src/chrome/browser/ui/panels/stacked_panel_collection.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 "chrome/browser/ui/panels/stacked_panel_collection.h"
   6
   7 #include <algorithm>
   8 #include "base/auto_reset.h"
   9 #include "base/logging.h"
  10 #include "base/strings/utf_string_conversions.h"
  11 #include "chrome/browser/ui/panels/detached_panel_collection.h"
  12 #include "chrome/browser/ui/panels/display_settings_provider.h"
  13 #include "chrome/browser/ui/panels/native_panel_stack_window.h"
  14 #include "chrome/browser/ui/panels/panel.h"
  15 #include "chrome/browser/ui/panels/panel_constants.h"
  16 #include "chrome/browser/ui/panels/panel_manager.h"
  17 #include "chrome/common/extensions/extension.h"
  18
  19 StackedPanelCollection::StackedPanelCollection(PanelManager* panel_manager)
  20     : PanelCollection(PanelCollection::STACKED),
  21       panel_manager_(panel_manager),
  22       primary_stack_window_(NULL),
  23       secondary_stack_window_(NULL),
  24       minimizing_all_(false) {
  25 }
  26
  27 StackedPanelCollection::~StackedPanelCollection() {
  28   DCHECK(panels_.empty());
  29   DCHECK(most_recently_active_panels_.empty());
  30 }
  31
  32 void StackedPanelCollection::OnDisplayChanged() {
  33   if (panels_.empty())
  34     return;
  35
  36   gfx::Rect enclosing_bounds = GetEnclosingBounds();
  37   gfx::Rect work_area = panel_manager_->display_settings_provider()->
  38       GetWorkAreaMatching(enclosing_bounds);
  39
  40   // If the height of the whole stack is bigger than the height of the new work
  41   // area, try to reduce the stack height by collapsing panels. In rare case,
  42   // all panels are collapsed and there is still not enough space. We simply
  43   // let the stack go beyond the work area limit.
  44   if (enclosing_bounds.height() > work_area.height()) {
  45     int needed_space = enclosing_bounds.height() - work_area.height();
  46     MinimizePanelsForSpace(needed_space);
  47   }
  48
  49   gfx::Rect top_bounds = top_panel()->GetBounds();
  50   int common_width = top_bounds.width();
  51   if (common_width > work_area.width())
  52     common_width = work_area.width();
  53
  54   int common_x = top_bounds.x();
  55   if (common_x + common_width > work_area.right())
  56     common_x = work_area.right() - common_width;
  57   if (common_x < work_area.x())
  58     common_x = work_area.x();
  59
  60   int total_height = bottom_panel()->GetBounds().bottom() - top_bounds.y();
  61   int start_y = top_bounds.y();
  62   if (start_y + total_height > work_area.bottom())
  63     start_y = work_area.bottom() - total_height;
  64   if (start_y < work_area.y())
  65     start_y = work_area.y();
  66
  67   RefreshLayoutWithTopPanelStartingAt(
  68       gfx::Point(common_x, start_y), common_width);
  69 }
  70
  71 void StackedPanelCollection::RefreshLayout() {
  72   if (panels_.empty())
  73     return;
  74   gfx::Rect top_bounds = top_panel()->GetBounds();
  75   RefreshLayoutWithTopPanelStartingAt(top_bounds.origin(), top_bounds.width());
  76 }
  77
  78 void StackedPanelCollection::RefreshLayoutWithTopPanelStartingAt(
  79     const gfx::Point& start_position, int common_width) {
  80   if (panels_.empty())
  81     return;
  82
  83   // If only one panel is left in the stack, we only need to check if it should
  84   // be moved to |start_y| position.
  85   if (panels_.size() == 1) {
  86     Panel* panel = panels_.front();
  87     gfx::Rect bounds = panel->GetBounds();
  88     if (bounds.origin() != start_position) {
  89       bounds.set_origin(start_position);
  90       panel->SetPanelBounds(bounds);
  91     }
  92     return;
  93   }
  94
  95   // We do not update bounds for affected panels one by one. Instead, all
  96   // changes are bundled and performed synchronously.
