root/chrome/browser/ui/panels/docked_panel_collection.cc

DEFINITIONS

1. refresh_action_factory_
2. OnDisplayChanged
3. AddPanel
4. GetDefaultPositionForPanel
5. StartingRightPosition
6. GetRightMostAvailablePosition
7. RemovePanel
8. SavePanelPlacement
9. RestorePanelToSavedPlacement
10. DiscardSavedPanelPlacement
11. GetPanelResizability
12. OnPanelResizedByMouse
13. OnPanelExpansionStateChanged
14. AdjustPanelBoundsPerExpansionState
15. OnPanelAttentionStateChanged
16. OnPanelTitlebarClicked
17. ActivatePanel
18. MinimizePanel
19. RestorePanel
20. MinimizeAll
21. RestoreAll
22. OnMinimizeButtonClicked
23. OnRestoreButtonClicked
24. CanShowMinimizeButton
25. CanShowRestoreButton
26. IsPanelMinimized
27. UsesAlwaysOnTopPanels
28. UpdateMinimizedPanelCount
29. ResizePanelWindow
30. ShouldBringUpTitlebars
31. BringUpOrDownTitlebars
32. DelayedBringUpOrDownTitlebarsCheck
33. DoBringUpOrDownTitlebars
34. GetBottomPositionForExpansionState
35. OnMouseMove
36. OnAutoHidingDesktopBarVisibilityChanged
37. OnAutoHidingDesktopBarThicknessChanged
38. RefreshLayout
39. WidthToDisplayPanelInCollection
40. CloseAll
41. UpdatePanelOnCollectionChange
42. ScheduleLayoutRefresh
43. OnPanelActiveStateChanged
44. GetInitialPanelBounds
45. HasPanel

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/ui/panels/docked_panel_collection.h"

#include <math.h>

#include <algorithm>
#include <vector>

#include "base/auto_reset.h"
#include "base/bind.h"
#include "base/logging.h"
#include "base/message_loop/message_loop.h"
#include "chrome/browser/chrome_notification_types.h"
#include "chrome/browser/ui/panels/panel_drag_controller.h"
#include "chrome/browser/ui/panels/panel_manager.h"
#include "chrome/browser/ui/panels/panel_mouse_watcher.h"
#include "content/public/browser/notification_service.h"
#include "content/public/browser/notification_source.h"

namespace {
// Width of spacing around panel collection and the left/right edges of the
// screen.
const int kPanelCollectionLeftMargin = 6;
const int kPanelCollectionRightMargin = 24;

// Occasionally some system, like Windows, might not bring up or down the bottom
// bar when the mouse enters or leaves the bottom screen area. This is the
// maximum time we will wait for the bottom bar visibility change notification.
// After the time expires, we bring up/down the titlebars as planned.
const int kMaxDelayWaitForBottomBarVisibilityChangeMs = 1000;

// See usage below.
#if defined(TOOLKIT_GTK)
const int kDelayBeforeCollapsingFromTitleOnlyStateMs = 2000;
#else
const int kDelayBeforeCollapsingFromTitleOnlyStateMs = 0;
#endif

// After focus changed, one panel lost active status, another got it,
// we refresh layout with a delay.
const int kRefreshLayoutAfterActivePanelChangeDelayMs = 600;  // arbitrary

// As we refresh panel positions, some or all panels may move. We make sure
// we do not animate too many panels at once as this tends to perform poorly.
const int kNumPanelsToAnimateSimultaneously = 3;

}  // namespace

DockedPanelCollection::DockedPanelCollection(PanelManager* panel_manager)
    : PanelCollection(PanelCollection::DOCKED),
      panel_manager_(panel_manager),
      minimized_panel_count_(0),
      are_titlebars_up_(false),
      minimizing_all_(false),
      delayed_titlebar_action_(NO_ACTION),
      titlebar_action_factory_(this),
      refresh_action_factory_(this) {
  panel_manager_->display_settings_provider()->AddDesktopBarObserver(this);
  OnDisplayChanged();
}

