extensions/browser/api/printer_provider/printer_provider_api.cc

   1 // Copyright 2015 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 "extensions/browser/api/printer_provider/printer_provider_api.h"
   6
   7 #include <map>
   8 #include <set>
   9 #include <utility>
  10 #include <vector>
  11
  12 #include "base/bind.h"
  13 #include "base/i18n/rtl.h"
  14 #include "base/json/json_string_value_serializer.h"
  15 #include "base/macros.h"
  16 #include "base/scoped_observer.h"
  17 #include "base/strings/string16.h"
  18 #include "base/strings/utf_string_conversions.h"
  19 #include "base/values.h"
  20 #include "device/usb/usb_device.h"
  21 #include "extensions/browser/api/printer_provider/printer_provider_print_job.h"
  22 #include "extensions/browser/api/printer_provider_internal/printer_provider_internal_api.h"
  23 #include "extensions/browser/api/printer_provider_internal/printer_provider_internal_api_observer.h"
  24 #include "extensions/browser/api/usb/usb_guid_map.h"
  25 #include "extensions/browser/event_router.h"
  26 #include "extensions/browser/extension_registry.h"
  27 #include "extensions/browser/extension_registry_observer.h"
  28 #include "extensions/common/api/printer_provider.h"
  29 #include "extensions/common/api/printer_provider_internal.h"
  30 #include "extensions/common/api/usb.h"
  31 #include "extensions/common/extension.h"
  32
  33 using device::UsbDevice;
  34
  35 namespace extensions {
  36
  37 namespace {
  38
  39 // The separator between extension id and the extension's internal printer id
  40 // used when generating a printer id unique across extensions.
  41 const char kPrinterIdSeparator = ':';
  42
  43 // Given an extension ID and an ID of a printer reported by the extension, it
  44 // generates a ID for the printer unique across extensions (assuming that the
  45 // printer id is unique in the extension's space).
  46 std::string GeneratePrinterId(const std::string& extension_id,
  47                               const std::string& internal_printer_id) {
  48   std::string result = extension_id;
  49   result.append(1, kPrinterIdSeparator);
  50   result.append(internal_printer_id);
  51   return result;
  52 }
  53
  54 // Parses an ID created using |GeneratePrinterId| to it's components:
  55 // the extension ID and the printer ID internal to the extension.
  56 // Returns whenter the ID was succesfully parsed.
  57 bool ParsePrinterId(const std::string& printer_id,
  58                     std::string* extension_id,
  59                     std::string* internal_printer_id) {
  60   size_t separator = printer_id.find_first_of(kPrinterIdSeparator);
  61   if (separator == std::string::npos)
  62     return false;
  63   *extension_id = printer_id.substr(0, separator);
  64   *internal_printer_id = printer_id.substr(separator + 1);
  65   return true;
  66 }
  67
  68 void UpdatePrinterWithExtensionInfo(base::DictionaryValue* printer,
  69                                     const Extension* extension) {
  70   std::string internal_printer_id;
  71   CHECK(printer->GetString("id", &internal_printer_id));
  72   printer->SetString("id",
  73                      GeneratePrinterId(extension->id(), internal_printer_id));
  74   printer->SetString("extensionId", extension->id());
  75   printer->SetString("extensionName", extension->name());
  76
  77   base::string16 printer_name;
  78   if (printer->GetString("name", &printer_name) &&
  79       base::i18n::AdjustStringForLocaleDirection(&printer_name)) {
  80     printer->SetString("name", printer_name);
  81   }
  82
  83   base::string16 printer_description;
  84   if (printer->GetString("description", &printer_description) &&
  85       base::i18n::AdjustStringForLocaleDirection(&printer_description)) {
  86     printer->SetString("description", printer_description);
  87   }
  88 }
  89
  90 // Holds information about a pending onGetPrintersRequested request;
  91 // in particular, the list of extensions to which the event was dispatched but
  92 // which haven't yet responded, and the |GetPrinters| callback associated with
  93 // the event.
