ash/shelf/shelf_layout_manager.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/shelf/shelf_layout_manager.h"
   6
   7 #include <algorithm>
   8 #include <cmath>
   9 #include <cstring>
  10 #include <string>
  11 #include <vector>
  12
  13 #include "ash/accelerators/accelerator_commands.h"
  14 #include "ash/ash_switches.h"
  15 #include "ash/root_window_controller.h"
  16 #include "ash/screen_util.h"
  17 #include "ash/session/session_state_delegate.h"
  18 #include "ash/shelf/shelf.h"
  19 #include "ash/shelf/shelf_bezel_event_filter.h"
  20 #include "ash/shelf/shelf_constants.h"
  21 #include "ash/shelf/shelf_layout_manager_observer.h"
  22 #include "ash/shelf/shelf_widget.h"
  23 #include "ash/shell.h"
  24 #include "ash/shell_window_ids.h"
  25 #include "ash/system/status_area_widget.h"
  26 #include "ash/wm/gestures/shelf_gesture_handler.h"
  27 #include "ash/wm/lock_state_controller.h"
  28 #include "ash/wm/mru_window_tracker.h"
  29 #include "ash/wm/window_animations.h"
  30 #include "ash/wm/window_state.h"
  31 #include "ash/wm/window_util.h"
  32 #include "ash/wm/workspace_controller.h"
  33 #include "base/auto_reset.h"
  34 #include "base/command_line.h"
  35 #include "base/command_line.h"
  36 #include "base/i18n/rtl.h"
  37 #include "base/strings/string_number_conversions.h"
  38 #include "base/strings/string_util.h"
  39 #include "ui/aura/client/cursor_client.h"
  40 #include "ui/aura/window_event_dispatcher.h"
  41 #include "ui/base/ui_base_switches.h"
  42 #include "ui/compositor/layer.h"
  43 #include "ui/compositor/layer_animation_observer.h"
  44 #include "ui/compositor/layer_animator.h"
  45 #include "ui/compositor/scoped_layer_animation_settings.h"
  46 #include "ui/events/event.h"
  47 #include "ui/events/event_handler.h"
  48 #include "ui/gfx/screen.h"
  49 #include "ui/keyboard/keyboard_util.h"
  50 #include "ui/views/widget/widget.h"
  51 #include "ui/wm/public/activation_client.h"
  52
  53 namespace ash {
  54 namespace {
  55
  56 // Delay before showing the shelf. This is after the mouse stops moving.
  57 const int kAutoHideDelayMS = 200;
  58
  59 // To avoid hiding the shelf when the mouse transitions from a message bubble
  60 // into the shelf, the hit test area is enlarged by this amount of pixels to
  61 // keep the shelf from hiding.
  62 const int kNotificationBubbleGapHeight = 6;
  63
  64 // The maximum size of the region on the display opposing the shelf managed by
  65 // this ShelfLayoutManager which can trigger showing the shelf.
  66 // For instance:
  67 // - Primary display is left of secondary display.
  68 // - Shelf is left aligned
  69 // - This ShelfLayoutManager manages the shelf for the secondary display.
  70 // |kMaxAutoHideShowShelfRegionSize| refers to the maximum size of the region
  71 // from the right edge of the primary display which can trigger showing the
  72 // auto hidden shelf. The region is used to make it easier to trigger showing
  73 // the auto hidden shelf when the shelf is on the boundary between displays.
  74 const int kMaxAutoHideShowShelfRegionSize = 10;
  75
  76 ui::Layer* GetLayer(views::Widget* widget) {
  77   return widget->GetNativeView()->layer();
  78 }
  79
  80 bool IsDraggingTrayEnabled() {
  81   static bool dragging_tray_allowed = CommandLine::ForCurrentProcess()->
  82       HasSwitch(ash::switches::kAshEnableTrayDragging);
  83   return dragging_tray_allowed;
  84 }
  85
  86 }  // namespace
  87
  88 // static
  89 const int ShelfLayoutManager::kWorkspaceAreaVisibleInset = 2;
  90
  91 // static
  92 const int ShelfLayoutManager::kWorkspaceAreaAutoHideInset = 5;
  93
  94 // static
  95 const int ShelfLayoutManager::kAutoHideSize = 3;
  96
  97 // static
  98 const int ShelfLayoutManager::kShelfItemInset = 3;
  99
 100 // ShelfLayoutManager::AutoHideEventFilter -------------------------------------
 101
 102 // Notifies ShelfLayoutManager any time the mouse moves.
 103 class ShelfLayoutManager::AutoHideEventFilter : public ui::EventHandler {
 104  public:
 105   explicit AutoHideEventFilter(ShelfLayoutManager* shelf);
 106   virtual ~AutoHideEventFilter();
 107
 108   // Returns true if the last mouse event was a mouse drag.
 109   bool in_mouse_drag() const { return in_mouse_drag_; }
 110
 111   // Overridden from ui::EventHandler:
 112   virtual void OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
 113   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 114
 115  private:
 116   ShelfLayoutManager* shelf_;
 117   bool in_mouse_drag_;
 118   ShelfGestureHandler gesture_handler_;
 119   DISALLOW_COPY_AND_ASSIGN(AutoHideEventFilter);
 120 };
 121
 122 ShelfLayoutManager::AutoHideEventFilter::AutoHideEventFilter(
 123     ShelfLayoutManager* shelf)
 124     : shelf_(shelf),
 125       in_mouse_drag_(false) {
 126   Shell::GetInstance()->AddPreTargetHandler(this);
 127 }
 128
 129 ShelfLayoutManager::AutoHideEventFilter::~AutoHideEventFilter() {
 130   Shell::GetInstance()->RemovePreTargetHandler(this);
 131 }
 132
 133 void ShelfLayoutManager::AutoHideEventFilter::OnMouseEvent(
 134     ui::MouseEvent* event) {
 135   // This also checks IsShelfWindow() to make sure we don't attempt to hide the
 136   // shelf if the mouse down occurs on the shelf.
 137   in_mouse_drag_ = (event->type() == ui::ET_MOUSE_DRAGGED ||
 138                     (in_mouse_drag_ && event->type() != ui::ET_MOUSE_RELEASED &&
 139                      event->type() != ui::ET_MOUSE_CAPTURE_CHANGED)) &&
 140       !shelf_->IsShelfWindow(static_cast<aura::Window*>(event->target()));
 141   if (event->type() == ui::ET_MOUSE_MOVED)
 142     shelf_->UpdateAutoHideState();
 143   return;
 144 }
 145
 146 void ShelfLayoutManager::AutoHideEventFilter::OnGestureEvent(
 147     ui::GestureEvent* event) {
 148   if (shelf_->IsShelfWindow(static_cast<aura::Window*>(event->target()))) {
 149     if (gesture_handler_.ProcessGestureEvent(*event))
 150       event->StopPropagation();
 151   }
 152 }
 153
 154 // ShelfLayoutManager:UpdateShelfObserver --------------------------------------
 155
 156 // UpdateShelfObserver is used to delay updating the background until the
 157 // animation completes.
