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_util.h"
15#include "ash/shelf/shelf_widget.h"
16#include "ash/shell.h"
17#include "ash/shell_window_ids.h"
18#include "ash/wm/window_animations.h"
19#include "ash/wm/window_state.h"
20#include "ash/wm/window_util.h"
21#include "base/auto_reset.h"
22#include "base/bind.h"
23#include "base/bind_helpers.h"
24#include "third_party/skia/include/core/SkColor.h"
25#include "third_party/skia/include/core/SkPaint.h"
26#include "third_party/skia/include/core/SkPath.h"
27#include "ui/aura/client/focus_client.h"
28#include "ui/aura/client/window_tree_client.h"
29#include "ui/aura/window.h"
30#include "ui/aura/window_delegate.h"
31#include "ui/aura/window_event_dispatcher.h"
32#include "ui/aura/window_tracker.h"
33#include "ui/compositor/scoped_layer_animation_settings.h"
34#include "ui/gfx/canvas.h"
35#include "ui/gfx/rect.h"
36#include "ui/gfx/vector2d.h"
37#include "ui/views/background.h"
38#include "ui/views/widget/widget.h"
39#include "ui/wm/public/activation_client.h"
40
41namespace ash {
42namespace {
43
44const int kPanelIdealSpacing = 4;
45
46const float kMaxHeightFactor = .80f;
47const float kMaxWidthFactor = .50f;
48
49// Duration for panel animations.
50const int kPanelSlideDurationMilliseconds = 50;
51const int kCalloutFadeDurationMilliseconds = 50;
52
53// Offset used when sliding panel in/out of the shelf. Used for minimizing,
54// restoring and the initial showing of a panel.
55const int kPanelSlideInOffset = 20;
56
57// Callout arrow dimensions.
58const int kArrowWidth = 18;
59const int kArrowHeight = 9;
60
61class CalloutWidgetBackground : public views::Background {
62 public:
63  CalloutWidgetBackground() : alignment_(SHELF_ALIGNMENT_BOTTOM) {
64  }
65
66  virtual void Paint(gfx::Canvas* canvas, views::View* view) const OVERRIDE {
67    SkPath path;
68    switch (alignment_) {
69      case SHELF_ALIGNMENT_BOTTOM:
70        path.moveTo(SkIntToScalar(0), SkIntToScalar(0));
71        path.lineTo(SkIntToScalar(kArrowWidth / 2),
72                    SkIntToScalar(kArrowHeight));
73        path.lineTo(SkIntToScalar(kArrowWidth), SkIntToScalar(0));
74        break;
75      case SHELF_ALIGNMENT_LEFT:
76        path.moveTo(SkIntToScalar(kArrowHeight), SkIntToScalar(kArrowWidth));
77        path.lineTo(SkIntToScalar(0), SkIntToScalar(kArrowWidth / 2));
78        path.lineTo(SkIntToScalar(kArrowHeight), SkIntToScalar(0));
79        break;
80      case SHELF_ALIGNMENT_TOP:
81        path.moveTo(SkIntToScalar(0), SkIntToScalar(kArrowHeight));
82        path.lineTo(SkIntToScalar(kArrowWidth / 2), SkIntToScalar(0));
83        path.lineTo(SkIntToScalar(kArrowWidth), SkIntToScalar(kArrowHeight));
84        break;
85      case SHELF_ALIGNMENT_RIGHT:
86        path.moveTo(SkIntToScalar(0), SkIntToScalar(0));
87        path.lineTo(SkIntToScalar(kArrowHeight),
88                    SkIntToScalar(kArrowWidth / 2));
89        path.lineTo(SkIntToScalar(0), SkIntToScalar(kArrowWidth));
90        break;
91    }
92    // Hard code the arrow color for now.
93    SkPaint paint;
94    paint.setStyle(SkPaint::kFill_Style);
95    paint.setColor(SkColorSetARGB(0xff, 0xe5, 0xe5, 0xe5));
96    canvas->DrawPath(path, paint);
97  }
98
99  ShelfAlignment alignment() {
100    return alignment_;
101  }
102
103  void set_alignment(ShelfAlignment alignment) {
104    alignment_ = alignment;
105  }
106
107 private:
108  ShelfAlignment alignment_;
109
110  DISALLOW_COPY_AND_ASSIGN(CalloutWidgetBackground);
111};
112
113struct VisiblePanelPositionInfo {
114  VisiblePanelPositionInfo()
115      : min_major(0),
116        max_major(0),
117        major_pos(0),
118        major_length(0),
119        window(NULL),
120        slide_in(false) {}
121
122  int min_major;
123  int max_major;
124  int major_pos;
125  int major_length;
126  aura::Window* window;
127  bool slide_in;
128};
129
130bool CompareWindowMajor(const VisiblePanelPositionInfo& win1,
131                        const VisiblePanelPositionInfo& win2) {
132  return win1.major_pos < win2.major_pos;
133}
134
135void FanOutPanels(std::vector<VisiblePanelPositionInfo>::iterator first,
136                  std::vector<VisiblePanelPositionInfo>::iterator last) {
137  int num_panels = last - first;
138  if (num_panels == 1) {
139    (*first).major_pos = std::max((*first).min_major, std::min(
140        (*first).max_major, (*first).major_pos));
141  }
142  if (num_panels <= 1)
143    return;
144
145  if (num_panels == 2) {
146    // If there are two adjacent overlapping windows, separate them by the
147    // minimum major_length necessary.