  94 class GetPrintersRequest {
  95  public:
  96   explicit GetPrintersRequest(
  97       const PrinterProviderAPI::GetPrintersCallback& callback);
  98   ~GetPrintersRequest();
  99
 100   // Adds an extension id to the list of the extensions that need to respond
 101   // to the event.
 102   void AddSource(const std::string& extension_id);
 103
 104   // Whether all extensions have responded to the event.
 105   bool IsDone() const;
 106
 107   // Runs the callback for an extension and removes the extension from the
 108   // list of extensions that still have to respond to the event.
 109   void ReportForExtension(const std::string& extension_id,
 110                           const base::ListValue& printers);
 111
 112  private:
 113   // Callback reporting event result for an extension. Called once for each
 114   // extension.
 115   PrinterProviderAPI::GetPrintersCallback callback_;
 116
 117   // The list of extensions that still have to respond to the event.
 118   std::set<std::string> extensions_;
 119 };
 120
 121 // Keeps track of pending chrome.printerProvider.onGetPrintersRequested
 122 // requests.
 123 class PendingGetPrintersRequests {
 124  public:
 125   PendingGetPrintersRequests();
 126   ~PendingGetPrintersRequests();
 127
 128   // Adds a new request to the set of pending requests. Returns the id
 129   // assigned to the request.
 130   int Add(const PrinterProviderAPI::GetPrintersCallback& callback);
 131
 132   // Completes a request for an extension. It runs the request callback with
 133   // values reported by the extension.
 134   bool CompleteForExtension(const std::string& extension_id,
 135                             int request_id,
 136                             const base::ListValue& result);
 137
 138   // Runs callbacks for the extension for all requests that are waiting for a
 139   // response from the extension with the provided extension id. Callbacks are
 140   // called as if the extension reported empty set of printers.
 141   void FailAllForExtension(const std::string& extension_id);
 142
 143   // Adds an extension id to the list of the extensions that need to respond to
 144   // the event.
 145   bool AddSource(int request_id, const std::string& extension_id);
 146
 147  private:
 148   int last_request_id_;
 149   std::map<int, GetPrintersRequest> pending_requests_;
 150
 151   DISALLOW_COPY_AND_ASSIGN(PendingGetPrintersRequests);
 152 };
 153
 154 // Keeps track of pending chrome.printerProvider.onGetCapabilityRequested
 155 // requests for an extension.
 156 class PendingGetCapabilityRequests {
 157  public:
 158   PendingGetCapabilityRequests();
 159   ~PendingGetCapabilityRequests();
 160
 161   // Adds a new request to the set. Only information needed is the callback
 162   // associated with the request. Returns the id assigned to the request.
 163   int Add(const PrinterProviderAPI::GetCapabilityCallback& callback);
 164
 165   // Completes the request with the provided request id. It runs the request
 166   // callback and removes the request from the set.
 167   bool Complete(int request_id, const base::DictionaryValue& result);
 168
 169   // Runs all pending callbacks with empty capability value and clears the
 170   // set of pending requests.
 171   void FailAll();
 172
 173  private:
 174   int last_request_id_;
 175   std::map<int, PrinterProviderAPI::GetCapabilityCallback> pending_requests_;
 176 };
 177
 178 // Keeps track of pending chrome.printerProvider.onPrintRequested requests
 179 // for an extension.
 180 class PendingPrintRequests {
 181  public:
 182   PendingPrintRequests();
 183   ~PendingPrintRequests();
 184
 185   // Adds a new request to the set. Only information needed is the callback
 186   // associated with the request. Returns the id assigned to the request.
 187   int Add(const PrinterProviderPrintJob& job,
 188           const PrinterProviderAPI::PrintCallback& callback);
 189
 190   // Gets print job associated with a request.
 191   const PrinterProviderPrintJob* GetPrintJob(int request_id) const;
 192
 193   // Completes the request with the provided request id. It runs the request
 194   // callback and removes the request from the set.