DockedPanelCollection::~DockedPanelCollection() {
  DCHECK(panels_.empty());
  DCHECK_EQ(0, minimized_panel_count_);
  panel_manager_->display_settings_provider()->RemoveDesktopBarObserver(this);
}

void DockedPanelCollection::OnDisplayChanged() {
  work_area_ =
      panel_manager_->display_settings_provider()->GetPrimaryWorkArea();
  work_area_.set_x(work_area_.x() + kPanelCollectionLeftMargin);
  work_area_.set_width(work_area_.width() -
      kPanelCollectionLeftMargin - kPanelCollectionRightMargin);

  if (panels_.empty())
    return;

  for (Panels::const_iterator iter = panels_.begin();
       iter != panels_.end(); ++iter) {
    (*iter)->LimitSizeToWorkArea(work_area_);
  }

  RefreshLayout();
}

void DockedPanelCollection::AddPanel(Panel* panel,
                                PositioningMask positioning_mask) {
  // This method does not handle minimized panels.
  DCHECK_EQ(Panel::EXPANDED, panel->expansion_state());

  DCHECK(panel->initialized());
  DCHECK_NE(this, panel->collection());
  panel->set_collection(this);

  bool default_position = (positioning_mask & KNOWN_POSITION) == 0;
  bool update_bounds = (positioning_mask & DO_NOT_UPDATE_BOUNDS) == 0;

  if (default_position) {
    gfx::Size full_size = panel->full_size();
    gfx::Point pt = GetDefaultPositionForPanel(full_size);
    panel->SetPanelBounds(gfx::Rect(pt, full_size));
    panels_.push_back(panel);
  } else {
    DCHECK(update_bounds);
    int x = panel->GetBounds().x();
    Panels::iterator iter = panels_.begin();
    for (; iter != panels_.end(); ++iter)
      if (x > (*iter)->GetBounds().x())
        break;
    panels_.insert(iter, panel);
  }

  if (update_bounds) {
    if ((positioning_mask & DELAY_LAYOUT_REFRESH) != 0)
      ScheduleLayoutRefresh();
    else
      RefreshLayout();
  }
}

gfx::Point DockedPanelCollection::GetDefaultPositionForPanel(
    const gfx::Size& full_size) const {
  int x = 0;
  if (!panels_.empty() &&
      panels_.back()->GetBounds().x() < work_area_.x()) {
    // Panels go off screen. Make sure the default position will place
    // the panel in view.
    Panels::const_reverse_iterator iter = panels_.rbegin();
    for (; iter != panels_.rend(); ++iter) {
      if ((*iter)->GetBounds().x() >= work_area_.x()) {
        x = (*iter)->GetBounds().x();
        break;
      }
    }
    // At least one panel should fit on the screen.
    DCHECK(x > work_area_.x());
  } else {
    x = std::max(GetRightMostAvailablePosition() - full_size.width(),
                 work_area_.x());
  }
  return gfx::Point(x, work_area_.bottom() - full_size.height());
}

int DockedPanelCollection::StartingRightPosition() const {
  return work_area_.right();
}

int DockedPanelCollection::GetRightMostAvailablePosition() const {
  return panels_.empty() ? StartingRightPosition() :
      (panels_.back()->GetBounds().x() - kPanelsHorizontalSpacing);
}

void DockedPanelCollection::RemovePanel(Panel* panel, RemovalReason reason) {
  DCHECK_EQ(this, panel->collection());
  panel->set_collection(NULL);

  // Optimize for the common case of removing the last panel.
  DCHECK(!panels_.empty());
  if (panels_.back() == panel) {
    panels_.pop_back();

    // Update the saved panel placement if needed. This is because
    // we might remove |saved_panel_placement_.left_panel|.
    if (saved_panel_placement_.panel &&
        saved_panel_placement_.left_panel == panel)
      saved_panel_placement_.left_panel = NULL;

  } else {
    Panels::iterator iter = find(panels_.begin(), panels_.end(), panel);
    DCHECK(iter != panels_.end());
    iter = panels_.erase(iter);