148    std::vector<VisiblePanelPositionInfo>::iterator second = first + 1;
149    int separation = (*first).major_length / 2 + (*second).major_length / 2 +
150                     kPanelIdealSpacing;
151    int overlap = (*first).major_pos + separation - (*second).major_pos;
152    (*first).major_pos = std::max((*first).min_major,
153                                  (*first).major_pos - overlap / 2);
154    (*second).major_pos = std::min((*second).max_major,
155                                   (*first).major_pos + separation);
156    // Recalculate the first panel position in case the second one was
157    // constrained on the right.
158    (*first).major_pos = std::max((*first).min_major,
159                                  (*second).major_pos - separation);
160    return;
161  }
162
163  // If there are more than two overlapping windows, fan them out from minimum
164  // position to maximum position equally spaced.
165  int delta = ((*(last - 1)).max_major - (*first).min_major) / (num_panels - 1);
166  int major_pos = (*first).min_major;
167  for (std::vector<VisiblePanelPositionInfo>::iterator iter = first;
168      iter != last; ++iter) {
169    (*iter).major_pos = std::max((*iter).min_major,
170                                 std::min((*iter).max_major, major_pos));
171    major_pos += delta;
172  }
173}
174
175bool BoundsAdjacent(const gfx::Rect& bounds1, const gfx::Rect& bounds2) {
176  return bounds1.x() == bounds2.right() ||
177         bounds1.y() == bounds2.bottom() ||
178         bounds1.right() == bounds2.x() ||
179         bounds1.bottom() == bounds2.y();
180}
181
182gfx::Vector2d GetSlideInAnimationOffset(ShelfAlignment alignment) {
183  gfx::Vector2d offset;
184  switch (alignment) {
185    case SHELF_ALIGNMENT_BOTTOM:
186      offset.set_y(kPanelSlideInOffset);
187      break;
188    case SHELF_ALIGNMENT_LEFT:
189      offset.set_x(-kPanelSlideInOffset);
190      break;
191    case SHELF_ALIGNMENT_RIGHT:
192      offset.set_x(kPanelSlideInOffset);
193      break;
194    case SHELF_ALIGNMENT_TOP:
195      offset.set_y(-kPanelSlideInOffset);
196      break;
197  }
198  return offset;
199}
200
201}  // namespace
202
203class PanelCalloutWidget : public views::Widget {
204 public:
205  explicit PanelCalloutWidget(aura::Window* container)
206      : background_(NULL) {
207    InitWidget(container);
208  }
209
210  void SetAlignment(ShelfAlignment alignment) {
211    gfx::Rect callout_bounds = GetWindowBoundsInScreen();
212    if (alignment == SHELF_ALIGNMENT_BOTTOM ||
213        alignment == SHELF_ALIGNMENT_TOP) {
214      callout_bounds.set_width(kArrowWidth);
215      callout_bounds.set_height(kArrowHeight);
216    } else {
217      callout_bounds.set_width(kArrowHeight);
218      callout_bounds.set_height(kArrowWidth);
219    }
220    GetNativeWindow()->SetBounds(callout_bounds);
221    if (background_->alignment() != alignment) {
222      background_->set_alignment(alignment);
223      SchedulePaintInRect(gfx::Rect(gfx::Point(), callout_bounds.size()));
224    }
225  }
226
227 private:
228  void InitWidget(aura::Window* parent) {
229    views::Widget::InitParams params;
230    params.type = views::Widget::InitParams::TYPE_POPUP;
231    params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
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    set_focus_on_creation(false);
240    Init(params);
241    DCHECK_EQ(GetNativeView()->GetRootWindow(), parent->GetRootWindow());
242    views::View* content_view = new views::View;
243    background_ = new CalloutWidgetBackground;
244    content_view->set_background(background_);
245    SetContentsView(content_view);
246    GetNativeWindow()->layer()->SetOpacity(0);
247  }
248
249  // Weak pointer owned by this widget's content view.