 195   bool Complete(int request_id, bool success, const std::string& result);
 196
 197   // Runs all pending callbacks with ERROR_FAILED and clears the set of
 198   // pending requests.
 199   void FailAll();
 200
 201  private:
 202   struct PrintRequest {
 203     PrinterProviderAPI::PrintCallback callback;
 204     PrinterProviderPrintJob job;
 205   };
 206
 207   int last_request_id_;
 208   std::map<int, PrintRequest> pending_requests_;
 209 };
 210
 211 // Keeps track of pending chrome.printerProvider.onGetUsbPrinterInfoRequested
 212 // requests for an extension.
 213 class PendingUsbPrinterInfoRequests {
 214  public:
 215   PendingUsbPrinterInfoRequests();
 216   ~PendingUsbPrinterInfoRequests();
 217
 218   // Adds a new request to the set. Only information needed is the callback
 219   // associated with the request. Returns the id assigned to the request.
 220   int Add(const PrinterProviderAPI::GetPrinterInfoCallback& callback);
 221
 222   // Completes the request with the provided request id. It runs the request
 223   // callback and removes the request from the set.
 224   void Complete(int request_id, const base::DictionaryValue& printer_info);
 225
 226   // Runs all pending callbacks with empty capability value and clears the
 227   // set of pending requests.
 228   void FailAll();
 229
 230  private:
 231   int last_request_id_ = 0;
 232   std::map<int, PrinterProviderAPI::GetPrinterInfoCallback> pending_requests_;
 233 };
 234
 235 // Implements chrome.printerProvider API events.
 236 class PrinterProviderAPIImpl : public PrinterProviderAPI,
 237                                public PrinterProviderInternalAPIObserver,
 238                                public ExtensionRegistryObserver {
 239  public:
 240   explicit PrinterProviderAPIImpl(content::BrowserContext* browser_context);
 241   ~PrinterProviderAPIImpl() override;
 242
 243  private:
 244   // PrinterProviderAPI implementation:
 245   void DispatchGetPrintersRequested(
 246       const PrinterProviderAPI::GetPrintersCallback& callback) override;
 247   void DispatchGetCapabilityRequested(
 248       const std::string& printer_id,
 249       const PrinterProviderAPI::GetCapabilityCallback& callback) override;
 250   void DispatchPrintRequested(
 251       const PrinterProviderPrintJob& job,
 252       const PrinterProviderAPI::PrintCallback& callback) override;
 253   const PrinterProviderPrintJob* GetPrintJob(const Extension* extension,
 254                                              int request_id) const override;
 255   void DispatchGetUsbPrinterInfoRequested(
 256       const std::string& extension_id,
 257       scoped_refptr<UsbDevice> device,
 258       const PrinterProviderAPI::GetPrinterInfoCallback& callback) override;
 259
 260   // PrinterProviderInternalAPIObserver implementation:
 261   void OnGetPrintersResult(
 262       const Extension* extension,
 263       int request_id,
 264       const PrinterProviderInternalAPIObserver::PrinterInfoVector& result)
 265       override;
 266   void OnGetCapabilityResult(const Extension* extension,
 267                              int request_id,
 268                              const base::DictionaryValue& result) override;
 269   void OnPrintResult(
 270       const Extension* extension,
 271       int request_id,
 272       core_api::printer_provider_internal::PrintError error) override;
 273   void OnGetUsbPrinterInfoResult(
 274       const Extension* extension,
 275       int request_id,
 276       const core_api::printer_provider::PrinterInfo* printer_info) override;
 277
 278   // ExtensionRegistryObserver implementation:
 279   void OnExtensionUnloaded(content::BrowserContext* browser_context,
 280                            const Extension* extension,
 281                            UnloadedExtensionInfo::Reason reason) override;
 282
 283   // Called before chrome.printerProvider.onGetPrintersRequested event is
 284   // dispatched to an extension. It returns whether the extension is interested
 285   // in the event. If the extension listens to the event, it's added to the set
 286   // of |request| sources. |request| is |GetPrintersRequest| object associated
 287   // with the event.