 158 class ShelfLayoutManager::UpdateShelfObserver
 159     : public ui::ImplicitAnimationObserver {
 160  public:
 161   explicit UpdateShelfObserver(ShelfLayoutManager* shelf) : shelf_(shelf) {
 162     shelf_->update_shelf_observer_ = this;
 163   }
 164
 165   void Detach() {
 166     shelf_ = NULL;
 167   }
 168
 169   virtual void OnImplicitAnimationsCompleted() OVERRIDE {
 170     if (shelf_)
 171       shelf_->UpdateShelfBackground(BACKGROUND_CHANGE_ANIMATE);
 172     delete this;
 173   }
 174
 175  private:
 176   virtual ~UpdateShelfObserver() {
 177     if (shelf_)
 178       shelf_->update_shelf_observer_ = NULL;
 179   }
 180
 181   // Shelf we're in. NULL if deleted before we're deleted.
 182   ShelfLayoutManager* shelf_;
 183
 184   DISALLOW_COPY_AND_ASSIGN(UpdateShelfObserver);
 185 };
 186
 187 // ShelfLayoutManager ----------------------------------------------------------
 188
 189 ShelfLayoutManager::ShelfLayoutManager(ShelfWidget* shelf)
 190     : SnapToPixelLayoutManager(shelf->GetNativeView()->parent()),
 191       root_window_(shelf->GetNativeView()->GetRootWindow()),
 192       updating_bounds_(false),
 193       auto_hide_behavior_(SHELF_AUTO_HIDE_BEHAVIOR_NEVER),
 194       alignment_(SHELF_ALIGNMENT_BOTTOM),
 195       shelf_(shelf),
 196       workspace_controller_(NULL),
 197       window_overlaps_shelf_(false),
 198       mouse_over_shelf_when_auto_hide_timer_started_(false),
 199       bezel_event_filter_(new ShelfBezelEventFilter(this)),
 200       gesture_drag_status_(GESTURE_DRAG_NONE),
 201       gesture_drag_amount_(0.f),
 202       gesture_drag_auto_hide_state_(SHELF_AUTO_HIDE_SHOWN),
 203       update_shelf_observer_(NULL),
 204       duration_override_in_ms_(0) {
 205   Shell::GetInstance()->AddShellObserver(this);
 206   Shell::GetInstance()->lock_state_controller()->AddObserver(this);
 207   aura::client::GetActivationClient(root_window_)->AddObserver(this);
 208   Shell::GetInstance()->session_state_delegate()->AddSessionStateObserver(this);
 209 }
 210
 211 ShelfLayoutManager::~ShelfLayoutManager() {
 212   if (update_shelf_observer_)
 213     update_shelf_observer_->Detach();
 214
 215   FOR_EACH_OBSERVER(ShelfLayoutManagerObserver, observers_, WillDeleteShelf());
 216   Shell::GetInstance()->RemoveShellObserver(this);
 217   Shell::GetInstance()->lock_state_controller()->RemoveObserver(this);
 218   aura::client::GetActivationClient(root_window_)->RemoveObserver(this);
 219   Shell::GetInstance()->
 220       session_state_delegate()->RemoveSessionStateObserver(this);
 221 }
 222
 223 void ShelfLayoutManager::SetAutoHideBehavior(ShelfAutoHideBehavior behavior) {
 224   if (auto_hide_behavior_ == behavior)
 225     return;
 226   auto_hide_behavior_ = behavior;
 227   UpdateVisibilityState();
 228   FOR_EACH_OBSERVER(ShelfLayoutManagerObserver, observers_,
 229                     OnAutoHideBehaviorChanged(root_window_,
 230                                               auto_hide_behavior_));
 231 }
 232
 233 void ShelfLayoutManager::PrepareForShutdown() {
 234   // Clear all event filters, otherwise sometimes those filters may catch
 235   // synthesized mouse event and cause crashes during the shutdown.
 236   set_workspace_controller(NULL);
 237   auto_hide_event_filter_.reset();
 238   bezel_event_filter_.reset();
 239 }
 240
 241 bool ShelfLayoutManager::IsVisible() const {
 242   // status_area_widget() may be NULL during the shutdown.
 243   return shelf_->status_area_widget() &&
 244       shelf_->status_area_widget()->IsVisible() &&
 245       (state_.visibility_state == SHELF_VISIBLE ||
 246        (state_.visibility_state == SHELF_AUTO_HIDE &&
 247         state_.auto_hide_state == SHELF_AUTO_HIDE_SHOWN));
 248 }
 249
 250 bool ShelfLayoutManager::SetAlignment(ShelfAlignment alignment) {
 251   if (alignment_ == alignment)
 252     return false;
 253
 254   // This should not be called during the lock screen transitions.
 255   DCHECK(!Shell::GetInstance()->session_state_delegate()->IsScreenLocked());
 256   alignment_ = alignment;
 257   shelf_->SetAlignment(alignment);
 258   LayoutShelf();
 259   return true;
 260 }
 261
 262 ShelfAlignment ShelfLayoutManager::GetAlignment() const {
 263   // When the screen is locked, the shelf is forced into bottom alignment.
 264   if (Shell::GetInstance()->session_state_delegate()->IsScreenLocked())
 265     return SHELF_ALIGNMENT_BOTTOM;
 266   return alignment_;
 267 }
 268
 269 gfx::Rect ShelfLayoutManager::GetIdealBounds() {
 270   gfx::Rect bounds(
 271       ScreenUtil::GetDisplayBoundsInParent(shelf_->GetNativeView()));
 272   int width = 0, height = 0;
 273   GetShelfSize(&width, &height);
 274   return SelectValueForShelfAlignment(
 275       gfx::Rect(bounds.x(), bounds.bottom() - height, bounds.width(), height),
 276       gfx::Rect(bounds.x(), bounds.y(), width, bounds.height()),
 277       gfx::Rect(bounds.right() - width, bounds.y(), width, bounds.height()),
 278       gfx::Rect(bounds.x(), bounds.y(), bounds.width(), height));
 279 }
 280
 281 void ShelfLayoutManager::LayoutShelf() {
 282   TargetBounds target_bounds;
 283   CalculateTargetBounds(state_, &target_bounds);
 284   UpdateBoundsAndOpacity(target_bounds, false, NULL);
 285
 286   if (shelf_->shelf()) {
 287     // This is not part of UpdateBoundsAndOpacity() because
 288     // SetShelfViewBounds() sets the bounds immediately and does not animate.
 289     // The height of the ShelfView for a horizontal shelf and the width of
 290     // the ShelfView for a vertical shelf are set when |shelf_|'s bounds
 291     // are changed via UpdateBoundsAndOpacity(). This sets the origin and the
 292     // dimension in the other direction.
