_global);
 222 }
 223
 224 void ClipboardWin::OnClipboardUpdate() {
 225   DCHECK(window_);
 226
 227   if (::IsClipboardFormatAvailable(CF_UNICODETEXT)) {
 228     base::string16 text;
 229     // Add a scope, so that we keep the clipboard open for as short a time as
 230     // possible.
 231     {
 232       ScopedClipboard clipboard;
 233       if (!clipboard.Init(window_->hwnd())) {
 234         LOG(WARNING) << "Couldn't open the clipboard." << GetLastError();
 235         return;
 236       }
 237
 238       HGLOBAL text_global = clipboard.GetData(CF_UNICODETEXT);
 239       if (!text_global) {
 240         LOG(WARNING) << "Couldn't get data from the clipboard: "
 241                      << GetLastError();
 242         return;
 243       }
 244
 245       base::win::ScopedHGlobal<WCHAR> text_lock(text_global);
 246       if (!text_lock.get()) {
 247         LOG(WARNING) << "Couldn't lock clipboard data: " << GetLastError();
 248         return;
 249       }
 250       text.assign(text_lock.get());
 251     }
 252
 253     protocol::ClipboardEvent event;
 254     event.set_mime_type(kMimeTypeTextUtf8);
 255     event.set_data(ReplaceCrLfByLf(base::UTF16ToUTF8(text)));
 256
 257     if (client_clipboard_.get()) {
 258       client_clipboard_->InjectClipboardEvent(event);
 259     }
 260   }
 261 }
 262
 263 bool ClipboardWin::HandleMessage(
 264     UINT message, WPARAM wparam, LPARAM lparam, LRESULT* result) {
 265   if (message == WM_CLIPBOARDUPDATE) {
 266     OnClipboardUpdate();
 267     *result = 0;
 268     return true;
 269   }
 270
 271   return false;
 272 }
 273
 274 scoped_ptr<Clipboard> Clipboard::Create() {
 275   return scoped_ptr<Clipboard>(new ClipboardWin());
 276 }
 277
 278 }  // namespace remoting