ash/wm/window_cycle_list.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ash/wm/window_cycle_list.h"
   6
   7 #include "ash/wm/window_util.h"
   8 #include "ui/aura/window.h"
   9
  10 namespace ash {
  11
  12 WindowCycleList::WindowCycleList(const WindowList& windows)
  13     : windows_(windows),
  14       current_index_(-1) {
  15   // Locate the currently active window in the list to use as our start point.
  16   aura::Window* active_window = wm::GetActiveWindow();
  17
  18   // The active window may not be in the cycle list, which is expected if there
  19   // are additional modal windows on the screen.
  20   current_index_ = GetWindowIndex(active_window);
  21
  22   for (WindowList::const_iterator i = windows_.begin(); i != windows_.end();
  23        ++i) {
  24     (*i)->AddObserver(this);
  25   }
  26 }
  27
  28 WindowCycleList::~WindowCycleList() {
  29   for (WindowList::const_iterator i = windows_.begin(); i != windows_.end();
  30        ++i) {
  31     (*i)->RemoveObserver(this);
  32   }
  33 }
  34
  35 void WindowCycleList::Step(Direction direction) {
  36   if (windows_.empty())
  37     return;
  38
  39   if (current_index_ == -1) {
  40     // We weren't able to find our active window in the shell delegate's
  41     // provided window list.  Just switch to the first (or last) one.
  42     current_index_ = (direction == FORWARD ? 0 : windows_.size() - 1);
  43   } else {
  44     if (windows_.size() == 1)
  45       return;
  46     // We're in a valid cycle, so step forward or backward.
  47     current_index_ += (direction == FORWARD ? 1 : -1);
  48   }
  49   // Wrap to window list size.
  50   current_index_ = (current_index_ + windows_.size()) % windows_.size();
  51   DCHECK(windows_[current_index_]);
  52   // Make sure the next window is visible.
  53   windows_[current_index_]->Show();
  54   wm::ActivateWindow(windows_[current_index_]);
  55 }
  56
  57 int WindowCycleList::GetWindowIndex(aura::Window* window) {
  58   WindowList::const_iterator it =
  59       std::find(windows_.begin(), windows_.end(), window);
  60   if (it == windows_.end())
  61     return -1;  // Not found.
  62   return it - windows_.begin();
  63 }
  64
  65 void WindowCycleList::OnWindowDestroyed(aura::Window* window) {
  66   window->RemoveObserver(this);
  67
  68   WindowList::iterator i = std::find(windows_.begin(), windows_.end(), window);
  69   DCHECK(i != windows_.end());
  70   int removed_index = static_cast<int>(i - windows_.begin());
  71   windows_.erase(i);
  72   if (current_index_ > removed_index)
  73     current_index_--;
  74   else if (current_index_ == static_cast<int>(windows_.size()))
  75     current_index_--;
  76 }
  77
  78 }  // namespace ash