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      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 #ifndef UI_VIEWS_CONTROLS_TREE_TREE_VIEW_VIEWS_H_
      6 #define UI_VIEWS_CONTROLS_TREE_TREE_VIEW_VIEWS_H_
      7 
      8 #include <vector>
      9 
     10 #include "base/basictypes.h"
     11 #include "base/compiler_specific.h"
     12 #include "base/memory/scoped_ptr.h"
     13 #include "ui/base/models/tree_node_model.h"
     14 #include "ui/gfx/font.h"
     15 #include "ui/gfx/image/image_skia.h"
     16 #include "ui/views/controls/prefix_delegate.h"
     17 #include "ui/views/controls/textfield/textfield_controller.h"
     18 #include "ui/views/focus/focus_manager.h"
     19 #include "ui/views/view.h"
     20 
     21 namespace views {
     22 
     23 class Textfield;
     24 class TreeViewController;
     25 class PrefixSelector;
     26 
     27 // TreeView displays hierarchical data as returned from a TreeModel. The user
     28 // can expand, collapse and edit the items. A Controller may be attached to
     29 // receive notification of selection changes and restrict editing.
     30 //
     31 // Note on implementation. This implementation doesn't scale well. In particular
     32 // it does not store any row information, but instead calculates it as
     33 // necessary. But it's more than adequate for current uses.
     34 class VIEWS_EXPORT TreeView : public ui::TreeModelObserver,
     35                               public TextfieldController,
     36                               public FocusChangeListener,
     37                               public PrefixDelegate {
     38  public:
     39   // The tree view's class name.
     40   static const char kViewClassName[];
     41 
     42   TreeView();
     43   virtual ~TreeView();
     44 
     45   // Returns new ScrollPane that contains the receiver.
     46   View* CreateParentIfNecessary();
     47 
     48   // Sets the model. TreeView does not take ownership of the model.
     49   void SetModel(ui::TreeModel* model);
     50   ui::TreeModel* model() const { return model_; }
     51 
     52   // Sets whether to automatically expand children when a parent node is
     53   // expanded. The default is false. If true, when a node in the tree is
     54   // expanded for the first time, its children are also automatically expanded.
     55   // If a node is subsequently collapsed and expanded again, the children
     56   // will not be automatically expanded.
     57   void set_auto_expand_children(bool auto_expand_children) {
     58     auto_expand_children_ = auto_expand_children;
     59   }
     60 
     61   // Sets whether the user can edit the nodes. The default is true. If true,
     62   // the Controller is queried to determine if a particular node can be edited.
     63   void SetEditable(bool editable);
     64 
     65   // Edits the specified node. This cancels the current edit and expands all
     66   // parents of node.
     67   void StartEditing(ui::TreeModelNode* node);
     68 
     69   // Cancels the current edit. Does nothing if not editing.
     70   void CancelEdit();
     71 
     72   // Commits the current edit. Does nothing if not editing.
     73   void CommitEdit();
     74 
     75   // If the user is editing a node, it is returned. If the user is not
     76   // editing a node, NULL is returned.
     77   ui::TreeModelNode* GetEditingNode();
     78 
     79   // Selects the specified node. This expands all the parents of node.
     80   void SetSelectedNode(ui::TreeModelNode* model_node);
     81 
     82   // Returns the selected node, or NULL if nothing is selected.
     83   ui::TreeModelNode* GetSelectedNode();
     84 
     85   // Marks |model_node| as collapsed. This only effects the UI if node and all
     86   // its parents are expanded (IsExpanded(model_node) returns true).
     87   void Collapse(ui::TreeModelNode* model_node);
     88 
     89   // Make sure node and all its parents are expanded.
     90   void Expand(ui::TreeModelNode* node);
     91 
     92   // Invoked from ExpandAll(). Expands the supplied node and recursively
     93   // invokes itself with all children.
     94   void ExpandAll(ui::TreeModelNode* node);
     95 
     96   // Returns true if the specified node is expanded.