 288   bool WillRequestPrinters(int request_id,
 289                            content::BrowserContext* browser_context,
 290                            const Extension* extension,
 291                            base::ListValue* args);
 292
 293   content::BrowserContext* browser_context_;
 294
 295   PendingGetPrintersRequests pending_get_printers_requests_;
 296
 297   std::map<std::string, PendingPrintRequests> pending_print_requests_;
 298
 299   std::map<std::string, PendingGetCapabilityRequests>
 300       pending_capability_requests_;
 301
 302   std::map<std::string, PendingUsbPrinterInfoRequests>
 303       pending_usb_printer_info_requests_;
 304
 305   ScopedObserver<PrinterProviderInternalAPI, PrinterProviderInternalAPIObserver>
 306       internal_api_observer_;
 307
 308   ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
 309       extension_registry_observer_;
 310
 311   DISALLOW_COPY_AND_ASSIGN(PrinterProviderAPIImpl);
 312 };
 313
 314 GetPrintersRequest::GetPrintersRequest(
 315     const PrinterProviderAPI::GetPrintersCallback& callback)
 316     : callback_(callback) {
 317 }
 318
 319 GetPrintersRequest::~GetPrintersRequest() {
 320 }
 321
 322 void GetPrintersRequest::AddSource(const std::string& extension_id) {
 323   extensions_.insert(extension_id);
 324 }
 325
 326 bool GetPrintersRequest::IsDone() const {
 327   return extensions_.empty();
 328 }
 329
 330 void GetPrintersRequest::ReportForExtension(const std::string& extension_id,
 331                                             const base::ListValue& printers) {
 332   if (extensions_.erase(extension_id) > 0)
 333     callback_.Run(printers, IsDone());
 334 }
 335
 336 PendingGetPrintersRequests::PendingGetPrintersRequests() : last_request_id_(0) {
 337 }
 338
 339 PendingGetPrintersRequests::~PendingGetPrintersRequests() {
 340 }
 341
 342 int PendingGetPrintersRequests::Add(
 343     const PrinterProviderAPI::GetPrintersCallback& callback) {
 344   pending_requests_.insert(
 345       std::make_pair(++last_request_id_, GetPrintersRequest(callback)));
 346   return last_request_id_;
 347 }
 348
 349 bool PendingGetPrintersRequests::CompleteForExtension(
 350     const std::string& extension_id,
 351     int request_id,
 352     const base::ListValue& result) {
 353   auto it = pending_requests_.find(request_id);
 354   if (it == pending_requests_.end())
 355     return false;
 356
 357   it->second.ReportForExtension(extension_id, result);
 358   if (it->second.IsDone()) {
 359     pending_requests_.erase(it);
 360   }
 361   return true;
 362 }
 363
 364 void PendingGetPrintersRequests::FailAllForExtension(
 365     const std::string& extension_id) {
 366   auto it = pending_requests_.begin();
 367   while (it != pending_requests_.end()) {
 368     int request_id = it->first;
 369     // |it| may get deleted during |CompleteForExtension|, so progress it to the
 370     // next item before calling the method.