  97   primary_stack_window_->BeginBatchUpdatePanelBounds(true);
  98   if (secondary_stack_window_)
  99     secondary_stack_window_->BeginBatchUpdatePanelBounds(true);
 100
 101   int y = start_position.y();
 102   int common_x = start_position.x();
 103   for (Panels::const_iterator iter = panels_.begin();
 104        iter != panels_.end(); ++iter) {
 105     Panel* panel = *iter;
 106
 107     // The visibility of minimize button might need to be updated due to that
 108     // top panel might change when a panel is being added or removed from
 109     // the stack.
 110     panel->UpdateMinimizeRestoreButtonVisibility();
 111
 112     // Don't update the stacked panel that is in preview mode.
 113     gfx::Rect bounds = panel->GetBounds();
 114     if (panel->in_preview_mode()) {
 115       y += bounds.height();
 116       continue;
 117     }
 118
 119     // Update the restored size.
 120     gfx::Size full_size = panel->full_size();
 121     full_size.set_width(common_width);
 122     panel->set_full_size(full_size);
 123
 124     // Recompute the bounds.
 125     bounds.SetRect(
 126         common_x,
 127         y,
 128         common_width,
 129         panel->expansion_state() == Panel::EXPANDED ?
 130             panel->full_size().height() : panel->TitleOnlyHeight());
 131
 132     GetStackWindowForPanel(panel)->AddPanelBoundsForBatchUpdate(panel, bounds);
 133
 134     y += bounds.height();
 135   }
 136
 137   primary_stack_window_->EndBatchUpdatePanelBounds();
 138   if (secondary_stack_window_)
 139     secondary_stack_window_->EndBatchUpdatePanelBounds();
 140 }
 141
 142 string16 StackedPanelCollection::GetTitle() const {
 143   if (panels_.empty())
 144     return string16();
 145
 146   Panel* panel = panels_.front();
 147   const extensions::Extension* extension = panel->GetExtension();
 148   return UTF8ToUTF16(extension && !extension->name().empty() ?
 149       extension->name() : panel->app_name());
 150 }
 151
 152 gfx::Image StackedPanelCollection::GetIcon() const {
 153   if (panels_.empty())
 154     return gfx::Image();
 155   return panels_.front()->app_icon();
 156 }
 157
 158 void StackedPanelCollection::PanelBoundsBatchUpdateCompleted() {
 159   if (!secondary_stack_window_ || panels_.empty())
 160     return;
 161
 162   if (top_panel()->in_preview_mode() != bottom_panel()->in_preview_mode() ||
 163       primary_stack_window_->IsAnimatingPanelBounds() ||
 164       secondary_stack_window_->IsAnimatingPanelBounds())
 165     return;
 166
 167   // Move all panels from secondary stack window to primary stack window.
 168   primary_stack_window_->MergeWith(secondary_stack_window_);
 169   secondary_stack_window_->Close();
 170   secondary_stack_window_ = NULL;
 171 }
 172
 173 gfx::Rect StackedPanelCollection::GetEnclosingBounds() const {
 174   gfx::Rect enclosing_bounds = top_panel()->GetBounds();
 175   enclosing_bounds.set_height(
 176       bottom_panel()->GetBounds().bottom() - enclosing_bounds.y());
 177   return enclosing_bounds;
 178 }
 179
 180 int StackedPanelCollection::MinimizePanelsForSpace(int needed_space) {
 181   int available_space = GetCurrentAvailableBottomSpace();
 182
 183   // Only the most recently active panel might be active.
 184   Panel* active_panel = NULL;
 185   if (!most_recently_active_panels_.empty()) {
 186     Panel* most_recently_active_panel = most_recently_active_panels_.front();
 187     if (most_recently_active_panel->IsActive())
 188       active_panel = most_recently_active_panel;
 189   }
 190
 191   for (Panels::const_reverse_iterator iter =
 192            most_recently_active_panels_.rbegin();
 193        iter != most_recently_active_panels_.rend() &&
 194            available_space < needed_space;
 195        ++iter) {
 196     Panel* current_panel = *iter;
 197     if (current_panel != active_panel && !IsPanelMinimized(current_panel)) {
 198       available_space +=
 199           current_panel->GetBounds().height() - panel::kTitlebarHeight;
 200       MinimizePanel(current_panel);
 201     }
 202   }
 203   return available_space;
 204 }
 205
 206 void StackedPanelCollection::AddPanel(Panel* panel,
 207                                       PositioningMask positioning_mask) {
 208   DCHECK_NE(this, panel->collection());
 209   panel->set_collection(this);
 210   Panel* adjacent_panel = NULL;
 211   if (positioning_mask & PanelCollection::TOP_POSITION) {
 212     adjacent_panel = top_panel();
 213     panels_.push_front(panel);
 214   } else {
 215     // To fit the new panel within the working area, collapse unfocused panels
 216     // in the least recent active order until there is enough space.