250  CalloutWidgetBackground* background_;
251
252  DISALLOW_COPY_AND_ASSIGN(PanelCalloutWidget);
253};
254
255////////////////////////////////////////////////////////////////////////////////
256// PanelLayoutManager public implementation:
257PanelLayoutManager::PanelLayoutManager(aura::Window* panel_container)
258    : panel_container_(panel_container),
259      in_add_window_(false),
260      in_layout_(false),
261      show_callout_widgets_(true),
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
274PanelLayoutManager::~PanelLayoutManager() {
275  Shutdown();
276}
277
278void 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
296void PanelLayoutManager::StartDragging(aura::Window* panel) {
297  DCHECK(!dragged_panel_);
298  dragged_panel_ = panel;
299  Relayout();
300}
301
302void PanelLayoutManager::FinishDragging() {
303  dragged_panel_ = NULL;
304  Relayout();
305}
306
307void 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::ShelfLayoutManager::ForShelf(
314        shelf_->shelf_widget()->GetNativeWindow());
315    WillChangeVisibilityState(shelf_layout_manager_->visibility_state());
316    shelf_layout_manager_->AddObserver(this);
317  }
318}
319
320void 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
329void PanelLayoutManager::SetShowCalloutWidgets(bool show) {
330  if (show_callout_widgets_ == show)
331    return;
332  show_callout_widgets_ = show;
333  UpdateCallouts();
334}
335
336views::Widget* PanelLayoutManager::GetCalloutWidgetForPanel(
337    aura::Window* panel) {
338  DCHECK(panel->parent() == panel_container_);
339  PanelList::iterator found =
340      std::find(panel_windows_.begin(), panel_windows_.end(), panel);
341  DCHECK(found != panel_windows_.end());
342  return found->callout_widget;
343}
344
345////////////////////////////////////////////////////////////////////////////////
346// PanelLayoutManager, aura::LayoutManager implementation:
347void PanelLayoutManager::OnWindowResized() {
348  Relayout();
349}
350
351void PanelLayoutManager::OnWindowAddedToLayout(aura::Window* child) {
352  if (child->type() == ui::wm::WINDOW_TYPE_POPUP)
353    return;
354  if (in_add_window_)
355    return;
356  base::AutoReset<bool> auto_reset_in_add_window(&in_add_window_, true);
357  if (!wm::GetWindowState(child)->panel_attached()) {
358    // This should only happen when a window is added to panel container as a
359    // result of bounds change from within the application during a drag.
360    // If so we have already stopped the drag and should reparent the panel
361    // back to appropriate container and ignore it.
362    // TODO(varkha): Updating bounds during a drag can cause problems and a more
363    // general solution is needed. See http://crbug.com/251813 .
364    aura::Window* old_parent = child->parent();
365    aura::client::ParentWindowWithContext(
366        child, child, child->GetRootWindow()->GetBoundsInScreen());
367    wm::ReparentTransientChildrenOfChild(child, old_parent, child->parent());
368    DCHECK(child->parent()->id() != kShellWindowId_PanelContainer);
369    return;
370  }
371  PanelInfo panel_info;
372  panel_info.window = child;
373  panel_info.callout_widget = new PanelCalloutWidget(panel_container_);
374  panel_info.slide_in = child != dragged_panel_;
375  panel_windows_.push_back(panel_info);
376  child->AddObserver(this);
377  wm::GetWindowState(child)->AddObserver(this);
378  Relayout();
379}
380
381void PanelLayoutManager::OnWillRemoveWindowFromLayout(aura::Window* child) {
382}
383
384void PanelLayoutManager::OnWindowRemovedFromLayout(aura::Window* child) {
385  if (child->type() == ui::wm::WINDOW_TYPE_POPUP)
386    return;
387  PanelList::iterator found =
388      std::find(panel_windows_.begin(), panel_windows_.end(), child);
389  if (found != panel_windows_.end()) {
390    delete found->callout_widget;
391    panel_windows_.erase(found);
392  }
393  if (restore_windows_on_shelf_visible_)
394    restore_windows_on_shelf_visible_->Remove(child);
395  child->RemoveObserver(this);
396  wm::GetWindowState(child)->RemoveObserver(this);
397
398  if (dragged_panel_ == child)
399    dragged_panel_ = NULL;
400
401  if (last_active_panel_ == child)
402    last_active_panel_ = NULL;
403
404  Relayout();
405}
406
407void PanelLayoutManager::OnChildWindowVisibilityChanged(aura::Window* child,
408                                                        bool visible) {
409  if (visible)
410    wm::GetWindowState(child)->Restore();
411  Relayout();
412}
413
414void PanelLayoutManager::SetChildBounds(aura::Window* child,
415                                        const gfx::Rect& requested_bounds) {
416  gfx::Rect bounds(requested_bounds);
417  const gfx::Rect& max_bounds = panel_container_->GetRootWindow()->bounds();
418  const int max_width = max_bounds.width() * kMaxWidthFactor;
419  const int max_height = max_bounds.height() * kMaxHeightFactor;
420  if (bounds.width() > max_width)
421    bounds.set_width(max_width);
422  if (bounds.height() > max_height)
423    bounds.set_height(max_height);
424
425  // Reposition dragged panel in the panel order.
