Indicate tab recording state in tab strip

chrome/browser/media/media_stream_capture_indicator.cc

 // Copyright (c) 2012 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/media_stream_capture_indicator.h"
 
 #include "base/bind.h"
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
@@ skipping 106 matching lines @@
     const MediaStreamCaptureIndicator::CaptureDeviceTab& tab) {
     return (render_process_id_ == tab.render_process_id &&
             render_view_id_ == tab.render_view_id);
 }
 
 MediaStreamCaptureIndicator::MediaStreamCaptureIndicator()
     : status_icon_(NULL),
       mic_image_(NULL),
       camera_image_(NULL),
       balloon_image_(NULL),
-      request_index_(0) {
+      request_index_(0),
+      weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
 }
 
 MediaStreamCaptureIndicator::~MediaStreamCaptureIndicator() {
   // The user is responsible for cleaning up by closing all the opened devices.
   DCHECK(tabs_.empty());
 }
 
 bool MediaStreamCaptureIndicator::IsCommandIdChecked(
     int command_id) const {
   NOTIMPLEMENTED() << "There are no checked items in the MediaStream menu.";
@@ skipping 30 matching lines @@
 void MediaStreamCaptureIndicator::CaptureDevicesOpened(
     int render_process_id,
     int render_view_id,
     const content::MediaStreamDevices& devices) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(!devices.empty());
 
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&MediaStreamCaptureIndicator::DoDevicesOpenedOnUIThread,
-                 this, render_process_id, render_view_id, devices));
+                 weak_ptr_factory_.GetWeakPtr(),
+                 render_process_id, render_view_id, devices));
 }
 
 void MediaStreamCaptureIndicator::CaptureDevicesClosed(
     int render_process_id,
     int render_view_id,
     const content::MediaStreamDevices& devices) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(!devices.empty());
 
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&MediaStreamCaptureIndicator::DoDevicesClosedOnUIThread,
-                 this, render_process_id, render_view_id, devices));
+                 weak_ptr_factory_.GetWeakPtr(),

[no longer working on chromium, 2012/10/23 08:56:53]

Do we know that if MediaInternals will always outlive UI thread?
When the browser is shutting down, we will get here and send
DoDevicesClosedOnUIThread tasks to UI thread, if UI thread is busy, there will
be delay on executing tasks. 

[stevenjb, 2012/10/23 18:11:31]

As a Singleton, yes, it will outlive the UI message loop. However, Bind +
WeakPtr will also ensure that if MediaInternals were deleted before the callback
would be called, the result is a no-op instead of a crash. Since the callback
happens on the UI thread (where the Singleton is created/destroyed), this is
safe.

+                 render_process_id, render_view_id, devices));
 }
 
 void MediaStreamCaptureIndicator::DoDevicesOpenedOnUIThread(
     int render_process_id,
     int render_view_id,
     const content::MediaStreamDevices& devices) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   CreateStatusTray();
 
@@ skipping 242 matching lines @@
     }
 
     // Remove the tab if all the devices have been closed.
     if (iter->audio_ref_count == 0 && iter->video_ref_count == 0)
       tabs_.erase(iter);
   }
 
   UpdateStatusTrayIconContextMenu();
 }
 
+bool MediaStreamCaptureIndicator::IsProcessCapturing(int render_process_id,
+                                                     int render_view_id) const {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  CaptureDeviceTabs::const_iterator iter = std::find_if(
+      tabs_.begin(), tabs_.end(), TabEquals(render_process_id, render_view_id));
+  if (iter == tabs_.end())
+    return false;
+  return (iter->audio_ref_count > 0 || iter->video_ref_count > 0);
+}
+
 void MediaStreamCaptureIndicator::EnsureImageLoadingTracker() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (tracker_.get())
     return;
 
   tracker_.reset(new ImageLoadingTracker(this));
   pending_messages_.clear();
   request_index_ = 0;
 }