ash/wm/activation_controller.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/activation_controller.h"
   6
   7 #include "ash/root_window_controller.h"
   8 #include "ash/shell.h"
   9 #include "ash/shell_window_ids.h"
  10 #include "ash/wm/activation_controller_delegate.h"
  11 #include "ash/wm/property_util.h"
  12 #include "ash/wm/window_util.h"
  13 #include "ash/wm/workspace_controller.h"
  14 #include "base/auto_reset.h"
  15 #include "ui/aura/client/activation_change_observer.h"
  16 #include "ui/aura/client/activation_delegate.h"
  17 #include "ui/aura/client/aura_constants.h"
  18 #include "ui/aura/client/focus_client.h"
  19 #include "ui/aura/env.h"
  20 #include "ui/aura/root_window.h"
  21 #include "ui/aura/window.h"
  22 #include "ui/aura/window_delegate.h"
  23 #include "ui/base/ui_base_types.h"
  24 #include "ui/compositor/layer.h"
  25 #include "ui/views/corewm/window_modality_controller.h"
  26
  27 namespace ash {
  28 namespace internal {
  29 namespace {
  30
  31 // These are the list of container ids of containers which may contain windows
  32 // that need to be activated in the order that they should be activated.
  33 const int kWindowContainerIds[] = {
  34     kShellWindowId_LockSystemModalContainer,
  35     kShellWindowId_SettingBubbleContainer,
  36     kShellWindowId_LockScreenContainer,
  37     kShellWindowId_SystemModalContainer,
  38     kShellWindowId_AlwaysOnTopContainer,
  39     kShellWindowId_AppListContainer,
  40     kShellWindowId_DefaultContainer,
  41
  42     // Panel, launcher and status are intentionally checked after other
  43     // containers even though these layers are higher. The user expects their
  44     // windows to be focused before these elements.
  45     kShellWindowId_PanelContainer,
  46     kShellWindowId_LauncherContainer,
  47     kShellWindowId_StatusContainer,
  48 };
  49
  50 bool BelongsToContainerWithEqualOrGreaterId(const aura::Window* window,
  51                                             int container_id) {
  52   for (; window; window = window->parent()) {
  53     if (window->id() >= container_id)
  54       return true;
  55   }
  56   return false;
  57 }
  58
  59 // Returns true if children of |window| can be activated.
  60 // These are the only containers in which windows can receive focus.
  61 bool SupportsChildActivation(aura::Window* window) {
  62   if (window->id() == kShellWindowId_WorkspaceContainer)
  63     return true;
  64
  65   for (size_t i = 0; i < arraysize(kWindowContainerIds); i++) {
  66     if (window->id() == kWindowContainerIds[i] &&
  67         window->id() != kShellWindowId_DefaultContainer) {
  68       return true;
  69     }
  70   }
  71   return false;
  72 }
  73
  74 bool HasModalTransientChild(aura::Window* window) {
  75   aura::Window::Windows::const_iterator it;
  76   for (it = window->transient_children().begin();
  77        it != window->transient_children().end();
  78        ++it) {
  79     if ((*it)->GetProperty(aura::client::kModalKey) == ui::MODAL_TYPE_WINDOW)
  80       return true;
  81   }
  82   return false;
  83 }
  84
  85 // See description in VisibilityMatches.
  86 enum ActivateVisibilityType {
  87   TARGET_VISIBILITY,
  88   CURRENT_VISIBILITY,
  89 };
  90
  91 // Used by CanActivateWindowWithEvent() to test the visibility of a window.
  92 // This is used by two distinct code paths:
  93 // . when activating from an event we only care about the actual visibility.
  94 // . when activating because of a keyboard accelerator, in which case we
  95 //   care about the TargetVisibility.
  96 bool VisibilityMatches(aura::Window* window, ActivateVisibilityType type) {
  97   bool visible = (type == CURRENT_VISIBILITY) ? window->IsVisible() :
  98       window->TargetVisibility();
  99   return visible || wm::IsWindowMinimized(window) ||
 100       (window->TargetVisibility() &&
 101         (window->parent()->id() == kShellWindowId_WorkspaceContainer ||
 102          window->parent()->id() == kShellWindowId_LockScreenContainer));
 103 }
 104
 105 // Returns true if |window| can be activated or deactivated.
 106 // A window manager typically defines some notion of "top level window" that
 107 // supports activation/deactivation.
