Adding new user menu section to the SystemTrayMenu & refactoring of user access

ash/session_state_delegate.h

 // Copyright (c) 2013 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_SESSION_STATE_DELEGATE_H_
 #define ASH_SESSION_STATE_DELEGATE_H_
 
+#include <string>
+#include <vector>
+
 #include "ash/ash_export.h"
+#include "base/string16.h"
+
+namespace gfx {
+class ImageSkia;
+}  // namespace gfx
 
 namespace ash {
 
+// The index for the multi-profile item to use. The list is always LRU sorted
+// So that the index #0 is the currently active user.
+typedef int MultiProfileIndex;
+
+// A list of email addresses.
+typedef std::vector<std::string> UserEmailList;
+
 // Delegate for checking and modifying the session state.
 class ASH_EXPORT SessionStateDelegate {
  public:
   virtual ~SessionStateDelegate() {};
 
-  // Returns |true| if a session is in progress and there is an active user.
-  virtual bool HasActiveUser() const = 0;
+  // Returns the maximum possible number of logged in users.
+  virtual int GetMaximumNumberOfLoggedInUsers() const = 0;
+
+  // Returns the number of signed in users. If 0 is returned, there is either
+  // no session in progress or no active user.
+  virtual int NumberOfLoggedInUsers() const = 0;
 
   // Returns |true| if the session has been fully started for the active user.
   // When a user becomes active, the profile and browser UI are not immediately
   // available. Only once this method starts returning |true| is the browser
   // startup complete and both profile and UI are fully available.
   virtual bool IsActiveUserSessionStarted() const = 0;
 
   // Returns true if the screen can be locked.
   virtual bool CanLockScreen() const = 0;
 
   // Returns true if the screen is currently locked.
   virtual bool IsScreenLocked() const = 0;
 
   // Locks the screen. The locking happens asynchronously.
   virtual void LockScreen() = 0;
 
   // Unlocks the screen.
   virtual void UnlockScreen() = 0;
+
+  // Gets the displayed name for the user with the given |index|.
+  // Note that |index| can at maximum be |NumberOfLoggedInUsers() - 1|.
+  virtual const base::string16 GetUserDisplayName(
+      MultiProfileIndex index) const = 0;
+
+  // Gets the email address for the user with the given |index|.
+  // Note that |index| can at maximum be |NumberOfLoggedInUsers() - 1|.
+  virtual const std::string GetUserEmail(MultiProfileIndex index) const = 0;

[bartfab (slow), 2013/05/21 09:26:01]

Ugh. I was added as a reviewer but then the CL was committed before I got a
chance to take a look at it.

Although the CL has landed, I still think there is one thing that needs
changing: We use the terms |email|, |username|, |user_id| for the same thing in
different parts of the code. We discussed this recently and settled on "user ID"
as the single term to use in the future. Could you make a follow-up CL that
modifies this code to use "UserId" instead of "Email" in its method signatures
and comments?

[Mr4D (OOO till 08-26), 2013/05/21 15:48:44]

This function is needed by the UI in order to show the logged in eMail address.
It does not show a UserID since that might change in the future to something
else then the eMail address (or the name is not clear). As such this function
should have exactly this name and nothing with UserID in it. That would be
really confusing.

I discussed this now with nkostylev and we will run this namechange (email
->userid) by the team and see for any objections. If everyone is happy I will
change.

On a side note: The UI faces the user name and the user eMail to the user. As
such using the term eMail is much clearer then user_id. Granted it only makes
sense with GAIA, but that is the main use case we care about in the UI planning
(other non logged in users won't show this).

Once everyone agrees on this name change I can change the names in a later CL.

+
+  // Gets the avatar image for the user with the given |index|.
+  // Note that |index| can at maximum be |NumberOfLoggedInUsers() - 1|.
+  virtual const gfx::ImageSkia& GetUserImage(MultiProfileIndex index) const = 0;
+
+  // Returns a list of all logged in users.
+  virtual void GetLoggedInUsers(UserEmailList* users) = 0;
+
+  // Switches to another active user (if that user has already signed in).
+  virtual void SwitchActiveUser(const std::string& email) = 0;
 };
 
 }  // namespace ash
 
 #endif  // ASH_SESSION_STATE_DELEGATE_H_