Blt_TreeCreateNode(3) Creates a node in a tree data object.


#include <bltTree.h>

Blt_TreeCreateNode(tree, parent, name, position)


Blt_Tree    tree    (in)
Tree containing the parent node.
Blt_TreeNode    parent    (in)
Node in which to insert the new child.
const char    *name    (in)
Node label. If NULL, a label will automatically be generated.
int    position    (in)
Position in the parent's list of children to insert the new node.


This procedure creates a new node is a tree data object. The node is initially empty, but data values can be added with Blt_TreeSetValue. Each node has a serial number that identifies it within the tree. No two nodes in the same tree will ever have the same ID. You can find a node's ID with Blt_TreeNodeId.

The arguments are as follows:

The tree containing the parent node.
Node in which the new child will be inserted.
Label of the new node. If name is NULL, a label in the form "node0", "node1", etc. will automatically be generated. Name can be any string. Labels are non-unique. A parent can contain two nodes with the same label. Nodes can be relabeled using Blt_TreeRelabelNode.
Position the parent's list of children to insert the new node. For example, if position is 0, then the new node is prepended to the beginning of the list. If position is -1, then the node is appended onto the end of the parent's list.


The new node returned is of type Blt_TreeNode. It's a token that can be used with other routines to add/delete data values or children nodes.


The following example creates a new node from the root node.

Blt_Tree token;
Blt_TreeNode root, node;
if (Blt_TreeGetToken(interp, "myTree", &token) != TCL_OK) {
    return TCL_ERROR;
root = Blt_TreeRootNode(token);
node = Blt_TreeCreateNode(token, root, "myNode", -1);


Blt_TreeCreateNode can trigger tree notify events. You can be notified whenever a node is created by using the Blt_TreeCreateNotifyHandler. A callback routine is registered that will be automatically invoked whenever a new node is added via Blt_TreeCreateNode to the tree.


tree, token