 217     if (positioning_mask & PanelCollection::COLLAPSE_TO_FIT) {
 218       int needed_space = panel->GetBounds().height();
 219       int available_space = MinimizePanelsForSpace(needed_space);
 220       DCHECK(available_space >= needed_space);
 221     }
 222
 223     adjacent_panel = bottom_panel();
 224     panels_.push_back(panel);
 225   }
 226
 227   if (panel->IsActive())
 228     most_recently_active_panels_.push_front(panel);
 229   else
 230     most_recently_active_panels_.push_back(panel);
 231
 232   if (adjacent_panel)
 233     UpdatePanelCornerStyle(adjacent_panel);
 234
 235   // The secondary stack window should be used when one of the following occurs:
 236   // 1) Some panels but not all panels are being dragged. This is because
 237   //    those panels being dragged might not be fully aligned with other panels
 238   //    not being dragged.
 239   // 2) The newly added panel is not fully aligned with the existing panel, in
 240   //    terms of both x and width.
 241   NativePanelStackWindow* stack_window;
 242   if (top_panel()->in_preview_mode() == bottom_panel()->in_preview_mode() &&
 243       top_panel()->GetBounds().x() == bottom_panel()->GetBounds().x() &&
 244       top_panel()->GetBounds().width() == bottom_panel()->GetBounds().width()) {
 245     if (!primary_stack_window_)
 246       primary_stack_window_ = NativePanelStackWindow::Create(this);
 247     stack_window = primary_stack_window_;
 248   } else {
 249     if (!secondary_stack_window_)
 250       secondary_stack_window_ = NativePanelStackWindow::Create(this);
 251     stack_window = secondary_stack_window_;
 252   }
 253   stack_window->AddPanel(panel);
 254
 255   if ((positioning_mask & NO_LAYOUT_REFRESH) == 0)
 256     RefreshLayout();
 257 }
 258
 259 void StackedPanelCollection::RemovePanel(Panel* panel, RemovalReason reason) {
 260   bool is_top = panel == top_panel();
 261   bool is_bottom = panel == bottom_panel();
 262
 263   // If the top panel is being closed, all panels below it should move up. To
 264   // do this, the top y position of top panel needs to be tracked first.
 265   bool top_panel_closed = false;
 266   gfx::Point top_origin;
 267   int top_width = 0;
 268   if (reason == PanelCollection::PANEL_CLOSED && is_top) {
 269     top_panel_closed = true;
 270     top_origin = panel->GetBounds().origin();
 271     top_width = panel->GetBounds().width();
 272   }
 273
 274   panel->set_collection(NULL);
 275   panels_.remove(panel);
 276   most_recently_active_panels_.remove(panel);
 277
 278   if (is_top) {
 279     Panel* new_top_panel = top_panel();
 280     if (new_top_panel)
 281       UpdatePanelCornerStyle(new_top_panel);
 282   } else if (is_bottom) {
 283     Panel* new_bottom_panel = bottom_panel();
 284     if (new_bottom_panel)
 285       UpdatePanelCornerStyle(new_bottom_panel);
 286   }
 287
 288   // If an active panel is being closed, try to focus the next recently active
 289   // panel in the stack that is not minimized.
 290   if (reason == PanelCollection::PANEL_CLOSED &&
 291       panel->IsActive() &&
 292       !most_recently_active_panels_.empty()) {
 293     for (Panels::const_iterator iter = most_recently_active_panels_.begin();
 294        iter != most_recently_active_panels_.end(); ++iter) {
 295       Panel* other_panel = *iter;
 296       if (!IsPanelMinimized(other_panel)) {
 297         other_panel->Activate();
 298         break;
 299       }
 300     }
 301   }
 302
 303   // If the top panel is closed, move up all other panels to stay at the same
 304   // y position as the top panel being closed.