    // Update the saved panel placement if needed. This is because
    // we might remove |saved_panel_placement_.left_panel|.
    if (saved_panel_placement_.panel &&
        saved_panel_placement_.left_panel == panel)
      saved_panel_placement_.left_panel = *iter;
  }

  if (panel->expansion_state() != Panel::EXPANDED)
    UpdateMinimizedPanelCount();

  RefreshLayout();
}

void DockedPanelCollection::SavePanelPlacement(Panel* panel) {
  DCHECK(!saved_panel_placement_.panel);

  saved_panel_placement_.panel = panel;

  // To recover panel to its original placement, we only need to track the panel
  // that is placed after it.
  Panels::iterator iter = find(panels_.begin(), panels_.end(), panel);
  DCHECK(iter != panels_.end());
  ++iter;
  saved_panel_placement_.left_panel = (iter == panels_.end()) ? NULL : *iter;
}

void DockedPanelCollection::RestorePanelToSavedPlacement() {
  DCHECK(saved_panel_placement_.panel);

  Panel* panel = saved_panel_placement_.panel;

  // Find next panel after this panel.
  Panels::iterator iter = std::find(panels_.begin(), panels_.end(), panel);
  DCHECK(iter != panels_.end());
  Panels::iterator next_iter = iter;
  next_iter++;
  Panel* next_panel = (next_iter == panels_.end()) ? NULL : *iter;

  // Restoring is only needed when this panel is not in the right position.
  if (next_panel != saved_panel_placement_.left_panel) {
    // Remove this panel from its current position.
    panels_.erase(iter);

    // Insert this panel into its previous position.
    if (saved_panel_placement_.left_panel) {
      Panels::iterator iter_to_insert_before = std::find(panels_.begin(),
          panels_.end(), saved_panel_placement_.left_panel);
      DCHECK(iter_to_insert_before != panels_.end());
      panels_.insert(iter_to_insert_before, panel);
    } else {
      panels_.push_back(panel);
    }
  }

  RefreshLayout();

  DiscardSavedPanelPlacement();
}

void DockedPanelCollection::DiscardSavedPanelPlacement() {
  DCHECK(saved_panel_placement_.panel);
  saved_panel_placement_.panel = NULL;
  saved_panel_placement_.left_panel = NULL;
}

panel::Resizability DockedPanelCollection::GetPanelResizability(
    const Panel* panel) const {
  return (panel->expansion_state() == Panel::EXPANDED) ?
      panel::RESIZABLE_EXCEPT_BOTTOM : panel::NOT_RESIZABLE;
}

void DockedPanelCollection::OnPanelResizedByMouse(Panel* panel,
                                                  const gfx::Rect& new_bounds) {
  DCHECK_EQ(this, panel->collection());
  panel->set_full_size(new_bounds.size());
}

void DockedPanelCollection::OnPanelExpansionStateChanged(Panel* panel) {
  gfx::Rect panel_bounds = panel->GetBounds();
  AdjustPanelBoundsPerExpansionState(panel, &panel_bounds);
  panel->SetPanelBounds(panel_bounds);

  UpdateMinimizedPanelCount();

  // Ensure minimized panel does not get the focus. If minimizing all,
  // the active panel will be deactivated once when all panels are minimized
  // rather than per minimized panel.
  if (panel->expansion_state() != Panel::EXPANDED && !minimizing_all_ &&
      panel->IsActive()) {
    panel->Deactivate();
    // The layout will refresh itself in response
    // to (de)activation notification.
  }
}

void DockedPanelCollection::AdjustPanelBoundsPerExpansionState(Panel* panel,
                                                          gfx::Rect* bounds) {
  Panel::ExpansionState expansion_state = panel->expansion_state();
  switch (expansion_state) {
    case Panel::EXPANDED:
      bounds->set_height(panel->full_size().height());

      break;
    case Panel::TITLE_ONLY:
      bounds->set_height(panel->TitleOnlyHeight());

      break;
    case Panel::MINIMIZED:
      bounds->set_height(panel::kMinimizedPanelHeight);

      break;
    default:
      NOTREACHED();
      break;
  }

  int bottom = GetBottomPositionForExpansionState(expansion_state);
  bounds->set_y(bottom - bounds->height());
}

void DockedPanelCollection::OnPanelAttentionStateChanged(Panel* panel) {
  DCHECK_EQ(this, panel->collection());
  Panel::ExpansionState state = panel->expansion_state();
  if (panel->IsDrawingAttention()) {
    // Bring up the titlebar to get user's attention.
    if (state == Panel::MINIMIZED)
      panel->SetExpansionState(Panel::TITLE_ONLY);
    return;
  }

