src/ash/wm/panels/panel_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/wm/panels/panel_layout_manager.h"
   6
   7 #include <algorithm>
   8 #include <map>
   9
  10 #include "ash/screen_util.h"
  11 #include "ash/shelf/shelf.h"
  12 #include "ash/shelf/shelf_layout_manager.h"
  13 #include "ash/shelf/shelf_types.h"
  14 #include "ash/shelf/shelf_widget.h"
  15 #include "ash/shell.h"
  16 #include "ash/shell_window_ids.h"
  17 #include "ash/wm/window_animations.h"
  18 #include "ash/wm/window_state.h"
  19 #include "ash/wm/window_util.h"
  20 #include "base/auto_reset.h"
  21 #include "base/bind.h"
  22 #include "base/bind_helpers.h"
  23 #include "third_party/skia/include/core/SkColor.h"
  24 #include "third_party/skia/include/core/SkPaint.h"
  25 #include "third_party/skia/include/core/SkPath.h"
  26 #include "ui/aura/client/focus_client.h"
  27 #include "ui/aura/client/window_tree_client.h"
  28 #include "ui/aura/window.h"
  29 #include "ui/aura/window_event_dispatcher.h"
  30 #include "ui/aura/window_tracker.h"
  31 #include "ui/compositor/scoped_layer_animation_settings.h"
  32 #include "ui/gfx/canvas.h"
  33 #include "ui/gfx/rect.h"
  34 #include "ui/gfx/vector2d.h"
  35 #include "ui/views/background.h"
  36 #include "ui/views/widget/widget.h"
  37 #include "ui/wm/public/activation_client.h"
  38
  39 namespace ash {
  40 namespace internal {
  41
  42 namespace {
  43 const int kPanelIdealSpacing = 4;
  44
  45 const float kMaxHeightFactor = .80f;
  46 const float kMaxWidthFactor = .50f;
  47
  48 // Duration for panel animations.
  49 const int kPanelSlideDurationMilliseconds = 50;
  50 const int kCalloutFadeDurationMilliseconds = 50;
  51
  52 // Offset used when sliding panel in/out of the shelf. Used for minimizing,
  53 // restoring and the initial showing of a panel.
  54 const int kPanelSlideInOffset = 20;
  55
  56 // Callout arrow dimensions.
  57 const int kArrowWidth = 18;
  58 const int kArrowHeight = 9;
  59
  60 class CalloutWidgetBackground : public views::Background {
  61  public:
  62   CalloutWidgetBackground() : alignment_(SHELF_ALIGNMENT_BOTTOM) {
  63   }
  64
  65   virtual void Paint(gfx::Canvas* canvas, views::View* view) const OVERRIDE {
  66     SkPath path;
  67     switch (alignment_) {
  68       case SHELF_ALIGNMENT_BOTTOM:
  69         path.moveTo(SkIntToScalar(0), SkIntToScalar(0));
  70         path.lineTo(SkIntToScalar(kArrowWidth / 2),
  71                     SkIntToScalar(kArrowHeight));
  72         path.lineTo(SkIntToScalar(kArrowWidth), SkIntToScalar(0));
  73         break;
  74       case SHELF_ALIGNMENT_LEFT:
  75         path.moveTo(SkIntToScalar(kArrowHeight), SkIntToScalar(kArrowWidth));
  76         path.lineTo(SkIntToScalar(0), SkIntToScalar(kArrowWidth / 2));
  77         path.lineTo(SkIntToScalar(kArrowHeight), SkIntToScalar(0));
  78         break;
  79       case SHELF_ALIGNMENT_TOP:
  80         path.moveTo(SkIntToScalar(0), SkIntToScalar(kArrowHeight));
  81         path.lineTo(SkIntToScalar(kArrowWidth / 2), SkIntToScalar(0));
  82         path.lineTo(SkIntToScalar(kArrowWidth), SkIntToScalar(kArrowHeight));
  83         break;
  84       case SHELF_ALIGNMENT_RIGHT:
  85         path.moveTo(SkIntToScalar(0), SkIntToScalar(0));
  86         path.lineTo(SkIntToScalar(kArrowHeight),
  87                     SkIntToScalar(kArrowWidth / 2));
  88         path.lineTo(SkIntToScalar(0), SkIntToScalar(kArrowWidth));
  89         break;
  90     }
  91     // Hard code the arrow color for now.
