app/tree_model.h

   1 // Copyright (c) 2009 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 APP_TREE_MODEL_H_
   6 #define APP_TREE_MODEL_H_
   7 #pragma once
   8
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/logging.h"
  13
  14 class SkBitmap;
  15
  16 class TreeModel;
  17
  18 // TreeModelNode --------------------------------------------------------------
  19
  20 // Type of class returned from the model.
  21 class TreeModelNode {
  22  public:
  23   // Returns the title for the node.
  24   virtual std::wstring GetTitle() const = 0;
  25
  26  protected:
  27   virtual ~TreeModelNode() {}
  28 };
  29
  30 // Observer for the TreeModel. Notified of significant events to the model.
  31 class TreeModelObserver {
  32  public:
  33   // Notification that nodes were added to the specified parent.
  34   virtual void TreeNodesAdded(TreeModel* model,
  35                               TreeModelNode* parent,
  36                               int start,
  37                               int count) = 0;
  38
  39   // Notification that nodes were removed from the specified parent.
  40   virtual void TreeNodesRemoved(TreeModel* model,
  41                                 TreeModelNode* parent,
  42                                 int start,
  43                                 int count) = 0;
  44
  45   // Notification that the contents of a node has changed.
  46   virtual void TreeNodeChanged(TreeModel* model, TreeModelNode* node) = 0;
  47
  48  protected:
  49   virtual ~TreeModelObserver() {}
  50 };
  51
  52 // TreeModel ------------------------------------------------------------------
  53
  54 // The model for TreeView.
  55 class TreeModel {
  56  public:
  57   // Returns the root of the tree. This may or may not be shown in the tree,
  58   // see SetRootShown for details.
  59   virtual TreeModelNode* GetRoot() = 0;
  60
  61   // Returns the number of children in the specified node.
  62   virtual int GetChildCount(TreeModelNode* parent) = 0;
  63
  64   // Returns the child node at the specified index.
  65   virtual TreeModelNode* GetChild(TreeModelNode* parent, int index) = 0;
  66
  67   // Returns the index of child node at the specified index.
  68   virtual int IndexOfChild(TreeModelNode* parent, TreeModelNode* child) = 0;
  69
  70   // Returns the parent of a node, or NULL if node is the root.
  71   virtual TreeModelNode* GetParent(TreeModelNode* node) = 0;
  72
  73   // Adds an observer of the model.
  74   virtual void AddObserver(TreeModelObserver* observer) = 0;
  75
  76   // Removes an observer of the model.
  77   virtual void RemoveObserver(TreeModelObserver* observer) = 0;
  78
  79   // Sets the title of the specified node.
  80   // This is only invoked if the node is editable and the user edits a node.
  81   virtual void SetTitle(TreeModelNode* node,
  82                         const std::wstring& title) {
  83     NOTREACHED();
  84   }
  85
  86   // Returns the set of icons for the nodes in the tree. You only need override
  87   // this if you don't want to use the default folder icons.
  88   virtual void GetIcons(std::vector<SkBitmap>* icons) {}
  89
  90   // Returns the index of the icon to use for |node|. Return -1 to use the
  91   // default icon. The index is relative to the list of icons returned from
  92   // GetIcons.
  93   virtual int GetIconIndex(TreeModelNode* node) { return -1; }
  94
  95  protected:
  96   virtual ~TreeModel() {}
  97 };
  98
  99 #endif  // APP_TREE_MODEL_H_