content/browser/renderer_host/clipboard_message_filter.cc

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/renderer_host/clipboard_message_filter.h"

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/stl_util.h"
#include "content/common/clipboard_messages.h"
#include "content/public/browser/browser_context.h"
#include "ipc/ipc_message_macros.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "third_party/zlib/zlib.h"
#include "ui/gfx/codec/png_codec.h"
#include "ui/gfx/size.h"
#include "url/gurl.h"

namespace content {

#if defined(OS_WIN)

namespace {

// The write must be performed on the UI thread because the clipboard object
// from the IO thread cannot create windows so it cannot be the "owner" of the
// clipboard's contents.  // See http://crbug.com/5823.
void WriteObjectsOnUIThread(ui::Clipboard::ObjectMap* objects) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  static ui::Clipboard* clipboard = ui::Clipboard::GetForCurrentThread();
  clipboard->WriteObjects(ui::Clipboard::BUFFER_STANDARD, *objects);
}

}  // namespace

#endif

ClipboardMessageFilter::ClipboardMessageFilter() {}

void ClipboardMessageFilter::OverrideThreadForMessage(
    const IPC::Message& message, BrowserThread::ID* thread) {
  // Clipboard writes should always occur on the UI thread due the restrictions
  // of various platform APIs. In general, the clipboard is not thread-safe, so
  // all clipboard calls should be serviced from the UI thread.
  //
  // Windows needs clipboard reads to be serviced from the IO thread because
  // these are sync IPCs which can result in deadlocks with NPAPI plugins if
  // serviced from the UI thread. Note that Windows clipboard calls ARE
  // thread-safe so it is ok for reads and writes to be serviced from different
  // threads.
#if !defined(OS_WIN)
  if (IPC_MESSAGE_CLASS(message) == ClipboardMsgStart)
    *thread = BrowserThread::UI;
#endif

#if defined(OS_WIN)
  if (message.type() == ClipboardHostMsg_ReadImage::ID)
    *thread = BrowserThread::FILE;
#endif
}

bool ClipboardMessageFilter::OnMessageReceived(const IPC::Message& message,
                                               bool* message_was_ok) {
  bool handled = true;
  IPC_BEGIN_MESSAGE_MAP_EX(ClipboardMessageFilter, message, *message_was_ok)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_WriteObjectsAsync, OnWriteObjectsAsync)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_WriteObjectsSync, OnWriteObjectsSync)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_GetSequenceNumber, OnGetSequenceNumber)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_IsFormatAvailable, OnIsFormatAvailable)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_Clear, OnClear)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_ReadAvailableTypes,
                        OnReadAvailableTypes)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_ReadText, OnReadText)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_ReadAsciiText, OnReadAsciiText)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_ReadHTML, OnReadHTML)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_ReadRTF, OnReadRTF)
    IPC_MESSAGE_HANDLER_DELAY_REPLY(ClipboardHostMsg_ReadImage, OnReadImage)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_ReadCustomData, OnReadCustomData)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_ReadData, OnReadData)
#if defined(OS_MACOSX)
    IPC_MESSAGE_HANDLER(ClipboardHostMsg_FindPboardWriteStringAsync,
                        OnFindPboardWriteString)
#endif
    IPC_MESSAGE_UNHANDLED(handled = false)
  IPC_END_MESSAGE_MAP()
  return handled;
}

ClipboardMessageFilter::~ClipboardMessageFilter() {
}

void ClipboardMessageFilter::OnWriteObjectsSync(
    ui::Clipboard::ObjectMap objects,
    base::SharedMemoryHandle bitmap_handle) {
  DCHECK(base::SharedMemory::IsHandleValid(bitmap_handle))
      << "Bad bitmap handle";
  // Splice the shared memory handle into the clipboard data.
  ui::Clipboard::ReplaceSharedMemHandle(&objects, bitmap_handle, PeerHandle());
#if defined(OS_WIN)
  // We cannot write directly from the IO thread, and cannot service the IPC
  // on the UI thread. We'll copy the relevant data and get a handle to any
  // shared memory so it doesn't go away when we resume the renderer, and post
  // a task to perform the write on the UI thread.
  ui::Clipboard::ObjectMap* long_living_objects = new ui::Clipboard::ObjectMap;
  long_living_objects->swap(objects);

  BrowserThread::PostTask(
      BrowserThread::UI,
      FROM_HERE,
      base::Bind(&WriteObjectsOnUIThread, base::Owned(long_living_objects)));
#else
  GetClipboard()->WriteObjects(ui::Clipboard::BUFFER_STANDARD, objects);
#endif
}

void ClipboardMessageFilter::OnWriteObjectsAsync(
    const ui::Clipboard::ObjectMap& objects) {
#if defined(OS_WIN)
  // We cannot write directly from the IO thread, and cannot service the IPC
  // on the UI thread. We'll copy the relevant data and post a task to preform
  // the write on the UI thread.
  ui::Clipboard::ObjectMap* long_living_objects =
      new ui::Clipboard::ObjectMap(objects);

