src/chrome/browser/printing/printer_query.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 "chrome/browser/printing/printer_query.h"
   6
   7 #include "base/bind.h"
   8 #include "base/bind_helpers.h"
   9 #include "base/message_loop/message_loop.h"
  10 #include "base/threading/thread_restrictions.h"
  11 #include "base/values.h"
  12 #include "chrome/browser/printing/print_job_worker.h"
  13 #include "chrome/browser/printing/printing_ui_web_contents_observer.h"
  14
  15 namespace printing {
  16
  17 PrinterQuery::PrinterQuery()
  18     : io_message_loop_(base::MessageLoop::current()),
  19       worker_(new PrintJobWorker(this)),
  20       is_print_dialog_box_shown_(false),
  21       cookie_(PrintSettings::NewCookie()),
  22       last_status_(PrintingContext::FAILED) {
  23   DCHECK(base::MessageLoopForIO::IsCurrent());
  24 }
  25
  26 PrinterQuery::~PrinterQuery() {
  27   // The job should be finished (or at least canceled) when it is destroyed.
  28   DCHECK(!is_print_dialog_box_shown_);
  29   // If this fires, it is that this pending printer context has leaked.
  30   DCHECK(!worker_.get());
  31 }
  32
  33 void PrinterQuery::GetSettingsDone(const PrintSettings& new_settings,
  34                                    PrintingContext::Result result) {
  35   is_print_dialog_box_shown_ = false;
  36   last_status_ = result;
  37   if (result != PrintingContext::FAILED) {
  38     settings_ = new_settings;
  39     cookie_ = PrintSettings::NewCookie();
  40   } else {
  41     // Failure.
  42     cookie_ = 0;
  43   }
  44
  45   if (!callback_.is_null()) {
  46     // This may cause reentrancy like to call StopWorker().
  47     callback_.Run();
  48     callback_.Reset();
  49   }
  50 }
  51
  52 PrintJobWorker* PrinterQuery::DetachWorker(PrintJobWorkerOwner* new_owner) {
  53   DCHECK(callback_.is_null());
  54   DCHECK(worker_.get());
  55
  56   worker_->SetNewOwner(new_owner);
  57   return worker_.release();
  58 }
  59
  60 base::MessageLoop* PrinterQuery::message_loop() {
  61   return io_message_loop_;
  62 }
  63
  64 const PrintSettings& PrinterQuery::settings() const {
  65   return settings_;
  66 }
  67
  68 int PrinterQuery::cookie() const {
  69   return cookie_;
  70 }
  71
  72 void PrinterQuery::GetSettings(
  73     GetSettingsAskParam ask_user_for_settings,
  74     scoped_ptr<PrintingUIWebContentsObserver> web_contents_observer,
  75     int expected_page_count,
  76     bool has_selection,
  77     MarginType margin_type,
  78     const base::Closure& callback) {
  79   DCHECK_EQ(io_message_loop_, base::MessageLoop::current());
  80   DCHECK(!is_print_dialog_box_shown_);
  81
  82   StartWorker(callback);
  83
  84   // Real work is done in PrintJobWorker::GetSettings().
  85   is_print_dialog_box_shown_ = ask_user_for_settings == ASK_USER;
  86   worker_->message_loop()->PostTask(
  87       FROM_HERE,
  88       base::Bind(&PrintJobWorker::GetSettings,
  89                  base::Unretained(worker_.get()),
  90                  is_print_dialog_box_shown_,
  91                  base::Passed(&web_contents_observer),
  92                  expected_page_count,
  93                  has_selection,
  94                  margin_type));
  95 }
  96
  97 void PrinterQuery::SetSettings(const base::DictionaryValue& new_settings,
  98                                const base::Closure& callback) {
  99   StartWorker(callback);
 100
 101   worker_->message_loop()->PostTask(
 102       FROM_HERE,
 103       base::Bind(&PrintJobWorker::SetSettings,
 104                  base::Unretained(worker_.get()),
 105                  new_settings.DeepCopy()));
 106 }
 107
 108 void PrinterQuery::SetWorkerDestination(
 109     PrintDestinationInterface* destination) {
 110   worker_->SetPrintDestination(destination);
 111 }
 112
 113 void PrinterQuery::StartWorker(const base::Closure& callback) {
 114   DCHECK(callback_.is_null());
 115   DCHECK(worker_.get());
 116
 117   // Lazily create the worker thread. There is one worker thread per print job.
 118   if (!worker_->message_loop())
 119     worker_->Start();
 120
 121   callback_ = callback;
 122 }
 123
 124 void PrinterQuery::StopWorker() {
 125   if (worker_.get()) {
 126     // http://crbug.com/66082: We're blocking on the PrinterQuery's worker
 127     // thread.  It's not clear to me if this may result in blocking the current
 128     // thread for an unacceptable time.  We should probably fix it.
 129     base::ThreadRestrictions::ScopedAllowIO allow_io;
 130     worker_->Stop();
 131     worker_.reset();
 132   }
 133 }
 134
 135 bool PrinterQuery::is_callback_pending() const {
 136   return !callback_.is_null();
 137 }
 138
 139 bool PrinterQuery::is_valid() const {
 140   return worker_.get() != NULL;
 141 }
 142
 143 }  // namespace printing