Media indicator for background recording task

ash/system/tray/media_security/media_tray_item.cc

+// 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 "ash/system/tray/media_security/media_tray_item.h"
+
+#include "ash/ash_view_ids.h"
+#include "ash/media_delegate.h"
+#include "ash/session/session_state_delegate.h"
+#include "ash/shell.h"
+#include "ash/system/tray/media_security/media_capture_observer.h"
+#include "ash/system/tray/system_tray_notifier.h"
+#include "ash/system/tray/tray_item_view.h"
+#include "grit/ash_resources.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/views/controls/image_view.h"
+#include "ui/views/layout/fill_layout.h"
+
+namespace ash {
+namespace tray {
+
+class MediaTrayView : public TrayItemView, public MediaCaptureObserver {
+ public:
+  explicit MediaTrayView(SystemTrayItem* system_tray_item)
+      : TrayItemView(system_tray_item) {
+    SetLayoutManager(new views::FillLayout);
+    views::ImageView* icon = new views::ImageView;
+    ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
+    icon->SetImage(
+        bundle.GetImageNamed(IDR_AURA_UBER_TRAY_RECORDING).ToImageSkia());
+    AddChildView(icon);
+    OnMediaCaptureChanged();
+    Shell::GetInstance()->system_tray_notifier()->AddMediaCaptureObserver(this);
+    set_id(VIEW_ID_MEDIA_TRAY_VIEW);
+  }
+
+  virtual ~MediaTrayView() {
+    Shell::GetInstance()->system_tray_notifier()->RemoveMediaCaptureObserver(
+        this);
+  }
+
+  virtual void OnMediaCaptureChanged() OVERRIDE {

[Mr4D (OOO till 08-26), 2014/04/30 18:24:36]

Please add the

 // MediaCaptureObserver overrides:

comment.

[oshima, 2014/04/30 20:40:31]

Done.

+    MediaDelegate* media_delegate = Shell::GetInstance()->media_delegate();
+    SessionStateDelegate* session_state_delegate =
+        Shell::GetInstance()->session_state_delegate();
+    // The user at 0 is the current desktop user.
+    for (MultiProfileIndex index = 1;
+         index < session_state_delegate->NumberOfLoggedInUsers();
+         ++index) {
+      content::BrowserContext* context =
+          session_state_delegate->GetBrowserContextByIndex(index);

[Mr4D (OOO till 08-26), 2014/04/30 18:24:36]

What do we do with visiting windows? Shouldn't we check that the associated
window is visible on the current screen - or did we say that we show the icon no
matter on which desktop it is?

[oshima, 2014/04/30 20:40:31]

That is handled in GetBackgroundMediaCaptureState. 

+      if (media_delegate->GetBackgroundMediaCaptureState(context) !=
+          MEDIA_CAPTURE_NONE) {
+        SetVisible(true);
+        return;
+      }
+    }
+    SetVisible(false);
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MediaTrayView);
+};
+
+}  // namespace tray
+
+MediaTrayItem::MediaTrayItem(SystemTray* system_tray)
+    : SystemTrayItem(system_tray), tray_view_(NULL) {
+}

[Mr4D (OOO till 08-26), 2014/04/30 18:24:36]

Since this indicator does only get shown for inactive users I would be tempted
to name it something like MultiUserMediaTrayItem?

[oshima, 2014/04/30 20:40:31]

There is no "multi user" keyword in ash so far (except kAshEnableMultiUserKey,
which seems to be obsolete),
so I'd like to sway away from "MultiUser" in ash if you're ok.

[Mr4D (OOO till 08-26), 2014/05/01 14:36:57]

Only because it appears not not to be used (I think there were some usages in
the past but got recently removed since UX has changed) does not mean that it
shouldn't be used. Since this indicator is only used for multi user use cases it
feels rather misleading to not add it.

If you think that we might show the indicator for the current user in the future
you can leave it as it is.

+
+MediaTrayItem::~MediaTrayItem() {
+}
+
+views::View* MediaTrayItem::CreateTrayView(user::LoginStatus status) {
+  tray_view_ = new tray::MediaTrayView(this);
+  return tray_view_;
+}
+
+void MediaTrayItem::DestroyTrayView() {
+  tray_view_ = NULL;
+}
+
+}  // namespace ash