athena: Add a test for split-view controller.

athena/wm/split_view_controller.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 "athena/wm/split_view_controller.h"
 
 #include <cmath>
 
 #include "athena/wm/public/window_list_provider.h"
 #include "athena/wm/public/window_manager.h"
@@ skipping 38 matching lines @@
     WindowManager* window_manager)
     : state_(INACTIVE),
       container_(container),
       window_manager_(window_manager),
       window_list_provider_(window_list_provider),
       current_activity_window_(NULL),
       left_window_(NULL),
       right_window_(NULL),
       separator_position_(0),
       weak_factory_(this) {
-  window_manager->AddObserver(this);
+  if (window_manager_)
+    window_manager_->AddObserver(this);
 }
 
 SplitViewController::~SplitViewController() {
-  window_manager_->RemoveObserver(this);
+  if (window_manager_)
+    window_manager_->RemoveObserver(this);
 }
 
 bool SplitViewController::IsSplitViewModeActive() const {
   return state_ == ACTIVE;
 }
 
 void SplitViewController::ActivateSplitMode(aura::Window* left,
                                             aura::Window* right) {
   aura::Window::Windows windows = window_list_provider_->GetWindowList();
   aura::Window::Windows::reverse_iterator iter = windows.rbegin();
   if (state_ == ACTIVE) {
+    if (left_window_ == right)
+      left_window_ = left;
+    if (right_window_ == left)
+      right_window_ = right;
+
     if (!left)
       left = left_window_;
     if (!right)
       right = right_window_;
   }
 
   if (!left && iter != windows.rend()) {
     left = *iter;
     iter++;
     if (left == right && iter != windows.rend()) {
@@ skipping 188 matching lines @@
 
 void SplitViewController::ScrollUpdate(float delta) {
   if (state_ != SCROLLING)
     return;
   UpdateSeparatorPositionFromScrollDelta(delta);
   UpdateLayout(false);
 }
 
 bool SplitViewController::CanScroll() {
   // TODO(mfomitchev): return false in vertical orientation, in full screen.
-  bool result = (!window_manager_->IsOverviewModeActive() &&
+  bool result = (window_manager_ && !window_manager_->IsOverviewModeActive() &&
                  !IsSplitViewModeActive() &&
                  window_list_provider_->GetWindowList().size() >= 2);
   return result;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // WindowManagerObserver overrides
 void SplitViewController::OnOverviewModeEnter() {
   if (state_ == ACTIVE) {
     CHECK(left_window_);
@@ skipping 10 matching lines @@
   state_ = INACTIVE;
   left_window_ = NULL;
   right_window_ = NULL;
   current_activity_window_ = NULL;
 }
 
 void SplitViewController::OnOverviewModeExit() {
 }
 
 }  // namespace athena