add print to pdf for headless

headless/lib/browser/headless_print_manager.cc

+// Copyright 2017 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 "headless/lib/browser/headless_print_manager.h"
+
+#include <utility>
+#include <vector>
+
+#include "base/base64.h"
+#include "components/printing/browser/print_manager_utils.h"
+#include "components/printing/common/print_messages.h"
+#include "printing/pdf_metafile_skia.h"
+#include "printing/print_settings.h"
+#include "printing/units.h"
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(printing::HeadlessPrintManager);
+
+namespace printing {
+
+namespace {
+
+// TODO(jzfeng): let the print settings to be configurable.
+const double kTopMarginInInch = 0.25;
+const double kBottomMarginInInch = 0.56;
+const double kLeftMarginInInch = 0.25;
+const double kRightMarginInInch = 0.25;
+
+PrintSettings GetDefaultPDFPrinterSettings() {
+  int dpi = kDefaultPdfDpi;
+  gfx::Size physical_size_device_units;
+  gfx::Rect printable_area_device_units;
+  double page_width_in_pixel = kLetterWidthInch * dpi;
+  double page_height_in_pixel = kLetterHeightInch * dpi;
+  physical_size_device_units.SetSize(static_cast<int>(page_width_in_pixel),
+                                     static_cast<int>(page_height_in_pixel));
+  printable_area_device_units.SetRect(
+      static_cast<int>(kLeftMarginInInch * dpi),
+      static_cast<int>(kTopMarginInInch * dpi),
+      page_width_in_pixel - (kLeftMarginInInch + kRightMarginInInch) * dpi,
+      page_height_in_pixel - (kTopMarginInInch + kBottomMarginInInch) * dpi);
+
+  PrintSettings settings;
+  settings.set_dpi(dpi);
+  settings.SetPrinterPrintableArea(physical_size_device_units,
+                                   printable_area_device_units, true);
+  settings.set_should_print_backgrounds(true);
+  return settings;
+}
+
+}  // namespace
+
+void HeadlessPrintManager::Reset() {

[Lei Zhang, 2017/03/29 05:30:16]

Can you put these in the same order as they are declared in the header?

[jzfeng, 2017/03/30 03:04:57]

Done.

+  printing_rfh_ = nullptr;
+  data_.clear();
+  is_active_ = false;
+#if !defined(OS_MACOSX)
+  expecting_first_page_ = true;
+#endif
+  number_pages_ = 0;
+}
+
+HeadlessPrintManager::HeadlessPrintManager(content::WebContents* web_contents)
+    : PrintManager(web_contents) {
+  Reset();
+}
+
+HeadlessPrintManager::~HeadlessPrintManager() {}
+
+// static
+std::string HeadlessPrintManager::PrintResultToErrMsg(PrintResult result) {

[Eric Seckler, 2017/03/29 11:21:20]

nit: PrintResultToString

[jzfeng, 2017/03/30 03:04:57]

Done.

+  switch (result) {
+    case kPrintSuccess:
+      return "";  // no error message
+    case kPrintingFailed:
+      return "PrintingFailed";
+    case kInvalidPrinterSettings:
+      return "ShowInvalidPrinterSettingsError";
+    case kInvalidMemoryHandle:
+      return "Invalid memory handle";
+    case kMetafileMapError:
+      return "Map to SharedMemory error";
+    case kUnexpectedValidMemoryHandle:
+      return "Unexpected valide memory handle";
+    case kMetafileInvalidHeader:
+      return "Invalid metafile header";
+    case kMetafileGetDataError:
+      return "Get data from metafile error";
+    case kDuplicatedPrintingError:
+      return "The previous printing job hasn't finished";
+    default:
+      NOTREACHED();
+      return "Unknown PrintResult";
+  }
+}
+
+// static
+std::unique_ptr<base::DictionaryValue>
+HeadlessPrintManager::PDFContentsToDictionaryValue(const std::string& data) {
+  std::string base_64_data;
+  base::Base64Encode(data, &base_64_data);
+  auto result = base::MakeUnique<base::DictionaryValue>();
+  result->SetString("data", base_64_data);
+  return result;
+}
+
+void HeadlessPrintManager::GetPDFContents(content::RenderFrameHost* rfh,
+                                          const GetPDFCallback& callback) {

[Lei Zhang, 2017/03/29 05:30:15]

Add DCHECK(callback);

[jzfeng, 2017/03/30 03:04:57]

Done.