 371     ++it;
 372     CompleteForExtension(extension_id, request_id, base::ListValue());
 373   }
 374 }
 375
 376 bool PendingGetPrintersRequests::AddSource(int request_id,
 377                                            const std::string& extension_id) {
 378   auto it = pending_requests_.find(request_id);
 379   if (it == pending_requests_.end())
 380     return false;
 381
 382   it->second.AddSource(extension_id);
 383   return true;
 384 }
 385
 386 PendingGetCapabilityRequests::PendingGetCapabilityRequests()
 387     : last_request_id_(0) {
 388 }
 389
 390 PendingGetCapabilityRequests::~PendingGetCapabilityRequests() {
 391 }
 392
 393 int PendingGetCapabilityRequests::Add(
 394     const PrinterProviderAPI::GetCapabilityCallback& callback) {
 395   pending_requests_[++last_request_id_] = callback;
 396   return last_request_id_;
 397 }
 398
 399 bool PendingGetCapabilityRequests::Complete(
 400     int request_id,
 401     const base::DictionaryValue& response) {
 402   auto it = pending_requests_.find(request_id);
 403   if (it == pending_requests_.end())
 404     return false;
 405
 406   PrinterProviderAPI::GetCapabilityCallback callback = it->second;
 407   pending_requests_.erase(it);
 408
 409   callback.Run(response);
 410   return true;
 411 }
 412
 413 void PendingGetCapabilityRequests::FailAll() {
 414   for (auto& request : pending_requests_)
 415     request.second.Run(base::DictionaryValue());
 416   pending_requests_.clear();
 417 }
 418
 419 PendingPrintRequests::PendingPrintRequests() : last_request_id_(0) {
 420 }
 421
 422 PendingPrintRequests::~PendingPrintRequests() {
 423 }
 424
 425 int PendingPrintRequests::Add(
 426     const PrinterProviderPrintJob& job,
 427     const PrinterProviderAPI::PrintCallback& callback) {
 428   PrintRequest request;
 429   request.callback = callback;
 430   request.job = job;
 431   pending_requests_[++last_request_id_] = request;
 432   return last_request_id_;
 433 }
 434
 435 bool PendingPrintRequests::Complete(int request_id,
 436                                     bool success,
 437                                     const std::string& response) {
 438   auto it = pending_requests_.find(request_id);
 439   if (it == pending_requests_.end())
 440     return false;
 441
 442   PrinterProviderAPI::PrintCallback callback = it->second.callback;
 443   pending_requests_.erase(it);
 444
 445   callback.Run(success, response);
 446   return true;
 447 }
 448
 449 const PrinterProviderPrintJob* PendingPrintRequests::GetPrintJob(
 450     int request_id) const {
 451   auto it = pending_requests_.find(request_id);
 452   if (it == pending_requests_.end())
 453     return nullptr;
 454
 455   return &it->second.job;
 456 }
 457
 458 void PendingPrintRequests::FailAll() {
 459   for (auto& request : pending_requests_)
 460     request.second.callback.Run(false,
 461                                 PrinterProviderAPI::GetDefaultPrintError());
 462   pending_requests_.clear();
 463 }
 464
 465 PendingUsbPrinterInfoRequests::PendingUsbPrinterInfoRequests() {
 466 }
 467
 468 PendingUsbPrinterInfoRequests::~PendingUsbPrinterInfoRequests() {
 469 }
 470
 471 int PendingUsbPrinterInfoRequests::Add(
 472     const PrinterProviderAPI::GetPrinterInfoCallback& callback) {
 473   pending_requests_[++last_request_id_] = callback;
 474   return last_request_id_;
 475 }
 476
 477 void PendingUsbPrinterInfoRequests::Complete(
 478     int request_id,
 479     const base::DictionaryValue& printer_info) {
 480   auto it = pending_requests_.find(request_id);
 481   if (it == pending_requests_.end())
 482     return;
 483
 484   PrinterProviderAPI::GetPrinterInfoCallback callback = it->second;
 485   pending_requests_.erase(it);
 486
 487   callback.Run(printer_info);
 488 }
 489
 490 void PendingUsbPrinterInfoRequests::FailAll() {
 491   for (auto& request : pending_requests_) {
 492     request.second.Run(base::DictionaryValue());
 493   }
 494   pending_requests_.clear();
 495 }
 496
 497 PrinterProviderAPIImpl::PrinterProviderAPIImpl(
 498     content::BrowserContext* browser_context)
 499     : browser_context_(browser_context),
 500       internal_api_observer_(this),
 501       extension_registry_observer_(this) {
 502   internal_api_observer_.Add(
 503       PrinterProviderInternalAPI::GetFactoryInstance()->Get(browser_context));
 504   extension_registry_observer_.Add(ExtensionRegistry::Get(browser_context));
 505 }
 506
 507 PrinterProviderAPIImpl::~PrinterProviderAPIImpl() {
 508 }
 509
 510 void PrinterProviderAPIImpl::DispatchGetPrintersRequested(
 511     const GetPrintersCallback& callback) {
 512   EventRouter* event_router = EventRouter::Get(browser_context_);
 513   if (!event_router->HasEventListener(
 514           core_api::printer_provider::OnGetPrintersRequested::kEventName)) {
 515     callback.Run(base::ListValue(), true /* done */);
 516     return;
 517   }
 518
 519   // |pending_get_printers_requests_| take ownership of |request| which gets
 520   // NULLed out. Save the pointer before passing it to the requests, as it will
 521   // be needed later on.