  // Panel is no longer drawing attention, but leave the panel in
  // title-only mode if all titlebars are currently up.
  if (state != Panel::TITLE_ONLY || are_titlebars_up_)
    return;

  // Leave titlebar up if panel is being dragged.
  if (panel_manager_->drag_controller()->dragging_panel() == panel)
    return;

  // Leave titlebar up if mouse is in/below the panel.
  const gfx::Point mouse_position =
      panel_manager_->mouse_watcher()->GetMousePosition();
  gfx::Rect bounds = panel->GetBounds();
  if (bounds.x() <= mouse_position.x() &&
      mouse_position.x() <= bounds.right() &&
      mouse_position.y() >= bounds.y())
    return;

  // Bring down the titlebar now that panel is not drawing attention.
  panel->SetExpansionState(Panel::MINIMIZED);
}

void DockedPanelCollection::OnPanelTitlebarClicked(Panel* panel,
                                              panel::ClickModifier modifier) {
  DCHECK_EQ(this, panel->collection());
  if (!IsPanelMinimized(panel))
    return;

  if (modifier == panel::APPLY_TO_ALL)
    RestoreAll();
  else
    RestorePanel(panel);
}

void DockedPanelCollection::ActivatePanel(Panel* panel) {
  DCHECK_EQ(this, panel->collection());

  // Make sure the panel is expanded when activated so the user input
  // does not go into a collapsed window.
  panel->SetExpansionState(Panel::EXPANDED);

  // If the layout needs to be refreshed, it will happen in response to
  // the activation notification (and with a slight delay to let things settle).
}

void DockedPanelCollection::MinimizePanel(Panel* panel) {
  DCHECK_EQ(this, panel->collection());

  if (panel->expansion_state() != Panel::EXPANDED)
    return;

  panel->SetExpansionState(panel->IsDrawingAttention() ?
      Panel::TITLE_ONLY : Panel::MINIMIZED);
}

void DockedPanelCollection::RestorePanel(Panel* panel) {
  DCHECK_EQ(this, panel->collection());
  panel->SetExpansionState(Panel::EXPANDED);
}

void DockedPanelCollection::MinimizeAll() {
  // Set minimizing_all_ to prevent deactivation of each panel when it
  // is minimized. See comments in OnPanelExpansionStateChanged.
  base::AutoReset<bool> pin(&minimizing_all_, true);
  Panel* minimized_active_panel = NULL;
  for (Panels::const_iterator iter = panels_.begin();
       iter != panels_.end(); ++iter) {
    if ((*iter)->IsActive())
      minimized_active_panel = *iter;
    MinimizePanel(*iter);
  }

  // When a single panel is minimized, it is deactivated to ensure that
  // a minimized panel does not have focus. However, when minimizing all,
  // the deactivation is only done once after all panels are minimized,
  // rather than per minimized panel, both for efficiency and to avoid
  // temporary activations of random not-yet-minimized panels.
  if (minimized_active_panel) {
    minimized_active_panel->Deactivate();
    // Layout will be refreshed in response to (de)activation notification.
  }
}

void DockedPanelCollection::RestoreAll() {
  for (Panels::const_iterator iter = panels_.begin();
       iter != panels_.end(); ++iter) {
    RestorePanel(*iter);
  }
}

void DockedPanelCollection::OnMinimizeButtonClicked(
    Panel* panel, panel::ClickModifier modifier) {
  if (modifier == panel::APPLY_TO_ALL)
    MinimizeAll();
  else
    MinimizePanel(panel);
}

void DockedPanelCollection::OnRestoreButtonClicked(
    Panel* panel, panel::ClickModifier modifier) {
  if (modifier == panel::APPLY_TO_ALL)
    RestoreAll();
  else
    RestorePanel(panel);
}

