Index: chrome/browser/chromeos/printing/printer_discoverer.cc |
diff --git a/chrome/browser/chromeos/printing/printer_discoverer.cc b/chrome/browser/chromeos/printing/printer_discoverer.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..e6f91591cd6080de08144e1cabeaae076bc3bf26 |
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+++ b/chrome/browser/chromeos/printing/printer_discoverer.cc |
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+// 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 "chrome/browser/chromeos/printing/printer_discoverer.h" |
+ |
+#include "base/bind.h" |
+#include "base/memory/ptr_util.h" |
+#include "base/memory/weak_ptr.h" |
+#include "base/observer_list.h" |
+#include "base/scoped_observer.h" |
+#include "base/threading/sequenced_task_runner_handle.h" |
+#include "chrome/browser/chromeos/printer_detector/printer_detector.h" |
+#include "chrome/browser/chromeos/printer_detector/printer_detector_factory.h" |
+#include "chrome/browser/chromeos/printing/printers_manager.h" |
+#include "chrome/browser/chromeos/printing/printers_manager_factory.h" |
+#include "chrome/browser/profiles/profile.h" |
+#include "chromeos/printing/printer_configuration.h" |
+ |
+namespace chromeos { |
+namespace { |
+ |
+// Implementation of PrinterDiscoverer interface. |
+class PrinterDiscovererImpl : public PrinterDiscoverer, |
+ public PrinterDetector::Observer { |
+ public: |
+ explicit PrinterDiscovererImpl(Profile* profile) |
+ : detector_observer_(this), profile_(profile), weak_ptr_factory_(this) { |
+ PrinterDetector* detector = |
+ PrinterDetectorFactory::GetInstance()->Get(profile); |
+ DCHECK(detector); |
+ detector_observer_.Add(detector); |
+ usb_printers_ = detector->GetPrinters(); |
+ } |
+ ~PrinterDiscovererImpl() override = default; |
+ |
+ // PrinterDiscoverer interface function. |
+ void AddObserver(PrinterDiscoverer::Observer* observer) override { |
+ observer_list_.AddObserver(observer); |
+ // WrappedOnPrintersFound is a simple wrapper around |
+ // Observer::OnPrintersFound which lets us safely do the initial |
+ // OnPrintersFound call to the registered observer. This wrapper buys us |
+ // weak_ptr semantics on 'this', and also guards against removal of the |
+ // observer from the Discoverer before this callback is issued. |
+ base::SequencedTaskRunnerHandle::Get()->PostTask( |
+ FROM_HERE, base::Bind(&PrinterDiscovererImpl::WrappedOnPrintersFound, |
+ weak_ptr_factory_.GetWeakPtr(), observer, |
+ GetAvailablePrinters())); |
+ } |
+ |
+ // PrinterDiscoverer interface function. |
+ void RemoveObserver(PrinterDiscoverer::Observer* observer) override { |
+ observer_list_.RemoveObserver(observer); |
+ } |
+ |
+ // PrinterDetector::Observer interface function. |
+ void OnAvailableUsbPrintersChanged( |
+ const std::vector<Printer>& printers) override { |
+ usb_printers_ = printers; |
+ std::vector<Printer> all_printers = GetAvailablePrinters(); |
+ for (PrinterDiscoverer::Observer& observer : observer_list_) { |
+ observer.OnPrintersFound(all_printers); |
+ } |
+ } |
+ |
+ private: |
+ // Wrapper for doing the initial OnPrintersFound call on an observer of this |
+ // object. |
+ void WrappedOnPrintersFound(PrinterDiscoverer::Observer* observer, |
+ const std::vector<Printer>& printers) { |
+ if (observer_list_.HasObserver(observer)) { |
+ observer->OnPrintersFound(printers); |
+ // Since USB is the only thing we're worried about at the moment, and we |
+ // don't have to wait for those printers to be scanned, we can just tell |
+ // the observer the initial scan is done now. This will change when we're |
+ // also doing network discovery -- we'll hold off on issuing this callback |
+ // until the network discovery is done as well. |
+ observer->OnDiscoveryInitialScanDone(); |
+ } |
+ } |
+ |
+ // Get the current set of discovered printers that are not already known |
+ // to the user's PrintersManager. |
+ std::vector<Printer> GetAvailablePrinters() { |
+ // Only know about usb printers for now. Eventually we'll add discovered |
+ // network printers as well. |
+ std::vector<Printer> ret; |
+ PrintersManager* printers_manager = |
+ PrintersManagerFactory::GetForBrowserContext(profile_); |
+ if (!printers_manager) { |
+ LOG(WARNING) << "Failing to get available printers because no " |
+ "PrintersManager exists."; |
+ return ret; |
+ } |
+ |
+ for (const Printer& printer : usb_printers_) { |
+ if (printers_manager->GetPrinter(printer.id()).get() == nullptr) { |
+ ret.push_back(printer); |
+ } |
+ } |
+ return ret; |
+ } |
+ |
+ std::vector<Printer> usb_printers_; |
+ base::ObserverList<PrinterDiscoverer::Observer> observer_list_; |
+ ScopedObserver<PrinterDetector, PrinterDetector::Observer> detector_observer_; |
+ Profile* profile_; |
+ base::WeakPtrFactory<PrinterDiscovererImpl> weak_ptr_factory_; |
+}; |
+ |
+} // namespace |
+ |
+// static |
+std::unique_ptr<PrinterDiscoverer> PrinterDiscoverer::CreateForProfile( |
+ Profile* profile) { |
+ return base::MakeUnique<PrinterDiscovererImpl>(profile); |
+} |
+ |
+} // namespace chromeos |