Allow Alt-Tab to move the focus to docked windows.

ash/wm/overview/window_selector.cc

 // Copyright 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.
 
 #include "ash/wm/overview/window_selector.h"
 
 #include <algorithm>
 #include <functional>
 #include <set>
 #include <vector>
@@ skipping 200 matching lines @@
   textfield->RequestFocus();
 
   return widget;
 }
 
 }  // namespace
 
 const int WindowSelector::kTextFilterBottomEdge =
     kTextFilterDistanceFromTop + kTextFilterHeight;
 
+// static
+bool WindowSelector::IsSelectable(aura::Window* window) {
+  wm::WindowState* state = wm::GetWindowState(window);
+  if (state->GetStateType() == wm::WINDOW_STATE_TYPE_DOCKED ||
+      state->GetStateType() == wm::WINDOW_STATE_TYPE_DOCKED_MINIMIZED)
+    return false;
+  return window->type() == ui::wm::WINDOW_TYPE_NORMAL ||
+         window->type() == ui::wm::WINDOW_TYPE_PANEL;
+}
+
 WindowSelector::WindowSelector(WindowSelectorDelegate* delegate)
     : delegate_(delegate),
       restore_focus_window_(aura::client::GetFocusClient(
           Shell::GetPrimaryRootWindow())->GetFocusedWindow()),
       ignore_activations_(false),
       selected_grid_index_(0),
       overview_start_time_(base::Time::Now()),
       num_key_presses_(0),
       num_items_(0),
       showing_selection_widget_(false),
@@ skipping 218 matching lines @@
   // TODO(flackr): Keep window selection active on remaining displays.
   CancelSelection();
 }
 
 void WindowSelector::OnDisplayMetricsChanged(const gfx::Display& display,
                                              uint32_t metrics) {
   PositionWindows(/* animate */ false);
 }
 
 void WindowSelector::OnWindowAdded(aura::Window* new_window) {
-  if (new_window->type() != ui::wm::WINDOW_TYPE_NORMAL &&
-      new_window->type() != ui::wm::WINDOW_TYPE_PANEL) {
+  if (!IsSelectable(new_window))
     return;
-  }
 
   for (size_t i = 0; i < kSwitchableWindowContainerIdsLength; ++i) {
     if (new_window->parent()->id() == kSwitchableWindowContainerIds[i] &&
         !::wm::GetTransientParent(new_window)) {
       // The new window is in one of the switchable containers, abort overview.
       CancelSelection();
       return;
     }
   }
 }
@@ skipping 88 matching lines @@
   // while hiding them they are tracked.
   for (ScopedVector<WindowGrid>::iterator grid_iter = grid_list_.begin();
       grid_iter != grid_list_.end(); ++grid_iter) {
     for (size_t i = 0; i < kSwitchableWindowContainerIdsLength; ++i) {
       const aura::Window* container =
           Shell::GetContainer((*grid_iter)->root_window(),
                               kSwitchableWindowContainerIds[i]);
       for (aura::Window::Windows::const_iterator iter =
            container->children().begin(); iter != container->children().end();
            ++iter) {
-        if (!(*iter)->IsVisible() || (*grid_iter)->Contains(*iter))
+        if (!(*iter)->IsVisible() || (*grid_iter)->Contains(*iter) ||
+            !IsSelectable(*iter)) {

[flackr, 2015/04/07 15:08:39]

It's confusing that IsSelectable is not a subset of the windows in the mru
window list (i.e. mru window list checks ash::wm::CanActivateWindow). If it was,
we could remove HideAndTrackNonOverviewWindows as we would skip every remaining
window with this IsSelectable test.

It's probably too much for this CL, but we should check if
HideAndTrackNonOverviewWindows is necessary anymore (http://crbug.com/295862)
since with transient windows included in selection (http://crbug.com/304289) I
think it may no longer be needed.

[oshima, 2015/04/07 18:00:32]

My understanding is that WindowSelector accepts window list in Init, which
implies that it's independent of MRU list, at least conceptually (otherwise,
Init should be able to just use MRU window list inside).

If we can remove this, that'd be better. let me look into it.

[flackr, 2015/04/07 18:10:33]

This is historical from when we engaged overview automatically after a short
pause while alt tabbing. It is only ever initialized with the mru window list:
https://code.google.com/p/chromium/codesearch#chromium/src/ash/wm/overview/wi...
That'd be great.

[oshima, 2015/04/07 18:20:47]

WindowSelectorTest.NonActivatableWindowsHiddens fails without this code. I
assume we can remove this because there is no other non activatable windows to
hide?

[flackr, 2015/04/07 18:26:22]

I believe so. I can't think of any non activatable normal windows which are not
transient parents or children of an activatable window.

[oshima, 2015/04/07 20:35:29]

Done.

           continue;
+        }
         hidden_windows_.Add(*iter);
       }
     }
   }
 
   // Copy the window list as it can change during iteration.
   const aura::WindowTracker::Windows hidden_windows(hidden_windows_.windows());
   for (aura::WindowTracker::Windows::const_iterator iter =
        hidden_windows.begin(); iter != hidden_windows.end(); ++iter) {
     if (!hidden_windows_.Contains(*iter))
@@ skipping 31 matching lines @@
   for (size_t i = 0;
       i <= grid_list_.size() &&
       grid_list_[selected_grid_index_]->Move(direction, animate); i++) {
     // TODO(flackr): If there are more than two monitors, move between grids
     // in the requested direction.
     selected_grid_index_ = (selected_grid_index_ + 1) % grid_list_.size();
   }
 }
 
 }  // namespace ash