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      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
    689     // illegal state. We therefore hide the shelf here if required.
    690     if (!target_bounds.status_opacity)
    691       shelf_->status_area_widget()->Hide();
    692     // Setting visibility during an animation causes the visibility property to
    693     // animate. Override the animation settings to immediately set the
    694     // visibility property. Opacity will still animate.
    695 
    696     // TODO(harrym): Once status area widget is a child view of shelf
    697     // this can be simplified.
    698     gfx::Rect status_bounds = target_bounds.status_bounds_in_shelf;
    699     status_bounds.set_x(status_bounds.x() +
    700                         target_bounds.shelf_bounds_in_root.x());
    701     status_bounds.set_y(status_bounds.y() +
    702                         target_bounds.shelf_bounds_in_root.y());
    703     shelf_->status_area_widget()->SetBounds(
    704         ScreenUtil::ConvertRectToScreen(
    705             shelf_->status_area_widget()->GetNativeView()->parent(),
    706             status_bounds));
    707     SessionStateDelegate* session_state_delegate =
    708         Shell::GetInstance()->session_state_delegate();
    709     if (!state_.is_screen_locked) {
    710       gfx::Insets insets;
    711       // If user session is blocked (login to new user session or add user to
    712       // the existing session - multi-profile) then give 100% of work area only
    713       // if keyboard is not shown.
    714       if (!session_state_delegate->IsUserSessionBlocked() ||
    715           !keyboard_bounds_.IsEmpty()) {
    716         insets = target_bounds.work_area_insets;
    717       }
    718       Shell::GetInstance()->SetDisplayWorkAreaInsets(root_window_, insets);
    719     }
    720   }
    721 
    722   // Setting visibility during an animation causes the visibility property to
    723   // animate. Set the visibility property without an animation.
    724   if (target_bounds.status_opacity)
    725     shelf_->status_area_widget()->Show();
    726 }
    727 
    728 void ShelfLayoutManager::StopAnimating() {
    729   GetLayer(shelf_)->GetAnimator()->StopAnimating();
    730   GetLayer(shelf_->status_area_widget())->GetAnimator()->StopAnimating();
    731 }
    732 
    733 void ShelfLayoutManager::GetShelfSize(int* width, int* height) {
    734   *width = *height = 0;
    735   gfx::Size status_size(
    736       shelf_->status_area_widget()->GetWindowBoundsInScreen().size());
    737   if (IsHorizontalAlignment())
    738     *height = kShelfSize;
    739   else
    740     *width = kShelfSize;
    741 }
    742 
    743 void ShelfLayoutManager::AdjustBoundsBasedOnAlignment(int inset,
    744                                                       gfx::Rect* bounds) const {
    745   bounds->Inset(SelectValueForShelfAlignment(
    746       gfx::Insets(0, 0, inset, 0),
    747       gfx::Insets(0, inset, 0, 0),
    748       gfx::Insets(0, 0, 0, inset),
    749       gfx::Insets(inset, 0, 0, 0)));
    750 }
    751 
    752 void ShelfLayoutManager::CalculateTargetBounds(
    753     const State& state,
    754     TargetBounds* target_bounds) {
    755   const gfx::Rect available_bounds(root_window_->bounds());
    756   gfx::Rect status_size(
    757       shelf_->status_area_widget()->GetWindowBoundsInScreen().size());
    758   int shelf_width = 0, shelf_height = 0;
    759   GetShelfSize(&shelf_width, &shelf_height);
    760   if (IsHorizontalAlignment())
    761     shelf_width = available_bounds.width();
    762   else
    763     shelf_height = available_bounds.height();
    764 
    765   if (state.visibility_state == SHELF_AUTO_HIDE &&
    766       state.auto_hide_state == SHELF_AUTO_HIDE_HIDDEN) {
    767     // Auto-hidden shelf always starts with the default size. If a gesture-drag
    768     // is in progress, then the call to UpdateTargetBoundsForGesture() below
    769     // takes care of setting the height properly.