+  if (is_active_) {
+    callback.Run(kDuplicatedPrintingError, "");
+    return;
+  }
+  is_active_ = true;
+  printing_rfh_ = rfh;
+  callback_ = callback;
+  rfh->Send(new PrintMsg_PrintPages(rfh->GetRoutingID()));
+}
+
+bool HeadlessPrintManager::OnMessageReceived(
+    const IPC::Message& message,
+    content::RenderFrameHost* render_frame_host) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(HeadlessPrintManager, message)
+    IPC_MESSAGE_HANDLER(PrintHostMsg_ShowInvalidPrinterSettingsError,
+                        OnShowInvalidPrinterSettingsError)
+    IPC_MESSAGE_HANDLER(PrintHostMsg_DidPrintPage, OnDidPrintPage)
+    IPC_MESSAGE_HANDLER_DELAY_REPLY(PrintHostMsg_GetDefaultPrintSettings,
+                                    OnGetDefaultPrintSettings)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled || PrintManager::OnMessageReceived(message, render_frame_host);
+}
+
+void HeadlessPrintManager::OnGetDefaultPrintSettings(IPC::Message* reply_msg) {
+  PrintMsg_Print_Params print_params;
+  RenderParamsFromPrintSettings(GetDefaultPDFPrinterSettings(), &print_params);
+  print_params.document_cookie = PrintSettings::NewCookie();
+  PrintHostMsg_GetDefaultPrintSettings::WriteReplyParams(reply_msg,
+                                                         print_params);
+  printing_rfh_->Send(reply_msg);
+}
+
+void HeadlessPrintManager::OnShowInvalidPrinterSettingsError() {
+  ReleaseJob(kInvalidPrinterSettings);
+}
+
+void HeadlessPrintManager::OnPrintingFailed(int cookie) {
+  ReleaseJob(kPrintingFailed);
+}
+
+void HeadlessPrintManager::OnDidPrintPage(
+    const PrintHostMsg_DidPrintPage_Params& params) {
+#if defined(OS_MACOSX)
+  const bool metafile_must_be_valid = true;
+#else
+  const bool metafile_must_be_valid = expecting_first_page_;
+  expecting_first_page_ = false;
+#endif
+
+  // Only used when |metafile_must_be_valid| is true.
+  std::unique_ptr<base::SharedMemory> shared_buf;
+  if (metafile_must_be_valid) {
+    if (!base::SharedMemory::IsHandleValid(params.metafile_data_handle)) {
+      ReleaseJob(kInvalidMemoryHandle);
+      return;
+    }
+    shared_buf =
+        base::MakeUnique<base::SharedMemory>(params.metafile_data_handle, true);
+    if (!shared_buf->Map(params.data_size)) {
+      ReleaseJob(kMetafileMapError);
+      return;
+    }
+  } else {
+    if (base::SharedMemory::IsHandleValid(params.metafile_data_handle)) {
+      base::SharedMemory::CloseHandle(params.metafile_data_handle);
+      ReleaseJob(kUnexpectedValidMemoryHandle);
+      return;
+    }
+  }
+
+  auto metafile = base::MakeUnique<PdfMetafileSkia>(PDF_SKIA_DOCUMENT_TYPE);
+  if (metafile_must_be_valid) {
+    if (!metafile->InitFromData(shared_buf->memory(), params.data_size)) {
+      ReleaseJob(kMetafileInvalidHeader);
+      return;
+    }
+    std::vector<char> buffer;
+    if (!metafile->GetDataAsVector(&buffer)) {
+      ReleaseJob(kMetafileGetDataError);
+      return;
+    }
+    data_ = std::string(buffer.data(), buffer.size());

[Eric Seckler, 2017/03/29 11:21:19]

This seems to override whatever is in data_. What happens if we receive more
than one page (DidPrintPage message)? I'd expect that we need to somehow stitch
together the pages?

(Lei:) Or are we guaranteed that that we only get one DidPrintPage callback with
all the pages? If so, can we ReleaseJob if we get more than one and remove the
expecting_first_page_ stuff?

[jzfeng, 2017/03/30 03:04:57]

You are right. This is a temporary solution. Looks like linux and windows only
have one valid metafile. And mac requires to stitch the pages, though I don't
know how at the moment.

I will do some experiment on windows and mac.

[Lei Zhang, 2017/04/06 08:08:42]

Under normal operations, you should get 1 per page. Only the 1st page has the
metadata in patch set 5 and onwards.

If a renderer is compromised, anything can happen. This is why we do some
validation and we can potentially hit the UNEXPECTED_VALID_MEMORY_HANDLE case.

+  }
+
+  if (--number_pages_ == 0)
+    ReleaseJob(kPrintSuccess);
+}
+
+void HeadlessPrintManager::ReleaseJob(PrintResult result) {
+  if (result == kPrintSuccess)
+    callback_.Run(result, std::move(data_));
+  else
+    callback_.Run(result, "");

[Eric Seckler, 2017/03/29 11:21:19]

nit: std::string()

[jzfeng, 2017/03/30 03:04:57]

Done.

+  printing_rfh_->Send(new PrintMsg_PrintingDone(printing_rfh_->GetRoutingID(),
+                                                result == kPrintSuccess));
+  Reset();
+}
+
+}  // namespace printing