Show the Cast toolbar icon ephemerally when Cast is in use

chrome/browser/ui/webui/media_router/media_router_dialog_controller_impl.cc

Index: chrome/browser/ui/webui/media_router/media_router_dialog_controller_impl.cc
diff --git a/chrome/browser/ui/webui/media_router/media_router_dialog_controller_impl.cc b/chrome/browser/ui/webui/media_router/media_router_dialog_controller_impl.cc
index ad69808749ce7dd72bfd8aedcdc801c2c8f82e9b..3ae9fada4a6bfeb13226509c5d9f9322d7dd85ac 100644
--- a/chrome/browser/ui/webui/media_router/media_router_dialog_controller_impl.cc
+++ b/chrome/browser/ui/webui/media_router/media_router_dialog_controller_impl.cc
@@ -15,6 +15,8 @@
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_window.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/browser/ui/toolbar/component_toolbar_actions_factory.h"
 #include "chrome/browser/ui/toolbar/media_router_action.h"
 #include "chrome/browser/ui/webui/constrained_web_dialog_ui.h"
 #include "chrome/browser/ui/webui/media_router/media_router_ui.h"
@@ -52,10 +54,9 @@ constexpr const int kWidth = 340;
 // will look like.
 class MediaRouterDialogDelegate : public WebDialogDelegate {
  public:
-  MediaRouterDialogDelegate(base::WeakPtr<MediaRouterAction> action,
+  MediaRouterDialogDelegate(

[msw, 2016/07/26 19:59:32]

nit: explicit.

[takumif, 2016/07/28 20:04:11]

Done.

       const base::WeakPtr<MediaRouterDialogControllerImpl>& controller)
-      : action_(action),
-        controller_(controller) {}
+      : controller_(controller) {}
   ~MediaRouterDialogDelegate() override {}
 
   // WebDialogDelegate implementation.
@@ -86,8 +87,7 @@ class MediaRouterDialogDelegate : public WebDialogDelegate {
   void OnDialogClosed(const std::string& json_retval) override {
     // We don't delete |this| here because this class is owned
     // by ConstrainedWebDialogDelegate.
-    if (action_)
-      action_->OnPopupHidden();
+    controller_.get()->OnDialogClosed();
   }
 
   void OnCloseContents(WebContents* source, bool* out_close_dialog) override {
@@ -100,7 +100,6 @@ class MediaRouterDialogDelegate : public WebDialogDelegate {
   }
 
  private:
-  base::WeakPtr<MediaRouterAction> action_;
   base::WeakPtr<MediaRouterDialogControllerImpl> controller_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterDialogDelegate);
@@ -160,7 +159,10 @@ MediaRouterDialogControllerImpl::MediaRouterDialogControllerImpl(
     WebContents* web_contents)
     : MediaRouterDialogController(web_contents),
       media_router_dialog_pending_(false),
+      tab_strip_model_observer_(this),
       weak_ptr_factory_(this) {
+  tab_strip_model_observer_.Add(
+      chrome::FindBrowserWithWebContents(initiator())->tab_strip_model());
 }
 
 MediaRouterDialogControllerImpl::~MediaRouterDialogControllerImpl() {
@@ -173,8 +175,7 @@ WebContents* MediaRouterDialogControllerImpl::GetMediaRouterDialog() const {
 
 void MediaRouterDialogControllerImpl::SetMediaRouterAction(
     const base::WeakPtr<MediaRouterAction>& action) {
-  if (!action_)
-    action_ = action;
+  action_ = action;
 }
 
 bool MediaRouterDialogControllerImpl::IsShowingMediaRouterDialog() const {
@@ -235,7 +236,7 @@ void MediaRouterDialogControllerImpl::CreateMediaRouterDialog() {
   // |web_dialog_delegate|'s owner is |constrained_delegate|.
   // |constrained_delegate| is owned by the parent |views::View|.
   WebDialogDelegate* web_dialog_delegate =
-      new MediaRouterDialogDelegate(action_, weak_ptr_factory_.GetWeakPtr());
+      new MediaRouterDialogDelegate(weak_ptr_factory_.GetWeakPtr());
 
