'\"
'\" Copyright (c) 1995-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: Blt_Tree.man3,v 1.1.1.1 2009/05/09 16:27:39 pcmacdon Exp $
'\" 
.so man.macros
.TH Blt_Tree 3 BLT_VERSION BLT "Blt Library Procedures"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
Blt_Tree \- Tree data object.
.SH SYNOPSIS
.nf
#include <bltTree.h>
.sp
struct Blt_Tree {
\fBTcl_Alloc\fR(\fIsize\fR)
.sp
\fBTcl_Free\fR(\fIptr\fR)
.sp
char *
\fBTcl_Realloc\fR(\fIptr, size\fR)
.fi
.SH ARGUMENTS
.AS char *size
.AP int size in
Size in bytes of the memory block to allocate.
.AP char *ptr in
Pointer to memory block to free or realloc.
.BE

.SH DESCRIPTION
.PP
These procedures provide a platform and compiler independent interface
for memory allocation.  Programs that need to transfer ownership of
memory blocks between Tcl and other modules should use these routines
rather than the native \fBmalloc()\fR and \fBfree()\fR routines
provided by the C run-time library.
.PP
\fBTcl_Alloc\fR returns a pointer to a block of at least \fIsize\fR
bytes suitably aligned for any use.
.PP
\fBTcl_Free\fR makes the space referred to by \fIptr\fR available for
further allocation.
.PP
\fBTcl_Realloc\fR changes the size of the block pointed to by
\fIptr\fR to \fIsize\fR bytes and returns a pointer to the new block.
The contents will be unchanged up to the lesser of the new and old
sizes.  The returned location may be different from \fIptr\fR.
.SH TREE OBJECT ROUTINES
The following library routines allow you to create and destroy tree
objects.  Each tree object has a name that uniquely identifies it.
Tree objects can also be shared.  For example, the \fBtree\fR
and \fBhiertable\fR commands may access the same tree data object.
Each client grabs a token associated with the tree.  When all tokens
are released the tree data object is automatically destroyed.
.TP 2.0i 
\fBBlt_TreeCreate\fR
Create a tree data object and optionally obtains a token associated
with it.
.TP
\fBBlt_TreeExists\fR
Indicates if a tree by a given name exists.
.TP
\fBBlt_TreeGetToken\fR
Obtains a token for an existing tree data object.
.TP
\fBBlt_TreeReleaseToken\fR
Releases a token for a tree data object.  The tree object is deleted
when all outstanding tokens have been released.
.TP
\fBBlt_TreeName\fR
Returns the name of the tree object.
.TP
\fBBlt_TreeChangeRoot\fR
Specifies a node as the new root to a tree.
.SH TREENODE ROUTINES
Tree objects initially contain only a root node. You can add or
delete nodes with the following routines.
.TP 2i
\fBBlt_TreeCreateNode\fR
Creates a new child node for a given parent in the tree.  
.TP
\fBBlt_TreeDeleteNode\fR
Deletes a node and its children.
.TP
\fBBlt_TreeNodeId\fR
Returns the unique node identifier for a node.
.TP
\fBBlt_TreeGetNode\fR
Gets a node based upon its identifier.
.TP
\fBBlt_TreeFindChild\fR
Searches for a child node given by its label in a parent node.
.TP
\fBBlt_TreeNodeLabel\fR
Returns the current label for a node.
.TP
\fBBlt_TreeRelabelNode\fR
Resets a node's label.
.TP
\fBBlt_TreeNodePath\fR
Returns the fullpath to a node.
.TP
\fBBlt_TreeNodeDepth\fR
Returns the depth of the node.  
.TP
\fBBlt_TreeNodeDegree\fR
Returns the number of children for a node.
.TP
\fBBlt_TreeIsLeaf\fR
Indicates if a node has no children.
.TP
\fBBlt_TreeIsBefore\fR
Indicates if a node is before another node in depth-first search order.
.TP
\fBBlt_TreeIsAncestor\fR
Indicates if a node is an ancestor or another.
.TP
\fBBlt_TreeSortNode\fR
Sorts the children of a node.
.TP
\fBBlt_TreeSize\fR
Returns the number of nodes in a node and its descendants.
.TP
\fBBlt_TreeMoveNode\fR
.SH NODE NAVIGATION
Each node can have zero or more children nodes.  These routines
let you navigate the tree hierarchy.
.TP 2i
\fBBlt_TreeNodeParent\fR
Returns the parent node. 
.TP
\fBBlt_TreeFirstChild\fR
Returns the first child of a parent node.
.TP
\fBBlt_TreeLastChild\fR
Returns the last child of a parent node.
.TP
\fBBlt_TreeNextSibling\fR
Returns the next sibling node in the parent's list of children.
.TP
\fBBlt_TreePrevSibling\fR
Returns the previous sibling node in the parent's list of children.
.TP
\fBBlt_TreeRootNode\fR
Returns the root node of the tree.
.TP
\fBBlt_TreeNextNode\fR
Returns the next node in depth-first order.
.TP
\fBBlt_TreePrevNode\fR 
Returns the previous node in depth-first order.
.TP
\fBBlt_TreeEndNode\fR
Returns the last node in the tree as determined by depth-first order.
.TP
\fBBlt_TreeApply\fR
Walks through a node and all it descendants, applying a given
callback procedure.
.TP
\fBBlt_TreeApplyDFS\fR
Walks through a node and all it descendants in depth-first search
order, applying a given callback procedure.
.TP
\fBBlt_TreeApplyBFS\fR
Walks through a node and all it descendants in breadth-first search
order, applying a given callback procedure.
.SH NODE DATA VALUES
Data values can be stored at any node.  Values have by both a string
key and a Tcl_Obj value.  Data value keys do not have to be homogenous 
across all nodes (i.e. nodes do not have to contain the same keys).  
There is also a special node array data type.
.TP 2i
\fBBlt_TreeGetValue\fR
Gets the node data value given by a key.
.TP
\fBBlt_TreeValueExists\fR
Indicates if a node data value given by a key exists.
.TP
\fBBlt_TreeSetValue\fR
Sets a node's value of a key.
.TP
\fBBlt_TreeUnsetValue\fR
Remove the node data value and key.
.TP
\fBBlt_TreeGetArrayValue\fR 
Gets the node data array value given by a key and an array index.
.TP
\fBBlt_TreeSetArrayValue\fR
Sets the node data array value given by a key and an array index.
.TP
\fBBlt_TreeUnsetArrayValue\fR
Remove the node data array value.
.TP
\fBBlt_TreeArrayValueExists\fR
Determines if an array element by a given index exists.
.TP
\fBBlt_TreeFirstKey\fR
Returns the key of the first value in the node. 
.TP
\fBBlt_TreeNextKey\fR
Returns the key of the next value in the node.
.TP
\fBBlt_TreePrivateValue\fR
Lock the value to current client, making it private.
.TP
\fBBlt_TreePublicValue\fR
Unlock the value so that all clients can access it.
.TP
\fBBlt_TreeGetKey\fR 
.SH NODE TRACES
.TP 2i
\fBBlt_TreeCreateTrace\fR
Sets up a trace callback to be invoked when the node value is
read, set, or unset.
.TP 
\fBBlt_TreeDeleteTrace\fR
Deletes an existing trace.
.SH NODE EVENTS
.TP 2i
\fBBlt_TreeCreateEventHandler\fR
Sets up a callback to be invoked when events (create, delete, 
relabel, etc) take place on a node.
.TP
\fBBlt_TreeDeleteEventHandler\fR 
Deletes an existing node callback.
.SH KEYWORDS
alloc, allocation, free, malloc, memory, realloc