bool DockedPanelCollection::CanShowMinimizeButton(const Panel* panel) const {
  return !IsPanelMinimized(panel);
}

bool DockedPanelCollection::CanShowRestoreButton(const Panel* panel) const {
  return IsPanelMinimized(panel);
}

bool DockedPanelCollection::IsPanelMinimized(const Panel* panel) const {
  return panel->expansion_state() != Panel::EXPANDED;
}

bool DockedPanelCollection::UsesAlwaysOnTopPanels() const {
  return true;
}

void DockedPanelCollection::UpdateMinimizedPanelCount() {
  int prev_minimized_panel_count = minimized_panel_count_;
  minimized_panel_count_ = 0;
  for (Panels::const_iterator panel_iter = panels_.begin();
        panel_iter != panels_.end(); ++panel_iter) {
    if ((*panel_iter)->expansion_state() != Panel::EXPANDED)
      minimized_panel_count_++;
  }

  if (prev_minimized_panel_count == 0 && minimized_panel_count_ > 0)
    panel_manager_->mouse_watcher()->AddObserver(this);
  else if (prev_minimized_panel_count > 0 &&  minimized_panel_count_ == 0)
    panel_manager_->mouse_watcher()->RemoveObserver(this);

  DCHECK_LE(minimized_panel_count_, num_panels());
}

void DockedPanelCollection::ResizePanelWindow(
    Panel* panel,
    const gfx::Size& preferred_window_size) {
  DCHECK_EQ(this, panel->collection());
  // Make sure the new size does not violate panel's size restrictions.
  gfx::Size new_size(preferred_window_size.width(),
                     preferred_window_size.height());
  new_size = panel->ClampSize(new_size);

  if (new_size == panel->full_size())
    return;

  panel->set_full_size(new_size);

  RefreshLayout();
}

bool DockedPanelCollection::ShouldBringUpTitlebars(int mouse_x,
                                                   int mouse_y) const {
  // We should always bring up the titlebar if the mouse is over the
  // visible auto-hiding bottom bar.
  DisplaySettingsProvider* provider =
      panel_manager_->display_settings_provider();
  if (provider->IsAutoHidingDesktopBarEnabled(
          DisplaySettingsProvider::DESKTOP_BAR_ALIGNED_BOTTOM) &&
      provider->GetDesktopBarVisibility(
          DisplaySettingsProvider::DESKTOP_BAR_ALIGNED_BOTTOM) ==
              DisplaySettingsProvider::DESKTOP_BAR_VISIBLE) {
    int bottom_bar_bottom = work_area_.bottom();
    int bottom_bar_y = bottom_bar_bottom - provider->GetDesktopBarThickness(
        DisplaySettingsProvider::DESKTOP_BAR_ALIGNED_BOTTOM);
    if (bottom_bar_y <= mouse_y && mouse_y <= bottom_bar_bottom)
      return true;
  }

  // Bring up titlebars if any panel needs the titlebar up.
  Panel* dragging_panel = panel_manager_->drag_controller()->dragging_panel();
  if (dragging_panel &&
      dragging_panel->collection()->type() != PanelCollection::DOCKED)
    dragging_panel = NULL;
  for (Panels::const_iterator iter = panels_.begin();
       iter != panels_.end(); ++iter) {
    Panel* panel = *iter;
    Panel::ExpansionState state = panel->expansion_state();
    // Skip the expanded panel.
    if (state == Panel::EXPANDED)
      continue;

    // If the panel is showing titlebar only, we want to keep it up when it is
    // being dragged.
    if (state == Panel::TITLE_ONLY && panel == dragging_panel)
      return true;

    // We do not want to bring up other minimized panels if the mouse is over
    // the panel that pops up the titlebar to attract attention.
    if (panel->IsDrawingAttention())
      continue;

    gfx::Rect bounds = panel->GetBounds();
    if (bounds.x() <= mouse_x && mouse_x <= bounds.right() &&
        mouse_y >= bounds.y())
      return true;
  }
  return false;
}

void DockedPanelCollection::BringUpOrDownTitlebars(bool bring_up) {
  if (are_titlebars_up_ == bring_up)
    return;

  are_titlebars_up_ = bring_up;
  int task_delay_ms = 0;