426  if (dragged_panel_ == child) {
427    PanelList::iterator dragged_panel_iter =
428      std::find(panel_windows_.begin(), panel_windows_.end(), dragged_panel_);
429    DCHECK(dragged_panel_iter != panel_windows_.end());
430    PanelList::iterator new_position;
431    for (new_position = panel_windows_.begin();
432         new_position != panel_windows_.end();
433         ++new_position) {
434      const gfx::Rect& bounds = (*new_position).window->bounds();
435      if (bounds.x() + bounds.width()/2 <= requested_bounds.x()) break;
436    }
437    if (new_position != dragged_panel_iter) {
438      PanelInfo dragged_panel_info = *dragged_panel_iter;
439      panel_windows_.erase(dragged_panel_iter);
440      panel_windows_.insert(new_position, dragged_panel_info);
441    }
442  }
443  // Respect the minimum size of the window.
444  if (child->delegate()) {
445    const gfx::Size& min_size = child->delegate()->GetMinimumSize();
446    bounds.set_width(std::max(min_size.width(), bounds.width()));
447    bounds.set_height(std::max(min_size.height(), bounds.height()));
448  }
449
450  SetChildBoundsDirect(child, bounds);
451  Relayout();
452}
453
454////////////////////////////////////////////////////////////////////////////////
455// PanelLayoutManager, ShelfIconObserver implementation:
456
457void PanelLayoutManager::OnShelfIconPositionsChanged() {
458  // TODO: As this is called for every animation step now. Relayout needs to be
459  // updated to use current icon position instead of use the ideal bounds so
460  // that the panels slide with their icons instead of jumping.
461  Relayout();
462}
463
464////////////////////////////////////////////////////////////////////////////////
465// PanelLayoutManager, ash::ShellObserver implementation:
466
467void PanelLayoutManager::OnShelfAlignmentChanged(aura::Window* root_window) {
468  if (panel_container_->GetRootWindow() == root_window)
469    Relayout();
470}
471
472/////////////////////////////////////////////////////////////////////////////
473// PanelLayoutManager, WindowObserver implementation:
474
475void PanelLayoutManager::OnWindowPropertyChanged(aura::Window* window,
476                                                 const void* key,
477                                                 intptr_t old) {
478  // Trigger a relayout to position the panels whenever the panel icon is set
479  // or changes.
480  if (key == kShelfID)
481    Relayout();
482}
483
484/////////////////////////////////////////////////////////////////////////////
485// PanelLayoutManager, WindowStateObserver implementation:
486
487void PanelLayoutManager::OnPostWindowStateTypeChange(
488    wm::WindowState* window_state,
489    wm::WindowStateType old_type) {
490  // If the shelf is currently hidden then windows will not actually be shown
491  // but the set to restore when the shelf becomes visible is updated.
492  if (restore_windows_on_shelf_visible_) {
493    if (window_state->IsMinimized()) {
494      MinimizePanel(window_state->window());
495      restore_windows_on_shelf_visible_->Remove(window_state->window());
496    } else {
497      restore_windows_on_shelf_visible_->Add(window_state->window());
498    }
499    return;
500  }
501
502  if (window_state->IsMinimized())
503    MinimizePanel(window_state->window());
504  else
505    RestorePanel(window_state->window());
506}
507
508////////////////////////////////////////////////////////////////////////////////
509// PanelLayoutManager, aura::client::ActivationChangeObserver implementation:
510
511void PanelLayoutManager::OnWindowActivated(aura::Window* gained_active,
512                                           aura::Window* lost_active) {
513  // Ignore if the panel that is not managed by this was activated.
514  if (gained_active && gained_active->type() == ui::wm::WINDOW_TYPE_PANEL &&
515      gained_active->parent() == panel_container_) {
516    UpdateStacking(gained_active);
517    UpdateCallouts();
518  }
519}
520
521////////////////////////////////////////////////////////////////////////////////
522// PanelLayoutManager, DisplayController::Observer implementation:
523
524void PanelLayoutManager::OnDisplayConfigurationChanged() {
525  Relayout();
526}
527
528////////////////////////////////////////////////////////////////////////////////
529// PanelLayoutManager, ShelfLayoutManagerObserver implementation:
530
531void PanelLayoutManager::WillChangeVisibilityState(
532    ShelfVisibilityState new_state) {
533  // On entering / leaving full screen mode the shelf visibility state is
534  // changed to / from SHELF_HIDDEN. In this state, panel windows should hide
535  // to allow the full-screen application to use the full screen.