  92     SkPaint paint;
  93     paint.setStyle(SkPaint::kFill_Style);
  94     paint.setColor(SkColorSetARGB(0xff, 0xe5, 0xe5, 0xe5));
  95     canvas->DrawPath(path, paint);
  96   }
  97
  98   ShelfAlignment alignment() {
  99     return alignment_;
 100   }
 101
 102   void set_alignment(ShelfAlignment alignment) {
 103     alignment_ = alignment;
 104   }
 105
 106  private:
 107   ShelfAlignment alignment_;
 108
 109   DISALLOW_COPY_AND_ASSIGN(CalloutWidgetBackground);
 110 };
 111
 112 struct VisiblePanelPositionInfo {
 113   VisiblePanelPositionInfo()
 114       : min_major(0),
 115         max_major(0),
 116         major_pos(0),
 117         major_length(0),
 118         window(NULL),
 119         slide_in(false) {}
 120
 121   int min_major;
 122   int max_major;
 123   int major_pos;
 124   int major_length;
 125   aura::Window* window;
 126   bool slide_in;
 127 };
 128
 129 bool CompareWindowMajor(const VisiblePanelPositionInfo& win1,
 130                         const VisiblePanelPositionInfo& win2) {
 131   return win1.major_pos < win2.major_pos;
 132 }
 133
 134 void FanOutPanels(std::vector<VisiblePanelPositionInfo>::iterator first,
 135                   std::vector<VisiblePanelPositionInfo>::iterator last) {
 136   int num_panels = last - first;
 137   if (num_panels == 1) {
 138     (*first).major_pos = std::max((*first).min_major, std::min(
 139         (*first).max_major, (*first).major_pos));
 140   }
 141   if (num_panels <= 1)
 142     return;
 143
 144   if (num_panels == 2) {
 145     // If there are two adjacent overlapping windows, separate them by the
 146     // minimum major_length necessary.
 147     std::vector<VisiblePanelPositionInfo>::iterator second = first + 1;
 148     int separation = (*first).major_length / 2 + (*second).major_length / 2 +
 149                      kPanelIdealSpacing;
 150     int overlap = (*first).major_pos + separation - (*second).major_pos;
 151     (*first).major_pos = std::max((*first).min_major,
 152                                   (*first).major_pos - overlap / 2);
 153     (*second).major_pos = std::min((*second).max_major,
 154                                    (*first).major_pos + separation);
 155     // Recalculate the first panel position in case the second one was
 156     // constrained on the right.
 157     (*first).major_pos = std::max((*first).min_major,
 158                                   (*second).major_pos - separation);
 159     return;
 160   }
 161
 162   // If there are more than two overlapping windows, fan them out from minimum
 163   // position to maximum position equally spaced.
 164   int delta = ((*(last - 1)).max_major - (*first).min_major) / (num_panels - 1);
 165   int major_pos = (*first).min_major;
 166   for (std::vector<VisiblePanelPositionInfo>::iterator iter = first;
 167       iter != last; ++iter) {
 168     (*iter).major_pos = std::max((*iter).min_major,
 169                                  std::min((*iter).max_major, major_pos));
 170     major_pos += delta;
 171   }
 172 }
 173
 174 bool BoundsAdjacent(const gfx::Rect& bounds1, const gfx::Rect& bounds2) {
 175   return bounds1.x() == bounds2.right() ||
 176          bounds1.y() == bounds2.bottom() ||
 177          bounds1.right() == bounds2.x() ||
 178          bounds1.bottom() == bounds2.y();
 179 }
 180
 181 gfx::Vector2d GetSlideInAnimationOffset(ShelfAlignment alignment) {
 182   gfx::Vector2d offset;
 183   switch (alignment) {
 184     case SHELF_ALIGNMENT_BOTTOM:
 185       offset.set_y(kPanelSlideInOffset);
 186       break;
 187     case SHELF_ALIGNMENT_LEFT:
 188       offset.set_x(-kPanelSlideInOffset);
 189       break;
 190     case SHELF_ALIGNMENT_RIGHT:
 191       offset.set_x(kPanelSlideInOffset);
 192       break;
 193     case SHELF_ALIGNMENT_TOP:
 194       offset.set_y(-kPanelSlideInOffset);
 195       break;
 196   }
 197   return offset;
 198 }
 199
 200 }  // namespace
 201
 202 class PanelCalloutWidget : public views::Widget {
 203  public:
 204   explicit PanelCalloutWidget(aura::Window* container)
 205       : background_(NULL) {
 206     InitWidget(container);
 207   }
 208
 209   void SetAlignment(ShelfAlignment alignment) {
 210     gfx::Rect callout_bounds = GetWindowBoundsInScreen();
 211     if (alignment == SHELF_ALIGNMENT_BOTTOM ||
 212         alignment == SHELF_ALIGNMENT_TOP) {
 213       callout_bounds.set_width(kArrowWidth);
 214       callout_bounds.set_height(kArrowHeight);
 215     } else {
 216       callout_bounds.set_width(kArrowHeight);
 217       callout_bounds.set_height(kArrowWidth);
 218     }
 219     GetNativeWindow()->SetBounds(callout_bounds);
 220     if (background_->alignment() != alignment) {
 221       background_->set_alignment(alignment);
 222       SchedulePaintInRect(gfx::Rect(gfx::Point(), callout_bounds.size()));
 223     }
 224   }
 225
 226  private:
 227   void InitWidget(aura::Window* parent) {
 228     views::Widget::InitParams params;
 229     params.type = views::Widget::InitParams::TYPE_POPUP;
 230     params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
 231     params.can_activate = false;
 232     params.keep_on_top = true;
 233     params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
 234     params.parent = parent;
 235     params.bounds = ScreenUtil::ConvertRectToScreen(parent, gfx::Rect());
 236     params.bounds.set_width(kArrowWidth);
 237     params.bounds.set_height(kArrowHeight);
 238     params.accept_events = false;
 239     // Why do we need this and can_activate = false?
