Switch global error menu icon to vectorized MD asset
[chromium-blink-merge.git] / chrome / browser / chromeos / camera_detector.cc
blob918a8693712f3929a5e2d0840821490b31c5e37e
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.
5 #include "chrome/browser/chromeos/camera_detector.h"
7 #include "base/bind.h"
8 #include "base/files/file_enumerator.h"
9 #include "base/files/file_util.h"
10 #include "base/location.h"
11 #include "base/strings/string_split.h"
12 #include "base/strings/string_util.h"
13 #include "base/task_runner_util.h"
14 #include "base/threading/sequenced_worker_pool.h"
15 #include "components/storage_monitor/udev_util_linux.h"
16 #include "content/public/browser/browser_thread.h"
18 namespace chromeos {
20 namespace {
22 // Sysfs directory containing V4L devices.
23 const char kV4LSubsystemDir[] = "/sys/class/video4linux/";
24 // Name of the udev property with V4L capabilities.
25 const char kV4LCapabilities[] = "ID_V4L_CAPABILITIES";
26 // Delimiter character for udev V4L capabilities.
27 const char kV4LCapabilitiesDelim = ':';
28 // V4L capability that denotes a capture-enabled device.
29 const char kV4LCaptureCapability[] = "capture";
31 } // namespace
33 using content::BrowserThread;
35 // static
36 CameraDetector::CameraPresence CameraDetector::camera_presence_ =
37 CameraDetector::kCameraPresenceUnknown;
39 // static
40 bool CameraDetector::presence_check_in_progress_ = false;
42 // static
43 void CameraDetector::StartPresenceCheck(const base::Closure& callback) {
44 DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
45 if (presence_check_in_progress_)
46 return;
47 DVLOG(1) << "Starting camera presence check";
48 presence_check_in_progress_ = true;
49 base::PostTaskAndReplyWithResult(
50 BrowserThread::GetBlockingPool()->GetTaskRunnerWithShutdownBehavior(
51 base::SequencedWorkerPool::SKIP_ON_SHUTDOWN).get(),
52 FROM_HERE,
53 base::Bind(&CameraDetector::CheckPresence),
54 base::Bind(&CameraDetector::OnPresenceCheckDone, callback));
57 // static
58 void CameraDetector::OnPresenceCheckDone(const base::Closure& callback,
59 bool present) {
60 DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
61 camera_presence_ = present ? kCameraPresent : kCameraAbsent;
62 presence_check_in_progress_ = false;
63 callback.Run();
66 // static
67 bool CameraDetector::CheckPresence() {
68 // We do a quick check using udev database because opening each /dev/videoX
69 // device may trigger costly device initialization.
70 base::FileEnumerator file_enum(
71 base::FilePath(kV4LSubsystemDir), false /* not recursive */,
72 base::FileEnumerator::FILES | base::FileEnumerator::SHOW_SYM_LINKS);
73 for (base::FilePath path = file_enum.Next(); !path.empty();
74 path = file_enum.Next()) {
75 std::string v4l_capabilities;
76 if (storage_monitor::GetUdevDevicePropertyValueByPath(
77 path, kV4LCapabilities, &v4l_capabilities)) {
78 std::vector<std::string> caps = base::SplitString(
79 v4l_capabilities, std::string(1, kV4LCapabilitiesDelim),
80 base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
81 if (find(caps.begin(), caps.end(), kV4LCaptureCapability) != caps.end()) {
82 return true;
86 return false;
89 } // namespace chromeos