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1 // Copyright 2017 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/chromeos/printing/printer_discoverer.h" | |
6 | |
7 #include "base/bind.h" | |
8 #include "base/memory/ptr_util.h" | |
9 #include "base/memory/weak_ptr.h" | |
10 #include "base/observer_list.h" | |
11 #include "base/scoped_observer.h" | |
12 #include "base/threading/sequenced_task_runner_handle.h" | |
13 #include "chrome/browser/chromeos/printer_detector/printer_detector.h" | |
14 #include "chrome/browser/chromeos/printer_detector/printer_detector_factory.h" | |
15 #include "chrome/browser/chromeos/printing/printers_manager.h" | |
16 #include "chrome/browser/chromeos/printing/printers_manager_factory.h" | |
17 #include "chrome/browser/profiles/profile.h" | |
18 #include "chromeos/printing/printer_configuration.h" | |
19 | |
20 namespace chromeos { | |
21 namespace { | |
22 | |
23 // Implementation of PrinterDiscoverer interface. | |
24 class PrinterDiscovererImpl : public PrinterDiscoverer, | |
25 public PrinterDetector::Observer { | |
26 public: | |
27 explicit PrinterDiscovererImpl(Profile* profile) | |
28 : observer_(this), | |
29 printers_manager_( | |
30 PrintersManagerFactory::GetForBrowserContext(profile)), | |
stevenjb
2017/04/10 19:49:55
Even though this class is associated with |profile
Carlson
2017/04/10 22:16:42
Hmm, this is a good point.
Practically speaking
stevenjb
2017/04/11 16:27:42
There may be but I don't know off the top of my he
Carlson
2017/04/11 17:47:45
Done.
| |
31 weak_ptr_factory_(this) { | |
32 PrinterDetector* detector = | |
33 PrinterDetectorFactory::GetInstance()->Get(profile); | |
stevenjb
2017/04/10 19:49:55
DCHECK(detector);
Carlson
2017/04/10 22:16:42
Done.
| |
34 observer_.Add(detector); | |
35 usb_printers_ = detector->GetPrinters(); | |
36 } | |
37 ~PrinterDiscovererImpl() override = default; | |
38 | |
39 // PrinterDiscoverer interface function. | |
40 void AddObserver(PrinterDiscoverer::Observer* observer) override { | |
41 observer_list_.AddObserver(observer); | |
42 // WrappedOnPrintersFound is a simple wrapper around | |
43 // Observer::OnPrintersFound which lets us safely do the initial | |
44 // OnPrintersFound call to the registered observer. This wrapper buys us | |
45 // weak_ptr semantics on 'this', and also guards against removal of the | |
46 // observer from the Discoverer before this callback is issued. | |
47 base::SequencedTaskRunnerHandle::Get()->PostTask( | |
48 FROM_HERE, base::Bind(&PrinterDiscovererImpl::WrappedOnPrintersFound, | |
49 weak_ptr_factory_.GetWeakPtr(), observer, | |
50 GetAvailablePrinters())); | |
stevenjb
2017/04/10 19:49:55
This is awkward. I would suggest instead providing
Carlson
2017/04/10 22:16:41
I don't think I understand what you're suggesting
stevenjb
2017/04/11 16:27:42
So, that is what I was suggesting, it's a pretty c
skau
2017/04/11 17:12:49
The behavior for detection is a little abnormal.
stevenjb
2017/04/11 17:19:15
What confuses me is that "actively scan" appears t
Carlson
2017/04/11 17:47:45
I agree the API seems weird given the current impl
| |
51 } | |
52 | |
53 // PrinterDiscoverer interface function. | |
54 void RemoveObserver(PrinterDiscoverer::Observer* observer) override { | |
55 observer_list_.RemoveObserver(observer); | |
56 } | |
57 | |
58 // PrinterDetector::Observer interface function. | |
59 void OnAvailableUsbPrintersChanged( | |
60 const std::vector<Printer>& printers) override { | |
61 usb_printers_ = printers; | |
62 std::vector<Printer> all_printers = GetAvailablePrinters(); | |
63 for (PrinterDiscoverer::Observer& observer : observer_list_) { | |
64 observer.OnPrintersFound(all_printers); | |
65 } | |
66 } | |
67 | |
68 private: | |
69 // Wrapper for doing the initial OnPrintersFound call on an observer of this | |
70 // object. | |
71 void WrappedOnPrintersFound(PrinterDiscoverer::Observer* observer, | |
72 const std::vector<Printer>& printers) { | |
73 if (observer_list_.HasObserver(observer)) { | |
74 observer->OnPrintersFound(printers); | |
75 // Since USB is the only thing we're worried about at the moment, | |
76 // and we don't have to wait for those printers to be scanned, we | |
77 // can just tell the observer the initial scan is done now. | |
78 observer->OnDiscoveryInitialScanDone(); | |
79 } | |
80 } | |
81 | |
82 // Get the current set of discovered printers that are not already known | |
83 // to the user's PrintersManager. | |
84 std::vector<Printer> GetAvailablePrinters() { | |
85 // Only know about usb printers for now. Eventually we'll add discovered | |
86 // network printers as well. | |
87 std::vector<Printer> ret; | |
88 | |
89 for (const Printer& printer : usb_printers_) { | |
90 if (printers_manager_->GetPrinter(printer.id()).get() == nullptr) { | |
91 ret.push_back(printer); | |
92 } | |
93 } | |
94 return ret; | |
95 } | |
96 | |
97 std::vector<Printer> usb_printers_; | |
98 base::ObserverList<PrinterDiscoverer::Observer> observer_list_; | |
99 ScopedObserver<PrinterDetector, PrinterDetector::Observer> observer_; | |
stevenjb
2017/04/10 19:49:55
nit: detector_observer_ would be a little more cle
Carlson
2017/04/10 22:16:42
Done.
| |
100 PrintersManager* printers_manager_; | |
101 base::WeakPtrFactory<PrinterDiscovererImpl> weak_ptr_factory_; | |
102 }; | |
103 | |
104 } // namespace | |
105 | |
106 // static | |
107 std::unique_ptr<PrinterDiscoverer> PrinterDiscoverer::Create(Profile* profile) { | |
108 return base::MakeUnique<PrinterDiscovererImpl>(profile); | |
109 } | |
110 | |
111 } // namespace chromeos | |
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