 108 bool CanActivateWindowWithEvent(aura::Window* window,
 109                                 const ui::Event* event,
 110                                 ActivateVisibilityType visibility_type) {
 111   return window &&
 112       VisibilityMatches(window, visibility_type) &&
 113       (!aura::client::GetActivationDelegate(window) ||
 114         aura::client::GetActivationDelegate(window)->ShouldActivate()) &&
 115       SupportsChildActivation(window->parent()) &&
 116       (BelongsToContainerWithEqualOrGreaterId(
 117           window, kShellWindowId_SystemModalContainer) ||
 118        !Shell::GetInstance()->IsSystemModalWindowOpen());
 119 }
 120
 121 // When a modal window is activated, we bring its entire transient parent chain
 122 // to the front. This function must be called before the modal transient is
 123 // stacked at the top to ensure correct stacking order.
 124 void StackTransientParentsBelowModalWindow(aura::Window* window) {
 125   if (window->GetProperty(aura::client::kModalKey) != ui::MODAL_TYPE_WINDOW)
 126     return;
 127
 128   aura::Window* transient_parent = window->transient_parent();
 129   while (transient_parent) {
 130     transient_parent->parent()->StackChildAtTop(transient_parent);
 131     transient_parent = transient_parent->transient_parent();
 132   }
 133 }
 134
 135 aura::Window* FindFocusableWindowFor(aura::Window* window) {
 136   while (window && !window->CanFocus())
 137     window = window->parent();
 138   return window;
 139 }
 140
 141 }  // namespace
 142
 143 ////////////////////////////////////////////////////////////////////////////////
 144 // ActivationController, public:
 145
 146 ActivationController::ActivationController(
 147     aura::client::FocusClient* focus_client,
 148     ActivationControllerDelegate* delegate)
 149     : focus_client_(focus_client),
 150       updating_activation_(false),
 151       active_window_(NULL),
 152       ALLOW_THIS_IN_INITIALIZER_LIST(observer_manager_(this)),
 153       delegate_(delegate) {
 154   aura::Env::GetInstance()->AddObserver(this);
 155   focus_client_->AddObserver(this);
 156 }
 157
 158 ActivationController::~ActivationController() {
 159   aura::Env::GetInstance()->RemoveObserver(this);
 160   focus_client_->RemoveObserver(this);
 161 }
 162
 163 // static
 164 aura::Window* ActivationController::GetActivatableWindow(
 165     aura::Window* window,
 166     const ui::Event* event) {
 167   aura::Window* parent = window->parent();
 168   aura::Window* child = window;
 169   while (parent) {
 170     if (CanActivateWindowWithEvent(child, event, CURRENT_VISIBILITY))
 171       return child;
 172     // If |child| isn't activatable, but has transient parent, trace
 173     // that path instead.
 174     if (child->transient_parent())
 175       return GetActivatableWindow(child->transient_parent(), event);
 176     parent = parent->parent();
 177     child = child->parent();
 178   }
 179   return NULL;
 180 }
 181
 182 bool ActivationController::CanActivateWindow(aura::Window* window) const {
 183   return CanActivateWindowWithEvent(window, NULL, TARGET_VISIBILITY) &&
 184          !HasModalTransientChild(window);
 185 }
 186
 187 ////////////////////////////////////////////////////////////////////////////////
 188 // ActivationController, aura::client::ActivationClient implementation:
 189
 190 void ActivationController::AddObserver(
 191     aura::client::ActivationChangeObserver* observer) {
 192   observers_.AddObserver(observer);
 193 }
 194
 195 void ActivationController::RemoveObserver(
 196     aura::client::ActivationChangeObserver* observer) {
 197   observers_.RemoveObserver(observer);
 198 }
 199
 200 void ActivationController::ActivateWindow(aura::Window* window) {
 201   ActivateWindowWithEvent(window, NULL);
 202 }
 203
 204 void ActivationController::DeactivateWindow(aura::Window* window) {
 205   if (window)
 206     ActivateNextWindow(window);
 207 }
 208
 209 aura::Window* ActivationController::GetActiveWindow() {
 210   return active_window_;
 211 }
 212
 213 aura::Window* ActivationController::GetActivatableWindow(aura::Window* window) {
 214   return GetActivatableWindow(window, NULL);
 215 }
 216
 217 aura::Window* ActivationController::GetToplevelWindow(aura::Window* window) {
 218   return GetActivatableWindow(window, NULL);
 219 }
 220
 221 bool ActivationController::OnWillFocusWindow(aura::Window* window,
 222                                              const ui::Event* event) {
 223   return CanActivateWindowWithEvent(
 224       GetActivatableWindow(window, event), event, CURRENT_VISIBILITY);
 225 }
 226
 227 ////////////////////////////////////////////////////////////////////////////////
 228 // ActivationController, aura::WindowObserver implementation:
 229
 230 void ActivationController::OnWindowVisibilityChanged(aura::Window* window,
 231                                                      bool visible) {
 232   if (!visible) {
 233     aura::Window* next_window = ActivateNextWindow(window);
 234     if (next_window && next_window->parent() == window->parent()) {
 235       // Despite the activation change, we need to keep the window being hidden
 236       // stacked above the new window so it stays on top as it animates away.
