electron/chromium_src/chrome/browser/printing/print_job.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 "chrome/browser/printing/print_job.h"

#include <memory>
#include <utility>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/location.h"
#include "base/memory/ptr_util.h"
#include "base/message_loop/message_loop.h"
#include "base/run_loop.h"
#include "base/single_thread_task_runner.h"
#include "base/threading/sequenced_worker_pool.h"
#include "base/threading/thread_restrictions.h"
#include "base/threading/thread_task_runner_handle.h"
#include "base/threading/worker_pool.h"
#include "build/build_config.h"
#include "chrome/browser/chrome_notification_types.h"
#include "chrome/browser/printing/print_job_worker.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/notification_service.h"
#include "printing/printed_document.h"
#include "printing/printed_page.h"

#if defined(OS_WIN)
#include "chrome/browser/printing/pdf_to_emf_converter.h"
#include "printing/pdf_render_settings.h"
#endif

using base::TimeDelta;

namespace printing {

namespace {

// Helper function to ensure |owner| is valid until at least |callback| returns.
void HoldRefCallback(const scoped_refptr<PrintJobWorkerOwner>& owner,
                     const base::Closure& callback) {
  callback.Run();
}

}  // namespace

PrintJob::PrintJob()
    : source_(nullptr),
      is_job_pending_(false),
      is_canceling_(false),
      quit_factory_(this) {
  // This is normally a UI message loop, but in unit tests, the message loop is
  // of the 'default' type.
  DCHECK(base::MessageLoopForUI::IsCurrent() ||
         base::MessageLoop::current()->type() ==
             base::MessageLoop::TYPE_DEFAULT);
}

PrintJob::~PrintJob() {
  // The job should be finished (or at least canceled) when it is destroyed.
  DCHECK(!is_job_pending_);
  DCHECK(!is_canceling_);
  DCHECK(!worker_ || !worker_->IsRunning());
  DCHECK(RunsTasksOnCurrentThread());
}

void PrintJob::Initialize(PrintJobWorkerOwner* job,
                          PrintedPagesSource* source,
                          int page_count) {
  DCHECK(!source_);
  DCHECK(!worker_);
  DCHECK(!is_job_pending_);
  DCHECK(!is_canceling_);
  DCHECK(!document_.get());
  source_ = source;
  worker_ = job->DetachWorker(this);
  settings_ = job->settings();

  PrintedDocument* new_doc =
      new PrintedDocument(settings_,
                          source_,
                          job->cookie(),
                          content::BrowserThread::GetBlockingPool());
  new_doc->set_page_count(page_count);
  UpdatePrintedDocument(new_doc);

  // Don't forget to register to our own messages.
  registrar_.Add(this, chrome::NOTIFICATION_PRINT_JOB_EVENT,
                 content::Source<PrintJob>(this));
}

void PrintJob::Observe(int type,
                       const content::NotificationSource& source,
                       const content::NotificationDetails& details) {
  DCHECK(RunsTasksOnCurrentThread());
  DCHECK_EQ(chrome::NOTIFICATION_PRINT_JOB_EVENT, type);

  OnNotifyPrintJobEvent(*content::Details<JobEventDetails>(details).ptr());
}

void PrintJob::GetSettingsDone(const PrintSettings& new_settings,
                               PrintingContext::Result result) {
  NOTREACHED();
}

std::unique_ptr<PrintJobWorker> PrintJob::DetachWorker(
    PrintJobWorkerOwner* new_owner) {
  NOTREACHED();
  return nullptr;
}

const PrintSettings& PrintJob::settings() const {
  return settings_;
}

int PrintJob::cookie() const {
  // Always use an invalid cookie in this case.
  if (!document_.get())
    return 0;
  return document_->cookie();
}

void PrintJob::StartPrinting() {
  DCHECK(RunsTasksOnCurrentThread());
  if (!worker_->IsRunning() || is_job_pending_) {
    NOTREACHED();
    return;
  }