 293     shelf_->shelf()->SetShelfViewBounds(
 294         target_bounds.shelf_bounds_in_shelf);
 295   }
 296 }
 297
 298 ShelfVisibilityState ShelfLayoutManager::CalculateShelfVisibility() {
 299   switch(auto_hide_behavior_) {
 300     case SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS:
 301       return SHELF_AUTO_HIDE;
 302     case SHELF_AUTO_HIDE_BEHAVIOR_NEVER:
 303       return SHELF_VISIBLE;
 304     case SHELF_AUTO_HIDE_ALWAYS_HIDDEN:
 305       return SHELF_HIDDEN;
 306   }
 307   return SHELF_VISIBLE;
 308 }
 309
 310 void ShelfLayoutManager::UpdateVisibilityState() {
 311   // Bail out early when there is no |workspace_controller_|, which happens
 312   // during shutdown after PrepareForShutdown.
 313   if (!workspace_controller_)
 314     return;
 315
 316   if (Shell::GetInstance()->session_state_delegate()->IsScreenLocked()) {
 317     SetState(SHELF_VISIBLE);
 318   } else {
 319     // TODO(zelidrag): Verify shelf drag animation still shows on the device
 320     // when we are in SHELF_AUTO_HIDE_ALWAYS_HIDDEN.
 321     WorkspaceWindowState window_state(workspace_controller_->GetWindowState());
 322     switch (window_state) {
 323       case WORKSPACE_WINDOW_STATE_FULL_SCREEN: {
 324         const aura::Window* fullscreen_window = GetRootWindowController(
 325             root_window_)->GetWindowForFullscreenMode();
 326         if (fullscreen_window && wm::GetWindowState(fullscreen_window)->
 327                 hide_shelf_when_fullscreen()) {
 328           SetState(SHELF_HIDDEN);
 329         } else {
 330           // The shelf is sometimes not hidden when in immersive fullscreen.
 331           // Force the shelf to be auto hidden in this case.
 332           SetState(SHELF_AUTO_HIDE);
 333         }
 334         break;
 335       }
 336
 337       case WORKSPACE_WINDOW_STATE_MAXIMIZED:
 338         SetState(CalculateShelfVisibility());
 339         break;
 340
 341       case WORKSPACE_WINDOW_STATE_WINDOW_OVERLAPS_SHELF:
 342       case WORKSPACE_WINDOW_STATE_DEFAULT:
 343         SetState(CalculateShelfVisibility());
 344         SetWindowOverlapsShelf(window_state ==
 345                                WORKSPACE_WINDOW_STATE_WINDOW_OVERLAPS_SHELF);
 346         break;
 347     }
 348   }
 349 }
 350
 351 void ShelfLayoutManager::UpdateAutoHideState() {
 352   ShelfAutoHideState auto_hide_state =
 353       CalculateAutoHideState(state_.visibility_state);
 354   if (auto_hide_state != state_.auto_hide_state) {
 355     if (auto_hide_state == SHELF_AUTO_HIDE_HIDDEN) {
 356       // Hides happen immediately.
 357       SetState(state_.visibility_state);
 358     } else {
 359       if (!auto_hide_timer_.IsRunning()) {
 360         mouse_over_shelf_when_auto_hide_timer_started_ =
 361             shelf_->GetWindowBoundsInScreen().Contains(
 362                 Shell::GetScreen()->GetCursorScreenPoint());
 363       }
 364       auto_hide_timer_.Start(
 365           FROM_HERE,
 366           base::TimeDelta::FromMilliseconds(kAutoHideDelayMS),
 367           this, &ShelfLayoutManager::UpdateAutoHideStateNow);
 368     }
 369   } else {
 370     StopAutoHideTimer();
 371   }
 372 }
 373
 374 void ShelfLayoutManager::SetWindowOverlapsShelf(bool value) {
 375   window_overlaps_shelf_ = value;
 376   UpdateShelfBackground(BACKGROUND_CHANGE_ANIMATE);
 377 }
 378
 379 void ShelfLayoutManager::AddObserver(ShelfLayoutManagerObserver* observer) {
 380   observers_.AddObserver(observer);
 381 }
 382
 383 void ShelfLayoutManager::RemoveObserver(ShelfLayoutManagerObserver* observer) {
 384   observers_.RemoveObserver(observer);
 385 }
 386
 387 ////////////////////////////////////////////////////////////////////////////////
 388 // ShelfLayoutManager, Gesture functions:
 389
 390 void ShelfLayoutManager::OnGestureEdgeSwipe(const ui::GestureEvent& gesture) {
 391   if (visibility_state() == SHELF_AUTO_HIDE) {
 392     gesture_drag_auto_hide_state_ = SHELF_AUTO_HIDE_SHOWN;
 393     gesture_drag_status_ = GESTURE_DRAG_COMPLETE_IN_PROGRESS;
 394     UpdateVisibilityState();
 395     gesture_drag_status_ = GESTURE_DRAG_NONE;
 396   }
 397 }
 398
 399 void ShelfLayoutManager::StartGestureDrag(const ui::GestureEvent& gesture) {
 400   gesture_drag_status_ = GESTURE_DRAG_IN_PROGRESS;
 401   gesture_drag_amount_ = 0.f;
 402   gesture_drag_auto_hide_state_ = visibility_state() == SHELF_AUTO_HIDE ?
 403       auto_hide_state() : SHELF_AUTO_HIDE_SHOWN;
 404   UpdateShelfBackground(BACKGROUND_CHANGE_ANIMATE);
 405 }
 406
 407 ShelfLayoutManager::DragState ShelfLayoutManager::UpdateGestureDrag(
 408     const ui::GestureEvent& gesture) {
 409   bool horizontal = IsHorizontalAlignment();
 410   gesture_drag_amount_ += horizontal ? gesture.details().scroll_y() :
 411                                        gesture.details().scroll_x();
 412   LayoutShelf();
 413
 414   // Start reveling the status menu when:
 415   //   - dragging up on an already visible shelf
 416   //   - dragging up on a hidden shelf, but it is currently completely visible.
 417   if (horizontal && gesture.details().scroll_y() < 0) {
 418     int min_height = 0;
 419     if (gesture_drag_auto_hide_state_ == SHELF_AUTO_HIDE_HIDDEN && shelf_)
 420       min_height = shelf_->GetContentsView()->GetPreferredSize().height();
 421
 422     if (min_height < shelf_->GetWindowBoundsInScreen().height() &&
 423         gesture.root_location().x() >=
 424         shelf_->status_area_widget()->GetWindowBoundsInScreen().x() &&
 425         IsDraggingTrayEnabled())
 426       return DRAG_TRAY;
 427   }
 428
 429   return DRAG_SHELF;
 430 }
 431
 432 void ShelfLayoutManager::CompleteGestureDrag(const ui::GestureEvent& gesture) {
 433   bool horizontal = IsHorizontalAlignment();
 434   bool should_change = false;
 435   if (gesture.type() == ui::ET_GESTURE_SCROLL_END) {
 436     // The visibility of the shelf changes only if the shelf was dragged X%
 437     // along the correct axis. If the shelf was already visible, then the
 438     // direction of the drag does not matter.
