ui/views/controls/tree/tree_view.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 "ui/views/controls/tree/tree_view.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/i18n/rtl.h"
  10 #include "base/message_loop/message_loop.h"
  11 #include "grit/ui_resources.h"
  12 #include "ui/base/accessibility/accessible_view_state.h"
  13 #include "ui/base/resource/resource_bundle.h"
  14 #include "ui/events/event.h"
  15 #include "ui/events/keycodes/keyboard_codes.h"
  16 #include "ui/gfx/canvas.h"
  17 #include "ui/gfx/image/image.h"
  18 #include "ui/gfx/rect_conversions.h"
  19 #include "ui/gfx/skia_util.h"
  20 #include "ui/native_theme/native_theme.h"
  21 #include "ui/views/controls/prefix_selector.h"
  22 #include "ui/views/controls/scroll_view.h"
  23 #include "ui/views/controls/textfield/textfield.h"
  24 #include "ui/views/controls/tree/tree_view_controller.h"
  25 #include "ui/views/ime/input_method.h"
  26
  27 using ui::TreeModel;
  28 using ui::TreeModelNode;
  29
  30 namespace views {
  31
  32 // Insets around the view.
  33 static const int kHorizontalInset = 2;
  34 static const int kVerticalInset = 2;
  35 // Padding before/after the image.
  36 static const int kImagePadding = 4;
  37 // Size of the arrow region.
  38 static const int kArrowRegionSize = 12;
  39 // Padding around the text (on each side).
  40 static const int kTextVerticalPadding = 3;
  41 static const int kTextHorizontalPadding = 2;
  42 // How much children are indented from their parent.
  43 static const int kIndent = 20;
  44
  45 // static
  46 const char TreeView::kViewClassName[] = "TreeView";
  47
  48 namespace {
  49
  50 // Returns the color id for the background of selected text. |has_focus|
  51 // indicates if the tree has focus.
  52 ui::NativeTheme::ColorId text_background_color_id(bool has_focus) {
  53   return has_focus ?
  54       ui::NativeTheme::kColorId_TreeSelectionBackgroundFocused :
  55       ui::NativeTheme::kColorId_TreeSelectionBackgroundUnfocused;
  56 }
  57
  58 // Returns the color id for text. |has_focus| indicates if the tree has focus
  59 // and |is_selected| is true if the item is selected.
  60 ui::NativeTheme::ColorId text_color_id(bool has_focus, bool is_selected) {
  61   if (is_selected) {
  62     if (has_focus)
  63       return ui::NativeTheme::kColorId_TreeSelectedText;
  64     return ui::NativeTheme::kColorId_TreeSelectedTextUnfocused;
  65   }
  66   return ui::NativeTheme::kColorId_TreeText;
  67 }
  68
  69 }  // namespace
  70
  71 TreeView::TreeView()
  72     : model_(NULL),
  73       selected_node_(NULL),
  74       editing_(false),
  75       editor_(NULL),
  76       focus_manager_(NULL),
  77       auto_expand_children_(false),
  78       editable_(true),
  79       controller_(NULL),
  80       root_shown_(true),
  81       has_custom_icons_(false),
  82       row_height_(font_.GetHeight() + kTextVerticalPadding * 2) {
  83   SetFocusable(true);
  84   closed_icon_ = *ui::ResourceBundle::GetSharedInstance().GetImageNamed(
  85       (base::i18n::IsRTL() ? IDR_FOLDER_CLOSED_RTL
  86                            : IDR_FOLDER_CLOSED)).ToImageSkia();
  87   open_icon_ = *ui::ResourceBundle::GetSharedInstance().GetImageNamed(
  88       (base::i18n::IsRTL() ? IDR_FOLDER_OPEN_RTL
  89                            : IDR_FOLDER_OPEN)).ToImageSkia();
  90   text_offset_ = closed_icon_.width() + kImagePadding + kImagePadding +
  91       kArrowRegionSize;
  92 }
  93
  94 TreeView::~TreeView() {
  95   if (model_)
  96     model_->RemoveObserver(this);
  97   if (focus_manager_) {
  98     focus_manager_->RemoveFocusChangeListener(this);
  99     focus_manager_ = NULL;
 100   }
 101 }
 102
 103 View* TreeView::CreateParentIfNecessary() {
 104   ScrollView* scroll_view = ScrollView::CreateScrollViewWithBorder();
 105   scroll_view->SetContents(this);
 106   return scroll_view;
 107 }
 108
 109 void TreeView::SetModel(TreeModel* model) {
 110   if (model == model_)
 111     return;
 112   if (model_)
 113     model_->RemoveObserver(this);
 114
 115   CancelEdit();
 116
 117   model_ = model;
 118   selected_node_ = NULL;
 119   icons_.clear();
 120   if (model_) {
 121     model_->AddObserver(this);
 122     model_->GetIcons(&icons_);
 123
 124     root_.RemoveAll();
 125     ConfigureInternalNode(model_->GetRoot(), &root_);
 126     LoadChildren(&root_);
 127     root_.set_is_expanded(true);
 128     if (root_shown_)
 129       selected_node_ = &root_;
 130     else if (root_.child_count())
 131       selected_node_ = root_.GetChild(0);
 132   }
 133   DrawnNodesChanged();
 134 }
 135
 136 void TreeView::SetEditable(bool editable) {
 137   if (editable == editable_)
 138     return;
 139   editable_ = editable;
 140   CancelEdit();
 141 }
 142
 143 void TreeView::StartEditing(TreeModelNode* node) {
 144   DCHECK(node);
 145   // Cancel the current edit.