 240     set_focus_on_creation(false);
 241     Init(params);
 242     DCHECK_EQ(GetNativeView()->GetRootWindow(), parent->GetRootWindow());
 243     views::View* content_view = new views::View;
 244     background_ = new CalloutWidgetBackground;
 245     content_view->set_background(background_);
 246     SetContentsView(content_view);
 247     GetNativeWindow()->layer()->SetOpacity(0);
 248   }
 249
 250   // Weak pointer owned by this widget's content view.
 251   CalloutWidgetBackground* background_;
 252
 253   DISALLOW_COPY_AND_ASSIGN(PanelCalloutWidget);
 254 };
 255
 256 ////////////////////////////////////////////////////////////////////////////////
 257 // PanelLayoutManager public implementation:
 258 PanelLayoutManager::PanelLayoutManager(aura::Window* panel_container)
 259     : panel_container_(panel_container),
 260       in_add_window_(false),
 261       in_layout_(false),
 262       dragged_panel_(NULL),
 263       shelf_(NULL),
 264       shelf_layout_manager_(NULL),
 265       last_active_panel_(NULL),
 266       weak_factory_(this) {
 267   DCHECK(panel_container);
 268   aura::client::GetActivationClient(Shell::GetPrimaryRootWindow())->
 269       AddObserver(this);
 270   Shell::GetInstance()->display_controller()->AddObserver(this);
 271   Shell::GetInstance()->AddShellObserver(this);
 272 }
 273
 274 PanelLayoutManager::~PanelLayoutManager() {
 275   Shutdown();
 276 }
 277
 278 void PanelLayoutManager::Shutdown() {
 279   if (shelf_layout_manager_)
 280     shelf_layout_manager_->RemoveObserver(this);
 281   shelf_layout_manager_ = NULL;
 282   for (PanelList::iterator iter = panel_windows_.begin();
 283        iter != panel_windows_.end(); ++iter) {
 284     delete iter->callout_widget;
 285   }
 286   panel_windows_.clear();
 287   if (shelf_)
 288     shelf_->RemoveIconObserver(this);
 289   shelf_ = NULL;
 290   aura::client::GetActivationClient(Shell::GetPrimaryRootWindow())->
 291       RemoveObserver(this);
 292   Shell::GetInstance()->display_controller()->RemoveObserver(this);
 293   Shell::GetInstance()->RemoveShellObserver(this);
 294 }
 295
 296 void PanelLayoutManager::StartDragging(aura::Window* panel) {
 297   DCHECK(!dragged_panel_);
 298   dragged_panel_ = panel;
 299   Relayout();
 300 }
 301
 302 void PanelLayoutManager::FinishDragging() {
 303   dragged_panel_ = NULL;
 304   Relayout();
 305 }
 306
 307 void PanelLayoutManager::SetShelf(Shelf* shelf) {
 308   DCHECK(!shelf_);
 309   DCHECK(!shelf_layout_manager_);
 310   shelf_ = shelf;
 311   shelf_->AddIconObserver(this);
 312   if (shelf_->shelf_widget()) {
 313     shelf_layout_manager_ = ash::internal::ShelfLayoutManager::ForShelf(
 314         shelf_->shelf_widget()->GetNativeWindow());
 315     WillChangeVisibilityState(shelf_layout_manager_->visibility_state());
 316     shelf_layout_manager_->AddObserver(this);
 317   }
 318 }
 319
 320 void PanelLayoutManager::ToggleMinimize(aura::Window* panel) {
 321   DCHECK(panel->parent() == panel_container_);
 322   wm::WindowState* window_state = wm::GetWindowState(panel);
 323   if (window_state->IsMinimized())
 324     window_state->Restore();
 325   else
 326     window_state->Minimize();
 327 }
 328
 329 views::Widget* PanelLayoutManager::GetCalloutWidgetForPanel(
 330     aura::Window* panel) {
 331   DCHECK(panel->parent() == panel_container_);
 332   PanelList::iterator found =
 333       std::find(panel_windows_.begin(), panel_windows_.end(), panel);
 334   DCHECK(found != panel_windows_.end());
 335   return found->callout_widget;
 336 }
 337
 338 ////////////////////////////////////////////////////////////////////////////////
 339 // PanelLayoutManager, aura::LayoutManager implementation:
 340 void PanelLayoutManager::OnWindowResized() {
 341   Relayout();
 342 }
 343
 344 void PanelLayoutManager::OnWindowAddedToLayout(aura::Window* child) {
 345   if (child->type() == ui::wm::WINDOW_TYPE_POPUP)
 346     return;
 347   if (in_add_window_)
 348     return;
 349   base::AutoReset<bool> auto_reset_in_add_window(&in_add_window_, true);
 350   if (!wm::GetWindowState(child)->panel_attached()) {
 351     // This should only happen when a window is added to panel container as a
 352     // result of bounds change from within the application during a drag.