 439     const float kDragHideThreshold = 0.4f;
 440     gfx::Rect bounds = GetIdealBounds();
 441     float drag_ratio = fabs(gesture_drag_amount_) /
 442                        (horizontal ?  bounds.height() : bounds.width());
 443     if (gesture_drag_auto_hide_state_ == SHELF_AUTO_HIDE_SHOWN) {
 444       should_change = drag_ratio > kDragHideThreshold;
 445     } else {
 446       bool correct_direction = false;
 447       switch (GetAlignment()) {
 448         case SHELF_ALIGNMENT_BOTTOM:
 449         case SHELF_ALIGNMENT_RIGHT:
 450           correct_direction = gesture_drag_amount_ < 0;
 451           break;
 452         case SHELF_ALIGNMENT_LEFT:
 453         case SHELF_ALIGNMENT_TOP:
 454           correct_direction = gesture_drag_amount_ > 0;
 455           break;
 456       }
 457       should_change = correct_direction && drag_ratio > kDragHideThreshold;
 458     }
 459   } else if (gesture.type() == ui::ET_SCROLL_FLING_START) {
 460     if (gesture_drag_auto_hide_state_ == SHELF_AUTO_HIDE_SHOWN) {
 461       should_change = horizontal ? fabs(gesture.details().velocity_y()) > 0 :
 462                                    fabs(gesture.details().velocity_x()) > 0;
 463     } else {
 464       should_change = SelectValueForShelfAlignment(
 465           gesture.details().velocity_y() < 0,
 466           gesture.details().velocity_x() > 0,
 467           gesture.details().velocity_x() < 0,
 468           gesture.details().velocity_y() > 0);
 469     }
 470   } else {
 471     NOTREACHED();
 472   }
 473
 474   if (!should_change) {
 475     CancelGestureDrag();
 476     return;
 477   }
 478   if (shelf_) {
 479     shelf_->Deactivate();
 480     shelf_->status_area_widget()->Deactivate();
 481   }
 482   gesture_drag_auto_hide_state_ =
 483       gesture_drag_auto_hide_state_ == SHELF_AUTO_HIDE_SHOWN ?
 484       SHELF_AUTO_HIDE_HIDDEN : SHELF_AUTO_HIDE_SHOWN;
 485   ShelfAutoHideBehavior new_auto_hide_behavior =
 486       gesture_drag_auto_hide_state_ == SHELF_AUTO_HIDE_SHOWN ?
 487       SHELF_AUTO_HIDE_BEHAVIOR_NEVER : SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS;
 488
 489   // When in fullscreen and the shelf is forced to be auto hidden, the auto hide
 490   // behavior affects neither the visibility state nor the auto hide state. Set
 491   // |gesture_drag_status_| to GESTURE_DRAG_COMPLETE_IN_PROGRESS to set the auto
 492   // hide state to |gesture_drag_auto_hide_state_|.
 493   gesture_drag_status_ = GESTURE_DRAG_COMPLETE_IN_PROGRESS;
 494   if (auto_hide_behavior_ != new_auto_hide_behavior)
 495     SetAutoHideBehavior(new_auto_hide_behavior);
 496   else
 497     UpdateVisibilityState();
 498   gesture_drag_status_ = GESTURE_DRAG_NONE;
 499 }
 500
 501 void ShelfLayoutManager::CancelGestureDrag() {
 502   gesture_drag_status_ = GESTURE_DRAG_CANCEL_IN_PROGRESS;
 503   UpdateVisibilityState();
 504   gesture_drag_status_ = GESTURE_DRAG_NONE;
 505 }
 506
 507 void ShelfLayoutManager::SetAnimationDurationOverride(
 508     int duration_override_in_ms) {
 509   duration_override_in_ms_ = duration_override_in_ms;
 510 }
 511
 512 ////////////////////////////////////////////////////////////////////////////////
 513 // ShelfLayoutManager, aura::LayoutManager implementation:
 514
 515 void ShelfLayoutManager::OnWindowResized() {
 516   LayoutShelf();
 517 }
 518
 519 void ShelfLayoutManager::SetChildBounds(aura::Window* child,
 520                                         const gfx::Rect& requested_bounds) {
 521   SnapToPixelLayoutManager::SetChildBounds(child, requested_bounds);
 522   // We may contain other widgets (such as frame maximize bubble) but they don't
 523   // effect the layout in anyway.
 524   if (!updating_bounds_ &&
 525       ((shelf_->GetNativeView() == child) ||
 526        (shelf_->status_area_widget()->GetNativeView() == child))) {
 527     LayoutShelf();
 528   }
 529 }
 530
 531 void ShelfLayoutManager::OnLockStateChanged(bool locked) {
 532   // Force the shelf to layout for alignment (bottom if locked, restore
 533   // the previous alignment otherwise).
 534   state_.is_screen_locked = locked;
 535   shelf_->SetAlignment(locked ? SHELF_ALIGNMENT_BOTTOM : alignment_);
 536   UpdateVisibilityState();
 537   LayoutShelf();
 538 }
 539
 540 void ShelfLayoutManager::OnWindowActivated(aura::Window* gained_active,
 541                                            aura::Window* lost_active) {
 542   UpdateAutoHideStateNow();
 543 }
 544
 545 bool ShelfLayoutManager::IsHorizontalAlignment() const {
 546   return GetAlignment() == SHELF_ALIGNMENT_BOTTOM ||
 547          GetAlignment() == SHELF_ALIGNMENT_TOP;
 548 }
 549
 550 // static
 551 ShelfLayoutManager* ShelfLayoutManager::ForShelf(aura::Window* window) {
 552   ShelfWidget* shelf = RootWindowController::ForShelf(window)->shelf();
 553   return shelf ? shelf->shelf_layout_manager() : NULL;
 554 }
 555
 556 ////////////////////////////////////////////////////////////////////////////////
 557 // ShelfLayoutManager, private:
 558
 559 ShelfLayoutManager::TargetBounds::TargetBounds() : opacity(0.0f) {}
 560 ShelfLayoutManager::TargetBounds::~TargetBounds() {}
 561
 562 void ShelfLayoutManager::SetState(ShelfVisibilityState visibility_state) {
 563   if (!shelf_->GetNativeView())
 564     return;
 565
 566   State state;
 567   state.visibility_state = visibility_state;
 568   state.auto_hide_state = CalculateAutoHideState(visibility_state);
 569   state.window_state = workspace_controller_ ?
 570       workspace_controller_->GetWindowState() : WORKSPACE_WINDOW_STATE_DEFAULT;
 571
 572   // Force an update because gesture drags affect the shelf bounds and we
 573   // should animate back to the normal bounds at the end of a gesture.
 574   bool force_update =
 575       (gesture_drag_status_ == GESTURE_DRAG_CANCEL_IN_PROGRESS ||
 576        gesture_drag_status_ == GESTURE_DRAG_COMPLETE_IN_PROGRESS);
 577
 578   if (!force_update && state_.Equals(state))
 579     return;  // Nothing changed.
 580
 581   FOR_EACH_OBSERVER(ShelfLayoutManagerObserver, observers_,
 582                     WillChangeVisibilityState(visibility_state));
 583
 584   if (state.visibility_state == SHELF_AUTO_HIDE) {
 585     // When state is SHELF_AUTO_HIDE we need to track when the mouse is over the
 586     // shelf to unhide it. AutoHideEventFilter does that for us.