536  bool shelf_hidden = new_state == ash::SHELF_HIDDEN;
537  if (!shelf_hidden) {
538    if (restore_windows_on_shelf_visible_) {
539      scoped_ptr<aura::WindowTracker> restore_windows(
540          restore_windows_on_shelf_visible_.Pass());
541      for (aura::WindowTracker::Windows::const_iterator iter =
542           restore_windows->windows().begin(); iter !=
543           restore_windows->windows().end(); ++iter) {
544        RestorePanel(*iter);
545      }
546    }
547    return;
548  }
549
550  if (restore_windows_on_shelf_visible_)
551    return;
552  scoped_ptr<aura::WindowTracker> minimized_windows(new aura::WindowTracker);
553  for (PanelList::iterator iter = panel_windows_.begin();
554       iter != panel_windows_.end();) {
555    aura::Window* window = iter->window;
556    // Minimizing a panel window may remove it from the panel_windows_ list.
557    // Advance the iterator before minimizing it: http://crbug.com/393047.
558    ++iter;
559    if (window != dragged_panel_ && window->IsVisible()) {
560      minimized_windows->Add(window);
561      wm::GetWindowState(window)->Minimize();
562    }
563  }
564  restore_windows_on_shelf_visible_ = minimized_windows.Pass();
565}
566
567////////////////////////////////////////////////////////////////////////////////
568// PanelLayoutManager private implementation:
569
570void PanelLayoutManager::MinimizePanel(aura::Window* panel) {
571  ::wm::SetWindowVisibilityAnimationType(
572      panel, WINDOW_VISIBILITY_ANIMATION_TYPE_MINIMIZE);
573  ui::Layer* layer = panel->layer();
574  ui::ScopedLayerAnimationSettings panel_slide_settings(layer->GetAnimator());
575  panel_slide_settings.SetPreemptionStrategy(
576      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
577  panel_slide_settings.SetTransitionDuration(
578      base::TimeDelta::FromMilliseconds(kPanelSlideDurationMilliseconds));
579  gfx::Rect bounds(panel->bounds());
580  bounds.Offset(GetSlideInAnimationOffset(
581      shelf_->shelf_widget()->GetAlignment()));
582  SetChildBoundsDirect(panel, bounds);
583  panel->Hide();
584  layer->SetOpacity(0);
585  if (wm::IsActiveWindow(panel))
586    wm::DeactivateWindow(panel);
587  Relayout();
588}
589
590void PanelLayoutManager::RestorePanel(aura::Window* panel) {
591  PanelList::iterator found =
592      std::find(panel_windows_.begin(), panel_windows_.end(), panel);
593  DCHECK(found != panel_windows_.end());
594  found->slide_in = true;
595  Relayout();
596}
597
598void PanelLayoutManager::Relayout() {
599  if (!shelf_ || !shelf_->shelf_widget())
600    return;
601
602  if (in_layout_)
603    return;
604  base::AutoReset<bool> auto_reset_in_layout(&in_layout_, true);
605
606  ShelfAlignment alignment = shelf_->shelf_widget()->GetAlignment();
607  bool horizontal = alignment == SHELF_ALIGNMENT_TOP ||
608                    alignment == SHELF_ALIGNMENT_BOTTOM;
609  gfx::Rect shelf_bounds = ash::ScreenUtil::ConvertRectFromScreen(
610      panel_container_, shelf_->shelf_widget()->GetWindowBoundsInScreen());
611  int panel_start_bounds = kPanelIdealSpacing;
612  int panel_end_bounds = horizontal ?
613      panel_container_->bounds().width() - kPanelIdealSpacing :
614      panel_container_->bounds().height() - kPanelIdealSpacing;
615  aura::Window* active_panel = NULL;
616  std::vector<VisiblePanelPositionInfo> visible_panels;
617  for (PanelList::iterator iter = panel_windows_.begin();
618       iter != panel_windows_.end(); ++iter) {
619    aura::Window* panel = iter->window;
620    iter->callout_widget->SetAlignment(alignment);
621
622    // Consider the dragged panel as part of the layout as long as it is
623    // touching the shelf.
624    if ((!panel->IsVisible() && !iter->slide_in) ||
625        (panel == dragged_panel_ &&
626         !BoundsAdjacent(panel->bounds(), shelf_bounds))) {
627      continue;
628    }
629
630    // If the shelf is currently hidden (full-screen mode), minimize panel until
631    // full-screen mode is exited. When a panel is dragged from another display
632    // the shelf state does not update before the panel is added so we exclude
633    // the dragged panel.