  // If the auto-hiding bottom bar exists, delay the action until the bottom
  // bar is fully visible or hidden. We do not want both bottom bar and panel
  // titlebar to move at the same time but with different speeds.
  DisplaySettingsProvider* provider =
      panel_manager_->display_settings_provider();
  if (provider->IsAutoHidingDesktopBarEnabled(
          DisplaySettingsProvider::DESKTOP_BAR_ALIGNED_BOTTOM)) {
    DisplaySettingsProvider::DesktopBarVisibility visibility =
        provider->GetDesktopBarVisibility(
            DisplaySettingsProvider::DESKTOP_BAR_ALIGNED_BOTTOM);
    if (visibility !=
        (bring_up ? DisplaySettingsProvider::DESKTOP_BAR_VISIBLE
                  : DisplaySettingsProvider::DESKTOP_BAR_HIDDEN)) {
      // Occasionally some system, like Windows, might not bring up or down the
      // bottom bar when the mouse enters or leaves the bottom screen area.
      // Thus, we schedule a delayed task to do the work if we do not receive
      // the bottom bar visibility change notification within a certain period
      // of time.
      task_delay_ms = kMaxDelayWaitForBottomBarVisibilityChangeMs;
    }
  }

  // On some OSes, the interaction with native Taskbars/Docks may be improved
  // if the panels do not go back to minimized state too fast. For example,
  // with a taskbar in auto-hide mode, the taskbar will cover the panel in
  // title-only mode which appears on hover. Leaving it up for a little longer
  // would allow the user to be able to click on it.
  //
  // Currently, no platforms use both delays.
  DCHECK(task_delay_ms == 0 ||
         kDelayBeforeCollapsingFromTitleOnlyStateMs == 0);
  if (!bring_up && task_delay_ms == 0) {
    task_delay_ms = kDelayBeforeCollapsingFromTitleOnlyStateMs;
  }

  // OnAutoHidingDesktopBarVisibilityChanged will handle this.
  delayed_titlebar_action_ = bring_up ? BRING_UP : BRING_DOWN;

  // If user moves the mouse in and out of mouse tracking area, we might have
  // previously posted but not yet dispatched task in the queue. New action
  // should always 'reset' the delays so cancel any tasks that haven't run yet
  // and post a new one.
  titlebar_action_factory_.InvalidateWeakPtrs();
  base::MessageLoop::current()->PostDelayedTask(
      FROM_HERE,
      base::Bind(&DockedPanelCollection::DelayedBringUpOrDownTitlebarsCheck,
                 titlebar_action_factory_.GetWeakPtr()),
      base::TimeDelta::FromMilliseconds(
          PanelManager::AdjustTimeInterval(task_delay_ms)));
}

void DockedPanelCollection::DelayedBringUpOrDownTitlebarsCheck() {
  // Task was already processed or cancelled - bail out.
  if (delayed_titlebar_action_ == NO_ACTION)
    return;

  bool need_to_bring_up_titlebars = (delayed_titlebar_action_ == BRING_UP);

  delayed_titlebar_action_ = NO_ACTION;

  // Check if the action is still needed based on the latest mouse position. The
  // user could move the mouse into the tracking area and then quickly move it
  // out of the area. In case of this, cancel the action.
  if (are_titlebars_up_ != need_to_bring_up_titlebars)
    return;

  DoBringUpOrDownTitlebars(need_to_bring_up_titlebars);
}

void DockedPanelCollection::DoBringUpOrDownTitlebars(bool bring_up) {
  for (Panels::const_iterator iter = panels_.begin();
       iter != panels_.end(); ++iter) {
    Panel* panel = *iter;