 587     if (!auto_hide_event_filter_)
 588       auto_hide_event_filter_.reset(new AutoHideEventFilter(this));
 589   } else {
 590     auto_hide_event_filter_.reset(NULL);
 591   }
 592
 593   StopAutoHideTimer();
 594
 595   State old_state = state_;
 596   state_ = state;
 597
 598   BackgroundAnimatorChangeType change_type = BACKGROUND_CHANGE_ANIMATE;
 599   bool delay_background_change = false;
 600
 601   // Do not animate the background when:
 602   // - Going from a hidden / auto hidden shelf in fullscreen to a visible shelf
 603   //   in maximized mode.
 604   // - Going from an auto hidden shelf in maximized mode to a visible shelf in
 605   //   maximized mode.
 606   if (state.visibility_state == SHELF_VISIBLE &&
 607       state.window_state == WORKSPACE_WINDOW_STATE_MAXIMIZED &&
 608       old_state.visibility_state != SHELF_VISIBLE) {
 609     change_type = BACKGROUND_CHANGE_IMMEDIATE;
 610   } else {
 611     // Delay the animation when the shelf was hidden, and has just been made
 612     // visible (e.g. using a gesture-drag).
 613     if (state.visibility_state == SHELF_VISIBLE &&
 614         old_state.visibility_state == SHELF_AUTO_HIDE &&
 615         old_state.auto_hide_state == SHELF_AUTO_HIDE_HIDDEN) {
 616       delay_background_change = true;
 617     }
 618   }
 619
 620   if (delay_background_change) {
 621     if (update_shelf_observer_)
 622       update_shelf_observer_->Detach();
 623     // UpdateShelfBackground deletes itself when the animation is done.
 624     update_shelf_observer_ = new UpdateShelfObserver(this);
 625   } else {
 626     UpdateShelfBackground(change_type);
 627   }
 628
 629   shelf_->SetDimsShelf(
 630       state.visibility_state == SHELF_VISIBLE &&
 631       state.window_state == WORKSPACE_WINDOW_STATE_MAXIMIZED);
 632
 633   TargetBounds target_bounds;
 634   CalculateTargetBounds(state_, &target_bounds);
 635   UpdateBoundsAndOpacity(target_bounds, true,
 636       delay_background_change ? update_shelf_observer_ : NULL);
 637
 638   // OnAutoHideStateChanged Should be emitted when:
 639   //  - firstly state changed to auto-hide from other state
 640   //  - or, auto_hide_state has changed
 641   if ((old_state.visibility_state != state_.visibility_state &&
 642        state_.visibility_state == SHELF_AUTO_HIDE) ||
 643       old_state.auto_hide_state != state_.auto_hide_state) {
 644     FOR_EACH_OBSERVER(ShelfLayoutManagerObserver, observers_,
 645                       OnAutoHideStateChanged(state_.auto_hide_state));
 646   }
 647 }
 648
 649 void ShelfLayoutManager::UpdateBoundsAndOpacity(
 650     const TargetBounds& target_bounds,
 651     bool animate,
 652     ui::ImplicitAnimationObserver* observer) {
 653   base::AutoReset<bool> auto_reset_updating_bounds(&updating_bounds_, true);
 654
 655   ui::ScopedLayerAnimationSettings shelf_animation_setter(
 656       GetLayer(shelf_)->GetAnimator());
 657   ui::ScopedLayerAnimationSettings status_animation_setter(
 658       GetLayer(shelf_->status_area_widget())->GetAnimator());
 659   if (animate) {
 660     int duration = duration_override_in_ms_ ? duration_override_in_ms_ :
 661                                               kCrossFadeDurationMS;
 662     shelf_animation_setter.SetTransitionDuration(
 663         base::TimeDelta::FromMilliseconds(duration));
 664     shelf_animation_setter.SetTweenType(gfx::Tween::EASE_OUT);
 665     shelf_animation_setter.SetPreemptionStrategy(
 666         ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 667     status_animation_setter.SetTransitionDuration(
 668         base::TimeDelta::FromMilliseconds(duration));
 669     status_animation_setter.SetTweenType(gfx::Tween::EASE_OUT);
 670     status_animation_setter.SetPreemptionStrategy(
 671         ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 672   } else {
 673     StopAnimating();
 674     shelf_animation_setter.SetTransitionDuration(base::TimeDelta());
 675     status_animation_setter.SetTransitionDuration(base::TimeDelta());
 676   }
 677   if (observer)
 678     status_animation_setter.AddObserver(observer);
 679
 680   GetLayer(shelf_)->SetOpacity(target_bounds.opacity);
 681   shelf_->SetBounds(ScreenUtil::ConvertRectToScreen(
 682        shelf_->GetNativeView()->parent(),
 683        target_bounds.shelf_bounds_in_root));
 684
 685   GetLayer(shelf_->status_area_widget())->SetOpacity(
 686       target_bounds.status_opacity);
 687
 688   // Having a window which is visible but does not have an opacity is an illegal
 689   // state. We therefore show / hide the shelf here if required.
 690   if (!target_bounds.status_opacity)
 691     shelf_->status_area_widget()->Hide();
 692   else if (target_bounds.status_opacity)
 693     shelf_->status_area_widget()->Show();
 694
 695   // TODO(harrym): Once status area widget is a child view of shelf
 696   // this can be simplified.
 697   gfx::Rect status_bounds = target_bounds.status_bounds_in_shelf;
 698   status_bounds.set_x(status_bounds.x() +
 699                       target_bounds.shelf_bounds_in_root.x());
 700   status_bounds.set_y(status_bounds.y() +
 701                       target_bounds.shelf_bounds_in_root.y());
 702   shelf_->status_area_widget()->SetBounds(
 703       ScreenUtil::ConvertRectToScreen(
 704           shelf_->status_area_widget()->GetNativeView()->parent(),
 705           status_bounds));
 706   SessionStateDelegate* session_state_delegate =
 707       Shell::GetInstance()->session_state_delegate();
 708   if (!state_.is_screen_locked) {
 709     gfx::Insets insets;
 710     // If user session is blocked (login to new user session or add user to
 711     // the existing session - multi-profile) then give 100% of work area only if
 712     // keyboard is not shown.