 237       window->layer()->parent()->StackAbove(window->layer(),
 238                                             next_window->layer());
 239     }
 240   }
 241 }
 242
 243 void ActivationController::OnWindowDestroying(aura::Window* window) {
 244   // Don't use wm::IsActiveWidnow in case the |window| has already been
 245   // removed from the root tree.
 246   if (active_window_ == window) {
 247     active_window_ = NULL;
 248     FOR_EACH_OBSERVER(aura::client::ActivationChangeObserver,
 249                       observers_,
 250                       OnWindowActivated(NULL, window));
 251     ActivateWindow(GetTopmostWindowToActivate(window));
 252   }
 253   observer_manager_.Remove(window);
 254 }
 255
 256 ////////////////////////////////////////////////////////////////////////////////
 257 // ActivationController, aura::EnvObserver implementation:
 258
 259 void ActivationController::OnWindowInitialized(aura::Window* window) {
 260   observer_manager_.Add(window);
 261 }
 262
 263 ////////////////////////////////////////////////////////////////////////////////
 264 // ActivationController, aura::RootWindowObserver implementation:
 265
 266 void ActivationController::OnWindowFocused(aura::Window* gained_focus,
 267                                            aura::Window* lost_focus) {
 268   if (gained_focus)
 269     ActivateWindow(GetActivatableWindow(gained_focus, NULL));
 270 }
 271
 272 ////////////////////////////////////////////////////////////////////////////////
 273 // ActivationController, ui::EventHandler implementation:
 274
 275 void ActivationController::OnKeyEvent(ui::KeyEvent* event) {
 276 }
 277
 278 void ActivationController::OnMouseEvent(ui::MouseEvent* event) {
 279   if (event->type() == ui::ET_MOUSE_PRESSED)
 280     FocusWindowWithEvent(event);
 281 }
 282
 283 void ActivationController::OnScrollEvent(ui::ScrollEvent* event) {
 284 }
 285
 286 void ActivationController::OnTouchEvent(ui::TouchEvent* event) {
 287   if (event->type() == ui::ET_TOUCH_PRESSED)
 288     FocusWindowWithEvent(event);
 289 }
 290
 291 void ActivationController::OnGestureEvent(ui::GestureEvent* event) {
 292   if (event->type() == ui::ET_GESTURE_BEGIN &&
 293       event->details().touch_points() == 1) {
 294     FocusWindowWithEvent(event);
 295   }
 296 }
 297
 298 ////////////////////////////////////////////////////////////////////////////////
 299 // ActivationController, private:
 300
 301 void ActivationController::ActivateWindowWithEvent(aura::Window* window,
 302                                                    const ui::Event* event) {
 303   // Prevent recursion when called from focus.
 304   if (updating_activation_)
 305     return;
 306   base::AutoReset<bool> in_activate_window(&updating_activation_, true);
 307
 308   // We allow the delegate to change which window gets activated, or to prevent
 309   // activation changes.
 310   aura::Window* original_active_window = window;
 311   window = delegate_->WillActivateWindow(window);
 312   // TODO(beng): note that this breaks the previous behavior where an activation
 313   //             attempt by a window behind the lock screen would at least
 314   //             restack that window frontmost within its container. fix this.
 315   if (!window && original_active_window != window)
 316     return;
 317
 318   // TODO(beng): This encapsulates additional Ash-specific restrictions on
 319   //             whether activation can change. Should move to the delegate.