 305   if (top_panel_closed)
 306     RefreshLayoutWithTopPanelStartingAt(top_origin, top_width);
 307   else if (reason == PanelCollection::PANEL_CLOSED)
 308     RefreshLayout();
 309
 310   // Remove the panel from the corresponding stack window.
 311   GetStackWindowForPanel(panel)->RemovePanel(panel);
 312
 313   // Close the secondary stack window if no panel is is shown inside it.
 314   // Note that we do not need to do this for primary stack window since the
 315   // whole stack will be gone when only one panel is left.
 316   if (secondary_stack_window_ && secondary_stack_window_->IsEmpty()) {
 317     secondary_stack_window_->Close();
 318     secondary_stack_window_ = NULL;
 319   }
 320 }
 321
 322 void StackedPanelCollection::CloseAll() {
 323   // Make a copy as closing panels can modify the iterator.
 324   Panels panels_copy = panels_;
 325
 326   for (Panels::const_iterator iter = panels_copy.begin();
 327        iter != panels_copy.end(); ++iter)
 328     (*iter)->Close();
 329
 330   if (primary_stack_window_) {
 331     primary_stack_window_->Close();
 332     primary_stack_window_ = NULL;
 333   }
 334   if (secondary_stack_window_) {
 335     secondary_stack_window_->Close();
 336     secondary_stack_window_ = NULL;
 337   }
 338 }
 339
 340 void StackedPanelCollection::OnPanelAttentionStateChanged(Panel* panel) {
 341   if ((panel->attention_mode() & Panel::USE_SYSTEM_ATTENTION) != 0)
 342     primary_stack_window_->DrawSystemAttention(panel->IsDrawingAttention());
 343 }
 344
 345 void StackedPanelCollection::OnPanelTitlebarClicked(
 346     Panel* panel, panel::ClickModifier modifier) {
 347   bool expanded = panel->expansion_state() == Panel::EXPANDED;
 348   if (modifier == panel::APPLY_TO_ALL) {
 349     if (expanded)
 350       MinimizeAll();
 351     else
 352       RestoreAll(panel);
 353   } else {
 354     if (expanded)
 355       MinimizePanel(panel);
 356     else
 357       RestorePanel(panel);
 358   }
 359 }
 360
 361 void StackedPanelCollection::ResizePanelWindow(
 362     Panel* panel,
 363     const gfx::Size& preferred_window_size) {
 364 }
 365
 366 void StackedPanelCollection::ActivatePanel(Panel* panel) {
 367   // Make sure the panel is expanded when activated so the user input
 368   // does not go into a collapsed window.
 369   if (panel->IsMinimized())
 370     panel->SetExpansionState(Panel::EXPANDED);
 371 }
 372
 373 void StackedPanelCollection::MinimizePanel(Panel* panel) {
 374   panel->SetExpansionState(Panel::TITLE_ONLY);
 375 }
 376
 377 void StackedPanelCollection::RestorePanel(Panel* panel) {
 378   // Ensure that the panel could fit within the work area after it is expanded.
 379   // First, try to collapse the unfocused panel in the least recent active
 380   // order in order to get enough space.
 381   int needed_space = panel->full_size().height() - panel->TitleOnlyHeight();
 382   int available_space = MinimizePanelsForSpace(needed_space);
 383
 384   // If there is still not enough space, try to move up the stack.
 385   int space_beyond_available = needed_space - available_space;
 386   if (space_beyond_available > 0) {
 387     int top_available_space = GetCurrentAvailableTopSpace();
 388     int move_delta = (space_beyond_available > top_available_space) ?
 389         top_available_space : space_beyond_available;
 390     for (Panels::const_iterator iter = panels_.begin();
 391          iter != panels_.end(); iter++) {
 392       Panel* current_panel = *iter;
 393       gfx::Rect bounds = current_panel->GetBounds();
 394       bounds.set_y(bounds.y() - move_delta);
 395       current_panel->SetPanelBounds(bounds);
 396     }
 397     available_space += move_delta;
 398   }
 399
 400   // If there is still not enough space, shrink the restored height to make it
 401   // fit at the last resort. Note that the restored height cannot be shrunk less
 402   // than the minimum panel height. If this is the case, we will just let it
 403   // expand beyond the screen boundary.