    // Skip any panel that is drawing the attention.
    if (panel->IsDrawingAttention())
      continue;

    if (bring_up) {
      if (panel->expansion_state() == Panel::MINIMIZED)
        panel->SetExpansionState(Panel::TITLE_ONLY);
    } else {
      if (panel->expansion_state() == Panel::TITLE_ONLY)
        panel->SetExpansionState(Panel::MINIMIZED);
    }
  }
}

int DockedPanelCollection::GetBottomPositionForExpansionState(
    Panel::ExpansionState expansion_state) const {
  int bottom = work_area_.bottom();
  // If there is an auto-hiding desktop bar aligned to the bottom edge, we need
  // to move the title-only panel above the auto-hiding desktop bar.
  DisplaySettingsProvider* provider =
      panel_manager_->display_settings_provider();
  if (expansion_state == Panel::TITLE_ONLY &&
      provider->IsAutoHidingDesktopBarEnabled(
          DisplaySettingsProvider::DESKTOP_BAR_ALIGNED_BOTTOM)) {
    bottom -= provider->GetDesktopBarThickness(
        DisplaySettingsProvider::DESKTOP_BAR_ALIGNED_BOTTOM);
  }

  return bottom;
}

void DockedPanelCollection::OnMouseMove(const gfx::Point& mouse_position) {
  bool bring_up_titlebars = ShouldBringUpTitlebars(mouse_position.x(),
                                                   mouse_position.y());
  BringUpOrDownTitlebars(bring_up_titlebars);
}

void DockedPanelCollection::OnAutoHidingDesktopBarVisibilityChanged(
    DisplaySettingsProvider::DesktopBarAlignment alignment,
    DisplaySettingsProvider::DesktopBarVisibility visibility) {
  if (delayed_titlebar_action_ == NO_ACTION)
    return;

  DisplaySettingsProvider::DesktopBarVisibility expected_visibility =
      delayed_titlebar_action_ == BRING_UP
          ? DisplaySettingsProvider::DESKTOP_BAR_VISIBLE
          : DisplaySettingsProvider::DESKTOP_BAR_HIDDEN;
  if (visibility != expected_visibility)
    return;

  DoBringUpOrDownTitlebars(delayed_titlebar_action_ == BRING_UP);
  delayed_titlebar_action_ = NO_ACTION;
}

void DockedPanelCollection::OnAutoHidingDesktopBarThicknessChanged(
    DisplaySettingsProvider::DesktopBarAlignment alignment, int thickness) {
  RefreshLayout();
}

void DockedPanelCollection::RefreshLayout() {
  int total_active_width = 0;
  int total_inactive_width = 0;

  for (Panels::const_iterator panel_iter = panels_.begin();
       panel_iter != panels_.end(); ++panel_iter) {
    Panel* panel = *panel_iter;
    if (panel->IsActive())
      total_active_width += panel->full_size().width();
    else
      total_inactive_width += panel->full_size().width();
  }

  double display_width_for_inactive_panels =
      work_area_.width() - total_active_width -
          kPanelsHorizontalSpacing * panels_.size();
  double overflow_squeeze_factor = (total_inactive_width > 0) ?
      std::min(display_width_for_inactive_panels / total_inactive_width, 1.0) :
      1.0;

  // We want to calculate all bounds first, then apply them in a specific order.
  typedef std::pair<Panel*, gfx::Rect> PanelBoundsInfo;
  // The next pair of variables will hold panels that move, respectively,
  // to the right and to the left. We want to process them from the center
  // outwards, so one is a stack and another is a queue.
  std::vector<PanelBoundsInfo> moving_right;
  std::queue<PanelBoundsInfo> moving_left;

  int rightmost_position = StartingRightPosition();
  for (Panels::const_iterator panel_iter = panels_.begin();
       panel_iter != panels_.end(); ++panel_iter) {
    Panel* panel = *panel_iter;
    gfx::Rect old_bounds = panel->GetBounds();
    gfx::Rect new_bounds = old_bounds;
    AdjustPanelBoundsPerExpansionState(panel, &new_bounds);

    new_bounds.set_width(
      WidthToDisplayPanelInCollection(panel->IsActive(),
                                      overflow_squeeze_factor,
                                      panel->full_size().width()));
    int x = rightmost_position - new_bounds.width();
    new_bounds.set_x(x);