 713     if (!session_state_delegate->IsUserSessionBlocked() ||
 714         !keyboard_bounds_.IsEmpty()) {
 715       insets = target_bounds.work_area_insets;
 716     }
 717     Shell::GetInstance()->SetDisplayWorkAreaInsets(root_window_, insets);
 718   }
 719 }
 720
 721 void ShelfLayoutManager::StopAnimating() {
 722   GetLayer(shelf_)->GetAnimator()->StopAnimating();
 723   GetLayer(shelf_->status_area_widget())->GetAnimator()->StopAnimating();
 724 }
 725
 726 void ShelfLayoutManager::GetShelfSize(int* width, int* height) {
 727   *width = *height = 0;
 728   gfx::Size status_size(
 729       shelf_->status_area_widget()->GetWindowBoundsInScreen().size());
 730   if (IsHorizontalAlignment())
 731     *height = kShelfSize;
 732   else
 733     *width = kShelfSize;
 734 }
 735
 736 void ShelfLayoutManager::AdjustBoundsBasedOnAlignment(int inset,
 737                                                       gfx::Rect* bounds) const {
 738   bounds->Inset(SelectValueForShelfAlignment(
 739       gfx::Insets(0, 0, inset, 0),
 740       gfx::Insets(0, inset, 0, 0),
 741       gfx::Insets(0, 0, 0, inset),
 742       gfx::Insets(inset, 0, 0, 0)));
 743 }
 744
 745 void ShelfLayoutManager::CalculateTargetBounds(
 746     const State& state,
 747     TargetBounds* target_bounds) {
 748   const gfx::Rect available_bounds(root_window_->bounds());
 749   gfx::Rect status_size(
 750       shelf_->status_area_widget()->GetWindowBoundsInScreen().size());
 751   int shelf_width = 0, shelf_height = 0;
 752   GetShelfSize(&shelf_width, &shelf_height);
 753   if (IsHorizontalAlignment())
 754     shelf_width = available_bounds.width();
 755   else
 756     shelf_height = available_bounds.height();
 757
 758   if (state.visibility_state == SHELF_AUTO_HIDE &&
 759       state.auto_hide_state == SHELF_AUTO_HIDE_HIDDEN) {
 760     // Auto-hidden shelf always starts with the default size. If a gesture-drag
 761     // is in progress, then the call to UpdateTargetBoundsForGesture() below
 762     // takes care of setting the height properly.
 763     if (IsHorizontalAlignment())
 764       shelf_height = kAutoHideSize;
 765     else
 766       shelf_width = kAutoHideSize;
 767   } else if (state.visibility_state == SHELF_HIDDEN ||
 768       (!keyboard_bounds_.IsEmpty() && !keyboard::IsKeyboardOverscrollEnabled()))
 769   {
 770     if (IsHorizontalAlignment())
 771       shelf_height = 0;
 772     else
 773       shelf_width = 0;
 774   }
 775
 776   int bottom_shelf_vertical_offset = available_bounds.bottom();
 777   if (keyboard_bounds_.IsEmpty())
 778     bottom_shelf_vertical_offset -= shelf_height;
 779   else
 780     bottom_shelf_vertical_offset -= keyboard_bounds_.height();
 781
 782   target_bounds->shelf_bounds_in_root = SelectValueForShelfAlignment(
 783       gfx::Rect(available_bounds.x(), bottom_shelf_vertical_offset,
 784                     available_bounds.width(), shelf_height),
 785       gfx::Rect(available_bounds.x(), available_bounds.y(),
 786                     shelf_width, available_bounds.height()),
 787       gfx::Rect(available_bounds.right() - shelf_width, available_bounds.y(),
 788                     shelf_width, available_bounds.height()),
 789       gfx::Rect(available_bounds.x(), available_bounds.y(),
 790                     available_bounds.width(), shelf_height));
 791
 792   if (IsHorizontalAlignment())
 793     status_size.set_height(kShelfSize);
 794   else
 795     status_size.set_width(kShelfSize);
 796
 797   target_bounds->status_bounds_in_shelf = SelectValueForShelfAlignment(
 798       gfx::Rect(base::i18n::IsRTL() ? 0 : shelf_width - status_size.width(),
 799                     0, status_size.width(), status_size.height()),
 800       gfx::Rect(shelf_width - status_size.width(),
 801                     shelf_height - status_size.height(), status_size.width(),
 802                     status_size.height()),
 803       gfx::Rect(0, shelf_height - status_size.height(),
 804                     status_size.width(), status_size.height()),
 805       gfx::Rect(base::i18n::IsRTL() ? 0 : shelf_width - status_size.width(),
 806                     shelf_height - status_size.height(),
 807                     status_size.width(), status_size.height()));
 808
 809   target_bounds->work_area_insets = SelectValueForShelfAlignment(
 810       gfx::Insets(0, 0, GetWorkAreaSize(state, shelf_height), 0),
 811       gfx::Insets(0, GetWorkAreaSize(state, shelf_width), 0, 0),
 812       gfx::Insets(0, 0, 0, GetWorkAreaSize(state, shelf_width)),
 813       gfx::Insets(GetWorkAreaSize(state, shelf_height), 0, 0, 0));
 814
 815   // TODO(varkha): The functionality of managing insets for display areas
 816   // should probably be pushed to a separate component. This would simplify or
 817   // remove entirely the dependency on keyboard and dock.
 818
 819   if (!keyboard_bounds_.IsEmpty() && !keyboard::IsKeyboardOverscrollEnabled()) {
 820     // Also push in the work area inset for the keyboard if it is visible.
 821     gfx::Insets keyboard_insets(0, 0, keyboard_bounds_.height(), 0);
 822     target_bounds->work_area_insets += keyboard_insets;
 823   }
 824
 825   // Also push in the work area inset for the dock if it is visible.
 826   if (!dock_bounds_.IsEmpty()) {
 827     gfx::Insets dock_insets(
 828         0, (dock_bounds_.x() > 0 ? 0 : dock_bounds_.width()),
 829         0, (dock_bounds_.x() > 0 ? dock_bounds_.width() : 0));
 830     target_bounds->work_area_insets += dock_insets;
 831   }
 832
 833   target_bounds->opacity =
 834       (gesture_drag_status_ == GESTURE_DRAG_IN_PROGRESS ||
 835        state.visibility_state == SHELF_VISIBLE ||
 836        state.visibility_state == SHELF_AUTO_HIDE) ? 1.0f : 0.0f;
 837   target_bounds->status_opacity =
 838       (state.visibility_state == SHELF_AUTO_HIDE &&
 839        state.auto_hide_state == SHELF_AUTO_HIDE_HIDDEN &&
 840        gesture_drag_status_ != GESTURE_DRAG_IN_PROGRESS) ?
 841       0.0f : target_bounds->opacity;
 842
 843   if (gesture_drag_status_ == GESTURE_DRAG_IN_PROGRESS)
 844     UpdateTargetBoundsForGesture(target_bounds);
 845
 846   // This needs to happen after calling UpdateTargetBoundsForGesture(), because
 847   // that can change the size of the shelf.
 848   target_bounds->shelf_bounds_in_shelf = SelectValueForShelfAlignment(
 849       gfx::Rect(0, 0,
 850                 shelf_width - status_size.width(),
 851                 target_bounds->shelf_bounds_in_root.height()),
 852       gfx::Rect(0, 0, target_bounds->shelf_bounds_in_root.width(),
 853                 shelf_height - status_size.height()),
 854       gfx::Rect(0, 0, target_bounds->shelf_bounds_in_root.width(),
 855                 shelf_height - status_size.height()),
 856       gfx::Rect(0, 0,
 857                 shelf_width - status_size.width(),
 858                 target_bounds->shelf_bounds_in_root.height()));
 859 }
 860
 861 void ShelfLayoutManager::UpdateTargetBoundsForGesture(
 862     TargetBounds* target_bounds) const {
 863   CHECK_EQ(GESTURE_DRAG_IN_PROGRESS, gesture_drag_status_);
 864   bool horizontal = IsHorizontalAlignment();
 865   const gfx::Rect& available_bounds(root_window_->bounds());
 866   int resistance_free_region = 0;
 867
 868   if (gesture_drag_auto_hide_state_ == SHELF_AUTO_HIDE_HIDDEN &&
 869       visibility_state() == SHELF_AUTO_HIDE &&
 870       auto_hide_state() != SHELF_AUTO_HIDE_SHOWN) {
 871     // If the shelf was hidden when the drag started (and the state hasn't
 872     // changed since then, e.g. because the tray-menu was shown because of the
 873     // drag), then allow the drag some resistance-free region at first to make
 874     // sure the shelf sticks with the finger until the shelf is visible.