 146   CancelEdit();
 147   // Make sure all ancestors are expanded.
 148   if (model_->GetParent(node))
 149     Expand(model_->GetParent(node));
 150   // Select the node, else if the user commits the edit the selection reverts.
 151   SetSelectedNode(node);
 152   if (GetSelectedNode() != node)
 153     return;  // Selection failed for some reason, don't start editing.
 154   DCHECK(!editing_);
 155   editing_ = true;
 156   if (!editor_) {
 157     editor_ = new Textfield;
 158     // Add the editor immediately as GetPreferredSize returns the wrong thing if
 159     // not parented.
 160     AddChildView(editor_);
 161     editor_->SetFont(font_);
 162     empty_editor_size_ = editor_->GetPreferredSize();
 163     editor_->SetController(this);
 164   }
 165   editor_->SetText(selected_node_->model_node()->GetTitle());
 166   LayoutEditor();
 167   editor_->SetVisible(true);
 168   SchedulePaintForNode(selected_node_);
 169   editor_->RequestFocus();
 170   editor_->SelectAll(false);
 171
 172   // Listen for focus changes so that we can cancel editing.
 173   focus_manager_ = GetFocusManager();
 174   if (focus_manager_)
 175     focus_manager_->AddFocusChangeListener(this);
 176
 177   // Accelerators to commit/cancel edit.
 178   AddAccelerator(ui::Accelerator(ui::VKEY_RETURN, ui::EF_NONE));
 179   AddAccelerator(ui::Accelerator(ui::VKEY_ESCAPE, ui::EF_NONE));
 180 }
 181
 182 void TreeView::CancelEdit() {
 183   if (!editing_)
 184     return;
 185
 186   // WARNING: don't touch |selected_node_|, it may be bogus.
 187
 188   editing_ = false;
 189   if (focus_manager_) {
 190     focus_manager_->RemoveFocusChangeListener(this);
 191     focus_manager_ = NULL;
 192   }
 193   editor_->SetVisible(false);
 194   SchedulePaint();
 195
 196   RemoveAccelerator(ui::Accelerator(ui::VKEY_RETURN, ui::EF_NONE));
 197   RemoveAccelerator(ui::Accelerator(ui::VKEY_ESCAPE, ui::EF_NONE));
 198 }
 199
 200 void TreeView::CommitEdit() {
 201   if (!editing_)
 202     return;
 203
 204   DCHECK(selected_node_);
 205   const bool editor_has_focus = editor_->HasFocus();
 206   model_->SetTitle(GetSelectedNode(), editor_->text());
 207   CancelEdit();
 208   if (editor_has_focus)
 209     RequestFocus();
 210 }
 211
 212 TreeModelNode* TreeView::GetEditingNode() {
 213   return editing_ ? selected_node_->model_node() : NULL;
 214 }
 215
 216 void TreeView::SetSelectedNode(TreeModelNode* model_node) {
 217   if (editing_ || model_node != selected_node_)
 218     CancelEdit();
 219   if (model_node && model_->GetParent(model_node))
 220     Expand(model_->GetParent(model_node));
 221   if (model_node && model_node == root_.model_node() && !root_shown_)
 222     return;  // Ignore requests to select the root when not shown.
 223   InternalNode* node = model_node ? GetInternalNodeForModelNode(
 224       model_node, CREATE_IF_NOT_LOADED) : NULL;
 225   bool was_empty_selection = (selected_node_ == NULL);
 226   bool changed = (selected_node_ != node);
 227   if (changed) {
 228     SchedulePaintForNode(selected_node_);
 229     selected_node_ = node;
 230     if (selected_node_ == &root_ && !root_shown_)
 231       selected_node_ = NULL;
 232     if (selected_node_ && selected_node_ != &root_)
 233       Expand(model_->GetParent(selected_node_->model_node()));
 234     SchedulePaintForNode(selected_node_);
 235   }
 236
 237   if (selected_node_)
 238     ScrollRectToVisible(GetBoundsForNode(selected_node_));
 239
 240   // Notify controller if the old selection was empty to handle the case of
 241   // remove explicitly resetting selected_node_ before invoking this.
 242   if (controller_ && (changed || was_empty_selection))
 243     controller_->OnTreeViewSelectionChanged(this);
 244
 245   if (changed) {
 246     // TODO(dmazzoni): Decide if EVENT_SELECTION_CHANGED is a better choice for
 247     // sub-item selection event.
 248     NotifyAccessibilityEvent(ui::AccessibilityTypes::EVENT_FOCUS, true);
 249   }
 250 }
 251
 252 TreeModelNode* TreeView::GetSelectedNode() {
 253   return selected_node_ ? selected_node_->model_node() : NULL;
 254 }
 255
 256 void TreeView::Collapse(ui::TreeModelNode* model_node) {
 257   // Don't collapse the root if the root isn't shown, otherwise nothing is
 258   // displayed.