     97   bool IsExpanded(ui::TreeModelNode* model_node);
     98 
     99   // Sets whether the root is shown. If true, the root node of the tree is
    100   // shown, if false only the children of the root are shown. The default is
    101   // true.
    102   void SetRootShown(bool root_visible);
    103 
    104   // Sets the controller, which may be null. TreeView does not take ownership
    105   // of the controller.
    106   void SetController(TreeViewController* controller) {
    107     controller_ = controller;
    108   }
    109 
    110   // Returns the node for the specified row, or NULL for an invalid row index.
    111   ui::TreeModelNode* GetNodeForRow(int row);
    112 
    113   // Maps a node to a row, returns -1 if node is not valid.
    114   int GetRowForNode(ui::TreeModelNode* node);
    115 
    116   views::Textfield* editor() { return editor_; }
    117 
    118   // View overrides:
    119   virtual void Layout() OVERRIDE;
    120   virtual gfx::Size GetPreferredSize() OVERRIDE;
    121   virtual bool AcceleratorPressed(const ui::Accelerator& accelerator) OVERRIDE;
    122   virtual bool OnMousePressed(const ui::MouseEvent& event) OVERRIDE;
    123   virtual ui::TextInputClient* GetTextInputClient() OVERRIDE;
    124   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
    125   virtual void ShowContextMenu(const gfx::Point& p,
    126                                ui::MenuSourceType source_type) OVERRIDE;
    127   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
    128   virtual const char* GetClassName() const OVERRIDE;
    129 
    130   // TreeModelObserver overrides:
    131   virtual void TreeNodesAdded(ui::TreeModel* model,
    132                               ui::TreeModelNode* parent,
    133                               int start,
    134                               int count) OVERRIDE;
    135   virtual void TreeNodesRemoved(ui::TreeModel* model,
    136                                 ui::TreeModelNode* parent,
    137                                 int start,
    138                                 int count) OVERRIDE;
    139   virtual void TreeNodeChanged(ui::TreeModel* model,
    140                                ui::TreeModelNode* model_node) OVERRIDE;
    141 
    142   // TextfieldController overrides:
    143   virtual void ContentsChanged(Textfield* sender,
    144                                const string16& new_contents) OVERRIDE;
    145   virtual bool HandleKeyEvent(Textfield* sender,
    146                               const ui::KeyEvent& key_event) OVERRIDE;
    147 
    148   // FocusChangeListener overrides:
    149   virtual void OnWillChangeFocus(View* focused_before,
    150                                  View* focused_now) OVERRIDE;
    151   virtual void OnDidChangeFocus(View* focused_before,
    152                                 View* focused_now) OVERRIDE;
    153 
    154   // PrefixDelegate overrides:
    155   virtual int GetRowCount() OVERRIDE;
    156   virtual int GetSelectedRow() OVERRIDE;
    157   virtual void SetSelectedRow(int row) OVERRIDE;
    158   virtual string16 GetTextForRow(int row) OVERRIDE;
    159 
    160  protected:
    161   // View overrides:
    162   virtual gfx::Point GetKeyboardContextMenuLocation() OVERRIDE;
    163   virtual bool OnKeyPressed(const ui::KeyEvent& event) OVERRIDE;
    164   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
    165   virtual void OnFocus() OVERRIDE;
    166   virtual void OnBlur() OVERRIDE;
    167 
    168  private:
    169   friend class TreeViewTest;
    170 
    171   // Selects, expands or collapses nodes in the tree.  Consistent behavior for
    172   // tap gesture and click events.
    173   bool OnClickOrTap(const ui::LocatedEvent& event);
    174 
    175   // InternalNode is used to track information about the set of nodes displayed
    176   // by TreeViewViews.
    177   class InternalNode : public ui::TreeNode<InternalNode> {
    178    public:
    179     InternalNode();
    180     virtual ~InternalNode();
    181 
    182     // Resets the state from |node|.
