Show invisible user on login screen if there is space after other user removal

chrome/browser/chromeos/login/existing_user_controller.cc

 // Copyright (c) 2010 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/chromeos/login/existing_user_controller.h"
 
 #include <algorithm>
 #include <functional>
 #include <map>
 
@@ skipping 30 matching lines @@
 #include "views/screen.h"
 #include "views/widget/widget_gtk.h"
 #include "views/window/window.h"
 
 namespace chromeos {
 
 namespace {
 
 // Max number of users we'll show. The true max is the min of this and the
 // number of windows that fit on the screen.
-const size_t kMaxUsers = 5;
+const size_t kMaxUsers = 6;
+
+// Minimum number of users we'll show (including Guest and New User pods).
+const size_t kMinUsers = 3;
 
 // Used to indicate no user has been selected.
 const size_t kNotSelected = -1;
 
 // Offset of cursor in first position from edit left side. It's used to position
 // info bubble arrow to cursor.
 const int kCursorOffset = 5;
 
 // Url for setting up sync authentication.
 const char kSettingsSyncLoginUrl[] = "chrome://settings/personal";
@@ skipping 62 matching lines @@
       background_window_(NULL),
       background_view_(NULL),
       selected_view_index_(kNotSelected),
       num_login_attempts_(0),
       bubble_(NULL),
       user_settings_(new UserCrosSettingsProvider),
       method_factory_(this) {
   if (delete_scheduled_instance_)
     delete_scheduled_instance_->Delete();
 
-  // Caclulate the max number of users from available screen size.
+  // Calculate the max number of users from available screen size.
+  bool show_guest = UserCrosSettingsProvider::cached_allow_guest();
+  bool show_new_user = true;
   if (UserCrosSettingsProvider::cached_show_users_on_signin()) {
     size_t max_users = kMaxUsers;
     int screen_width = background_bounds.width();
     if (screen_width > 0) {
-      max_users = std::max(static_cast<size_t>(2), std::min(kMaxUsers,
-          static_cast<size_t>((screen_width - login::kUserImageSize)
-                              / (UserController::kUnselectedSize +
-                                 UserController::kPadding))));
+      size_t users_per_screen = (screen_width - login::kUserImageSize)
+          / (UserController::kUnselectedSize + UserController::kPadding);
+      max_users = std::max(kMinUsers, std::min(kMaxUsers, users_per_screen));
     }
 
-    size_t visible_users_count = std::min(users.size(), max_users - 1);
+    size_t visible_users_count = std::min(users.size(), max_users -
+        static_cast<int>(show_guest) - static_cast<int>(show_new_user));
     for (size_t i = 0; i < users.size(); ++i) {
-      if (controllers_.size() == visible_users_count)
-        break;
-
       // TODO(xiyuan): Clean user profile whose email is not in whitelist.
       if (UserCrosSettingsProvider::cached_allow_new_user() ||
           UserCrosSettingsProvider::IsEmailInCachedWhitelist(
               users[i].email())) {
-        controllers_.push_back(new UserController(this, users[i]));
+        UserController* user_controller = new UserController(this, users[i]);
+        if (controllers_.size() < visible_users_count)
+          controllers_.push_back(user_controller);
+        else
+          invisible_controllers_.push_back(user_controller);
       }
     }
   }
 
-  if (!controllers_.empty() && UserCrosSettingsProvider::cached_allow_guest())
+  if (!controllers_.empty() && show_guest)
     controllers_.push_back(new UserController(this, true));
 
-  // Add the view representing the new user.
-  controllers_.push_back(new UserController(this, false));
+  if (show_new_user)
+    controllers_.push_back(new UserController(this, false));
 }
 
 void ExistingUserController::Init() {
   if (!background_window_) {
     std::string url_string =
         CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
             switches::kScreenSaverUrl);
 
     background_window_ = BackgroundView::CreateWindowContainingView(
         background_bounds_,
@@ skipping 59 matching lines @@
 
 ExistingUserController::~ExistingUserController() {
   ClearErrors();
 
   if (background_window_)
     background_window_->Close();
 
   WmMessageListener::GetInstance()->RemoveObserver(this);
 
   STLDeleteElements(&controllers_);
+  STLDeleteElements(&invisible_controllers_);
 }
 
 void ExistingUserController::Delete() {
   delete_scheduled_instance_ = NULL;
   delete this;
 }
 
 void ExistingUserController::ProcessWmMessage(const WmIpc::Message& message,
                                               GdkWindow* window) {
   if (message.type() != WM_IPC_MESSAGE_CHROME_CREATE_GUEST_WINDOW)
@@ skipping 127 matching lines @@
   // Update user count before unmapping windows, otherwise window manager won't
   // be in the right state.
   int new_size = static_cast<int>(controllers_.size());
   for (int i = 0; i < new_size; ++i)
     controllers_[i]->UpdateUserCount(i, new_size);
 
   // Delete the encrypted user directory.
   new RemoveAttempt(source->user().email());
   // We need to unmap entry windows, the windows will be unmapped in destructor.
   delete source;
+
+  // Nothing to insert.
+  if (invisible_controllers_.empty())
+    return;
+
+  // Insert just before guest or add new user pods if any.
+  int insert_position = new_size;
+  while (insert_position > 0 &&
+         (controllers_[insert_position - 1]->is_new_user() ||
+          controllers_[insert_position - 1]->is_guest()))
+    --insert_position;
+
+  controllers_.insert(controllers_.begin() + insert_position,
+                      invisible_controllers_[0]);
+  invisible_controllers_.erase(invisible_controllers_.begin());
+
+  // Update counts for exiting pods.
+  new_size = static_cast<int>(controllers_.size());
+  for (int i = 0; i < new_size; ++i) {
+    if (i != insert_position)
+      controllers_[i]->UpdateUserCount(i, new_size);
+  }
+
+  // And initialize new one that was invisible.
+  controllers_[insert_position]->Init(insert_position, new_size, false);
+
+  EnableTooltipsIfNeeded(controllers_);
 }
 
 void ExistingUserController::SelectUser(int index) {
   if (index >= 0 && index < static_cast<int>(controllers_.size()) &&
       index != static_cast<int>(selected_view_index_)) {
     WmIpc::Message message(WM_IPC_MESSAGE_WM_SELECT_LOGIN_USER);
     message.set_param(0, index);
     WmIpc::instance()->SendMessage(message);
   }
 }
@@ skipping 224 matching lines @@
     login_performer_->RecoverEncryptedData(old_password);
 }
 
 void ExistingUserController::ResyncEncryptedData() {
   // LoginPerformer instance has state of the user so it should exist.
   if (login_performer_.get())
     login_performer_->ResyncEncryptedData();
 }
 
 }  // namespace chromeos