 353     // If so we have already stopped the drag and should reparent the panel
 354     // back to appropriate container and ignore it.
 355     // TODO(varkha): Updating bounds during a drag can cause problems and a more
 356     // general solution is needed. See http://crbug.com/251813 .
 357     aura::Window* old_parent = child->parent();
 358     aura::client::ParentWindowWithContext(
 359         child, child, child->GetRootWindow()->GetBoundsInScreen());
 360     wm::ReparentTransientChildrenOfChild(child, old_parent, child->parent());
 361     DCHECK(child->parent()->id() != kShellWindowId_PanelContainer);
 362     return;
 363   }
 364   PanelInfo panel_info;
 365   panel_info.window = child;
 366   panel_info.callout_widget = new PanelCalloutWidget(panel_container_);
 367   if (child != dragged_panel_) {
 368     // Set the panel to 0 opacity until it has been positioned to prevent it
 369     // from flashing briefly at position (0, 0).
 370     child->layer()->SetOpacity(0);
 371     panel_info.slide_in = true;
 372   }
 373   panel_windows_.push_back(panel_info);
 374   wm::GetWindowState(child)->AddObserver(this);
 375   Relayout();
 376 }
 377
 378 void PanelLayoutManager::OnWillRemoveWindowFromLayout(aura::Window* child) {
 379 }
 380
 381 void PanelLayoutManager::OnWindowRemovedFromLayout(aura::Window* child) {
 382   if (child->type() == ui::wm::WINDOW_TYPE_POPUP)
 383     return;
 384   PanelList::iterator found =
 385       std::find(panel_windows_.begin(), panel_windows_.end(), child);
 386   if (found != panel_windows_.end()) {
 387     delete found->callout_widget;
 388     panel_windows_.erase(found);
 389   }
 390   wm::GetWindowState(child)->RemoveObserver(this);
 391
 392   if (dragged_panel_ == child)
 393     dragged_panel_ = NULL;
 394
 395   if (last_active_panel_ == child)
 396     last_active_panel_ = NULL;
 397
 398   Relayout();
 399 }
 400
 401 void PanelLayoutManager::OnChildWindowVisibilityChanged(aura::Window* child,
 402                                                         bool visible) {
 403   if (visible)
 404     wm::GetWindowState(child)->Restore();
 405   Relayout();
 406 }
 407
 408 void PanelLayoutManager::SetChildBounds(aura::Window* child,
 409                                         const gfx::Rect& requested_bounds) {
 410   gfx::Rect bounds(requested_bounds);
 411   const gfx::Rect& max_bounds = panel_container_->GetRootWindow()->bounds();
 412   const int max_width = max_bounds.width() * kMaxWidthFactor;
 413   const int max_height = max_bounds.height() * kMaxHeightFactor;
 414   if (bounds.width() > max_width)
 415     bounds.set_width(max_width);
 416   if (bounds.height() > max_height)
 417     bounds.set_height(max_height);
 418
 419   // Reposition dragged panel in the panel order.
 420   if (dragged_panel_ == child) {
 421     PanelList::iterator dragged_panel_iter =
 422       std::find(panel_windows_.begin(), panel_windows_.end(), dragged_panel_);
 423     DCHECK(dragged_panel_iter != panel_windows_.end());
 424     PanelList::iterator new_position;
 425     for (new_position = panel_windows_.begin();
 426          new_position != panel_windows_.end();
 427          ++new_position) {
 428       const gfx::Rect& bounds = (*new_position).window->bounds();
 429       if (bounds.x() + bounds.width()/2 <= requested_bounds.x()) break;
 430     }
 431     if (new_position != dragged_panel_iter) {
 432       PanelInfo dragged_panel_info = *dragged_panel_iter;
 433       panel_windows_.erase(dragged_panel_iter);
 434       panel_windows_.insert(new_position, dragged_panel_info);
 435     }
 436   }
 437
 438   SetChildBoundsDirect(child, bounds);
 439   Relayout();
 440 }
 441
 442 ////////////////////////////////////////////////////////////////////////////////
 443 // PanelLayoutManager, ShelfIconObserver implementation:
 444
 445 void PanelLayoutManager::OnShelfIconPositionsChanged() {
 446   // TODO: As this is called for every animation step now. Relayout needs to be
 447   // updated to use current icon position instead of use the ideal bounds so
 448   // that the panels slide with their icons instead of jumping.
 449   Relayout();
 450 }
 451
 452 ////////////////////////////////////////////////////////////////////////////////
 453 // PanelLayoutManager, ash::ShellObserver implementation:
 454
 455 void PanelLayoutManager::OnShelfAlignmentChanged(aura::Window* root_window) {
 456   if (panel_container_->GetRootWindow() == root_window)
 457     Relayout();
 458 }
 459
 460 /////////////////////////////////////////////////////////////////////////////
 461 // PanelLayoutManager, WindowObserver implementation:
 462
 463 void PanelLayoutManager::OnPostWindowStateTypeChange(
 464     wm::WindowState* window_state,
 465     wm::WindowStateType old_type) {
 466   // If the shelf is currently hidden then windows will not actually be shown
 467   // but the set to restore when the shelf becomes visible is updated.