 522   int request_id = pending_get_printers_requests_.Add(callback);
 523
 524   scoped_ptr<base::ListValue> internal_args(new base::ListValue);
 525   // Request id is not part of the public API, but it will be massaged out in
 526   // custom bindings.
 527   internal_args->AppendInteger(request_id);
 528
 529   scoped_ptr<Event> event(
 530       new Event(events::PRINTER_PROVIDER_ON_GET_PRINTERS_REQUESTED,
 531                 core_api::printer_provider::OnGetPrintersRequested::kEventName,
 532                 internal_args.Pass()));
 533   // This callback is called synchronously during |BroadcastEvent|, so
 534   // Unretained is safe.
 535   event->will_dispatch_callback =
 536       base::Bind(&PrinterProviderAPIImpl::WillRequestPrinters,
 537                  base::Unretained(this), request_id);
 538
 539   event_router->BroadcastEvent(event.Pass());
 540 }
 541
 542 void PrinterProviderAPIImpl::DispatchGetCapabilityRequested(
 543     const std::string& printer_id,
 544     const PrinterProviderAPI::GetCapabilityCallback& callback) {
 545   std::string extension_id;
 546   std::string internal_printer_id;
 547   if (!ParsePrinterId(printer_id, &extension_id, &internal_printer_id)) {
 548     callback.Run(base::DictionaryValue());
 549     return;
 550   }
 551
 552   EventRouter* event_router = EventRouter::Get(browser_context_);
 553   if (!event_router->ExtensionHasEventListener(
 554           extension_id,
 555           core_api::printer_provider::OnGetCapabilityRequested::kEventName)) {
 556     callback.Run(base::DictionaryValue());
 557     return;
 558   }
 559
 560   int request_id = pending_capability_requests_[extension_id].Add(callback);
 561
 562   scoped_ptr<base::ListValue> internal_args(new base::ListValue);
 563   // Request id is not part of the public API, but it will be massaged out in
 564   // custom bindings.
 565   internal_args->AppendInteger(request_id);
 566   internal_args->AppendString(internal_printer_id);
 567
 568   scoped_ptr<Event> event(new Event(
 569       events::PRINTER_PROVIDER_ON_GET_CAPABILITY_REQUESTED,
 570       core_api::printer_provider::OnGetCapabilityRequested::kEventName,
 571       internal_args.Pass()));
 572
 573   event_router->DispatchEventToExtension(extension_id, event.Pass());
 574 }
 575
 576 void PrinterProviderAPIImpl::DispatchPrintRequested(
 577     const PrinterProviderPrintJob& job,
 578     const PrinterProviderAPI::PrintCallback& callback) {
 579   std::string extension_id;
 580   std::string internal_printer_id;
 581   if (!ParsePrinterId(job.printer_id, &extension_id, &internal_printer_id)) {
 582     callback.Run(false, PrinterProviderAPI::GetDefaultPrintError());
 583     return;
 584   }
 585
 586   EventRouter* event_router = EventRouter::Get(browser_context_);
 587   if (!event_router->ExtensionHasEventListener(
 588           extension_id,
 589           core_api::printer_provider::OnPrintRequested::kEventName)) {
 590     callback.Run(false, PrinterProviderAPI::GetDefaultPrintError());
 591     return;
 592   }
 593
 594   core_api::printer_provider::PrintJob print_job;
 595   print_job.printer_id = internal_printer_id;
 596
 597   JSONStringValueDeserializer deserializer(job.ticket_json);
 598   scoped_ptr<base::Value> ticket_value(deserializer.Deserialize(NULL, NULL));
 599   if (!ticket_value ||
 600       !core_api::printer_provider::PrintJob::Ticket::Populate(
 601           *ticket_value, &print_job.ticket)) {
 602     callback.Run(false,
 603                  core_api::printer_provider::ToString(
 604                      core_api::printer_provider::PRINT_ERROR_INVALID_TICKET));
 605     return;
 606   }
 607
 608   print_job.content_type = job.content_type;
 609   print_job.title = base::UTF16ToUTF8(job.job_title);
 610   int request_id = pending_print_requests_[extension_id].Add(job, callback);
 611
 612   scoped_ptr<base::ListValue> internal_args(new base::ListValue);
 613   // Request id is not part of the public API and it will be massaged out in
 614   // custom bindings.