 404   space_beyond_available = needed_space - available_space;
 405   if (space_beyond_available > 0) {
 406     gfx::Size full_size = panel->full_size();
 407     int reduced_height = full_size.height() - space_beyond_available;
 408     if (reduced_height < panel::kPanelMinHeight)
 409       reduced_height = panel::kPanelMinHeight;
 410     full_size.set_height(reduced_height);
 411     panel->set_full_size(full_size);
 412   }
 413
 414   panel->SetExpansionState(Panel::EXPANDED);
 415 }
 416
 417 void StackedPanelCollection::MinimizeAll() {
 418   // Set minimizing_all_ to prevent deactivation of each panel when it
 419   // is minimized. See comments in OnPanelExpansionStateChanged.
 420   base::AutoReset<bool> pin(&minimizing_all_, true);
 421   Panel* minimized_active_panel = NULL;
 422   for (Panels::const_iterator iter = panels_.begin();
 423        iter != panels_.end(); ++iter) {
 424     if ((*iter)->IsActive())
 425       minimized_active_panel = *iter;
 426     MinimizePanel(*iter);
 427   }
 428
 429   // When a single panel is minimized, it is deactivated to ensure that
 430   // a minimized panel does not have focus. However, when minimizing all,
 431   // the deactivation is only done once after all panels are minimized,
 432   // rather than per minimized panel, both for efficiency and to avoid
 433   // temporary activations of random not-yet-minimized panels.
 434   if (minimized_active_panel) {
 435     minimized_active_panel->Deactivate();
 436     // Layout will be refreshed in response to (de)activation notification.
 437   }
 438 }
 439
 440 void StackedPanelCollection::RestoreAll(Panel* panel_clicked) {
 441   // Expand the panel being clicked first. This is to make sure at least one
 442   // panel that is clicked by the user will be expanded.
 443   RestorePanel(panel_clicked);
 444
 445   // Try to expand all other panels starting from the most recently active
 446   // panel.
 447   for (Panels::const_iterator iter = most_recently_active_panels_.begin();
 448        iter != most_recently_active_panels_.end(); ++iter) {
 449     // If the stack already extends to both top and bottom of the work area,
 450     // stop now since we cannot fit any more expanded panels.
 451     if (GetCurrentAvailableTopSpace() == 0 &&
 452         GetCurrentAvailableBottomSpace() == 0) {
 453       break;
 454     }
 455
 456     Panel* panel = *iter;
 457     if (panel != panel_clicked)
 458       RestorePanel(panel);
 459   }
 460 }
 461
 462 void StackedPanelCollection::OnMinimizeButtonClicked(
 463     Panel* panel, panel::ClickModifier modifier) {
 464   // The minimize button is only present in the top panel.
 465   DCHECK_EQ(top_panel(), panel);
 466
 467   primary_stack_window_->Minimize();
 468 }
 469
 470 void StackedPanelCollection::OnRestoreButtonClicked(
 471     Panel* panel, panel::ClickModifier modifier) {
 472   NOTREACHED();
 473 }
 474
 475 bool StackedPanelCollection::CanShowMinimizeButton(const Panel* panel) const {
 476   // Only the top panel in the stack shows the minimize button.
 477   return PanelManager::CanUseSystemMinimize() && panel == top_panel();
 478 }
 479
 480 bool StackedPanelCollection::CanShowRestoreButton(const Panel* panel) const {
 481   return false;
 482 }
 483
 484 bool StackedPanelCollection::IsPanelMinimized(const Panel* panel) const {
 485   return panel->expansion_state() != Panel::EXPANDED;
 486 }
 487
 488 bool StackedPanelCollection::UsesAlwaysOnTopPanels() const {
 489   return false;
 490 }
 491
 492 void StackedPanelCollection::SavePanelPlacement(Panel* panel) {
 493   DCHECK(!saved_panel_placement_.panel);
 494   saved_panel_placement_.panel = panel;
 495
 496   if (top_panel() != panel)
 497     saved_panel_placement_.top_panel = top_panel();
 498   else
 499     saved_panel_placement_.position = panel->GetBounds().origin();
 500
 501   saved_panel_placement_.top_panel = top_panel() != panel ? top_panel() : NULL;
 502 }
 503
 504 void StackedPanelCollection::RestorePanelToSavedPlacement() {
 505   DCHECK(saved_panel_placement_.panel);
 506
 507   if (saved_panel_placement_.top_panel) {
 508     // Restore the top panel if it has been moved out of the stack. This could
 509     // happen when there're 2 panels in the stack and the bottom panel is being
 510     // dragged out of the stack and thus cause both panels become detached.