634    if (panel != dragged_panel_ && restore_windows_on_shelf_visible_) {
635      wm::GetWindowState(panel)->Minimize();
636      restore_windows_on_shelf_visible_->Add(panel);
637      continue;
638    }
639
640    gfx::Rect icon_bounds = shelf_->GetScreenBoundsOfItemIconForWindow(panel);
641
642    // If both the icon width and height are 0 then there is no icon in the
643    // shelf. If the shelf is hidden, one of the height or width will be
644    // 0 but the position in the shelf and major dimension is still reported
645    // correctly and the panel can be aligned above where the hidden icon is.
646    if (icon_bounds.width() == 0 && icon_bounds.height() == 0)
647      continue;
648
649    if (panel->HasFocus() ||
650        panel->Contains(
651            aura::client::GetFocusClient(panel)->GetFocusedWindow())) {
652      DCHECK(!active_panel);
653      active_panel = panel;
654    }
655    icon_bounds = ScreenUtil::ConvertRectFromScreen(panel_container_,
656                                                    icon_bounds);
657    gfx::Point icon_origin = icon_bounds.origin();
658    VisiblePanelPositionInfo position_info;
659    int icon_start = horizontal ? icon_origin.x() : icon_origin.y();
660    int icon_end = icon_start + (horizontal ? icon_bounds.width() :
661                                 icon_bounds.height());
662    position_info.major_length = horizontal ?
663        panel->bounds().width() : panel->bounds().height();
664    position_info.min_major = std::max(
665        panel_start_bounds + position_info.major_length / 2,
666        icon_end - position_info.major_length / 2);
667    position_info.max_major = std::min(
668        icon_start + position_info.major_length / 2,
669        panel_end_bounds - position_info.major_length / 2);
670    position_info.major_pos = (icon_start + icon_end) / 2;
671    position_info.window = panel;
672    position_info.slide_in = iter->slide_in;
673    iter->slide_in = false;
674    visible_panels.push_back(position_info);
675  }
676
677  // Sort panels by their X positions and fan out groups of overlapping panels.
678  // The fan out method may result in new overlapping panels however given that
679  // the panels start at least a full panel width apart this overlap will
680  // never completely obscure a panel.
681  // TODO(flackr): Rearrange panels if new overlaps are introduced.
682  std::sort(visible_panels.begin(), visible_panels.end(), CompareWindowMajor);
683  size_t first_overlapping_panel = 0;
684  for (size_t i = 1; i < visible_panels.size(); ++i) {
685    if (visible_panels[i - 1].major_pos +
686        visible_panels[i - 1].major_length / 2 < visible_panels[i].major_pos -
687        visible_panels[i].major_length / 2) {
688      FanOutPanels(visible_panels.begin() + first_overlapping_panel,
689                   visible_panels.begin() + i);
690      first_overlapping_panel = i;
691    }
692  }
693  FanOutPanels(visible_panels.begin() + first_overlapping_panel,
694               visible_panels.end());
695
696  for (size_t i = 0; i < visible_panels.size(); ++i) {
697    if (visible_panels[i].window == dragged_panel_)
698      continue;
699    bool slide_in = visible_panels[i].slide_in;
700    gfx::Rect bounds = visible_panels[i].window->GetTargetBounds();
701    switch (alignment) {
702      case SHELF_ALIGNMENT_BOTTOM:
703        bounds.set_y(shelf_bounds.y() - bounds.height());
704        break;
705      case SHELF_ALIGNMENT_LEFT:
706        bounds.set_x(shelf_bounds.right());
707        break;
708      case SHELF_ALIGNMENT_RIGHT:
709        bounds.set_x(shelf_bounds.x() - bounds.width());
710        break;
711      case SHELF_ALIGNMENT_TOP:
712        bounds.set_y(shelf_bounds.bottom());
713        break;
714    }
715    bool on_shelf = visible_panels[i].window->GetTargetBounds() == bounds;
716
717    if (horizontal) {
718      bounds.set_x(visible_panels[i].major_pos -
719                   visible_panels[i].major_length / 2);
720    } else {
721      bounds.set_y(visible_panels[i].major_pos -
722                   visible_panels[i].major_length / 2);
723    }
724
725    ui::Layer* layer = visible_panels[i].window->layer();
726    if (slide_in) {
727      // New windows shift up from the shelf into position and fade in.
728      layer->SetOpacity(0);
729      gfx::Rect initial_bounds(bounds);
730      initial_bounds.Offset(GetSlideInAnimationOffset(alignment));
731      SetChildBoundsDirect(visible_panels[i].window, initial_bounds);
732      // Set on shelf so that the panel animates into its target position.
