Add an option to tree_view for whether to show lines from the root node...

views/controls/tree/tree_view.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef VIEWS_CONTROLS_TREE_TREE_VIEW_H_
 #define VIEWS_CONTROLS_TREE_TREE_VIEW_H_
 
 #include <windows.h>
 #include <commctrl.h>
 
@@ skipping 39 matching lines @@
   virtual ~TreeView();
 
   // Is dragging enabled? The default is false.
   void set_drag_enabled(bool drag_enabled) { drag_enabled_ = drag_enabled; }
   bool drag_enabled() const { return drag_enabled_; }
 
   // Sets the model. TreeView does not take ownership of the model.
   void SetModel(TreeModel* model);
   TreeModel* model() const { return model_; }
 
+  // Sets whether to automatically expand children when a parent node is
+  // expanded. The default is false. If true, when a node in the tree is
+  // expanded for the first time, its children are also automatically expanded.
+  // If a node is subsequently collapsed and expanded again, the children
+  // will not be automatically expanded.
+  void set_auto_expand_children(bool auto_expand_children) {
+    auto_expand_children_ = auto_expand_children;
+  }
+
   // Sets whether the user can edit the nodes. The default is true. If true,
   // the Controller is queried to determine if a particular node can be edited.
   void SetEditable(bool editable);
 
+  // Sets whether lines are drawn from the root node to child nodes (and
+  // whether plus boxes show up next to the root node.) The default is false.
+  // If root_shown_ is false, the children of the root act as the roots in the
+  // native control, and so this setting takes effect for them.
+  void set_lines_at_root(bool lines_at_root) {
+    lines_at_root_ = lines_at_root;
+  }
+
   // Edits the specified node. This cancels the current edit and expands
   // all parents of node.
   void StartEditing(TreeModelNode* node);
 
   // Cancels the current edit. Does nothing if not editing.
   void CancelEdit();
 
   // Commits the current edit. Does nothing if not editing.
   void CommitEdit();
 
@@ skipping 176 matching lines @@
                                       WPARAM w_param,
                                       LPARAM l_param);
 
   // Handle to the tree window.
   HWND tree_view_;
 
   // The model, may be null.
   TreeModel* model_;
 
   // Maps from id to NodeDetails.
-  std::map<int,NodeDetails*> id_to_details_map_;
+  std::map<int, NodeDetails*> id_to_details_map_;
 
   // Maps from model entry to NodeDetails.
-  std::map<TreeModelNode*,NodeDetails*> node_to_details_map_;
+  std::map<TreeModelNode*, NodeDetails*> node_to_details_map_;
+
+  // Whether to automatically expand children when a parent node is expanded.
+  bool auto_expand_children_;
 
   // Whether the user can edit the items.
   bool editable_;
 
   // Next id to create. Any time an item is added this is incremented by one.
   int next_id_;
 
   // The controller.
   TreeViewController* controller_;
 
   // Node being edited. If null, not editing.
   TreeModelNode* editing_node_;
 
   // Whether or not the root is shown in the tree.
   bool root_shown_;
 
+  // Whether lines are drawn from the root to the children.
+  bool lines_at_root_;
+
   // Whether enter should be processed by the tree when not editing.
   bool process_enter_;
 
   // Whether we notify context menu controller only when mouse is over node
   // and node is selected.
   bool show_context_menu_only_when_node_selected_;
 
   // Whether the selection is changed on right mouse down.
   bool select_on_right_mouse_down_;
 
   // A wrapper around 'this', used for subclassing the TreeView control.
   TreeViewWrapper wrapper_;
 
   // Original handler installed on the TreeView.
   WNDPROC original_handler_;
 
   bool drag_enabled_;
 
   // Did the model return a non-empty set of icons from GetIcons?
   bool has_custom_icons_;
 
   HIMAGELIST image_list_;
 
   DISALLOW_COPY_AND_ASSIGN(TreeView);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_CONTROLS_TREE_TREE_VIEW_H_