 615   internal_args->AppendInteger(request_id);
 616   internal_args->Append(print_job.ToValue().release());
 617   scoped_ptr<Event> event(
 618       new Event(events::PRINTER_PROVIDER_ON_PRINT_REQUESTED,
 619                 core_api::printer_provider::OnPrintRequested::kEventName,
 620                 internal_args.Pass()));
 621   event_router->DispatchEventToExtension(extension_id, event.Pass());
 622 }
 623
 624 const PrinterProviderPrintJob* PrinterProviderAPIImpl::GetPrintJob(
 625     const Extension* extension,
 626     int request_id) const {
 627   auto it = pending_print_requests_.find(extension->id());
 628   if (it == pending_print_requests_.end())
 629     return nullptr;
 630   return it->second.GetPrintJob(request_id);
 631 }
 632
 633 void PrinterProviderAPIImpl::DispatchGetUsbPrinterInfoRequested(
 634     const std::string& extension_id,
 635     scoped_refptr<UsbDevice> device,
 636     const PrinterProviderAPI::GetPrinterInfoCallback& callback) {
 637   EventRouter* event_router = EventRouter::Get(browser_context_);
 638   if (!event_router->ExtensionHasEventListener(
 639           extension_id, core_api::printer_provider::
 640                             OnGetUsbPrinterInfoRequested::kEventName)) {
 641     callback.Run(base::DictionaryValue());
 642     return;
 643   }
 644
 645   int request_id =
 646       pending_usb_printer_info_requests_[extension_id].Add(callback);
 647   core_api::usb::Device usb_device;
 648   usb_device.device =
 649       UsbGuidMap::Get(browser_context_)->GetIdFromGuid(device->guid());
 650   usb_device.vendor_id = device->vendor_id();
 651   usb_device.product_id = device->product_id();
 652
 653   scoped_ptr<base::ListValue> internal_args(new base::ListValue);
 654   // Request id is not part of the public API and it will be massaged out in
 655   // custom bindings.
 656   internal_args->AppendInteger(request_id);
 657   internal_args->Append(usb_device.ToValue().release());
 658   scoped_ptr<Event> event(new Event(
 659       events::PRINTER_PROVIDER_ON_GET_USB_PRINTER_INFO_REQUESTED,
 660       core_api::printer_provider::OnGetUsbPrinterInfoRequested::kEventName,
 661       internal_args.Pass()));
 662   event_router->DispatchEventToExtension(extension_id, event.Pass());
 663 }
 664
 665 void PrinterProviderAPIImpl::OnGetPrintersResult(
 666     const Extension* extension,
 667     int request_id,
 668     const PrinterProviderInternalAPIObserver::PrinterInfoVector& result) {
 669   base::ListValue printer_list;
 670
 671   // Update some printer description properties to better identify the extension
 672   // managing the printer.
