Stop using shell::GetInstance()->system_tray() in system tray items

ash/system/tray/system_tray_item.h

 // 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.
 
 #ifndef ASH_SYSTEM_TRAY_SYSTEM_TRAY_ITEM_H_
 #define ASH_SYSTEM_TRAY_SYSTEM_TRAY_ITEM_H_
 
 #include "ash/ash_export.h"
 #include "ash/system/user/login_status.h"
 #include "ash/wm/shelf_types.h"
@@ skipping 21 matching lines @@
   // Returns a view to be displayed in the system tray. If this returns NULL,
   // then this item is not displayed in the tray.
   // NOTE: The returned view should almost always be a TrayItemView, which
   // automatically resizes the widget when the size of the view changes, and
   // adds animation when the visibility of the view changes. If a view wants to
   // avoid these behaviour, then it should not be a TrayItemView.
   virtual views::View* CreateTrayView(user::LoginStatus status);
 
   // Returns a view for the item to be displayed in the list. This view can be
   // displayed with a number of other tray items, so this should not be too
-  // big.
-  virtual views::View* CreateDefaultView(user::LoginStatus status);
+  // big. |bubble_width| is the current width of the bubble.
+  virtual views::View* CreateDefaultView(user::LoginStatus status,
+                                         int bubble_width);

[stevenjb, 2012/11/15 21:42:04]

This is a lot of changes for one use case, and seems like something we would
want for CreateDetailedView() also if we did this.

We already have a bunch of code in SystemTrayItem that calls
Shell::GetInstance()->system_tray(). This will be invalid soon because there may
be more than one system tray, so we will need to set a system_tray_ member in
each SystemTrayItem eventually anyway.

I propose that instead of this change, we pass |this| to each SystemTrayItem
constructor in SystemTray::CreateItems(). Then, any SystemTrayItem code that
needs the bubble width can call:

DCHECK(system_tray()->GetBubbleView());
int width = system_tray()->GetBubbleView()->GetPreferredSize().width();

Make sense?

[bartfab (slow), 2012/11/16 14:56:24]

Done. This is a much bigger refactor than I had been planning on doing :).

[stevenjb, 2012/11/16 17:46:55]

Yeah, sorry about that, but really appreciate it. 

 
   // Returns a detailed view for the item. This view is displayed standalone.
   virtual views::View* CreateDetailedView(user::LoginStatus status);
 
   // Returns a notification view for the item. This view is displayed with
   // other notifications and should be the same size as default views.
   virtual views::View* CreateNotificationView(user::LoginStatus status);
 
   // These functions are called when the corresponding view item is about to be
   // removed. An item should do appropriate cleanup in these functions.
@@ skipping 39 matching lines @@
   // Shows a notification for this item.
   void ShowNotificationView();
 
   // Hides the notification for this item.
   void HideNotificationView();
 
   // Returns true if this item needs to force the launcher to be visible when
   // the launcher is in the auto-hide state. Default is true.
   virtual bool ShouldShowLauncher() const;
 
+  // For views displayed in a bubble, the width is normally determined by a
+  // fixed bubble with. If this returns true, the bubble width is adjusted when

[msw, 2012/11/15 21:08:48]

nit: s/with/width

+  // displaying this item's default view so that the view can be assigned at
+  // least its entire preferred size. Default is false.

[stevenjb, 2012/11/15 21:42:04]

This feels awkward. How about a GetMinWidth() that defaults to returning 0
(meaning no minimum)? Cases that would return 'true' here, would return
default_view_->GetPreferredSize().width(). Also, if the class needs LoginStatus
to determine this it should store it, instead of passing it here again.

[bartfab (slow), 2012/11/16 14:56:24]

Now that Tray*View can walk up the pointer chain all the way to the bubble, I
can make it explicitly modify the bubble width as needed by doing something like
this:

owner()->system_tray()->GetBubbleView()->SetWidth(x);

[stevenjb, 2012/11/16 17:46:55]

That sounds reasonable also.

+  virtual bool GuaranteeDefaultViewPreferredSize(
+      user::LoginStatus status) const;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(SystemTrayItem);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SYSTEM_TRAY_SYSTEM_TRAY_ITEM_H_