 259   if (model_node == root_.model_node() && !root_shown_)
 260     return;
 261   InternalNode* node =
 262       GetInternalNodeForModelNode(model_node, DONT_CREATE_IF_NOT_LOADED);
 263   if (!node)
 264     return;
 265   bool was_expanded = IsExpanded(model_node);
 266   if (node->is_expanded()) {
 267     if (selected_node_ && selected_node_->HasAncestor(node))
 268       SetSelectedNode(model_node);
 269     node->set_is_expanded(false);
 270   }
 271   if (was_expanded)
 272     DrawnNodesChanged();
 273 }
 274
 275 void TreeView::Expand(TreeModelNode* node) {
 276   if (ExpandImpl(node))
 277     DrawnNodesChanged();
 278   // TODO: need to support auto_expand_children_.
 279 }
 280
 281 void TreeView::ExpandAll(TreeModelNode* node) {
 282   DCHECK(node);
 283   // Expand the node.
 284   bool expanded_at_least_one = ExpandImpl(node);
 285   // And recursively expand all the children.
 286   for (int i = model_->GetChildCount(node) - 1; i >= 0; --i) {
 287     TreeModelNode* child = model_->GetChild(node, i);
 288     if (ExpandImpl(child))
 289       expanded_at_least_one = true;
 290   }
 291   if (expanded_at_least_one)
 292     DrawnNodesChanged();
 293 }
 294
 295 bool TreeView::IsExpanded(TreeModelNode* model_node) {
 296   if (!model_node) {
 297     // NULL check primarily for convenience for uses in this class so don't have
 298     // to add NULL checks every where we look up the parent.
 299     return true;
 300   }
 301   InternalNode* node = GetInternalNodeForModelNode(
 302       model_node, DONT_CREATE_IF_NOT_LOADED);
 303   if (!node)
 304     return false;
 305
 306   while (node) {
 307     if (!node->is_expanded())
 308       return false;
 309     node = node->parent();
 310   }
 311   return true;
 312 }
 313
 314 void TreeView::SetRootShown(bool root_shown) {
 315   if (root_shown_ == root_shown)
 316     return;
 317   root_shown_ = root_shown;
 318   if (!root_shown_ && selected_node_ == &root_) {
 319     if (model_->GetChildCount(root_.model_node()))
 320       SetSelectedNode(model_->GetChild(root_.model_node(), 0));
 321     else
 322       SetSelectedNode(NULL);
 323   }
 324   DrawnNodesChanged();
 325 }
 326
 327 ui::TreeModelNode* TreeView::GetNodeForRow(int row) {
 328   int depth = 0;
 329   InternalNode* node = GetNodeByRow(row, &depth);
 330   return node ? node->model_node() : NULL;
 331 }
 332
 333 int TreeView::GetRowForNode(ui::TreeModelNode* node) {
 334   InternalNode* internal_node =
 335       GetInternalNodeForModelNode(node, DONT_CREATE_IF_NOT_LOADED);
 336   if (!internal_node)
 337     return -1;
 338   int depth = 0;
 339   return GetRowForInternalNode(internal_node, &depth);
 340 }
 341
 342 void TreeView::Layout() {
 343   int width = preferred_size_.width();
 344   int height = preferred_size_.height();
 345   if (parent()) {
 346     width = std::max(parent()->width(), width);
 347     height = std::max(parent()->height(), height);
 348   }
 349   SetBounds(x(), y(), width, height);
 350   LayoutEditor();
 351 }
 352
 353 gfx::Size TreeView::GetPreferredSize() {
 354   return preferred_size_;
 355 }
 356
 357 bool TreeView::AcceleratorPressed(const ui::Accelerator& accelerator) {
 358   if (accelerator.key_code() == ui::VKEY_RETURN) {
 359     CommitEdit();
 360   } else {
 361     DCHECK_EQ(ui::VKEY_ESCAPE, accelerator.key_code());
 362     CancelEdit();
 363     RequestFocus();
 364   }
 365   return true;
 366 }
 367
 368 bool TreeView::OnMousePressed(const ui::MouseEvent& event) {
 369   return OnClickOrTap(event);
 370 }
 371
 372 ui::TextInputClient* TreeView::GetTextInputClient() {
 373   if (!selector_)
 374     selector_.reset(new PrefixSelector(this));
 375   return selector_.get();
 376 }
 377
 378 void TreeView::OnGestureEvent(ui::GestureEvent* event) {
 379   if (event->type() == ui::ET_GESTURE_TAP) {
 380     if (OnClickOrTap(*event))
 381       event->SetHandled();
 382   }
 383 }
 384
 385 void TreeView::ShowContextMenu(const gfx::Point& p,
 386                                ui::MenuSourceType source_type) {
 387   if (!model_)
 388     return;
 389   if (source_type == ui::MENU_SOURCE_MOUSE) {
 390     // Only invoke View's implementation (which notifies the
 391     // ContextMenuController) if over a node.