 320   if (window && !CanActivateWindowWithEvent(window, event, CURRENT_VISIBILITY))
 321     return;
 322
 323   if (active_window_ == window)
 324     return;
 325
 326   aura::Window* old_active = active_window_;
 327   active_window_ = window;
 328
 329   if (window &&
 330       !window->Contains(aura::client::GetFocusClient(window)->
 331           GetFocusedWindow())) {
 332     aura::client::GetFocusClient(window)->FocusWindow(window, event);
 333   }
 334
 335   if (window) {
 336     StackTransientParentsBelowModalWindow(window);
 337     window->parent()->StackChildAtTop(window);
 338   }
 339
 340   FOR_EACH_OBSERVER(aura::client::ActivationChangeObserver,
 341                     observers_,
 342                     OnWindowActivated(window, old_active));
 343   if (aura::client::GetActivationChangeObserver(old_active)) {
 344     aura::client::GetActivationChangeObserver(old_active)->OnWindowActivated(
 345         window, old_active);
 346   }
 347   if (aura::client::GetActivationChangeObserver(window)) {
 348     aura::client::GetActivationChangeObserver(window)->OnWindowActivated(
 349         window, old_active);
 350   }
 351 }
 352
 353 aura::Window* ActivationController::ActivateNextWindow(aura::Window* window) {
 354   aura::Window* next_window = NULL;
 355   if (wm::IsActiveWindow(window)) {
 356     next_window = GetTopmostWindowToActivate(window);
 357     ActivateWindow(next_window);
 358   }
 359   return next_window;
 360 }
 361
 362 aura::Window* ActivationController::GetTopmostWindowToActivate(
 363     aura::Window* ignore) const {
 364   size_t current_container_index = 0;
 365   // If the container of the window losing focus is in the list, start from that
 366   // container.
 367   aura::RootWindow* root = ignore->GetRootWindow();
 368   if (!root)
 369     root = Shell::GetActiveRootWindow();
 370   for (size_t i = 0; ignore && i < arraysize(kWindowContainerIds); i++) {
 371     aura::Window* container = Shell::GetContainer(root, kWindowContainerIds[i]);
 372     if (container && container->Contains(ignore)) {
 373       current_container_index = i;
 374       break;
 375     }
 376   }
 377
 378   // Look for windows to focus in that container and below.
 379   aura::Window* window = NULL;
 380   for (; !window && current_container_index < arraysize(kWindowContainerIds);
 381        current_container_index++) {
 382     aura::Window::Windows containers = Shell::GetContainersFromAllRootWindows(
 383         kWindowContainerIds[current_container_index],
 384         root);
 385     for (aura::Window::Windows::const_iterator iter = containers.begin();
 386          iter != containers.end() && !window; ++iter) {
 387       window = GetTopmostWindowToActivateInContainer((*iter), ignore);
 388     }
 389   }
 390   return window;
 391 }
 392
 393 aura::Window* ActivationController::GetTopmostWindowToActivateInContainer(
 394     aura::Window* container,
 395     aura::Window* ignore) const {
 396   // Workspace has an extra level of windows that needs to be special cased.
 397   if (container->id() == kShellWindowId_DefaultContainer) {
 398     for (aura::Window::Windows::const_reverse_iterator i =
 399              container->children().rbegin();
 400          i != container->children().rend(); ++i) {
 401       if ((*i)->IsVisible()) {
 402         aura::Window* window = GetTopmostWindowToActivateInContainer(
 403             *i, ignore);
 404         if (window)
 405           return window;
 406       }
 407     }
 408     return NULL;
 409   }
 410   for (aura::Window::Windows::const_reverse_iterator i =
 411            container->children().rbegin();
 412        i != container->children().rend();
 413        ++i) {
 414     if (*i != ignore &&
 415         CanActivateWindowWithEvent(*i, NULL, CURRENT_VISIBILITY) &&
 416         !wm::IsWindowMinimized(*i))
 417       return *i;
 418   }
 419   return NULL;
 420 }
 421
 422 void ActivationController::FocusWindowWithEvent(const ui::Event* event) {
 423   aura::Window* window = static_cast<aura::Window*>(event->target());
 424   window = delegate_->WillFocusWindow(window);
 425   if (GetActiveWindow() != window) {
 426     aura::client::GetFocusClient(window)->FocusWindow(
 427         FindFocusableWindowFor(window), event);
 428   }
 429 }
 430
 431 }  // namespace internal
 432 }  // namespace ash