733      on_shelf = true;
734    }
735
736    if (on_shelf) {
737      ui::ScopedLayerAnimationSettings panel_slide_settings(
738          layer->GetAnimator());
739      panel_slide_settings.SetPreemptionStrategy(
740          ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
741      panel_slide_settings.SetTransitionDuration(
742          base::TimeDelta::FromMilliseconds(kPanelSlideDurationMilliseconds));
743      SetChildBoundsDirect(visible_panels[i].window, bounds);
744      if (slide_in) {
745        layer->SetOpacity(1);
746        visible_panels[i].window->Show();
747      }
748    } else {
749      // If the shelf moved don't animate, move immediately to the new
750      // target location.
751      SetChildBoundsDirect(visible_panels[i].window, bounds);
752    }
753  }
754
755  UpdateStacking(active_panel);
756  UpdateCallouts();
757}
758
759void PanelLayoutManager::UpdateStacking(aura::Window* active_panel) {
760  if (!active_panel) {
761    if (!last_active_panel_)
762      return;
763    active_panel = last_active_panel_;
764  }
765
766  ShelfAlignment alignment = shelf_->alignment();
767  bool horizontal = alignment == SHELF_ALIGNMENT_TOP ||
768                    alignment == SHELF_ALIGNMENT_BOTTOM;
769
770  // We want to to stack the panels like a deck of cards:
771  // ,--,--,--,-------.--.--.
772  // |  |  |  |       |  |  |
773  // |  |  |  |       |  |  |
774  //
775  // We use the middle of each panel to figure out how to stack the panels. This
776  // allows us to update the stacking when a panel is being dragged around by
777  // the titlebar--even though it doesn't update the shelf icon positions, we
778  // still want the visual effect.
779  std::map<int, aura::Window*> window_ordering;
780  for (PanelList::const_iterator it = panel_windows_.begin();
781       it != panel_windows_.end(); ++it) {
782    gfx::Rect bounds = it->window->bounds();
783    window_ordering.insert(std::make_pair(horizontal ?
784                                              bounds.x() + bounds.width() / 2 :
785                                              bounds.y() + bounds.height() / 2,
786                                          it->window));
787  }
788
789  aura::Window* previous_panel = NULL;
790  for (std::map<int, aura::Window*>::const_iterator it =
791       window_ordering.begin();
792       it != window_ordering.end() && it->second != active_panel; ++it) {
793    if (previous_panel)
794      panel_container_->StackChildAbove(it->second, previous_panel);
795    previous_panel = it->second;
796  }
797
798  previous_panel = NULL;
799  for (std::map<int, aura::Window*>::const_reverse_iterator it =
800       window_ordering.rbegin();
801       it != window_ordering.rend() && it->second != active_panel; ++it) {
802    if (previous_panel)
803      panel_container_->StackChildAbove(it->second, previous_panel);
804    previous_panel = it->second;
805  }
806
807  panel_container_->StackChildAtTop(active_panel);
808  if (dragged_panel_ && dragged_panel_->parent() == panel_container_)
809    panel_container_->StackChildAtTop(dragged_panel_);
810  last_active_panel_ = active_panel;
811}
812
813void PanelLayoutManager::UpdateCallouts() {
814  ShelfAlignment alignment = shelf_->alignment();
815  bool horizontal = alignment == SHELF_ALIGNMENT_TOP ||
816                    alignment == SHELF_ALIGNMENT_BOTTOM;
817
818  for (PanelList::iterator iter = panel_windows_.begin();
819       iter != panel_windows_.end(); ++iter) {
820    aura::Window* panel = iter->window;
821    views::Widget* callout_widget = iter->callout_widget;
822
823    gfx::Rect current_bounds = panel->GetBoundsInScreen();
824    gfx::Rect bounds = ScreenUtil::ConvertRectToScreen(
825        panel->parent(),
826        panel->GetTargetBounds());
827    gfx::Rect icon_bounds = shelf_->GetScreenBoundsOfItemIconForWindow(panel);
828    if (icon_bounds.IsEmpty() || !panel->layer()->GetTargetVisibility() ||
829        panel == dragged_panel_ || !show_callout_widgets_) {
830      callout_widget->Hide();
831      callout_widget->GetNativeWindow()->layer()->SetOpacity(0);
832      continue;
833    }
834
835    gfx::Rect callout_bounds = callout_widget->GetWindowBoundsInScreen();
836    gfx::Vector2d slide_vector = bounds.origin() - current_bounds.origin();
837    int slide_distance = horizontal ? slide_vector.x() : slide_vector.y();
838    int distance_until_over_panel = 0;
839    if (horizontal) {
840      callout_bounds.set_x(
841          icon_bounds.x() + (icon_bounds.width() - callout_bounds.width()) / 2);
842      distance_until_over_panel = std::max(