    if (x < old_bounds.x() ||
        (x == old_bounds.x() && new_bounds.width() <= old_bounds.width()))
      moving_left.push(std::make_pair(panel, new_bounds));
    else
      moving_right.push_back(std::make_pair(panel, new_bounds));

    rightmost_position = x - kPanelsHorizontalSpacing;
  }

  // Update panels going in both directions.
  // This is important on Mac where bounds changes are slow and you see a
  // "wave" instead of a smooth sliding effect.
  int num_animated = 0;
  bool going_right = true;
  while (!moving_right.empty() || !moving_left.empty()) {
    PanelBoundsInfo bounds_info;
    // Alternate between processing the panels that moving left and right,
    // starting from the center.
    going_right = !going_right;
    bool take_panel_on_right =
        (going_right && !moving_right.empty()) ||
        moving_left.empty();
    if (take_panel_on_right) {
      bounds_info = moving_right.back();
      moving_right.pop_back();
    } else {
      bounds_info = moving_left.front();
      moving_left.pop();
    }

    // Don't update the docked panel that is in preview mode.
    Panel* panel = bounds_info.first;
    gfx::Rect bounds = bounds_info.second;
    if (!panel->in_preview_mode() && bounds != panel->GetBounds()) {
      // We animate a limited number of panels, starting with the
      // "most important" ones, that is, ones that are close to the center
      // of the action. Other panels are moved instantly to improve performance.
      if (num_animated < kNumPanelsToAnimateSimultaneously) {
        panel->SetPanelBounds(bounds);  // Animates.
        ++num_animated;
      } else {
        panel->SetPanelBoundsInstantly(bounds);
      }
    }
  }

  content::NotificationService::current()->Notify(
      chrome::NOTIFICATION_PANEL_COLLECTION_UPDATED,
      content::Source<PanelCollection>(this),
      content::NotificationService::NoDetails());
}

int DockedPanelCollection::WidthToDisplayPanelInCollection(
    bool is_for_active_panel, double squeeze_factor, int full_width) const {
  return is_for_active_panel ? full_width :
      std::max(panel::kPanelMinWidth,
               static_cast<int>(floor(full_width * squeeze_factor)));
}

void DockedPanelCollection::CloseAll() {
  // This should only be called at the end of tests to clean up.

  // Make a copy of the iterator as closing panels can modify the vector.
  Panels panels_copy = panels_;

  // Start from the bottom to avoid reshuffling.
  for (Panels::reverse_iterator iter = panels_copy.rbegin();
       iter != panels_copy.rend(); ++iter)
    (*iter)->Close();
}

void DockedPanelCollection::UpdatePanelOnCollectionChange(Panel* panel) {
  panel->set_attention_mode(Panel::USE_PANEL_ATTENTION);
  panel->ShowShadow(true);
  panel->UpdateMinimizeRestoreButtonVisibility();
  panel->SetWindowCornerStyle(panel::TOP_ROUNDED);
}

void DockedPanelCollection::ScheduleLayoutRefresh() {
  refresh_action_factory_.InvalidateWeakPtrs();
  base::MessageLoop::current()->PostDelayedTask(
      FROM_HERE,
      base::Bind(&DockedPanelCollection::RefreshLayout,
                 refresh_action_factory_.GetWeakPtr()),
      base::TimeDelta::FromMilliseconds(PanelManager::AdjustTimeInterval(
          kRefreshLayoutAfterActivePanelChangeDelayMs)));
}

void DockedPanelCollection::OnPanelActiveStateChanged(Panel* panel) {
  // Refresh layout, but wait till active states settle.
  // This lets us avoid refreshing too many times when one panel loses
  // focus and another gains it.
  ScheduleLayoutRefresh();
}

gfx::Rect DockedPanelCollection::GetInitialPanelBounds(
      const gfx::Rect& requested_bounds) const {
  gfx::Rect initial_bounds = requested_bounds;
  initial_bounds.set_origin(
      GetDefaultPositionForPanel(requested_bounds.size()));
  return initial_bounds;
}

bool DockedPanelCollection::HasPanel(Panel* panel) const {
  return find(panels_.begin(), panels_.end(), panel) != panels_.end();
}