 392     gfx::Point local_point(p);
 393     ConvertPointFromScreen(this, &local_point);
 394     int row = (local_point.y() - kVerticalInset) / row_height_;
 395     int depth = 0;
 396     InternalNode* node = GetNodeByRow(row, &depth);
 397     if (!node)
 398       return;
 399     gfx::Rect bounds(GetBoundsForNodeImpl(node, row, depth));
 400     if (!bounds.Contains(local_point))
 401       return;
 402   }
 403   View::ShowContextMenu(p, source_type);
 404 }
 405
 406 void TreeView::GetAccessibleState(ui::AccessibleViewState* state) {
 407   state->role = ui::AccessibilityTypes::ROLE_OUTLINE;
 408   state->state = ui::AccessibilityTypes::STATE_READONLY;
 409   if (!selected_node_)
 410     return;
 411
 412   // Get selected item info.
 413   state->role = ui::AccessibilityTypes::ROLE_OUTLINEITEM;
 414   state->name = selected_node_->model_node()->GetTitle();
 415 }
 416
 417 const char* TreeView::GetClassName() const {
 418   return kViewClassName;
 419 }
 420
 421 void TreeView::TreeNodesAdded(TreeModel* model,
 422                               TreeModelNode* parent,
 423                               int start,
 424                               int count) {
 425   InternalNode* parent_node =
 426       GetInternalNodeForModelNode(parent, DONT_CREATE_IF_NOT_LOADED);
 427   if (!parent_node || !parent_node->loaded_children())
 428     return;
 429   for (int i = 0; i < count; ++i) {
 430     InternalNode* child = new InternalNode;
 431     ConfigureInternalNode(model_->GetChild(parent, start + i), child);
 432     parent_node->Add(child, start + i);
 433   }
 434   if (IsExpanded(parent))
 435     DrawnNodesChanged();
 436 }
 437
 438 void TreeView::TreeNodesRemoved(TreeModel* model,
 439                                 TreeModelNode* parent,
 440                                 int start,
 441                                 int count) {
 442   InternalNode* parent_node =
 443       GetInternalNodeForModelNode(parent, DONT_CREATE_IF_NOT_LOADED);
 444   if (!parent_node || !parent_node->loaded_children())
 445     return;
 446   bool reset_selection = false;
 447   for (int i = 0; i < count; ++i) {
 448     InternalNode* child_removing = parent_node->GetChild(start);
 449     if (selected_node_ && selected_node_->HasAncestor(child_removing))
 450       reset_selection = true;
 451     delete parent_node->Remove(child_removing);
 452   }
 453   if (reset_selection) {
 454     // selected_node_ is no longer valid (at the time we enter this function
 455     // its model_node() is likely deleted). Explicitly NULL out the field
 456     // rather than invoking SetSelectedNode() otherwise, we'll try and use a
 457     // deleted value.
 458     selected_node_ = NULL;
 459     TreeModelNode* to_select = parent;
 460     if (parent == root_.model_node() && !root_shown_) {
 461       to_select = model_->GetChildCount(parent) > 0 ?
 462           model_->GetChild(parent, 0) : NULL;
 463     }
 464     SetSelectedNode(to_select);
 465   }
 466   if (IsExpanded(parent))
 467     DrawnNodesChanged();
 468 }
 469
 470 void TreeView::TreeNodeChanged(TreeModel* model, TreeModelNode* model_node) {
 471   InternalNode* node =
 472       GetInternalNodeForModelNode(model_node, DONT_CREATE_IF_NOT_LOADED);
 473   if (!node)
 474     return;
 475   int old_width = node->text_width();
 476   UpdateNodeTextWidth(node);
 477   if (old_width != node->text_width() &&
 478       ((node == &root_ && root_shown_) ||
 479        (node != &root_ && IsExpanded(node->parent()->model_node())))) {
 480     DrawnNodesChanged();
 481   }
 482 }
 483
 484 void TreeView::ContentsChanged(Textfield* sender,
 485                                const base::string16& new_contents) {
 486 }
 487
 488 bool TreeView::HandleKeyEvent(Textfield* sender,
 489                               const ui::KeyEvent& key_event) {
 490   switch (key_event.key_code()) {
 491     case ui::VKEY_RETURN:
 492       CommitEdit();
 493       return true;
 494
 495     case ui::VKEY_ESCAPE:
 496       CancelEdit();
 497       RequestFocus();
 498       return true;
 499
 500     default:
 501       return false;
 502   }
 503 }
 504
 505 void TreeView::OnWillChangeFocus(View* focused_before, View* focused_now) {
 506 }
 507
 508 void TreeView::OnDidChangeFocus(View* focused_before, View* focused_now) {
 509   CommitEdit();
 510 }
 511
 512 int TreeView::GetRowCount() {
 513   int row_count = root_.NumExpandedNodes();
 514   if (!root_shown_)
 515     row_count--;
 516   return row_count;
 517 }
 518
 519 int TreeView::GetSelectedRow() {
 520   ui::TreeModelNode* model_node = GetSelectedNode();
 521   return model_node ? GetRowForNode(model_node) : -1;
 522 }
 523
 524 void TreeView::SetSelectedRow(int row) {
 525   SetSelectedNode(GetNodeForRow(row));
 526 }
 527
 528 base::string16 TreeView::GetTextForRow(int row) {
 529   return GetNodeForRow(row)->GetTitle();
 530 }
 531
 532 gfx::Point TreeView::GetKeyboardContextMenuLocation() {
 533   int y = height() / 2;
 534   if (selected_node_) {
 535     gfx::Rect node_bounds(GetBoundsForNode(selected_node_));
 536     gfx::Rect vis_bounds(GetVisibleBounds());
 537     if (node_bounds.y() >= vis_bounds.y() &&
 538         node_bounds.y() < vis_bounds.bottom()) {
 539       y = node_bounds.y();
 540     }
 541   }
 542   gfx::Point screen_loc(0, y);
 543   if (base::i18n::IsRTL())
 544     screen_loc.set_x(width());
 545   ConvertPointToScreen(this, &screen_loc);
 546   return screen_loc;
 547 }
 548
 549 bool TreeView::OnKeyPressed(const ui::KeyEvent& event) {
 550   if (!HasFocus())
 551     return false;
 552
 553   switch (event.key_code()) {
 554     case ui::VKEY_F2:
 555       if (!editing_) {
 556         TreeModelNode* selected_node = GetSelectedNode();
 557         if (selected_node && (!controller_ ||
 558                               controller_->CanEdit(this, selected_node))) {
 559           StartEditing(selected_node);
 560         }
 561       }
 562       return true;
 563
 564     case ui::VKEY_UP:
 565     case ui::VKEY_DOWN:
 566       IncrementSelection(event.key_code() == ui::VKEY_UP ?
 567                          INCREMENT_PREVIOUS : INCREMENT_NEXT);
 568       return true;
 569
 570     case ui::VKEY_LEFT:
 571       if (base::i18n::IsRTL())
 572         ExpandOrSelectChild();
 573       else
 574         CollapseOrSelectParent();
 575       return true;
 576
 577     case ui::VKEY_RIGHT:
 578       if (base::i18n::IsRTL())
 579         CollapseOrSelectParent();
 580       else
 581         ExpandOrSelectChild();
 582       return true;
 583
 584     default:
 585       break;
 586   }
 587   return false;
 588 }
 589
 590 void TreeView::OnPaint(gfx::Canvas* canvas) {
 591   // Don't invoke View::OnPaint so that we can render our own focus border.
 592   canvas->DrawColor(GetNativeTheme()->GetSystemColor(
 593                         ui::NativeTheme::kColorId_TreeBackground));
 594
 595   int min_y, max_y;
 596   {
 597     SkRect sk_clip_rect;
 598     if (canvas->sk_canvas()->getClipBounds(&sk_clip_rect)) {
 599       // Pixels partially inside the clip rect should be included.
 600       gfx::Rect clip_rect = gfx::ToEnclosingRect(
 601           gfx::SkRectToRectF(sk_clip_rect));
 602       min_y = clip_rect.y();
 603       max_y = clip_rect.bottom();
 604     } else {
 605       gfx::Rect vis_bounds = GetVisibleBounds();
 606       min_y = vis_bounds.y();
 607       max_y = vis_bounds.bottom();
 608     }
 609   }
 610
 611   int min_row = std::max(0, (min_y - kVerticalInset) / row_height_);
 612   int max_row = (max_y - kVerticalInset) / row_height_;
 613   if ((max_y - kVerticalInset) % row_height_ != 0)
 614     max_row++;
 615   int current_row = root_row();
 616   PaintRows(canvas, min_row, max_row, &root_, root_depth(), &current_row);
 617 }
 618
 619 void TreeView::OnFocus() {
 620   GetInputMethod()->OnFocus();
 621   View::OnFocus();
 622   SchedulePaintForNode(selected_node_);
 623
 624   // Notify the InputMethod so that it knows to query the TextInputClient.