 511     if (saved_panel_placement_.top_panel->stack() != this) {
 512       DCHECK_EQ(PanelCollection::DETACHED,
 513                 saved_panel_placement_.top_panel->collection()->type());
 514       panel_manager_->MovePanelToCollection(
 515           saved_panel_placement_.top_panel,
 516           this,
 517           static_cast<PanelCollection::PositioningMask>(
 518               PanelCollection::TOP_POSITION |
 519               PanelCollection::NO_LAYOUT_REFRESH));
 520     }
 521     RefreshLayout();
 522   } else {
 523     // Restore the position when the top panel is being dragged.
 524     DCHECK_EQ(top_panel(), saved_panel_placement_.panel);
 525     RefreshLayoutWithTopPanelStartingAt(saved_panel_placement_.position,
 526                                         top_panel()->GetBounds().width());
 527   }
 528
 529   DiscardSavedPanelPlacement();
 530 }
 531
 532 void StackedPanelCollection::DiscardSavedPanelPlacement() {
 533   DCHECK(saved_panel_placement_.panel);
 534   saved_panel_placement_.panel = NULL;
 535   saved_panel_placement_.top_panel = NULL;
 536 }
 537
 538 panel::Resizability StackedPanelCollection::GetPanelResizability(
 539     const Panel* panel) const {
 540   // The panel in the stack can be resized by the following rules:
 541   // * If collapsed, it can only be resized by its left or right edge.
 542   // * Otherwise, it can be resized by its left or right edge plus:
 543   //   % top edge and corners, if it is at the top;
 544   //   % bottom edge, if it is not at the bottom.
 545   //   % bottom edge and corners, if it is at the bottom.
 546   panel::Resizability resizability = static_cast<panel::Resizability>(
 547       panel::RESIZABLE_LEFT | panel::RESIZABLE_RIGHT);
 548   if (panel->IsMinimized())
 549     return resizability;
 550   if (panel == top_panel()) {
 551     resizability = static_cast<panel::Resizability>(resizability |
 552         panel::RESIZABLE_TOP | panel::RESIZABLE_TOP_LEFT |
 553         panel::RESIZABLE_TOP_RIGHT);
 554   }
 555   if (panel == bottom_panel()) {
 556     resizability = static_cast<panel::Resizability>(resizability |
 557         panel::RESIZABLE_BOTTOM | panel::RESIZABLE_BOTTOM_LEFT |
 558         panel::RESIZABLE_BOTTOM_RIGHT);
 559   } else {
 560     resizability = static_cast<panel::Resizability>(resizability |
 561         panel::RESIZABLE_BOTTOM);
 562   }
 563   return resizability;
 564 }
 565
 566 void StackedPanelCollection::OnPanelResizedByMouse(
 567     Panel* resized_panel, const gfx::Rect& new_bounds) {
 568   resized_panel->set_full_size(new_bounds.size());
 569
 570   DCHECK(!secondary_stack_window_);
 571   primary_stack_window_->BeginBatchUpdatePanelBounds(false);
 572
 573   // The delta x and width can be computed from the difference between
 574   // the panel being resized and any other panel.
 575   Panel* other_panel = resized_panel == top_panel() ? bottom_panel()
 576                                                     : top_panel();
 577   gfx::Rect other_bounds = other_panel->GetBounds();
 578   int delta_x = new_bounds.x() - other_bounds.x();
 579   int delta_width = new_bounds.width() - other_bounds.width();
 580
 581   gfx::Rect previous_bounds;
 582   bool resized_panel_found = false;
 583   bool panel_below_resized_panel_updated = false;
 584   for (Panels::const_iterator iter = panels_.begin();
 585        iter != panels_.end(); iter++) {
 586     Panel* panel = *iter;
 587     if (panel == resized_panel) {
 588       // |new_bounds| should be used since the panel bounds have not been
 589       // updated yet.