    770     if (IsHorizontalAlignment())
    771       shelf_height = kAutoHideSize;
    772     else
    773       shelf_width = kAutoHideSize;
    774   } else if (state.visibility_state == SHELF_HIDDEN ||
    775       (!keyboard_bounds_.IsEmpty() && !keyboard::IsKeyboardOverscrollEnabled()))
    776   {
    777     if (IsHorizontalAlignment())
    778       shelf_height = 0;
    779     else
    780       shelf_width = 0;
    781   }
    782 
    783   int bottom_shelf_vertical_offset = available_bounds.bottom();
    784   if (keyboard_bounds_.IsEmpty())
    785     bottom_shelf_vertical_offset -= shelf_height;
    786   else
    787     bottom_shelf_vertical_offset -= keyboard_bounds_.height();
    788 
    789   target_bounds->shelf_bounds_in_root = SelectValueForShelfAlignment(
    790       gfx::Rect(available_bounds.x(), bottom_shelf_vertical_offset,
    791                     available_bounds.width(), shelf_height),
    792       gfx::Rect(available_bounds.x(), available_bounds.y(),
    793                     shelf_width, available_bounds.height()),
    794       gfx::Rect(available_bounds.right() - shelf_width, available_bounds.y(),
    795                     shelf_width, available_bounds.height()),
    796       gfx::Rect(available_bounds.x(), available_bounds.y(),
    797                     available_bounds.width(), shelf_height));
    798 
    799   if (IsHorizontalAlignment())
    800     status_size.set_height(kShelfSize);
    801   else
    802     status_size.set_width(kShelfSize);
    803 
    804   target_bounds->status_bounds_in_shelf = SelectValueForShelfAlignment(
    805       gfx::Rect(base::i18n::IsRTL() ? 0 : shelf_width - status_size.width(),
    806                     0, status_size.width(), status_size.height()),
    807       gfx::Rect(shelf_width - status_size.width(),
    808                     shelf_height - status_size.height(), status_size.width(),
    809                     status_size.height()),
    810       gfx::Rect(0, shelf_height - status_size.height(),
    811                     status_size.width(), status_size.height()),
    812       gfx::Rect(base::i18n::IsRTL() ? 0 : shelf_width - status_size.width(),
    813                     shelf_height - status_size.height(),
    814                     status_size.width(), status_size.height()));
    815 
    816   target_bounds->work_area_insets = SelectValueForShelfAlignment(
    817       gfx::Insets(0, 0, GetWorkAreaSize(state, shelf_height), 0),
    818       gfx::Insets(0, GetWorkAreaSize(state, shelf_width), 0, 0),
    819       gfx::Insets(0, 0, 0, GetWorkAreaSize(state, shelf_width)),
    820       gfx::Insets(GetWorkAreaSize(state, shelf_height), 0, 0, 0));
    821 
    822   // TODO(varkha): The functionality of managing insets for display areas
    823   // should probably be pushed to a separate component. This would simplify or
    824   // remove entirely the dependency on keyboard and dock.
    825 
    826   if (!keyboard_bounds_.IsEmpty() && !keyboard::IsKeyboardOverscrollEnabled()) {
    827     // Also push in the work area inset for the keyboard if it is visible.
    828     gfx::Insets keyboard_insets(0, 0, keyboard_bounds_.height(), 0);
    829     target_bounds->work_area_insets += keyboard_insets;
    830   }
    831 
    832   // Also push in the work area inset for the dock if it is visible.
    833   if (!dock_bounds_.IsEmpty()) {
    834     gfx::Insets dock_insets(
    835         0, (dock_bounds_.x() > 0 ? 0 : dock_bounds_.width()),
    836         0, (dock_bounds_.x() > 0 ? dock_bounds_.width() : 0));
    837     target_bounds->work_area_insets += dock_insets;
    838   }
    839 
    840   target_bounds->opacity =
    841       (gesture_drag_status_ == GESTURE_DRAG_IN_PROGRESS ||
    842        state.visibility_state == SHELF_VISIBLE ||
    843        state.visibility_state == SHELF_AUTO_HIDE) ? 1.0f : 0.0f;
    844   target_bounds->status_opacity =
    845       (state.visibility_state == SHELF_AUTO_HIDE &&
    846        state.auto_hide_state == SHELF_AUTO_HIDE_HIDDEN &&
    847        gesture_drag_status_ != GESTURE_DRAG_IN_PROGRESS) ?