  // This async message doesn't support shared-memory based bitmaps; they must
  // be removed otherwise we might dereference a rubbish pointer.
  long_living_objects->erase(ui::Clipboard::CBF_SMBITMAP);

  BrowserThread::PostTask(
      BrowserThread::UI,
      FROM_HERE,
      base::Bind(&WriteObjectsOnUIThread, base::Owned(long_living_objects)));
#else
  GetClipboard()->WriteObjects(ui::Clipboard::BUFFER_STANDARD, objects);
#endif
}

void ClipboardMessageFilter::OnGetSequenceNumber(
    ui::Clipboard::Buffer buffer, uint64* sequence_number) {
  *sequence_number = GetClipboard()->GetSequenceNumber(buffer);
}

void ClipboardMessageFilter::OnReadAvailableTypes(
    ui::Clipboard::Buffer buffer, std::vector<string16>* types,
    bool* contains_filenames) {
  GetClipboard()->ReadAvailableTypes(buffer, types, contains_filenames);
}

void ClipboardMessageFilter::OnIsFormatAvailable(
    const ui::Clipboard::FormatType& format, ui::Clipboard::Buffer buffer,
    bool* result) {
  *result = GetClipboard()->IsFormatAvailable(format, buffer);
}

void ClipboardMessageFilter::OnClear(ui::Clipboard::Buffer buffer) {
  GetClipboard()->Clear(buffer);
}

void ClipboardMessageFilter::OnReadText(
    ui::Clipboard::Buffer buffer, string16* result) {
  GetClipboard()->ReadText(buffer, result);
}

void ClipboardMessageFilter::OnReadAsciiText(
    ui::Clipboard::Buffer buffer, std::string* result) {
  GetClipboard()->ReadAsciiText(buffer, result);
}

void ClipboardMessageFilter::OnReadHTML(
    ui::Clipboard::Buffer buffer, string16* markup, GURL* url,
    uint32* fragment_start, uint32* fragment_end) {
  std::string src_url_str;
  GetClipboard()->ReadHTML(buffer, markup, &src_url_str, fragment_start,
                           fragment_end);
  *url = GURL(src_url_str);
}

void ClipboardMessageFilter::OnReadRTF(
    ui::Clipboard::Buffer buffer, std::string* result) {
  GetClipboard()->ReadRTF(buffer, result);
}

void ClipboardMessageFilter::OnReadImage(
    ui::Clipboard::Buffer buffer, IPC::Message* reply_msg) {
  SkBitmap bitmap = GetClipboard()->ReadImage(buffer);

#if defined(USE_X11)
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      base::Bind(
          &ClipboardMessageFilter::OnReadImageReply, this, bitmap, reply_msg));
#else
  OnReadImageReply(bitmap, reply_msg);
#endif
}

void ClipboardMessageFilter::OnReadImageReply(
    const SkBitmap& bitmap, IPC::Message* reply_msg) {
  base::SharedMemoryHandle image_handle = base::SharedMemory::NULLHandle();
  uint32 image_size = 0;
  std::string reply_data;
  if (!bitmap.isNull()) {
    std::vector<unsigned char> png_data;
    SkAutoLockPixels lock(bitmap);
    if (gfx::PNGCodec::EncodeWithCompressionLevel(
            static_cast<const unsigned char*>(bitmap.getPixels()),
            gfx::PNGCodec::FORMAT_BGRA,
            gfx::Size(bitmap.width(), bitmap.height()),
            bitmap.rowBytes(),
            false,
            std::vector<gfx::PNGCodec::Comment>(),
            Z_BEST_SPEED,
            &png_data)) {
      base::SharedMemory buffer;
      if (buffer.CreateAndMapAnonymous(png_data.size())) {
        memcpy(buffer.memory(), vector_as_array(&png_data), png_data.size());
        if (buffer.GiveToProcess(PeerHandle(), &image_handle)) {
          image_size = png_data.size();
        }
      }
    }
  }
  ClipboardHostMsg_ReadImage::WriteReplyParams(reply_msg, image_handle,
                                               image_size);
  Send(reply_msg);
}

void ClipboardMessageFilter::OnReadCustomData(
    ui::Clipboard::Buffer buffer, const string16& type, string16* result) {
  GetClipboard()->ReadCustomData(buffer, type, result);
}

void ClipboardMessageFilter::OnReadData(const ui::Clipboard::FormatType& format,
                                        std::string* data) {
  GetClipboard()->ReadData(format, data);
}

// static
ui::Clipboard* ClipboardMessageFilter::GetClipboard() {
  // We have a static instance of the clipboard service for use by all message
  // filters.  This instance lives for the life of the browser processes.
  static ui::Clipboard* clipboard = ui::Clipboard::GetForCurrentThread();
  return clipboard;
}

}  // namespace content