  // Real work is done in PrintJobWorker::StartPrinting().
  worker_->PostTask(FROM_HERE,
                    base::Bind(&HoldRefCallback, make_scoped_refptr(this),
                               base::Bind(&PrintJobWorker::StartPrinting,
                                          base::Unretained(worker_.get()),
                                          base::RetainedRef(document_))));
  // Set the flag right now.
  is_job_pending_ = true;

  // Tell everyone!
  scoped_refptr<JobEventDetails> details(
      new JobEventDetails(JobEventDetails::NEW_DOC, document_.get(), nullptr));
  content::NotificationService::current()->Notify(
      chrome::NOTIFICATION_PRINT_JOB_EVENT,
      content::Source<PrintJob>(this),
      content::Details<JobEventDetails>(details.get()));
}

void PrintJob::Stop() {
  DCHECK(RunsTasksOnCurrentThread());

  if (quit_factory_.HasWeakPtrs()) {
    // In case we're running a nested message loop to wait for a job to finish,
    // and we finished before the timeout, quit the nested loop right away.
    Quit();
    quit_factory_.InvalidateWeakPtrs();
  }

  // Be sure to live long enough.
  scoped_refptr<PrintJob> handle(this);

  if (worker_->IsRunning()) {
    ControlledWorkerShutdown();
  } else {
    // Flush the cached document.
    is_job_pending_ = false;
    UpdatePrintedDocument(nullptr);
  }
}

void PrintJob::Cancel() {
  if (is_canceling_)
    return;
  is_canceling_ = true;

  // Be sure to live long enough.
  scoped_refptr<PrintJob> handle(this);

  DCHECK(RunsTasksOnCurrentThread());
  if (worker_ && worker_->IsRunning()) {
    // Call this right now so it renders the context invalid. Do not use
    // InvokeLater since it would take too much time.
    worker_->Cancel();
  }
  // Make sure a Cancel() is broadcast.
  scoped_refptr<JobEventDetails> details(
      new JobEventDetails(JobEventDetails::FAILED, nullptr, nullptr));
  content::NotificationService::current()->Notify(
      chrome::NOTIFICATION_PRINT_JOB_EVENT,
      content::Source<PrintJob>(this),
      content::Details<JobEventDetails>(details.get()));
  Stop();
  is_canceling_ = false;
}

bool PrintJob::FlushJob(base::TimeDelta timeout) {
  // Make sure the object outlive this message loop.
  scoped_refptr<PrintJob> handle(this);

  base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
      FROM_HERE, base::Bind(&PrintJob::Quit, quit_factory_.GetWeakPtr()),
      timeout);

  base::MessageLoop::ScopedNestableTaskAllower allow(
      base::MessageLoop::current());
  base::RunLoop().Run();

  return true;
}

void PrintJob::DisconnectSource() {
  source_ = nullptr;
  if (document_.get())
    document_->DisconnectSource();
}

bool PrintJob::is_job_pending() const {
  return is_job_pending_;
}

PrintedDocument* PrintJob::document() const {
  return document_.get();
}

#if defined(OS_WIN)
class PrintJob::PdfConversionState {
 public:
  PdfConversionState(gfx::Size page_size, gfx::Rect content_area)
      : page_count_(0),
        current_page_(0),
        pages_in_progress_(0),
        page_size_(page_size),
        content_area_(content_area) {}

  void Start(const scoped_refptr<base::RefCountedMemory>& data,
             const PdfRenderSettings& conversion_settings,
             const PdfConverter::StartCallback& start_callback) {
    converter_ = PdfConverter::StartPdfConverter(
          data, conversion_settings, start_callback);
  }

  void GetMorePages(const PdfConverter::GetPageCallback& get_page_callback) {
    const int kMaxNumberOfTempFilesPerDocument = 3;
    while (pages_in_progress_ < kMaxNumberOfTempFilesPerDocument &&
           current_page_ < page_count_) {
      ++pages_in_progress_;
      converter_->GetPage(current_page_++, get_page_callback);
    }
  }

  void OnPageProcessed(const PdfConverter::GetPageCallback& get_page_callback) {
    --pages_in_progress_;
    GetMorePages(get_page_callback);
    // Release converter if we don't need this any more.
    if (!pages_in_progress_ && current_page_ >= page_count_)
      converter_.reset();
  }