 875     resistance_free_region = kShelfSize - kAutoHideSize;
 876   }
 877
 878   bool resist = SelectValueForShelfAlignment(
 879       gesture_drag_amount_ < -resistance_free_region,
 880       gesture_drag_amount_ > resistance_free_region,
 881       gesture_drag_amount_ < -resistance_free_region,
 882       gesture_drag_amount_ > resistance_free_region);
 883
 884   float translate = 0.f;
 885   if (resist) {
 886     float diff = fabsf(gesture_drag_amount_) - resistance_free_region;
 887     diff = std::min(diff, sqrtf(diff));
 888     if (gesture_drag_amount_ < 0)
 889       translate = -resistance_free_region - diff;
 890     else
 891       translate = resistance_free_region + diff;
 892   } else {
 893     translate = gesture_drag_amount_;
 894   }
 895
 896   if (horizontal) {
 897     // Move and size the shelf with the gesture.
 898     int shelf_height = target_bounds->shelf_bounds_in_root.height() - translate;
 899     shelf_height = std::max(shelf_height, kAutoHideSize);
 900     target_bounds->shelf_bounds_in_root.set_height(shelf_height);
 901     if (GetAlignment() == SHELF_ALIGNMENT_BOTTOM) {
 902       target_bounds->shelf_bounds_in_root.set_y(
 903           available_bounds.bottom() - shelf_height);
 904     }
 905
 906     target_bounds->status_bounds_in_shelf.set_y(0);
 907   } else {
 908     // Move and size the shelf with the gesture.
 909     int shelf_width = target_bounds->shelf_bounds_in_root.width();
 910     bool right_aligned = GetAlignment() == SHELF_ALIGNMENT_RIGHT;
 911     if (right_aligned)
 912       shelf_width -= translate;
 913     else
 914       shelf_width += translate;
 915     shelf_width = std::max(shelf_width, kAutoHideSize);
 916     target_bounds->shelf_bounds_in_root.set_width(shelf_width);
 917     if (right_aligned) {
 918       target_bounds->shelf_bounds_in_root.set_x(
 919           available_bounds.right() - shelf_width);
 920     }
 921
 922     if (right_aligned)
 923       target_bounds->status_bounds_in_shelf.set_x(0);
 924     else
 925       target_bounds->status_bounds_in_shelf.set_x(
 926           target_bounds->shelf_bounds_in_root.width() -
 927           kShelfSize);
 928   }
 929 }
 930
 931 void ShelfLayoutManager::UpdateShelfBackground(
 932     BackgroundAnimatorChangeType type) {
 933   const ShelfBackgroundType background_type(GetShelfBackgroundType());
 934   shelf_->SetPaintsBackground(background_type, type);
 935   FOR_EACH_OBSERVER(ShelfLayoutManagerObserver, observers_,
 936                     OnBackgroundUpdated(background_type, type));
 937 }
 938
 939 ShelfBackgroundType ShelfLayoutManager::GetShelfBackgroundType() const {
 940   if (state_.visibility_state != SHELF_AUTO_HIDE &&
 941       state_.window_state == WORKSPACE_WINDOW_STATE_MAXIMIZED) {
 942     return SHELF_BACKGROUND_MAXIMIZED;
 943   }
 944
 945   if (gesture_drag_status_ == GESTURE_DRAG_IN_PROGRESS ||
 946       (!state_.is_screen_locked && window_overlaps_shelf_) ||
 947       (state_.visibility_state == SHELF_AUTO_HIDE)) {
 948     return SHELF_BACKGROUND_OVERLAP;
 949   }
 950
 951   return SHELF_BACKGROUND_DEFAULT;
 952 }
 953
 954 void ShelfLayoutManager::UpdateAutoHideStateNow() {
 955   SetState(state_.visibility_state);
 956
 957   // If the state did not change, the auto hide timer may still be running.
 958   StopAutoHideTimer();
 959 }
 960
 961 void ShelfLayoutManager::StopAutoHideTimer() {
 962   auto_hide_timer_.Stop();
 963   mouse_over_shelf_when_auto_hide_timer_started_ = false;
 964 }
 965
 966 gfx::Rect ShelfLayoutManager::GetAutoHideShowShelfRegionInScreen() const {
 967   gfx::Rect shelf_bounds_in_screen = shelf_->GetWindowBoundsInScreen();
 968   gfx::Vector2d offset = SelectValueForShelfAlignment(
 969       gfx::Vector2d(0, shelf_bounds_in_screen.height()),
 970       gfx::Vector2d(-kMaxAutoHideShowShelfRegionSize, 0),
 971       gfx::Vector2d(shelf_bounds_in_screen.width(), 0),
 972       gfx::Vector2d(0, -kMaxAutoHideShowShelfRegionSize));
 973
 974   gfx::Rect show_shelf_region_in_screen = shelf_bounds_in_screen;
 975   show_shelf_region_in_screen += offset;
 976   if (IsHorizontalAlignment())
 977     show_shelf_region_in_screen.set_height(kMaxAutoHideShowShelfRegionSize);
 978   else
 979     show_shelf_region_in_screen.set_width(kMaxAutoHideShowShelfRegionSize);
 980
 981   // TODO: Figure out if we need any special handling when the keyboard is
 982   // visible.
 983   return show_shelf_region_in_screen;
 984 }
 985
 986 ShelfAutoHideState ShelfLayoutManager::CalculateAutoHideState(
 987     ShelfVisibilityState visibility_state) const {
 988   if (visibility_state != SHELF_AUTO_HIDE || !shelf_)
 989     return SHELF_AUTO_HIDE_HIDDEN;
 990
 991   Shell* shell = Shell::GetInstance();
 992   if (shell->GetAppListTargetVisibility())
 993     return SHELF_AUTO_HIDE_SHOWN;
 994
 995   if (shelf_->status_area_widget() &&
 996       shelf_->status_area_widget()->ShouldShowShelf())
 997     return SHELF_AUTO_HIDE_SHOWN;
 998
 999   if (shelf_->shelf() && shelf_->shelf()->IsShowingMenu())
1000     return SHELF_AUTO_HIDE_SHOWN;
1001
1002   if (shelf_->shelf() && shelf_->shelf()->IsShowingOverflowBubble())
1003     return SHELF_AUTO_HIDE_SHOWN;
1004
1005   if (shelf_->IsActive() ||
1006       (shelf_->status_area_widget() &&
1007        shelf_->status_area_widget()->IsActive()))
1008     return SHELF_AUTO_HIDE_SHOWN;
1009
1010   const std::vector<aura::Window*> windows =
1011       ash::MruWindowTracker::BuildWindowList(false);
1012
1013   // Process the window list and check if there are any visible windows.