 590       previous_bounds = new_bounds;
 591       resized_panel_found = true;
 592       primary_stack_window_->AddPanelBoundsForBatchUpdate(panel, new_bounds);
 593       continue;
 594     }
 595
 596     gfx::Rect bounds = panel->GetBounds();
 597     bounds.set_x(bounds.x() + delta_x);
 598     bounds.set_width(bounds.width() + delta_width);
 599
 600     // If the panel below the panel being resized is expanded, update its
 601     // height to offset the height change of the panel being resized.
 602     // For example, the stack has P1 and P2 (from top to bottom). P1's height
 603     // is 100 and P2's height is 120. If P1's bottom increases by 10, P2's
 604     // height needs to shrink by 10.
 605     if (resized_panel_found) {
 606       if (!panel_below_resized_panel_updated && !panel->IsMinimized()) {
 607         int old_bottom = bounds.bottom();
 608         bounds.set_y(previous_bounds.bottom());
 609         bounds.set_height(old_bottom - bounds.y());
 610       } else {
 611         bounds.set_y(previous_bounds.bottom());
 612       }
 613       panel_below_resized_panel_updated = true;
 614     }
 615
 616     if (!panel->IsMinimized())
 617       panel->set_full_size(bounds.size());
 618
 619     primary_stack_window_->AddPanelBoundsForBatchUpdate(panel, bounds);
 620     previous_bounds = bounds;
 621   }
 622
 623   primary_stack_window_->EndBatchUpdatePanelBounds();
 624 }
 625
 626 bool StackedPanelCollection::HasPanel(Panel* panel) const {
 627   return std::find(panels_.begin(), panels_.end(), panel) != panels_.end();
 628 }
 629
 630 void StackedPanelCollection::UpdatePanelOnCollectionChange(Panel* panel) {
 631   panel->set_attention_mode(
 632       static_cast<Panel::AttentionMode>(Panel::USE_PANEL_ATTENTION |
 633                                         Panel::USE_SYSTEM_ATTENTION));
 634   panel->ShowShadow(false);
 635   panel->UpdateMinimizeRestoreButtonVisibility();
 636   UpdatePanelCornerStyle(panel);
 637 }
 638
 639 void StackedPanelCollection::OnPanelExpansionStateChanged(Panel* panel) {
 640   DCHECK_NE(Panel::MINIMIZED, panel->expansion_state());
 641
 642   // Ensure minimized panel does not get the focus. If minimizing all,
 643   // the active panel will be deactivated once when all panels are minimized
 644   // rather than per minimized panel.
 645   if (panel->expansion_state() != Panel::EXPANDED && !minimizing_all_ &&
 646       panel->IsActive()) {
 647     panel->Deactivate();
 648   }
 649
 650   // The bounds change per expansion state will be done in RefreshLayout.
 651   RefreshLayout();
 652 }
 653
 654 void StackedPanelCollection::OnPanelActiveStateChanged(Panel* panel) {
 655   if (!panel->IsActive())
 656     return;
 657
 658   // Move the panel to the front if not yet.
 659   Panels::iterator iter = std::find(most_recently_active_panels_.begin(),
 660       most_recently_active_panels_.end(), panel);
 661   DCHECK(iter != most_recently_active_panels_.end());
 662   if (iter != most_recently_active_panels_.begin()) {
 663     most_recently_active_panels_.erase(iter);
 664     most_recently_active_panels_.push_front(panel);
 665   }
 666
 667   GetStackWindowForPanel(panel)->OnPanelActivated(panel);
 668 }
 669
 670 gfx::Rect StackedPanelCollection::GetInitialPanelBounds(
 671       const gfx::Rect& requested_bounds) const {
 672   DCHECK(!panels_.empty());
 673   gfx::Rect bottom_panel_bounds = bottom_panel()->GetBounds();
 674   return gfx::Rect(bottom_panel_bounds.x(),
 675                    bottom_panel_bounds.bottom(),
 676                    bottom_panel_bounds.width(),
 677                    requested_bounds.height());
 678 }
 679
 680 Panel* StackedPanelCollection::GetPanelAbove(Panel* panel) const {
 681   DCHECK(panel);
 682
 683   if (panels_.size() < 2)
 684     return NULL;
 685   Panels::const_iterator iter = panels_.begin();
 686   Panel* above_panel = *iter;