 625   if (GetInputMethod())
 626     GetInputMethod()->OnCaretBoundsChanged(this);
 627 }
 628
 629 void TreeView::OnBlur() {
 630   GetInputMethod()->OnBlur();
 631   SchedulePaintForNode(selected_node_);
 632   if (selector_)
 633     selector_->OnViewBlur();
 634 }
 635
 636 bool TreeView::OnClickOrTap(const ui::LocatedEvent& event) {
 637   CommitEdit();
 638   RequestFocus();
 639
 640   int row = (event.y() - kVerticalInset) / row_height_;
 641   int depth = 0;
 642   InternalNode* node = GetNodeByRow(row, &depth);
 643   if (node) {
 644     gfx::Rect bounds(GetBoundsForNodeImpl(node, row, depth));
 645     if (bounds.Contains(event.location())) {
 646       int relative_x = event.x() - bounds.x();
 647       if (base::i18n::IsRTL())
 648         relative_x = bounds.width() - relative_x;
 649       if (relative_x < kArrowRegionSize &&
 650           model_->GetChildCount(node->model_node())) {
 651         if (node->is_expanded())
 652           Collapse(node->model_node());
 653         else
 654           Expand(node->model_node());
 655       } else if (relative_x > kArrowRegionSize) {
 656         SetSelectedNode(node->model_node());
 657         bool should_toggle = false;
 658         if (event.type() == ui::ET_GESTURE_TAP) {
 659           const ui::GestureEvent& gesture =
 660               static_cast<const ui::GestureEvent&>(event);
 661           should_toggle = gesture.details().tap_count() == 2;
 662         } else {
 663           should_toggle = (event.flags() & ui::EF_IS_DOUBLE_CLICK) != 0;
 664         }
 665         if (should_toggle) {
 666           if (node->is_expanded())
 667             Collapse(node->model_node());
 668           else
 669             Expand(node->model_node());
 670         }
 671       }
 672     }
 673   }
 674   return true;
 675 }
 676
 677 void TreeView::LoadChildren(InternalNode* node) {
 678   DCHECK_EQ(0, node->child_count());
 679   DCHECK(!node->loaded_children());
 680   node->set_loaded_children(true);
 681   for (int i = 0, child_count = model_->GetChildCount(node->model_node());
 682        i < child_count; ++i) {
 683     InternalNode* child = new InternalNode;
 684     ConfigureInternalNode(model_->GetChild(node->model_node(), i), child);
 685     node->Add(child, node->child_count());
 686   }
 687 }
 688
 689 void TreeView::ConfigureInternalNode(TreeModelNode* model_node,
 690                                      InternalNode* node) {
 691   node->Reset(model_node);
 692   UpdateNodeTextWidth(node);
 693 }
 694
 695 void TreeView::UpdateNodeTextWidth(InternalNode* node) {
 696   int width = 0, height = 0;
 697   gfx::Canvas::SizeStringInt(node->model_node()->GetTitle(), font_,
 698                              &width, &height, 0, gfx::Canvas::NO_ELLIPSIS);
 699   node->set_text_width(width);
 700 }
 701
 702 void TreeView::DrawnNodesChanged() {
 703   UpdatePreferredSize();
 704   PreferredSizeChanged();
 705   SchedulePaint();
 706 }
 707
 708 void TreeView::UpdatePreferredSize() {
 709   preferred_size_ = gfx::Size();
 710   if (!model_)
 711     return;
 712
 713   preferred_size_.SetSize(
 714       root_.GetMaxWidth(text_offset_, root_shown_ ? 1 : 0) +
 715       kTextHorizontalPadding * 2,
 716       row_height_ * GetRowCount() + kVerticalInset * 2);
 717 }
 718
 719 void TreeView::LayoutEditor() {
 720   if (!editing_)
 721     return;
 722
 723   DCHECK(selected_node_);
 724   // Position the editor so that its text aligns with the text we drew.
 725   gfx::Rect row_bounds = GetBoundsForNode(selected_node_);
 726   row_bounds.set_x(
 727       GetMirroredXWithWidthInView(row_bounds.x(), row_bounds.width()));
 728   row_bounds.set_x(row_bounds.x() + text_offset_);
 729   row_bounds.set_width(row_bounds.width() - text_offset_);
 730   row_bounds.Inset(kTextHorizontalPadding, kTextVerticalPadding);
 731   row_bounds.Inset(-empty_editor_size_.width() / 2,
 732                    -(empty_editor_size_.height() - font_.GetHeight()) / 2);
 733   // Give a little extra space for editing.
 734   row_bounds.set_width(row_bounds.width() + 50);
 735   editor_->SetBoundsRect(row_bounds);
 736   editor_->Layout();
 737 }
 738
 739 void TreeView::SchedulePaintForNode(InternalNode* node) {
 740   if (!node)
 741     return;  // Explicitly allow NULL to be passed in.
 742   SchedulePaintInRect(GetBoundsForNode(node));
 743 }
 744
 745 void TreeView::PaintRows(gfx::Canvas* canvas,
 746                          int min_row,
 747                          int max_row,
 748                          InternalNode* node,
 749                          int depth,
 750                          int* row) {
 751   if (*row >= max_row)
 752     return;
 753
 754   if (*row >= min_row && *row < max_row)
 755     PaintRow(canvas, node, *row, depth);
 756   (*row)++;
 757   if (!node->is_expanded())
 758     return;
 759   depth++;
 760   for (int i = 0; i < node->child_count() && *row < max_row; ++i)
 761     PaintRows(canvas, min_row, max_row, node->GetChild(i), depth, row);
 762 }
 763
 764 void TreeView::PaintRow(gfx::Canvas* canvas,
 765                         InternalNode* node,
 766                         int row,
 767                         int depth) {
 768   gfx::Rect bounds(GetBoundsForNodeImpl(node, row, depth));
 769
 770   if (model_->GetChildCount(node->model_node()))
 771     PaintExpandControl(canvas, bounds, node->is_expanded());
 772
 773   // Paint the icon.