 468   if (restore_windows_on_shelf_visible_) {
 469     if (window_state->IsMinimized()) {
 470       MinimizePanel(window_state->window());
 471       restore_windows_on_shelf_visible_->Remove(window_state->window());
 472     } else {
 473       restore_windows_on_shelf_visible_->Add(window_state->window());
 474     }
 475     return;
 476   }
 477
 478   if (window_state->IsMinimized())
 479     MinimizePanel(window_state->window());
 480   else
 481     RestorePanel(window_state->window());
 482 }
 483
 484 ////////////////////////////////////////////////////////////////////////////////
 485 // PanelLayoutManager, aura::client::ActivationChangeObserver implementation:
 486
 487 void PanelLayoutManager::OnWindowActivated(aura::Window* gained_active,
 488                                            aura::Window* lost_active) {
 489   // Ignore if the panel that is not managed by this was activated.
 490   if (gained_active && gained_active->type() == ui::wm::WINDOW_TYPE_PANEL &&
 491       gained_active->parent() == panel_container_) {
 492     UpdateStacking(gained_active);
 493     UpdateCallouts();
 494   }
 495 }
 496
 497 ////////////////////////////////////////////////////////////////////////////////
 498 // PanelLayoutManager, DisplayController::Observer implementation:
 499
 500 void PanelLayoutManager::OnDisplayConfigurationChanged() {
 501   Relayout();
 502 }
 503
 504 ////////////////////////////////////////////////////////////////////////////////
 505 // PanelLayoutManager, ShelfLayoutManagerObserver implementation:
 506
 507 void PanelLayoutManager::WillChangeVisibilityState(
 508     ShelfVisibilityState new_state) {
 509   // On entering / leaving full screen mode the shelf visibility state is
 510   // changed to / from SHELF_HIDDEN. In this state, panel windows should hide
 511   // to allow the full-screen application to use the full screen.
 512   bool shelf_hidden = new_state == ash::SHELF_HIDDEN;
 513   if (!shelf_hidden) {
 514     if (restore_windows_on_shelf_visible_) {
 515       scoped_ptr<aura::WindowTracker> restore_windows(
 516           restore_windows_on_shelf_visible_.Pass());
 517       for (aura::WindowTracker::Windows::const_iterator iter =
 518            restore_windows->windows().begin(); iter !=
 519            restore_windows->windows().end(); ++iter) {
 520         RestorePanel(*iter);
 521       }
 522     }
 523     return;
 524   }
 525
 526   if (restore_windows_on_shelf_visible_)
 527     return;
 528   scoped_ptr<aura::WindowTracker> minimized_windows(new aura::WindowTracker);
 529   for (PanelList::iterator iter = panel_windows_.begin();
 530        iter != panel_windows_.end(); ++iter) {
 531     if (iter->window->IsVisible()) {
 532       minimized_windows->Add(iter->window);
 533       wm::GetWindowState(iter->window)->Minimize();
 534     }
 535   }
 536   restore_windows_on_shelf_visible_ = minimized_windows.Pass();
 537 }
 538
 539 ////////////////////////////////////////////////////////////////////////////////
 540 // PanelLayoutManager private implementation:
 541
 542 void PanelLayoutManager::MinimizePanel(aura::Window* panel) {
 543   ::wm::SetWindowVisibilityAnimationType(
 544       panel, WINDOW_VISIBILITY_ANIMATION_TYPE_MINIMIZE);
 545   ui::Layer* layer = panel->layer();
 546   ui::ScopedLayerAnimationSettings panel_slide_settings(layer->GetAnimator());
 547   panel_slide_settings.SetPreemptionStrategy(
 548       ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 549   panel_slide_settings.SetTransitionDuration(
 550       base::TimeDelta::FromMilliseconds(kPanelSlideDurationMilliseconds));
 551   gfx::Rect bounds(panel->bounds());
 552   bounds.Offset(GetSlideInAnimationOffset(
 553       shelf_->shelf_widget()->GetAlignment()));
 554   SetChildBoundsDirect(panel, bounds);
 555   panel->Hide();
 556   PanelList::iterator found =
 557       std::find(panel_windows_.begin(), panel_windows_.end(), panel);
 558   if (found != panel_windows_.end()) {
 559     layer->SetOpacity(0);
 560     // The next time the window is visible it should slide into place.