    183     void Reset(ui::TreeModelNode* node);
    184 
    185     // The model node this InternalNode represents.
    186     ui::TreeModelNode* model_node() { return model_node_; }
    187 
    188     // Whether the node is expanded.
    189     void set_is_expanded(bool expanded) { is_expanded_ = expanded; }
    190     bool is_expanded() const { return is_expanded_; }
    191 
    192     // Whether children have been loaded.
    193     void set_loaded_children(bool value) { loaded_children_ = value; }
    194     bool loaded_children() const { return loaded_children_; }
    195 
    196     // Width needed to display the string.
    197     void set_text_width(int width) { text_width_ = width; }
    198     int text_width() const { return text_width_; }
    199 
    200     // Returns the total number of descendants (including this node).
    201     int NumExpandedNodes() const;
    202 
    203     // Returns the max width of all descendants (including this node). |indent|
    204     // is how many pixels each child is indented and |depth| is the depth of
    205     // this node from its parent.
    206     int GetMaxWidth(int indent, int depth);
    207 
    208    private:
    209     // The node from the model.
    210     ui::TreeModelNode* model_node_;
    211 
    212     // Whether the children have been loaded.
    213     bool loaded_children_;
    214 
    215     bool is_expanded_;
    216 
    217     int text_width_;
    218 
    219     DISALLOW_COPY_AND_ASSIGN(InternalNode);
    220   };
    221 
    222   // Used by GetInternalNodeForModelNode.
    223   enum GetInternalNodeCreateType {
    224     // If an InternalNode hasn't been created yet, create it.
    225     CREATE_IF_NOT_LOADED,
    226 
    227     // Don't create an InternalNode if one hasn't been created yet.
    228     DONT_CREATE_IF_NOT_LOADED,
    229   };
    230 
    231   // Used by IncrementSelection.
    232   enum IncrementType {
    233     // Selects the next node.
    234     INCREMENT_NEXT,
    235 
    236     // Selects the previous node.
    237     INCREMENT_PREVIOUS
    238   };
    239 
    240   // Row of the root node. This varies depending upon whether the root is
    241   // visible.
    242   int root_row() const { return root_shown_ ? 0 : -1; }
    243 
    244   // Depth of the root node.
    245   int root_depth() const { return root_shown_ ? 0 : -1; }
    246 
    247   // Loads the children of the specified node.
    248   void LoadChildren(InternalNode* node);
    249 
    250   // Configures an InternalNode from a node from the model. This is used
    251   // when a node changes as well as when loading.
    252   void ConfigureInternalNode(ui::TreeModelNode* model_node, InternalNode* node);
    253 
    254   // Sets |node|s text_width.
    255   void UpdateNodeTextWidth(InternalNode* node);
    256 
    257   // Invoked when the set of drawn nodes changes.
    258   void DrawnNodesChanged();
    259 
    260   // Updates |preferred_size_| from the state of the UI.
    261   void UpdatePreferredSize();
    262 
    263   // Positions |editor_|.
    264   void LayoutEditor();
    265 
    266   // Schedules a paint for |node|.
    267   void SchedulePaintForNode(InternalNode* node);
    268 
    269   // Recursively paints rows from |min_row| to |max_row|. |node| is the node for
    270   // the row |*row|. |row| is updated as this walks the tree. Depth is the depth
    271   // of |*row|.
    272   void PaintRows(gfx::Canvas* canvas,
    273                  int min_row,
    274                  int max_row,
    275                  InternalNode* node,
    276                  int depth,
    277                  int* row);
    278 
    279   // Invoked to paint a single node.
    280   void PaintRow(gfx::Canvas* canvas,
    281                 InternalNode* node,
    282                 int row,
    283                 int depth);
    284 
    285   // Paints the expand control given the specified nodes bounds.
    286   void PaintExpandControl(gfx::Canvas* canvas,
    287                           const gfx::Rect& node_bounds,
    288                           bool expanded);
    289 
    290   // Returns the InternalNode for a model node. |create_type| indicates wheter
    291   // this should load InternalNode or not.