 774   gfx::ImageSkia icon;
 775   int icon_index = model_->GetIconIndex(node->model_node());
 776   if (icon_index != -1)
 777     icon = icons_[icon_index];
 778   else if (node == selected_node_)
 779     icon = open_icon_;
 780   else
 781     icon = closed_icon_;
 782   int icon_x = kArrowRegionSize + kImagePadding +
 783                (open_icon_.width() - icon.width()) / 2;
 784   if (base::i18n::IsRTL())
 785     icon_x = bounds.right() - icon_x - open_icon_.width();
 786   else
 787     icon_x += bounds.x();
 788   canvas->DrawImageInt(
 789       icon, icon_x,
 790       bounds.y() + (bounds.height() - icon.height()) / 2);
 791
 792   if (!editing_ || node != selected_node_) {
 793     gfx::Rect text_bounds(bounds.x() + text_offset_, bounds.y(),
 794                           bounds.width() - text_offset_, bounds.height());
 795     if (base::i18n::IsRTL())
 796       text_bounds.set_x(bounds.x());
 797     if (node == selected_node_) {
 798       const SkColor bg_color = GetNativeTheme()->GetSystemColor(
 799           text_background_color_id(HasFocus()));
 800       canvas->FillRect(text_bounds, bg_color);
 801       if (HasFocus())
 802         canvas->DrawFocusRect(text_bounds);
 803     }
 804     const ui::NativeTheme::ColorId color_id =
 805         text_color_id(HasFocus(), node == selected_node_);
 806     canvas->DrawStringInt(node->model_node()->GetTitle(), font_,
 807                           GetNativeTheme()->GetSystemColor(color_id),
 808                           text_bounds.x() + kTextHorizontalPadding,
 809                           text_bounds.y() + kTextVerticalPadding,
 810                           text_bounds.width() - kTextHorizontalPadding * 2,
 811                           text_bounds.height() - kTextVerticalPadding * 2);
 812   }
 813 }
 814
 815 void TreeView::PaintExpandControl(gfx::Canvas* canvas,
 816                                   const gfx::Rect& node_bounds,
 817                                   bool expanded) {
 818   int center_x;
 819   if (base::i18n::IsRTL()) {
 820     center_x = node_bounds.right() - kArrowRegionSize +
 821                (kArrowRegionSize - 4) / 2;
 822   } else {
 823     center_x = node_bounds.x() + (kArrowRegionSize - 4) / 2;
 824   }
 825   int center_y = node_bounds.y() + node_bounds.height() / 2;
 826   const SkColor arrow_color = GetNativeTheme()->GetSystemColor(
 827       ui::NativeTheme::kColorId_TreeArrow);
 828   // TODO: this should come from an image.
 829   if (!expanded) {
 830     int delta = base::i18n::IsRTL() ? 1 : -1;
 831     for (int i = 0; i < 4; ++i) {
 832       canvas->FillRect(gfx::Rect(center_x + delta * (2 - i),
 833                                  center_y - (3 - i), 1, (3 - i) * 2 + 1),
 834                        arrow_color);
 835     }
 836   } else {
 837     center_y -= 2;
 838     for (int i = 0; i < 4; ++i) {
 839       canvas->FillRect(gfx::Rect(center_x - (3 - i), center_y + i,
 840                                  (3 - i) * 2 + 1, 1), arrow_color);
 841     }
 842   }
 843 }
 844
 845 TreeView::InternalNode* TreeView::GetInternalNodeForModelNode(
 846     ui::TreeModelNode* model_node,
 847     GetInternalNodeCreateType create_type) {
 848   if (model_node == root_.model_node())
 849     return &root_;
 850   InternalNode* parent_internal_node =
 851       GetInternalNodeForModelNode(model_->GetParent(model_node), create_type);
 852   if (!parent_internal_node)
 853     return NULL;
 854   if (!parent_internal_node->loaded_children()) {
 855     if (create_type == DONT_CREATE_IF_NOT_LOADED)
 856       return NULL;
 857     LoadChildren(parent_internal_node);
 858   }
 859   return parent_internal_node->GetChild(
 860       model_->GetIndexOf(parent_internal_node->model_node(), model_node));
 861 }
 862
 863 gfx::Rect TreeView::GetBoundsForNode(InternalNode* node) {
 864   int row, depth;
 865   row = GetRowForInternalNode(node, &depth);
 866   return GetBoundsForNodeImpl(node, row, depth);
 867 }
 868
 869 gfx::Rect TreeView::GetBoundsForNodeImpl(InternalNode* node,
 870                                          int row,
 871                                          int depth) {
 872   gfx::Rect rect(depth * kIndent + kHorizontalInset,
 873                  row * row_height_ + kVerticalInset,
 874                  text_offset_ + node->text_width() +
 875                  kTextHorizontalPadding * 2,
 876                  row_height_);
 877   rect.set_x(GetMirroredXWithWidthInView(rect.x(), rect.width()));
 878   return rect;
 879 }
 880
 881 int TreeView::GetRowForInternalNode(InternalNode* node, int* depth) {
 882   DCHECK(!node->parent() || IsExpanded(node->parent()->model_node()));
 883   *depth = -1;
 884   int row = -1;
 885   InternalNode* tmp_node = node;
 886   while (tmp_node->parent()) {
 887     int index_in_parent = tmp_node->parent()->GetIndexOf(tmp_node);
 888     (*depth)++;
 889     row++;  // For node.