 561     found->slide_in = true;
 562   }
 563   if (wm::IsActiveWindow(panel))
 564     wm::DeactivateWindow(panel);
 565   Relayout();
 566 }
 567
 568 void PanelLayoutManager::RestorePanel(aura::Window* panel) {
 569   panel->Show();
 570   Relayout();
 571 }
 572
 573 void PanelLayoutManager::Relayout() {
 574   if (!shelf_ || !shelf_->shelf_widget())
 575     return;
 576
 577   if (in_layout_)
 578     return;
 579   base::AutoReset<bool> auto_reset_in_layout(&in_layout_, true);
 580
 581   ShelfAlignment alignment = shelf_->shelf_widget()->GetAlignment();
 582   bool horizontal = alignment == SHELF_ALIGNMENT_TOP ||
 583                     alignment == SHELF_ALIGNMENT_BOTTOM;
 584   gfx::Rect shelf_bounds = ash::ScreenUtil::ConvertRectFromScreen(
 585       panel_container_, shelf_->shelf_widget()->GetWindowBoundsInScreen());
 586   int panel_start_bounds = kPanelIdealSpacing;
 587   int panel_end_bounds = horizontal ?
 588       panel_container_->bounds().width() - kPanelIdealSpacing :
 589       panel_container_->bounds().height() - kPanelIdealSpacing;
 590   aura::Window* active_panel = NULL;
 591   std::vector<VisiblePanelPositionInfo> visible_panels;
 592   for (PanelList::iterator iter = panel_windows_.begin();
 593        iter != panel_windows_.end(); ++iter) {
 594     aura::Window* panel = iter->window;
 595     iter->callout_widget->SetAlignment(alignment);
 596
 597     // Consider the dragged panel as part of the layout as long as it is
 598     // touching the shelf.
 599     if (!panel->IsVisible() ||
 600         (panel == dragged_panel_ &&
 601          !BoundsAdjacent(panel->bounds(), shelf_bounds))) {
 602       continue;
 603     }
 604
 605     // If the shelf is currently hidden (full-screen mode), minimize panel until
 606     // full-screen mode is exited. When a panel is dragged from another display
 607     // the shelf state does not update before the panel is added so we exclude
 608     // the dragged panel.
 609     if (panel != dragged_panel_ && restore_windows_on_shelf_visible_) {
 610       wm::GetWindowState(panel)->Minimize();
 611       restore_windows_on_shelf_visible_->Add(panel);
 612       continue;
 613     }
 614
 615     gfx::Rect icon_bounds = shelf_->GetScreenBoundsOfItemIconForWindow(panel);
 616
 617     // If both the icon width and height are 0 then there is no icon in the
 618     // shelf. If the shelf is hidden, one of the height or width will be
 619     // 0 but the position in the shelf and major dimension is still reported
 620     // correctly and the panel can be aligned above where the hidden icon is.
 621     if (icon_bounds.width() == 0 && icon_bounds.height() == 0)
 622       continue;
 623
 624     if (panel->HasFocus() ||
 625         panel->Contains(
 626             aura::client::GetFocusClient(panel)->GetFocusedWindow())) {
 627       DCHECK(!active_panel);
 628       active_panel = panel;
 629     }
 630     icon_bounds = ScreenUtil::ConvertRectFromScreen(panel_container_,
 631                                                     icon_bounds);
 632     gfx::Point icon_origin = icon_bounds.origin();
 633     VisiblePanelPositionInfo position_info;
 634     int icon_start = horizontal ? icon_origin.x() : icon_origin.y();
 635     int icon_end = icon_start + (horizontal ? icon_bounds.width() :
 636                                  icon_bounds.height());
 637     position_info.major_length = horizontal ?
 638         panel->bounds().width() : panel->bounds().height();
 639     position_info.min_major = std::max(
 640         panel_start_bounds + position_info.major_length / 2,
 641         icon_end - position_info.major_length / 2);
 642     position_info.max_major = std::min(
 643         icon_start + position_info.major_length / 2,
 644         panel_end_bounds - position_info.major_length / 2);
 645     position_info.major_pos = (icon_start + icon_end) / 2;
 646     position_info.window = panel;
 647     position_info.slide_in = iter->slide_in;
 648     iter->slide_in = false;
 649     visible_panels.push_back(position_info);
 650   }
 651
 652   // Sort panels by their X positions and fan out groups of overlapping panels.
 653   // The fan out method may result in new overlapping panels however given that
 654   // the panels start at least a full panel width apart this overlap will
 655   // never completely obscure a panel.
 656   // TODO(flackr): Rearrange panels if new overlaps are introduced.