1014   bool visible_window = false;
1015   for (size_t i = 0; i < windows.size(); ++i) {
1016     if (windows[i] && windows[i]->IsVisible() &&
1017         !wm::GetWindowState(windows[i])->IsMinimized() &&
1018         root_window_ == windows[i]->GetRootWindow()) {
1019       visible_window = true;
1020       break;
1021     }
1022   }
1023   // If there are no visible windows do not hide the shelf.
1024   if (!visible_window)
1025     return SHELF_AUTO_HIDE_SHOWN;
1026
1027   if (gesture_drag_status_ == GESTURE_DRAG_COMPLETE_IN_PROGRESS)
1028     return gesture_drag_auto_hide_state_;
1029
1030   // Don't show if the user is dragging the mouse.
1031   if (auto_hide_event_filter_.get() && auto_hide_event_filter_->in_mouse_drag())
1032     return SHELF_AUTO_HIDE_HIDDEN;
1033
1034   // Ignore the mouse position if mouse events are disabled.
1035   aura::client::CursorClient* cursor_client = aura::client::GetCursorClient(
1036       shelf_->GetNativeWindow()->GetRootWindow());
1037   if (!cursor_client->IsMouseEventsEnabled())
1038     return SHELF_AUTO_HIDE_HIDDEN;
1039
1040   gfx::Rect shelf_region = shelf_->GetWindowBoundsInScreen();
1041   if (shelf_->status_area_widget() &&
1042       shelf_->status_area_widget()->IsMessageBubbleShown() &&
1043       IsVisible()) {
1044     // Increase the the hit test area to prevent the shelf from disappearing
1045     // when the mouse is over the bubble gap.
1046     ShelfAlignment alignment = GetAlignment();
1047     shelf_region.Inset(alignment == SHELF_ALIGNMENT_RIGHT ?
1048                            -kNotificationBubbleGapHeight : 0,
1049                        alignment == SHELF_ALIGNMENT_BOTTOM ?
1050                            -kNotificationBubbleGapHeight : 0,
1051                        alignment == SHELF_ALIGNMENT_LEFT ?
1052                            -kNotificationBubbleGapHeight : 0,
1053                        alignment == SHELF_ALIGNMENT_TOP ?
1054                            -kNotificationBubbleGapHeight : 0);
1055   }
1056
1057   gfx::Point cursor_position_in_screen =
1058       Shell::GetScreen()->GetCursorScreenPoint();
1059   if (shelf_region.Contains(cursor_position_in_screen))
1060     return SHELF_AUTO_HIDE_SHOWN;
1061
1062   // When the shelf is auto hidden and the shelf is on the boundary between two
1063   // displays, it is hard to trigger showing the shelf. For instance, if a
1064   // user's primary display is left of their secondary display, it is hard to
1065   // unautohide a left aligned shelf on the secondary display.
1066   // It is hard because:
1067   // - It is hard to stop the cursor in the shelf "light bar" and not overshoot.
1068   // - The cursor is warped to the other display if the cursor gets to the edge
1069   //   of the display.
1070   // Show the shelf if the cursor started on the shelf and the user overshot the
1071   // shelf slightly to make it easier to show the shelf in this situation. We
1072   // do not check |auto_hide_timer_|.IsRunning() because it returns false when
1073   // the timer's task is running.
1074   if ((state_.auto_hide_state == SHELF_AUTO_HIDE_SHOWN ||
1075        mouse_over_shelf_when_auto_hide_timer_started_) &&
1076       GetAutoHideShowShelfRegionInScreen().Contains(
1077           cursor_position_in_screen)) {
1078     return SHELF_AUTO_HIDE_SHOWN;
1079   }
1080
1081   return SHELF_AUTO_HIDE_HIDDEN;
1082 }
1083
1084 bool ShelfLayoutManager::IsShelfWindow(aura::Window* window) {
1085   if (!window)
1086     return false;
1087   return (shelf_ && shelf_->GetNativeWindow()->Contains(window)) ||
1088       (shelf_->status_area_widget() &&
1089        shelf_->status_area_widget()->GetNativeWindow()->Contains(window));
1090 }
1091
1092 int ShelfLayoutManager::GetWorkAreaSize(const State& state, int size) const {
1093   if (state.visibility_state == SHELF_VISIBLE)
1094     return size;
1095   if (state.visibility_state == SHELF_AUTO_HIDE)
1096     return kAutoHideSize;
1097   return 0;
1098 }
1099
1100 void ShelfLayoutManager::OnKeyboardBoundsChanging(const gfx::Rect& new_bounds) {
1101   bool keyboard_is_about_to_hide = false;
1102   if (new_bounds.IsEmpty() && !keyboard_bounds_.IsEmpty())
1103     keyboard_is_about_to_hide = true;
1104
1105   keyboard_bounds_ = new_bounds;
1106   OnWindowResized();
1107
1108   SessionStateDelegate* session_state_delegate =
1109       Shell::GetInstance()->session_state_delegate();
1110
1111   // On login screen if keyboard has been just hidden, update bounds just once
1112   // but ignore target_bounds.work_area_insets since shelf overlaps with login
1113   // window.
1114   if (session_state_delegate->IsUserSessionBlocked() &&
1115       keyboard_is_about_to_hide) {
1116     Shell::GetInstance()->SetDisplayWorkAreaInsets(root_window_, gfx::Insets());
1117   }
1118 }
1119
1120 void ShelfLayoutManager::OnDockBoundsChanging(
1121     const gfx::Rect& dock_bounds,
1122     DockedWindowLayoutManagerObserver::Reason reason) {
1123   // Skip shelf layout in case docked notification originates from this class.
1124   if (reason == DISPLAY_INSETS_CHANGED)
1125     return;
1126   if (dock_bounds_ != dock_bounds) {
1127     dock_bounds_ = dock_bounds;
1128     OnWindowResized();
1129     UpdateVisibilityState();
1130     UpdateShelfBackground(BACKGROUND_CHANGE_ANIMATE);
1131   }
1132 }
1133
1134 void ShelfLayoutManager::OnLockStateEvent(LockStateObserver::EventType event) {
1135   if (event == EVENT_LOCK_ANIMATION_STARTED) {
1136     // Enter the screen locked state.
1137     state_.is_screen_locked = true;
1138   }
1139 }
1140
1141 void ShelfLayoutManager::SessionStateChanged(
1142     SessionStateDelegate::SessionState state) {
1143   TargetBounds target_bounds;
1144   CalculateTargetBounds(state_, &target_bounds);
1145   UpdateBoundsAndOpacity(target_bounds, true, NULL);
1146   UpdateVisibilityState();
1147 }
1148
1149 }  // namespace ash