 673   for (size_t i = 0; i < result.size(); ++i) {
 674     scoped_ptr<base::DictionaryValue> printer(result[i]->ToValue());
 675     UpdatePrinterWithExtensionInfo(printer.get(), extension);
 676     printer_list.Append(printer.Pass());
 677   }
 678
 679   pending_get_printers_requests_.CompleteForExtension(extension->id(),
 680                                                       request_id, printer_list);
 681 }
 682
 683 void PrinterProviderAPIImpl::OnGetCapabilityResult(
 684     const Extension* extension,
 685     int request_id,
 686     const base::DictionaryValue& result) {
 687   pending_capability_requests_[extension->id()].Complete(request_id, result);
 688 }
 689
 690 void PrinterProviderAPIImpl::OnPrintResult(
 691     const Extension* extension,
 692     int request_id,
 693     core_api::printer_provider_internal::PrintError error) {
 694   const std::string error_str =
 695       error == core_api::printer_provider_internal::PRINT_ERROR_NONE
 696           ? PrinterProviderAPI::GetDefaultPrintError()
 697           : core_api::printer_provider_internal::ToString(error);
 698   pending_print_requests_[extension->id()].Complete(
 699       request_id, error == core_api::printer_provider_internal::PRINT_ERROR_OK,
 700       error_str);
 701 }
 702
 703 void PrinterProviderAPIImpl::OnGetUsbPrinterInfoResult(
 704     const Extension* extension,
 705     int request_id,
 706     const core_api::printer_provider::PrinterInfo* result) {
 707   if (result) {
 708     scoped_ptr<base::DictionaryValue> printer(result->ToValue());
 709     UpdatePrinterWithExtensionInfo(printer.get(), extension);
 710     pending_usb_printer_info_requests_[extension->id()].Complete(request_id,
 711                                                                  *printer);
 712   } else {
 713     pending_usb_printer_info_requests_[extension->id()].Complete(
 714         request_id, base::DictionaryValue());
 715   }
 716 }
 717
 718 void PrinterProviderAPIImpl::OnExtensionUnloaded(
 719     content::BrowserContext* browser_context,
 720     const Extension* extension,
 721     UnloadedExtensionInfo::Reason reason) {
 722   pending_get_printers_requests_.FailAllForExtension(extension->id());
 723
 724   auto print_it = pending_print_requests_.find(extension->id());
 725   if (print_it != pending_print_requests_.end()) {
 726     print_it->second.FailAll();
 727     pending_print_requests_.erase(print_it);
 728   }
 729
 730   auto capability_it = pending_capability_requests_.find(extension->id());
 731   if (capability_it != pending_capability_requests_.end()) {
 732     capability_it->second.FailAll();
 733     pending_capability_requests_.erase(capability_it);
 734   }
 735
 736   auto usb_it = pending_usb_printer_info_requests_.find(extension->id());
 737   if (usb_it != pending_usb_printer_info_requests_.end()) {
 738     usb_it->second.FailAll();
 739     pending_usb_printer_info_requests_.erase(usb_it);
 740   }
 741 }
 742
 743 bool PrinterProviderAPIImpl::WillRequestPrinters(
 744     int request_id,
 745     content::BrowserContext* browser_context,
 746     const Extension* extension,
 747     base::ListValue* args) {
 748   if (!extension)
 749     return false;
 750   EventRouter* event_router = EventRouter::Get(browser_context_);
 751   if (!event_router->ExtensionHasEventListener(
 752           extension->id(),
 753           core_api::printer_provider::OnGetPrintersRequested::kEventName)) {
 754     return false;
 755   }
 756
 757   return pending_get_printers_requests_.AddSource(request_id, extension->id());
 758 }
 759
 760 }  // namespace
 761
 762 // static
 763 PrinterProviderAPI* PrinterProviderAPI::Create(
 764     content::BrowserContext* context) {
 765   return new PrinterProviderAPIImpl(context);
 766 }
 767
 768 // static
 769 std::string PrinterProviderAPI::GetDefaultPrintError() {
 770   return core_api::printer_provider_internal::ToString(
 771       core_api::printer_provider_internal::PRINT_ERROR_FAILED);
 772 }
 773
 774 }  // namespace extensions