 657   std::sort(visible_panels.begin(), visible_panels.end(), CompareWindowMajor);
 658   size_t first_overlapping_panel = 0;
 659   for (size_t i = 1; i < visible_panels.size(); ++i) {
 660     if (visible_panels[i - 1].major_pos +
 661         visible_panels[i - 1].major_length / 2 < visible_panels[i].major_pos -
 662         visible_panels[i].major_length / 2) {
 663       FanOutPanels(visible_panels.begin() + first_overlapping_panel,
 664                    visible_panels.begin() + i);
 665       first_overlapping_panel = i;
 666     }
 667   }
 668   FanOutPanels(visible_panels.begin() + first_overlapping_panel,
 669                visible_panels.end());
 670
 671   for (size_t i = 0; i < visible_panels.size(); ++i) {
 672     if (visible_panels[i].window == dragged_panel_)
 673       continue;
 674     bool slide_in = visible_panels[i].slide_in;
 675     gfx::Rect bounds = visible_panels[i].window->GetTargetBounds();
 676     switch (alignment) {
 677       case SHELF_ALIGNMENT_BOTTOM:
 678         bounds.set_y(shelf_bounds.y() - bounds.height());
 679         break;
 680       case SHELF_ALIGNMENT_LEFT:
 681         bounds.set_x(shelf_bounds.right());
 682         break;
 683       case SHELF_ALIGNMENT_RIGHT:
 684         bounds.set_x(shelf_bounds.x() - bounds.width());
 685         break;
 686       case SHELF_ALIGNMENT_TOP:
 687         bounds.set_y(shelf_bounds.bottom());
 688         break;
 689     }
 690     bool on_shelf = visible_panels[i].window->GetTargetBounds() == bounds;
 691
 692     if (horizontal) {
 693       bounds.set_x(visible_panels[i].major_pos -
 694                    visible_panels[i].major_length / 2);
 695     } else {
 696       bounds.set_y(visible_panels[i].major_pos -
 697                    visible_panels[i].major_length / 2);
 698     }
 699
 700     ui::Layer* layer = visible_panels[i].window->layer();
 701     if (slide_in) {
 702       // New windows shift up from the shelf into position.
 703       gfx::Rect initial_bounds(bounds);
 704       initial_bounds.Offset(GetSlideInAnimationOffset(alignment));
 705       SetChildBoundsDirect(visible_panels[i].window, initial_bounds);
 706       // Set on shelf so that the panel animates into its target position.
 707       on_shelf = true;
 708     }
 709
 710     if (on_shelf) {
 711       ui::ScopedLayerAnimationSettings panel_slide_settings(
 712           layer->GetAnimator());
 713       panel_slide_settings.SetPreemptionStrategy(
 714           ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
 715       panel_slide_settings.SetTransitionDuration(
 716           base::TimeDelta::FromMilliseconds(kPanelSlideDurationMilliseconds));
 717       SetChildBoundsDirect(visible_panels[i].window, bounds);
 718       if (slide_in)
 719         layer->SetOpacity(1);
 720     } else {
 721       // If the shelf moved don't animate, move immediately to the new
 722       // target location.
 723       SetChildBoundsDirect(visible_panels[i].window, bounds);
 724     }
 725   }
 726
 727   UpdateStacking(active_panel);
 728   UpdateCallouts();
 729 }
 730
 731 void PanelLayoutManager::UpdateStacking(aura::Window* active_panel) {
 732   if (!active_panel) {
 733     if (!last_active_panel_)
 734       return;
 735     active_panel = last_active_panel_;
 736   }
 737
 738   ShelfAlignment alignment = shelf_->alignment();
 739   bool horizontal = alignment == SHELF_ALIGNMENT_TOP ||
 740                     alignment == SHELF_ALIGNMENT_BOTTOM;
 741
 742   // We want to to stack the panels like a deck of cards:
 743   // ,--,--,--,-------.--.--.
 744   // |  |  |  |       |  |  |
 745   // |  |  |  |       |  |  |
 746   //
 747   // We use the middle of each panel to figure out how to stack the panels. This
 748   // allows us to update the stacking when a panel is being dragged around by
 749   // the titlebar--even though it doesn't update the shelf icon positions, we
 750   // still want the visual effect.
 751   std::map<int, aura::Window*> window_ordering;
 752   for (PanelList::const_iterator it = panel_windows_.begin();
 753        it != panel_windows_.end(); ++it) {
 754     gfx::Rect bounds = it->window->bounds();
 755     window_ordering.insert(std::make_pair(horizontal ?