    292   InternalNode* GetInternalNodeForModelNode(
    293       ui::TreeModelNode* model_node,
    294       GetInternalNodeCreateType create_type);
    295 
    296   // Returns the bounds for a node.
    297   gfx::Rect GetBoundsForNode(InternalNode* node);
    298 
    299   // Implementation of GetBoundsForNode. Separated out as some callers already
    300   // know the row/depth.
    301   gfx::Rect GetBoundsForNodeImpl(InternalNode* node, int row, int depth);
    302 
    303   // Returns the row and depth of a node.
    304   int GetRowForInternalNode(InternalNode* node, int* depth);
    305 
    306   // Returns the row and depth of the specified node.
    307   InternalNode* GetNodeByRow(int row, int* depth);
    308 
    309   // Implementation of GetNodeByRow. |curent_row| is updated as we iterate.
    310   InternalNode* GetNodeByRowImpl(InternalNode* node,
    311                                  int target_row,
    312                                  int current_depth,
    313                                  int* current_row,
    314                                  int* node_depth);
    315 
    316   // Increments the selection. Invoked in response to up/down arrow.
    317   void IncrementSelection(IncrementType type);
    318 
    319   // If the current node is expanded, it's collapsed, otherwise selection is
    320   // moved to the parent.
    321   void CollapseOrSelectParent();
    322 
    323   // If the selected node is collapsed, it's expanded. Otherwise the first child
    324   // is seleected.
    325   void ExpandOrSelectChild();
    326 
    327   // Implementation of Expand(). Returns true if at least one node was expanded
    328   // that previously wasn't.
    329   bool ExpandImpl(ui::TreeModelNode* model_node);
    330 
    331   // The model, may be null.
    332   ui::TreeModel* model_;
    333 
    334   // Default icons for closed/open.
    335   gfx::ImageSkia closed_icon_;
    336   gfx::ImageSkia open_icon_;
    337 
    338   // Icons from the model.
    339   std::vector<gfx::ImageSkia> icons_;
    340 
    341   // The root node.
    342   InternalNode root_;
    343 
    344   // The selected node, may be NULL.
    345   InternalNode* selected_node_;
    346 
    347   bool editing_;
    348 
    349   // The editor; lazily created and never destroyed (well, until TreeView is
    350   // destroyed). Hidden when no longer editing. We do this avoid destruction
    351   // problems.
    352   Textfield* editor_;
    353 
    354   // Preferred size of |editor_| with no content.
    355   gfx::Size empty_editor_size_;
    356 
    357   // If non-NULL we've attached a listener to this focus manager. Used to know
    358   // when focus is changing to another view so that we can cancel the edit.
    359   FocusManager* focus_manager_;
    360 
    361   // Whether to automatically expand children when a parent node is expanded.
    362   bool auto_expand_children_;
    363 
    364   // Whether the user can edit the items.
    365   bool editable_;
    366 
    367   // The controller.
    368   TreeViewController* controller_;
    369 
    370   // Whether or not the root is shown in the tree.
    371   bool root_shown_;
    372 
    373   // Did the model return a non-empty set of icons from GetIcons?
    374   bool has_custom_icons_;
    375 
    376   // Cached preferred size.
    377   gfx::Size preferred_size_;
    378 
    379   // Font used to display text.
    380   gfx::Font font_;
    381 
    382   // Height of each row. Based on font and some padding.
    383   int row_height_;
    384 
    385   // Offset the text is drawn at. This accounts for the size of the expand
    386   // control, icon and offsets.
    387   int text_offset_;
    388 
    389   scoped_ptr<PrefixSelector> selector_;
    390 
    391   DISALLOW_COPY_AND_ASSIGN(TreeView);
    392 };
    393 
    394 }  // namespace views
    395 
    396 #endif  // UI_VIEWS_CONTROLS_TREE_TREE_VIEW_VIEWS_H_
    397