Blt_Tree - Tree data object.

#include <bltTree.h>

struct Blt_Tree {
Tcl_Alloc(size)

Tcl_Free(ptr)

char *
Tcl_Realloc(ptr, size)

Size in bytes of the memory block to allocate. Pointer to memory block to free or realloc.

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 malloc() and free() routines provided by the C run-time library.

Tcl_Alloc returns a pointer to a block of at least size bytes suitably aligned for any use.

Tcl_Free makes the space referred to by ptr available for further allocation.

Tcl_Realloc changes the size of the block pointed to by ptr to size 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 ptr.

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 tree and hiertable 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.

Blt_TreeCreate

Create a tree data object and optionally obtains a token associated with it.

Blt_TreeExists

Indicates if a tree by a given name exists.

Blt_TreeGetToken

Obtains a token for an existing tree data object.

Blt_TreeReleaseToken

Releases a token for a tree data object. The tree object is deleted when all outstanding tokens have been released.

Blt_TreeName

Returns the name of the tree object.

Blt_TreeChangeRoot

Specifies a node as the new root to a tree.

Tree objects initially contain only a root node. You can add or delete nodes with the following routines.

Blt_TreeCreateNode

Creates a new child node for a given parent in the tree.

Blt_TreeDeleteNode

Deletes a node and its children.

Blt_TreeNodeId

Returns the unique node identifier for a node.

Blt_TreeGetNode

Gets a node based upon its identifier.

Blt_TreeFindChild

Searches for a child node given by its label in a parent node.

Blt_TreeNodeLabel

Returns the current label for a node.

Blt_TreeRelabelNode

Resets a node's label.

Blt_TreeNodePath

Returns the fullpath to a node.

Blt_TreeNodeDepth

Returns the depth of the node.

Blt_TreeNodeDegree

Returns the number of children for a node.

Blt_TreeIsLeaf

Indicates if a node has no children.

Blt_TreeIsBefore

Indicates if a node is before another node in depth-first search order.

Blt_TreeIsAncestor

Indicates if a node is an ancestor or another.

Blt_TreeSortNode

Sorts the children of a node.

Blt_TreeSize

Returns the number of nodes in a node and its descendants.

Blt_TreeMoveNode

Each node can have zero or more children nodes. These routines let you navigate the tree hierarchy.

Blt_TreeNodeParent

Returns the parent node.

Blt_TreeFirstChild

Returns the first child of a parent node.

Blt_TreeLastChild

Returns the last child of a parent node.

Blt_TreeNextSibling

Returns the next sibling node in the parent's list of children.

Blt_TreePrevSibling

Returns the previous sibling node in the parent's list of children.

Blt_TreeRootNode

Returns the root node of the tree.

Blt_TreeNextNode

Returns the next node in depth-first order.

Blt_TreePrevNode

Returns the previous node in depth-first order.

Blt_TreeEndNode

Returns the last node in the tree as determined by depth-first order.

Blt_TreeApply

Walks through a node and all it descendants, applying a given callback procedure.

Blt_TreeApplyDFS

Walks through a node and all it descendants in depth-first search order, applying a given callback procedure.

Blt_TreeApplyBFS

Walks through a node and all it descendants in breadth-first search order, applying a given callback procedure.

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.

Blt_TreeGetValue

Gets the node data value given by a key.

Blt_TreeValueExists

Indicates if a node data value given by a key exists.

Blt_TreeSetValue

Sets a node's value of a key.

Blt_TreeUnsetValue

Remove the node data value and key.

Blt_TreeGetArrayValue

Gets the node data array value given by a key and an array index.

Blt_TreeSetArrayValue

Sets the node data array value given by a key and an array index.

Blt_TreeUnsetArrayValue

Remove the node data array value.

Blt_TreeArrayValueExists

Determines if an array element by a given index exists.

Blt_TreeFirstKey

Returns the key of the first value in the node.

Blt_TreeNextKey

Returns the key of the next value in the node.

Blt_TreePrivateValue

Lock the value to current client, making it private.

Blt_TreePublicValue

Unlock the value so that all clients can access it.

Blt_TreeGetKey

Blt_TreeCreateTrace

Sets up a trace callback to be invoked when the node value is read, set, or unset.

Blt_TreeDeleteTrace

Deletes an existing trace.

Blt_TreeCreateEventHandler

Sets up a callback to be invoked when events (create, delete, relabel, etc) take place on a node.

Blt_TreeDeleteEventHandler

Deletes an existing node callback.

alloc, allocation, free, malloc, memory, realloc