    848       0.0f : target_bounds->opacity;
    849 
    850   if (gesture_drag_status_ == GESTURE_DRAG_IN_PROGRESS)
    851     UpdateTargetBoundsForGesture(target_bounds);
    852 
    853   // This needs to happen after calling UpdateTargetBoundsForGesture(), because
    854   // that can change the size of the shelf.
    855   target_bounds->shelf_bounds_in_shelf = SelectValueForShelfAlignment(
    856       gfx::Rect(0, 0,
    857                 shelf_width - status_size.width(),
    858                 target_bounds->shelf_bounds_in_root.height()),
    859       gfx::Rect(0, 0, target_bounds->shelf_bounds_in_root.width(),
    860                 shelf_height - status_size.height()),
    861       gfx::Rect(0, 0, target_bounds->shelf_bounds_in_root.width(),
    862                 shelf_height - status_size.height()),
    863       gfx::Rect(0, 0,
    864                 shelf_width - status_size.width(),
    865                 target_bounds->shelf_bounds_in_root.height()));
    866 }
    867 
    868 void ShelfLayoutManager::UpdateTargetBoundsForGesture(
    869     TargetBounds* target_bounds) const {
    870   CHECK_EQ(GESTURE_DRAG_IN_PROGRESS, gesture_drag_status_);
    871   bool horizontal = IsHorizontalAlignment();
    872   const gfx::Rect& available_bounds(root_window_->bounds());
    873   int resistance_free_region = 0;
    874 
    875   if (gesture_drag_auto_hide_state_ == SHELF_AUTO_HIDE_HIDDEN &&
    876       visibility_state() == SHELF_AUTO_HIDE &&
    877       auto_hide_state() != SHELF_AUTO_HIDE_SHOWN) {
    878     // If the shelf was hidden when the drag started (and the state hasn't
    879     // changed since then, e.g. because the tray-menu was shown because of the
    880     // drag), then allow the drag some resistance-free region at first to make
    881     // sure the shelf sticks with the finger until the shelf is visible.
    882     resistance_free_region = kShelfSize - kAutoHideSize;
    883   }
    884 
    885   bool resist = SelectValueForShelfAlignment(
    886       gesture_drag_amount_ < -resistance_free_region,
    887       gesture_drag_amount_ > resistance_free_region,
    888       gesture_drag_amount_ < -resistance_free_region,
    889       gesture_drag_amount_ > resistance_free_region);
    890 
    891   float translate = 0.f;
    892   if (resist) {
    893     float diff = fabsf(gesture_drag_amount_) - resistance_free_region;
    894     diff = std::min(diff, sqrtf(diff));
    895     if (gesture_drag_amount_ < 0)
    896       translate = -resistance_free_region - diff;
    897     else
    898       translate = resistance_free_region + diff;
    899   } else {
    900     translate = gesture_drag_amount_;
    901   }
    902 
    903   if (horizontal) {
    904     // Move and size the shelf with the gesture.
    905     int shelf_height = target_bounds->shelf_bounds_in_root.height() - translate;
    906     shelf_height = std::max(shelf_height, kAutoHideSize);
    907     target_bounds->shelf_bounds_in_root.set_height(shelf_height);
    908     if (GetAlignment() == SHELF_ALIGNMENT_BOTTOM) {
    909       target_bounds->shelf_bounds_in_root.set_y(
    910           available_bounds.bottom() - shelf_height);
    911     }
    912 
    913     target_bounds->status_bounds_in_shelf.set_y(0);
    914   } else {
    915     // Move and size the shelf with the gesture.
