athena: Allow getting into split-view mode from overview-mode.

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 49 matching lines @@
 }
 
 SplitViewController::~SplitViewController() {
   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)
+      left = left_window_;
+    if (!right)
+      right = right_window_;
+  }
+
+  if (!left && iter != windows.rend()) {
+    left = *iter;
+    iter++;
+    if (left == right && iter != windows.rend()) {
+      left = *iter;
+      iter++;
+    }
+  }
+
+  if (!right && iter != windows.rend()) {
+    right = *iter;
+    iter++;
+    if (right == left && iter != windows.rend()) {
+      right = *iter;
+      iter++;
+    }
+  }
+
+  state_ = ACTIVE;
+  left_window_ = left;
+  right_window_ = right;
+  UpdateLayout(true);
+}
+
 void SplitViewController::UpdateLayout(bool animate) {
   if  (!left_window_)
     return;
   CHECK(right_window_);
   gfx::Transform left_transform;
   gfx::Transform right_transform;
   int container_width = container_->GetBoundsInScreen().width();
   if (state_ == ACTIVE) {
     // This method should only be called once in ACTIVE state when
     // the left and rightwindows are still full screen and need to be resized.
@@ skipping 187 matching lines @@
   state_ = INACTIVE;
   left_window_ = NULL;
   right_window_ = NULL;
   current_activity_window_ = NULL;
 }
 
 void SplitViewController::OnOverviewModeExit() {
 }
 
 }  // namespace athena