843          current_bounds.x() - callout_bounds.x(),
844          callout_bounds.right() - current_bounds.right());
845    } else {
846      callout_bounds.set_y(
847          icon_bounds.y() + (icon_bounds.height() -
848                             callout_bounds.height()) / 2);
849      distance_until_over_panel = std::max(
850          current_bounds.y() - callout_bounds.y(),
851          callout_bounds.bottom() - current_bounds.bottom());
852    }
853    switch (alignment) {
854      case SHELF_ALIGNMENT_BOTTOM:
855        callout_bounds.set_y(bounds.bottom());
856        break;
857      case SHELF_ALIGNMENT_LEFT:
858        callout_bounds.set_x(bounds.x() - callout_bounds.width());
859        break;
860      case SHELF_ALIGNMENT_RIGHT:
861        callout_bounds.set_x(bounds.right());
862        break;
863      case SHELF_ALIGNMENT_TOP:
864        callout_bounds.set_y(bounds.y() - callout_bounds.height());
865        break;
866    }
867    callout_bounds = ScreenUtil::ConvertRectFromScreen(
868        callout_widget->GetNativeWindow()->parent(),
869        callout_bounds);
870
871    SetChildBoundsDirect(callout_widget->GetNativeWindow(), callout_bounds);
872    panel_container_->StackChildAbove(callout_widget->GetNativeWindow(),
873                                      panel);
874
875    ui::Layer* layer = callout_widget->GetNativeWindow()->layer();
876    // If the panel is not over the callout position or has just become visible
877    // then fade in the callout.
878    if ((distance_until_over_panel > 0 || layer->GetTargetOpacity() < 1)) {
879      if (distance_until_over_panel > 0 &&
880          slide_distance >= distance_until_over_panel) {
881        // If the panel is not yet over the callout, then delay fading in
882        // the callout until after the panel should be over it.
883        int delay = kPanelSlideDurationMilliseconds *
884            distance_until_over_panel / slide_distance;
885        layer->SetOpacity(0);
886        layer->GetAnimator()->StopAnimating();
887        layer->GetAnimator()->SchedulePauseForProperties(
888            base::TimeDelta::FromMilliseconds(delay),
889            ui::LayerAnimationElement::OPACITY);
890      }
891      ui::ScopedLayerAnimationSettings callout_settings(layer->GetAnimator());
892      callout_settings.SetPreemptionStrategy(
893          ui::LayerAnimator::REPLACE_QUEUED_ANIMATIONS);
894      callout_settings.SetTransitionDuration(
895          base::TimeDelta::FromMilliseconds(
896              kCalloutFadeDurationMilliseconds));
897      layer->SetOpacity(1);
898    }
899
900    // Show after changing the opacity animation. This way we don't have a
901    // state where the widget is visible but the opacity is 0.
902    callout_widget->Show();
903  }
904}
905
906////////////////////////////////////////////////////////////////////////////////
907// keyboard::KeyboardControllerObserver implementation:
908
909void PanelLayoutManager::OnKeyboardBoundsChanging(
910    const gfx::Rect& keyboard_bounds) {
911  gfx::Rect parent_bounds = panel_container_->bounds();
912  int available_space = parent_bounds.height() - keyboard_bounds.height();
913  for (PanelList::iterator iter = panel_windows_.begin();
914       iter != panel_windows_.end();
915       ++iter) {
916    aura::Window* panel = iter->window;
917    wm::WindowState* panel_state = wm::GetWindowState(panel);
918    if (keyboard_bounds.height() > 0) {
919      // Save existing bounds, so that we can restore them when the keyboard
920      // hides.
921      panel_state->SaveCurrentBoundsForRestore();
922
923      gfx::Rect panel_bounds = ScreenUtil::ConvertRectToScreen(
924          panel->parent(), panel->GetTargetBounds());
925      int delta = panel_bounds.height() - available_space;
926      // Ensure panels are not pushed above the parent boundaries, shrink any
927      // panels that violate this constraint.
928      if (delta > 0) {
929        SetChildBounds(panel,
930                       gfx::Rect(panel_bounds.x(),
931                                 panel_bounds.y() + delta,
932                                 panel_bounds.width(),
933                                 panel_bounds.height() - delta));
934      }
935    } else if (panel_state->HasRestoreBounds()) {
936      // Keyboard hidden, restore original bounds if they exist.
937      SetChildBounds(panel, panel_state->GetRestoreBoundsInScreen());
938    }
939  }
940  // This bounds change will have caused a change to the Shelf which does not
941  // propogate automatically to this class, so manually recalculate bounds.
942  OnWindowResized();
943}
944
945}  // namespace ash
946