Index: chrome/browser/media/audio_stream_monitor.cc |
diff --git a/chrome/browser/media/audio_stream_monitor.cc b/chrome/browser/media/audio_stream_monitor.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..8633053d510684d1a69143590ec9d3047eb44194 |
--- /dev/null |
+++ b/chrome/browser/media/audio_stream_monitor.cc |
@@ -0,0 +1,86 @@ |
+// Copyright 2014 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/media/audio_stream_monitor.h" |
+ |
+#include "base/bind.h" |
+#include "base/bind_helpers.h" |
+#include "content/public/browser/invalidate_type.h" |
+#include "content/public/browser/web_contents.h" |
+ |
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(AudioStreamMonitor); |
+ |
+AudioStreamMonitor::AudioStreamMonitor(content::WebContents* contents) |
+ : web_contents_(contents), |
+ clock_(&default_tick_clock_), |
+ was_recently_audible_(false) { |
+ DCHECK(web_contents_); |
+} |
+ |
+AudioStreamMonitor::~AudioStreamMonitor() {} |
+ |
+bool AudioStreamMonitor::WasRecentlyAudible() const { |
+ DCHECK(thread_checker_.CalledOnValidThread()); |
+ return was_recently_audible_; |
+} |
+ |
+void AudioStreamMonitor::StartMonitoringStream( |
+ int stream_id, |
+ const ReadPowerAndClipCallback& read_power_callback) { |
+ DCHECK(thread_checker_.CalledOnValidThread()); |
+ DCHECK(!read_power_callback.is_null()); |
+ poll_callbacks_[stream_id] = read_power_callback; |
+ if (!poll_timer_.IsRunning()) { |
+ poll_timer_.Start( |
+ FROM_HERE, |
+ base::TimeDelta::FromSeconds(1) / kPowerMeasurementsPerSecond, |
+ base::Bind(&AudioStreamMonitor::Poll, base::Unretained(this))); |
+ } |
+} |
+ |
+void AudioStreamMonitor::StopMonitoringStream(int stream_id) { |
+ DCHECK(thread_checker_.CalledOnValidThread()); |
+ poll_callbacks_.erase(stream_id); |
+ if (poll_callbacks_.empty()) |
+ poll_timer_.Stop(); |
+} |
+ |
+void AudioStreamMonitor::Poll() { |
+ for (StreamPollCallbackMap::const_iterator it = poll_callbacks_.begin(); |
+ it != poll_callbacks_.end(); |
+ ++it) { |
+ // TODO(miu): A new UI for delivering specific power level and clipping |
+ // information is still in the works. For now, we throw away all |
+ // information except for "is it audible?" |
+ const float power_dbfs = it->second.Run().first; |
+ const float kSilenceThresholdDBFS = -72.24719896f; |
+ if (power_dbfs >= kSilenceThresholdDBFS) { |
+ last_blurt_time_ = clock_->NowTicks(); |
+ MaybeToggle(); |
+ break; // No need to poll remaining streams. |
+ } |
+ } |
+} |
+ |
+void AudioStreamMonitor::MaybeToggle() { |
+ const bool indicator_was_on = was_recently_audible_; |
+ const base::TimeTicks off_time = |
+ last_blurt_time_ + base::TimeDelta::FromMilliseconds(kHoldOnMilliseconds); |
+ const base::TimeTicks now = clock_->NowTicks(); |
+ const bool should_indicator_be_on = now < off_time; |
+ |
+ if (should_indicator_be_on != indicator_was_on) { |
+ was_recently_audible_ = should_indicator_be_on; |
+ web_contents_->NotifyNavigationStateChanged(content::INVALIDATE_TYPE_TAB); |
+ } |
+ |
+ if (!should_indicator_be_on) { |
+ off_timer_.Stop(); |
+ } else if (!off_timer_.IsRunning()) { |
+ off_timer_.Start( |
+ FROM_HERE, |
+ off_time - now, |
+ base::Bind(&AudioStreamMonitor::MaybeToggle, base::Unretained(this))); |
+ } |
+} |