 756                                               bounds.x() + bounds.width() / 2 :
 757                                               bounds.y() + bounds.height() / 2,
 758                                           it->window));
 759   }
 760
 761   aura::Window* previous_panel = NULL;
 762   for (std::map<int, aura::Window*>::const_iterator it =
 763        window_ordering.begin();
 764        it != window_ordering.end() && it->second != active_panel; ++it) {
 765     if (previous_panel)
 766       panel_container_->StackChildAbove(it->second, previous_panel);
 767     previous_panel = it->second;
 768   }
 769
 770   previous_panel = NULL;
 771   for (std::map<int, aura::Window*>::const_reverse_iterator it =
 772        window_ordering.rbegin();
 773        it != window_ordering.rend() && it->second != active_panel; ++it) {
 774     if (previous_panel)
 775       panel_container_->StackChildAbove(it->second, previous_panel);
 776     previous_panel = it->second;
 777   }
 778
 779   panel_container_->StackChildAtTop(active_panel);
 780   if (dragged_panel_ && dragged_panel_->parent() == panel_container_)
 781     panel_container_->StackChildAtTop(dragged_panel_);
 782   last_active_panel_ = active_panel;
 783 }
 784
 785 void PanelLayoutManager::UpdateCallouts() {
 786   ShelfAlignment alignment = shelf_->alignment();
 787   bool horizontal = alignment == SHELF_ALIGNMENT_TOP ||
 788                     alignment == SHELF_ALIGNMENT_BOTTOM;
 789
 790   for (PanelList::iterator iter = panel_windows_.begin();
 791        iter != panel_windows_.end(); ++iter) {
 792     aura::Window* panel = iter->window;
 793     views::Widget* callout_widget = iter->callout_widget;
 794
 795     gfx::Rect current_bounds = panel->GetBoundsInScreen();
 796     gfx::Rect bounds = ScreenUtil::ConvertRectToScreen(
 797         panel->parent(),
 798         panel->GetTargetBounds());
 799     gfx::Rect icon_bounds = shelf_->GetScreenBoundsOfItemIconForWindow(panel);
 800     if (icon_bounds.IsEmpty() || !panel->layer()->GetTargetVisibility() ||
 801         panel == dragged_panel_) {
 802       callout_widget->Hide();
 803       callout_widget->GetNativeWindow()->layer()->SetOpacity(0);
 804       continue;
 805     }
 806
 807     gfx::Rect callout_bounds = callout_widget->GetWindowBoundsInScreen();
 808     gfx::Vector2d slide_vector = bounds.origin() - current_bounds.origin();
 809     int slide_distance = horizontal ? slide_vector.x() : slide_vector.y();
 810     int distance_until_over_panel = 0;
 811     if (horizontal) {
 812       callout_bounds.set_x(
 813           icon_bounds.x() + (icon_bounds.width() - callout_bounds.width()) / 2);
 814       distance_until_over_panel = std::max(
 815           current_bounds.x() - callout_bounds.x(),
 816           callout_bounds.right() - current_bounds.right());
 817     } else {
 818       callout_bounds.set_y(
 819           icon_bounds.y() + (icon_bounds.height() -
 820                              callout_bounds.height()) / 2);
 821       distance_until_over_panel = std::max(
 822           current_bounds.y() - callout_bounds.y(),
 823           callout_bounds.bottom() - current_bounds.bottom());
 824     }
 825     switch (alignment) {
 826       case SHELF_ALIGNMENT_BOTTOM:
 827         callout_bounds.set_y(bounds.bottom());
 828         break;
 829       case SHELF_ALIGNMENT_LEFT:
 830         callout_bounds.set_x(bounds.x() - callout_bounds.width());
 831         break;
 832       case SHELF_ALIGNMENT_RIGHT:
 833         callout_bounds.set_x(bounds.right());
 834         break;
 835       case SHELF_ALIGNMENT_TOP:
 836         callout_bounds.set_y(bounds.y() - callout_bounds.height());
 837         break;
 838     }
 839     callout_bounds = ScreenUtil::ConvertRectFromScreen(
 840         callout_widget->GetNativeWindow()->parent(),
 841         callout_bounds);
 842
 843     SetChildBoundsDirect(callout_widget->GetNativeWindow(), callout_bounds);
 844     panel_container_->StackChildAbove(callout_widget->GetNativeWindow(),
 845                                       panel);
 846
 847     ui::Layer* layer = callout_widget->GetNativeWindow()->layer();
 848     // If the panel is not over the callout position or has just become visible
 849     // then fade in the callout.
 850     if ((distance_until_over_panel > 0 || layer->GetTargetOpacity() < 1)) {
 851       if (distance_until_over_panel > 0 &&
 852           slide_distance >= distance_until_over_panel) {
 853         // If the panel is not yet over the callout, then delay fading in
 854         // the callout until after the panel should be over it.
 855         int delay = kPanelSlideDurationMilliseconds *
 856             distance_until_over_panel / slide_distance;
 857         layer->SetOpacity(0);
 858         layer->GetAnimator()->StopAnimating();
 859         layer->GetAnimator()->SchedulePauseForProperties(
 860             base::TimeDelta::FromMilliseconds(delay),
 861             ui::LayerAnimationElement::OPACITY);
 862       }
 863       ui::ScopedLayerAnimationSettings callout_settings(layer->GetAnimator());
 864       callout_settings.SetPreemptionStrategy(
 865           ui::LayerAnimator::REPLACE_QUEUED_ANIMATIONS);
 866       callout_settings.SetTransitionDuration(
 867           base::TimeDelta::FromMilliseconds(
 868               kCalloutFadeDurationMilliseconds));
 869       layer->SetOpacity(1);
 870     }
 871
 872     // Show after changing the opacity animation. This way we don't have a
 873     // state where the widget is visible but the opacity is 0.
 874     callout_widget->Show();
 875   }
 876 }
 877
 878 ////////////////////////////////////////////////////////////////////////////////
 879 // keyboard::KeyboardControllerObserver implementation:
 880
 881 void PanelLayoutManager::OnKeyboardBoundsChanging(
 882     const gfx::Rect& keyboard_bounds) {
 883   // This bounds change will have caused a change to the Shelf which does not
 884   // propogate automatically to this class, so manually recalculate bounds.
 885   OnWindowResized();
 886 }
 887
 888 }  // namespace internal
 889 }  // namespace ash