 687   for (; iter != panels_.end(); ++iter) {
 688     if (*iter == panel)
 689       return above_panel;
 690     above_panel = *iter;
 691   }
 692   return NULL;
 693 }
 694
 695 Panel* StackedPanelCollection::GetPanelBelow(Panel* panel) const {
 696   DCHECK(panel);
 697
 698   if (panels_.size() < 2)
 699     return NULL;
 700   Panels::const_iterator iter =
 701       std::find(panels_.begin(), panels_.end(), panel);
 702   if (iter == panels_.end())
 703     return NULL;
 704   ++iter;
 705   return iter == panels_.end() ? NULL : *iter;
 706 }
 707
 708 void StackedPanelCollection::MoveAllDraggingPanelsInstantly(
 709     const gfx::Vector2d& delta_origin) {
 710   for (Panels::const_iterator iter = panels_.begin();
 711        iter != panels_.end(); iter++) {
 712     Panel* panel = *iter;
 713     if (panel->in_preview_mode()) {
 714       GetStackWindowForPanel(panel)->MovePanelsBy(delta_origin);
 715       return;
 716     }
 717   }
 718 }
 719
 720 bool StackedPanelCollection::IsMinimized() const {
 721   return primary_stack_window_->IsMinimized();
 722 }
 723
 724 bool StackedPanelCollection::IsAnimatingPanelBounds(Panel* panel) const {
 725   return GetStackWindowForPanel(panel)->IsAnimatingPanelBounds();
 726 }
 727
 728 void StackedPanelCollection::UpdatePanelCornerStyle(Panel* panel) {
 729   panel::CornerStyle corner_style;
 730   bool at_top = panel == top_panel();
 731   bool at_bottom = panel == bottom_panel();
 732   if (at_top && at_bottom)
 733     corner_style = panel::ALL_ROUNDED;
 734   else if (at_top)
 735     corner_style = panel::TOP_ROUNDED;
 736   else if (at_bottom)
 737     corner_style = panel::BOTTOM_ROUNDED;
 738   else
 739     corner_style = panel::NOT_ROUNDED;
 740   panel->SetWindowCornerStyle(corner_style);
 741 }
 742
 743 gfx::Rect StackedPanelCollection::GetWorkArea() const {
 744   if (panels_.empty())
 745     return panel_manager_->display_settings_provider()->GetPrimaryWorkArea();
 746   return panel_manager_->display_settings_provider()->GetWorkAreaMatching(
 747       GetEnclosingBounds());
 748 }
 749
 750 int StackedPanelCollection::GetCurrentAvailableTopSpace() const {
 751   gfx::Rect work_area = GetWorkArea();
 752   if (panels_.empty())
 753     return work_area.height();
 754
 755   int available_space = top_panel()->GetBounds().y() - work_area.y();
 756   if (available_space < 0)
 757     available_space = 0;
 758   return available_space;
 759 }
 760
 761 int StackedPanelCollection::GetCurrentAvailableBottomSpace() const {
 762   gfx::Rect work_area = GetWorkArea();
 763   if (panels_.empty())
 764     return work_area.height();
 765
 766   int available_space = work_area.bottom() -
 767       bottom_panel()->GetBounds().bottom();
 768   if (available_space < 0)
 769     available_space = 0;
 770   return available_space;
 771 }
 772
 773 int StackedPanelCollection::GetMaximiumAvailableBottomSpace() const {
 774   gfx::Rect work_area = GetWorkArea();
 775   if (panels_.empty())
 776     return work_area.height();
 777
 778   int bottom = top_panel()->GetBounds().y();
 779   for (Panels::const_iterator iter = panels_.begin();
 780        iter != panels_.end(); iter++) {
 781     Panel* panel = *iter;
 782     // Only the most recently active panel might be active.
 783     if (iter == panels_.begin() && panel->IsActive())
 784       bottom += panel->GetBounds().height();
 785     else
 786       bottom += panel::kTitlebarHeight;
 787   }
 788   int available_space = work_area.bottom() - bottom;
 789   if (available_space < 0)
 790     available_space = 0;
 791   return available_space;
 792 }
 793
 794 NativePanelStackWindow* StackedPanelCollection::GetStackWindowForPanel(
 795     Panel* panel) const {
 796   return secondary_stack_window_ && secondary_stack_window_->HasPanel(panel) ?
 797       secondary_stack_window_ : primary_stack_window_;
 798 }