 890     for (int i = 0; i < index_in_parent; ++i)
 891       row += tmp_node->parent()->GetChild(i)->NumExpandedNodes();
 892     tmp_node = tmp_node->parent();
 893   }
 894   if (root_shown_) {
 895     (*depth)++;
 896     row++;
 897   }
 898   return row;
 899 }
 900
 901 TreeView::InternalNode* TreeView::GetNodeByRow(int row, int* depth) {
 902   int current_row = root_row();
 903   *depth = 0;
 904   return GetNodeByRowImpl(&root_, row, root_depth(), &current_row, depth);
 905 }
 906
 907 TreeView::InternalNode* TreeView::GetNodeByRowImpl(InternalNode* node,
 908                                                    int target_row,
 909                                                    int current_depth,
 910                                                    int* current_row,
 911                                                    int* node_depth) {
 912   if (*current_row == target_row) {
 913     *node_depth = current_depth;
 914     return node;
 915   }
 916   (*current_row)++;
 917   if (node->is_expanded()) {
 918     current_depth++;
 919     for (int i = 0; i < node->child_count(); ++i) {
 920       InternalNode* result = GetNodeByRowImpl(
 921           node->GetChild(i), target_row, current_depth, current_row,
 922           node_depth);
 923       if (result)
 924         return result;
 925     }
 926   }
 927   return NULL;
 928 }
 929
 930 void TreeView::IncrementSelection(IncrementType type) {
 931   if (!model_)
 932     return;
 933
 934   if (!GetSelectedNode()) {
 935     // If nothing is selected select the first or last node.
 936     if (!root_.child_count())
 937       return;
 938     if (type == INCREMENT_PREVIOUS) {
 939       int row_count = GetRowCount();
 940       int depth = 0;
 941       DCHECK(row_count);
 942       InternalNode* node = GetNodeByRow(row_count - 1, &depth);
 943       SetSelectedNode(node->model_node());
 944     } else if (root_shown_) {
 945       SetSelectedNode(root_.model_node());
 946     } else {
 947       SetSelectedNode(root_.GetChild(0)->model_node());
 948     }
 949     return;
 950   }
 951
 952   int depth = 0;
 953   int delta = type == INCREMENT_PREVIOUS ? -1 : 1;
 954   int row = GetRowForInternalNode(selected_node_, &depth);
 955   int new_row = std::min(GetRowCount() - 1, std::max(0, row + delta));
 956   if (new_row == row)
 957     return;  // At the end/beginning.
 958   SetSelectedNode(GetNodeByRow(new_row, &depth)->model_node());
 959 }
 960
 961 void TreeView::CollapseOrSelectParent() {
 962   if (selected_node_) {
 963     if (selected_node_->is_expanded())
 964       Collapse(selected_node_->model_node());
 965     else if (selected_node_->parent())
 966       SetSelectedNode(selected_node_->parent()->model_node());
 967   }
 968 }
 969
 970 void TreeView::ExpandOrSelectChild() {
 971   if (selected_node_) {
 972     if (!selected_node_->is_expanded())
 973       Expand(selected_node_->model_node());
 974     else if (selected_node_->child_count())
 975       SetSelectedNode(selected_node_->GetChild(0)->model_node());
 976   }
 977 }
 978
 979 bool TreeView::ExpandImpl(TreeModelNode* model_node) {
 980   TreeModelNode* parent = model_->GetParent(model_node);
 981   if (!parent) {
 982     // Node should be the root.
 983     DCHECK_EQ(root_.model_node(), model_node);
 984     bool was_expanded = root_.is_expanded();
 985     root_.set_is_expanded(true);
 986     return !was_expanded;
 987   }
 988
 989   // Expand all the parents.
 990   bool return_value = ExpandImpl(parent);
 991   InternalNode* internal_node =
 992       GetInternalNodeForModelNode(model_node, CREATE_IF_NOT_LOADED);
 993   DCHECK(internal_node);
 994   if (!internal_node->is_expanded()) {
 995     if (!internal_node->loaded_children())
 996       LoadChildren(internal_node);
 997     internal_node->set_is_expanded(true);
 998     return_value = true;
 999   }
1000   return return_value;
1001 }
1002
1003 // InternalNode ----------------------------------------------------------------
1004
1005 TreeView::InternalNode::InternalNode()
1006     : model_node_(NULL),
1007       loaded_children_(false),
1008       is_expanded_(false),
1009       text_width_(0) {
1010 }
1011
1012 TreeView::InternalNode::~InternalNode() {
1013 }
1014
1015 void TreeView::InternalNode::Reset(ui::TreeModelNode* node) {
1016   model_node_ = node;
1017   loaded_children_ = false;
1018   is_expanded_ = false;
1019   text_width_ = 0;
1020 }
1021
1022 int TreeView::InternalNode::NumExpandedNodes() const {
1023   int result = 1;  // For this.
1024   if (!is_expanded_)
1025     return result;
1026   for (int i = 0; i < child_count(); ++i)
1027     result += GetChild(i)->NumExpandedNodes();
1028   return result;
1029 }
1030
1031 int TreeView::InternalNode::GetMaxWidth(int indent, int depth) {
1032   int max_width = text_width_ + indent * depth;
1033   if (!is_expanded_)
1034     return max_width;
1035   for (int i = 0; i < child_count(); ++i) {
1036     max_width = std::max(max_width,
1037                          GetChild(i)->GetMaxWidth(indent, depth + 1));
1038   }
1039   return max_width;
1040 }
1041
1042 }  // namespace views