   // |ShowConstrainedWebDialogWithAutoResize()| will end up creating
   // ConstrainedWebDialogDelegateViewViews containing a WebContents containing
@@ -266,9 +267,11 @@ void MediaRouterDialogControllerImpl::CreateMediaRouterDialog() {
 
   dialog_observer_.reset(new DialogWebContentsObserver(
       media_router_dialog, this));
+}
 
+void MediaRouterDialogControllerImpl::OnDialogClosed() {
   if (action_)
-    action_->OnPopupShown();

[msw, 2016/07/26 19:59:32]

Why doesn't CreateMediaRouterDialog still call OnPopupShown?
(is the call in OnDialogNavigated replacing this for some reason?)

[takumif, 2016/07/28 20:04:11]

The only thing MediaRouterAction::OnPopupShown does right now is to call
ToolbarActionView::OnPopupShown, which depresses the icon. I had to remove
OnPopupShown from here due to an issue in which the depression shadow appears in
a wrong place if we're animating the icon into existence at the same time. That
case is dealt with in MediaRouterAction::OnToolbarActionsBarAnimationEnded, and
the case in which the icon is already on the toolbar is taken care of by
OnPopupShown in OnDialogNavigated.

+    action_->OnPopupHidden();
 }
 
 void MediaRouterDialogControllerImpl::Reset() {
@@ -295,6 +298,9 @@ void MediaRouterDialogControllerImpl::OnDialogNavigated(
   media_router_dialog_pending_ = false;
 
   PopulateDialog(media_router_dialog);
+
+  if (action_)
+    action_->OnPopupShown();
 }
 
 void MediaRouterDialogControllerImpl::PopulateDialog(
@@ -325,4 +331,33 @@ void MediaRouterDialogControllerImpl::PopulateDialog(
   }
 }
 
+bool MediaRouterDialogControllerImpl::ShowMediaRouterDialog() {
+  if (!action_)
+    ShowMediaRouterAction();

[msw, 2016/07/26 19:59:32]

Why doesn't the MediaRouterDialogController base class own |action_| and handle
its management? It seems like that's not dependent upon any WebUI impl details.

[takumif, 2016/07/28 20:04:12]

The base class contains logic that's shared across desktop and Android, and the
Impl class contains desktop-only logic. Since the toolbar action is desktop
specific, we keep it here.

+  return MediaRouterDialogController::ShowMediaRouterDialog();
+}
+
+void MediaRouterDialogControllerImpl::ActiveTabChanged(
+    content::WebContents* old_contents,
+    content::WebContents* new_contents,
+    int index,
+    int reason) {
+  if (IsShowingMediaRouterDialog() && !action_)

[msw, 2016/07/26 19:59:32]

Can the user actually change tabs while the dialog is showing? Or is the dialog
somehow shown/hidden when switching tabs and left somewhat modal to the tab?

[takumif, 2016/07/28 20:04:11]

Yes, the user can switch tabs while the dialog is open, and have the dialog open
in one tab but not in another, just like the print preview dialog.

+    ShowMediaRouterAction();
+}
+
+void MediaRouterDialogControllerImpl::ShowMediaRouterAction() {
+  Profile* profile =
+      Profile::FromBrowserContext(initiator()->GetBrowserContext());
+  if (!profile)
+    return;
+
+  ToolbarActionsModel* model = ToolbarActionsModel::Get(profile);
+  if (model && !model->HasComponentAction(
+      ComponentToolbarActionsFactory::kMediaRouterActionId)) {
+    model->AddComponentAction(
+        ComponentToolbarActionsFactory::kMediaRouterActionId);
+  }
+}
+
 }  // namespace media_router