    916     int shelf_width = target_bounds->shelf_bounds_in_root.width();
    917     bool right_aligned = GetAlignment() == SHELF_ALIGNMENT_RIGHT;
    918     if (right_aligned)
    919       shelf_width -= translate;
    920     else
    921       shelf_width += translate;
    922     shelf_width = std::max(shelf_width, kAutoHideSize);
    923     target_bounds->shelf_bounds_in_root.set_width(shelf_width);
    924     if (right_aligned) {
    925       target_bounds->shelf_bounds_in_root.set_x(
    926           available_bounds.right() - shelf_width);
    927     }
    928 
    929     if (right_aligned)
    930       target_bounds->status_bounds_in_shelf.set_x(0);
    931     else
    932       target_bounds->status_bounds_in_shelf.set_x(
    933           target_bounds->shelf_bounds_in_root.width() -
    934           kShelfSize);
    935   }
    936 }
    937 
    938 void ShelfLayoutManager::UpdateShelfBackground(
    939     BackgroundAnimatorChangeType type) {
    940   const ShelfBackgroundType background_type(GetShelfBackgroundType());
    941   shelf_->SetPaintsBackground(background_type, type);
    942   FOR_EACH_OBSERVER(ShelfLayoutManagerObserver, observers_,
    943                     OnBackgroundUpdated(background_type, type));
    944 }
    945 
    946 ShelfBackgroundType ShelfLayoutManager::GetShelfBackgroundType() const {
    947   if (state_.visibility_state != SHELF_AUTO_HIDE &&
    948       state_.window_state == WORKSPACE_WINDOW_STATE_MAXIMIZED) {
    949     return SHELF_BACKGROUND_MAXIMIZED;
    950   }
    951 
    952   if (gesture_drag_status_ == GESTURE_DRAG_IN_PROGRESS ||
    953       (!state_.is_screen_locked && window_overlaps_shelf_) ||
    954       (state_.visibility_state == SHELF_AUTO_HIDE)) {
    955     return SHELF_BACKGROUND_OVERLAP;
    956   }
    957 
    958   return SHELF_BACKGROUND_DEFAULT;
    959 }
    960 
    961 void ShelfLayoutManager::UpdateAutoHideStateNow() {
    962   SetState(state_.visibility_state);
    963 
    964   // If the state did not change, the auto hide timer may still be running.
    965   StopAutoHideTimer();
    966 }
    967 
    968 void ShelfLayoutManager::StopAutoHideTimer() {
    969   auto_hide_timer_.Stop();
    970   mouse_over_shelf_when_auto_hide_timer_started_ = false;
    971 }
    972 
    973 gfx::Rect ShelfLayoutManager::GetAutoHideShowShelfRegionInScreen() const {
    974   gfx::Rect shelf_bounds_in_screen = shelf_->GetWindowBoundsInScreen();
    975   gfx::Vector2d offset = SelectValueForShelfAlignment(
    976       gfx::Vector2d(0, shelf_bounds_in_screen.height()),
    977       gfx::Vector2d(-kMaxAutoHideShowShelfRegionSize, 0),
    978       gfx::Vector2d(shelf_bounds_in_screen.width(), 0),
    979       gfx::Vector2d(0, -kMaxAutoHideShowShelfRegionSize));
    980 
    981   gfx::Rect show_shelf_region_in_screen = shelf_bounds_in_screen;
    982   show_shelf_region_in_screen += offset;
    983   if (IsHorizontalAlignment())
    984     show_shelf_region_in_screen.set_height(kMaxAutoHideShowShelfRegionSize);
    985   else
    986     show_shelf_region_in_screen.set_width(kMaxAutoHideShowShelfRegionSize);
    987 
    988   // TODO: Figure out if we need any special handling when the keyboard is
    989   // visible.