  void set_page_count(int page_count) { page_count_ = page_count; }
  gfx::Size page_size() const { return page_size_; }
  gfx::Rect content_area() const { return content_area_; }

 private:
  int page_count_;
  int current_page_;
  int pages_in_progress_;
  gfx::Size page_size_;
  gfx::Rect content_area_;
  std::unique_ptr<PdfConverter> converter_;
};

void PrintJob::AppendPrintedPage(int page_number) {
  pdf_page_mapping_.push_back(page_number);
}

void PrintJob::StartPdfToEmfConversion(
    const scoped_refptr<base::RefCountedMemory>& bytes,
    const gfx::Size& page_size,
    const gfx::Rect& content_area,
    bool print_text_with_gdi) {
  DCHECK(!pdf_conversion_state_);
  pdf_conversion_state_ =
      base::MakeUnique<PdfConversionState>(page_size, content_area);
  const int kPrinterDpi = settings().dpi();
  PdfRenderSettings settings(
      content_area, gfx::Point(0, 0), kPrinterDpi, /*autorotate=*/true,
      print_text_with_gdi ? PdfRenderSettings::Mode::GDI_TEXT
                          : PdfRenderSettings::Mode::NORMAL);
  pdf_conversion_state_->Start(
      bytes, settings, base::Bind(&PrintJob::OnPdfConversionStarted, this));
}

void PrintJob::OnPdfConversionStarted(int page_count) {
  if (page_count <= 0) {
    pdf_conversion_state_.reset();
    Cancel();
    return;
  }
  pdf_conversion_state_->set_page_count(page_count);
  pdf_conversion_state_->GetMorePages(
      base::Bind(&PrintJob::OnPdfPageConverted, this));
}

void PrintJob::OnPdfPageConverted(int page_number,
                                  float scale_factor,
                                  std::unique_ptr<MetafilePlayer> metafile) {
  DCHECK(pdf_conversion_state_);
  if (!document_.get() || !metafile || page_number < 0 ||
      static_cast<size_t>(page_number) >= pdf_page_mapping_.size()) {
    pdf_conversion_state_.reset();
    Cancel();
    return;
  }

  // Update the rendered document. It will send notifications to the listener.
  document_->SetPage(pdf_page_mapping_[page_number], std::move(metafile),
                     scale_factor, pdf_conversion_state_->page_size(),
                     pdf_conversion_state_->content_area());

  pdf_conversion_state_->GetMorePages(
      base::Bind(&PrintJob::OnPdfPageConverted, this));
}

void PrintJob::StartPdfToPostScriptConversion(
    const scoped_refptr<base::RefCountedMemory>& bytes,
    const gfx::Rect& content_area,
    const gfx::Point& physical_offsets,
    bool ps_level2) {
  DCHECK(!pdf_conversion_state_);
  pdf_conversion_state_ = base::MakeUnique<PdfConversionState>(
      gfx::Size(), gfx::Rect());
  const int kPrinterDpi = settings().dpi();
  PdfRenderSettings settings(
      content_area, physical_offsets, kPrinterDpi, true /* autorotate? */,
      ps_level2 ? PdfRenderSettings::Mode::POSTSCRIPT_LEVEL2
                : PdfRenderSettings::Mode::POSTSCRIPT_LEVEL3);
  pdf_conversion_state_->Start(
      bytes, settings, base::Bind(&PrintJob::OnPdfConversionStarted, this));
}

#endif  // defined(OS_WIN)

void PrintJob::UpdatePrintedDocument(PrintedDocument* new_document) {
  if (document_.get() == new_document)
    return;

  document_ = new_document;

  if (document_.get())
    settings_ = document_->settings();

  if (worker_) {
    DCHECK(!is_job_pending_);
    // Sync the document with the worker.
    worker_->PostTask(FROM_HERE,
                      base::Bind(&HoldRefCallback, make_scoped_refptr(this),
                                 base::Bind(&PrintJobWorker::OnDocumentChanged,
                                            base::Unretained(worker_.get()),
                                            base::RetainedRef(document_))));
  }
}

void PrintJob::OnNotifyPrintJobEvent(const JobEventDetails& event_details) {
  switch (event_details.type()) {
    case JobEventDetails::FAILED: {
      settings_.Clear();
      // No need to cancel since the worker already canceled itself.
      Stop();
      break;
    }
    case JobEventDetails::USER_INIT_DONE:
    case JobEventDetails::DEFAULT_INIT_DONE:
    case JobEventDetails::USER_INIT_CANCELED: {
      DCHECK_EQ(event_details.document(), document_.get());
      break;
    }
    case JobEventDetails::NEW_DOC:
    case JobEventDetails::NEW_PAGE:
    case JobEventDetails::JOB_DONE:
    case JobEventDetails::ALL_PAGES_REQUESTED: {
      // Don't care.
      break;
    }
    case JobEventDetails::DOC_DONE: {
      // This will call Stop() and broadcast a JOB_DONE message.
      base::ThreadTaskRunnerHandle::Get()->PostTask(
          FROM_HERE, base::Bind(&PrintJob::OnDocumentDone, this));
      break;
    }
    case JobEventDetails::PAGE_DONE:
#if defined(OS_WIN)
      if (pdf_conversion_state_) {
        pdf_conversion_state_->OnPageProcessed(
            base::Bind(&PrintJob::OnPdfPageConverted, this));
      }
#endif  // defined(OS_WIN)
      break;
    default: {
      NOTREACHED();
      break;
    }
  }
}

void PrintJob::OnDocumentDone() {
  // Be sure to live long enough. The instance could be destroyed by the
  // JOB_DONE broadcast.
  scoped_refptr<PrintJob> handle(this);

  // Stop the worker thread.
  Stop();

  scoped_refptr<JobEventDetails> details(
      new JobEventDetails(JobEventDetails::JOB_DONE, document_.get(), nullptr));
  content::NotificationService::current()->Notify(
      chrome::NOTIFICATION_PRINT_JOB_EVENT,
      content::Source<PrintJob>(this),
      content::Details<JobEventDetails>(details.get()));
}

void PrintJob::ControlledWorkerShutdown() {
  DCHECK(RunsTasksOnCurrentThread());

  // The deadlock this code works around is specific to window messaging on
  // Windows, so we aren't likely to need it on any other platforms.
#if defined(OS_WIN)
  // We could easily get into a deadlock case if worker_->Stop() is used; the
  // printer driver created a window as a child of the browser window. By
  // canceling the job, the printer driver initiated dialog box is destroyed,
  // which sends a blocking message to its parent window. If the browser window
  // thread is not processing messages, a deadlock occurs.
  //
  // This function ensures that the dialog box will be destroyed in a timely
  // manner by the mere fact that the thread will terminate. So the potential
  // deadlock is eliminated.
  worker_->StopSoon();

  // Delay shutdown until the worker terminates.  We want this code path
  // to wait on the thread to quit before continuing.
  if (worker_->IsRunning()) {
    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
        FROM_HERE, base::Bind(&PrintJob::ControlledWorkerShutdown, this),
        base::TimeDelta::FromMilliseconds(100));
    return;
  }
#endif


  // Now make sure the thread object is cleaned up. Do this on a worker
  // thread because it may block.
  base::WorkerPool::PostTaskAndReply(
      FROM_HERE,
      base::Bind(&PrintJobWorker::Stop, base::Unretained(worker_.get())),
      base::Bind(&PrintJob::HoldUntilStopIsCalled, this),
      false);

  is_job_pending_ = false;
  registrar_.RemoveAll();
  UpdatePrintedDocument(nullptr);
}

void PrintJob::HoldUntilStopIsCalled() {
}

void PrintJob::Quit() {
  base::MessageLoop::current()->QuitWhenIdle();
}

// Takes settings_ ownership and will be deleted in the receiving thread.
JobEventDetails::JobEventDetails(Type type,
                                 PrintedDocument* document,
                                 PrintedPage* page)
    : document_(document),
      page_(page),
      type_(type) {
}

JobEventDetails::~JobEventDetails() {
}

PrintedDocument* JobEventDetails::document() const { return document_.get(); }

PrintedPage* JobEventDetails::page() const { return page_.get(); }

}  // namespace printing