    990   return show_shelf_region_in_screen;
    991 }
    992 
    993 ShelfAutoHideState ShelfLayoutManager::CalculateAutoHideState(
    994     ShelfVisibilityState visibility_state) const {
    995   if (visibility_state != SHELF_AUTO_HIDE || !shelf_)
    996     return SHELF_AUTO_HIDE_HIDDEN;
    997 
    998   Shell* shell = Shell::GetInstance();
    999   if (shell->GetAppListTargetVisibility())
   1000     return SHELF_AUTO_HIDE_SHOWN;
   1001 
   1002   if (shelf_->status_area_widget() &&
   1003       shelf_->status_area_widget()->ShouldShowShelf())
   1004     return SHELF_AUTO_HIDE_SHOWN;
   1005 
   1006   if (shelf_->shelf() && shelf_->shelf()->IsShowingMenu())
   1007     return SHELF_AUTO_HIDE_SHOWN;
   1008 
   1009   if (shelf_->shelf() && shelf_->shelf()->IsShowingOverflowBubble())
   1010     return SHELF_AUTO_HIDE_SHOWN;
   1011 
   1012   if (shelf_->IsActive() ||
   1013       (shelf_->status_area_widget() &&
   1014        shelf_->status_area_widget()->IsActive()))
   1015     return SHELF_AUTO_HIDE_SHOWN;
   1016 
   1017   const std::vector<aura::Window*> windows =
   1018       ash::MruWindowTracker::BuildWindowList(false);
   1019 
   1020   // Process the window list and check if there are any visible windows.
   1021   bool visible_window = false;
   1022   for (size_t i = 0; i < windows.size(); ++i) {
   1023     if (windows[i] && windows[i]->IsVisible() &&
   1024         !wm::GetWindowState(windows[i])->IsMinimized() &&
   1025         root_window_ == windows[i]->GetRootWindow()) {
   1026       visible_window = true;
   1027       break;
   1028     }
   1029   }
   1030   // If there are no visible windows do not hide the shelf.
   1031   if (!visible_window)
   1032     return SHELF_AUTO_HIDE_SHOWN;
   1033 
   1034   if (gesture_drag_status_ == GESTURE_DRAG_COMPLETE_IN_PROGRESS)
   1035     return gesture_drag_auto_hide_state_;
   1036 
   1037   // Don't show if the user is dragging the mouse.
   1038   if (auto_hide_event_filter_.get() && auto_hide_event_filter_->in_mouse_drag())
   1039     return SHELF_AUTO_HIDE_HIDDEN;
   1040 
   1041   // Ignore the mouse position if mouse events are disabled.
   1042   aura::client::CursorClient* cursor_client = aura::client::GetCursorClient(
   1043       shelf_->GetNativeWindow()->GetRootWindow());
   1044   if (!cursor_client->IsMouseEventsEnabled())
   1045     return SHELF_AUTO_HIDE_HIDDEN;
   1046 
   1047   gfx::Rect shelf_region = shelf_->GetWindowBoundsInScreen();
   1048   if (shelf_->status_area_widget() &&
   1049       shelf_->status_area_widget()->IsMessageBubbleShown() &&
   1050       IsVisible()) {
   1051     // Increase the the hit test area to prevent the shelf from disappearing
   1052     // when the mouse is over the bubble gap.
   1053     ShelfAlignment alignment = GetAlignment();
   1054     shelf_region.Inset(alignment == SHELF_ALIGNMENT_RIGHT ?
   1055                            -kNotificationBubbleGapHeight : 0,
   1056                        alignment == SHELF_ALIGNMENT_BOTTOM ?
   1057                            -kNotificationBubbleGapHeight : 0,
   1058                        alignment == SHELF_ALIGNMENT_LEFT ?
   1059                            -kNotificationBubbleGapHeight : 0,
   1060                        alignment == SHELF_ALIGNMENT_TOP ?
   1061                            -kNotificationBubbleGapHeight : 0);
   1062   }
   1063 
   1064   gfx::Point cursor_position_in_screen =
   1065       Shell::GetScreen()->GetCursorScreenPoint();
   1066   if (shelf_region.Contains(cursor_position_in_screen))
   1067     return SHELF_AUTO_HIDE_SHOWN;
   1068 
   1069   // When the shelf is auto hidden and the shelf is on the boundary between two
   1070   // displays, it is hard to trigger showing the shelf. For instance, if a
   1071   // user's primary display is left of their secondary display, it is hard to
   1072   // unautohide a left aligned shelf on the secondary display.
   1073   // It is hard because:
   1074   // - It is hard to stop the cursor in the shelf "light bar" and not overshoot.
   1075   // - The cursor is warped to the other display if the cursor gets to the edge
   1076   //   of the display.
   1077   // Show the shelf if the cursor started on the shelf and the user overshot the
   1078   // shelf slightly to make it easier to show the shelf in this situation. We
   1079   // do not check |auto_hide_timer_|.IsRunning() because it returns false when
   1080   // the timer's task is running.
   1081   if ((state_.auto_hide_state == SHELF_AUTO_HIDE_SHOWN ||
   1082        mouse_over_shelf_when_auto_hide_timer_started_) &&
   1083       GetAutoHideShowShelfRegionInScreen().Contains(
   1084           cursor_position_in_screen)) {
   1085     return SHELF_AUTO_HIDE_SHOWN;
   1086   }
   1087 
   1088   return SHELF_AUTO_HIDE_HIDDEN;
   1089 }
   1090 
   1091 bool ShelfLayoutManager::IsShelfWindow(aura::Window* window) {
   1092   if (!window)
   1093     return false;
   1094   return (shelf_ && shelf_->GetNativeWindow()->Contains(window)) ||
   1095       (shelf_->status_area_widget() &&
   1096        shelf_->status_area_widget()->GetNativeWindow()->Contains(window));
   1097 }
   1098 
   1099 int ShelfLayoutManager::GetWorkAreaSize(const State& state, int size) const {
   1100   if (state.visibility_state == SHELF_VISIBLE)
   1101     return size;
   1102   if (state.visibility_state == SHELF_AUTO_HIDE)
   1103     return kAutoHideSize;
   1104   return 0;
   1105 }
   1106 
   1107 void ShelfLayoutManager::OnKeyboardBoundsChanging(const gfx::Rect& new_bounds) {
   1108   bool keyboard_is_about_to_hide = false;
   1109   if (new_bounds.IsEmpty() && !keyboard_bounds_.IsEmpty())
   1110     keyboard_is_about_to_hide = true;
   1111 
   1112   keyboard_bounds_ = new_bounds;
   1113   OnWindowResized();
   1114 
   1115   SessionStateDelegate* session_state_delegate =
   1116       Shell::GetInstance()->session_state_delegate();
   1117 
   1118   // On login screen if keyboard has been just hidden, update bounds just once
   1119   // but ignore target_bounds.work_area_insets since shelf overlaps with login
   1120   // window.
   1121   if (session_state_delegate->IsUserSessionBlocked() &&
   1122       keyboard_is_about_to_hide) {
   1123     Shell::GetInstance()->SetDisplayWorkAreaInsets(root_window_, gfx::Insets());
   1124   }
   1125 }
   1126 
   1127 void ShelfLayoutManager::OnDockBoundsChanging(
   1128     const gfx::Rect& dock_bounds,
   1129     DockedWindowLayoutManagerObserver::Reason reason) {
   1130   // Skip shelf layout in case docked notification originates from this class.
   1131   if (reason == DISPLAY_INSETS_CHANGED)
   1132     return;
   1133   if (dock_bounds_ != dock_bounds) {
   1134     dock_bounds_ = dock_bounds;
   1135     OnWindowResized();
   1136     UpdateVisibilityState();
   1137     UpdateShelfBackground(BACKGROUND_CHANGE_ANIMATE);
   1138   }
   1139 }
   1140 
   1141 void ShelfLayoutManager::OnLockStateEvent(LockStateObserver::EventType event) {
   1142   if (event == EVENT_LOCK_ANIMATION_STARTED) {
   1143     // Enter the screen locked state.
   1144     state_.is_screen_locked = true;
   1145   }
   1146 }
   1147 
   1148 void ShelfLayoutManager::SessionStateChanged(
   1149     SessionStateDelegate::SessionState state) {
   1150   TargetBounds target_bounds;
   1151   CalculateTargetBounds(state_, &target_bounds);
   1152   UpdateBoundsAndOpacity(target_bounds, true, NULL);
   1153   UpdateVisibilityState();
   1154 }
   1155 
   1156 }  // namespace ash
   1157