/* GLIB - Library of useful routines for C programming * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald * * GNode: N-way tree implementation. * Copyright (C) 1998 Tim Janik * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ /* * Modified by the GLib Team and others 1997-2000. See the AUTHORS * file for a list of people on the GLib Team. See the ChangeLog * files for a list of changes. These files are distributed with * GLib at ftp://ftp.gtk.org/pub/gtk/. */ /* * MT safe */ #include "config.h" #include "gnode.h" #include "gtestutils.h" /** * SECTION: trees-nary * @title: N-ary Trees * @short_description: trees of data with any number of branches * * The #GNode struct and its associated functions provide a N-ary tree * data structure, where nodes in the tree can contain arbitrary data. * * To create a new tree use g_node_new(). * * To insert a node into a tree use g_node_insert(), * g_node_insert_before(), g_node_append() and g_node_prepend(). * * To create a new node and insert it into a tree use * g_node_insert_data(), g_node_insert_data_before(), * g_node_append_data() and g_node_prepend_data(). * * To reverse the children of a node use g_node_reverse_children(). * * To find a node use g_node_get_root(), g_node_find(), * g_node_find_child(), g_node_child_index(), g_node_child_position(), * g_node_first_child(), g_node_last_child(), g_node_nth_child(), * g_node_first_sibling(), g_node_prev_sibling(), g_node_next_sibling() * or g_node_last_sibling(). * * To get information about a node or tree use G_NODE_IS_LEAF(), * G_NODE_IS_ROOT(), g_node_depth(), g_node_n_nodes(), * g_node_n_children(), g_node_is_ancestor() or g_node_max_height(). * * To traverse a tree, calling a function for each node visited in the * traversal, use g_node_traverse() or g_node_children_foreach(). * * To remove a node or subtree from a tree use g_node_unlink() or * g_node_destroy(). **/ /** * GNode: * @data: contains the actual data of the node. * @next: points to the node's next sibling (a sibling is another * #GNode with the same parent). * @prev: points to the node's previous sibling. * @parent: points to the parent of the #GNode, or is %NULL if the * #GNode is the root of the tree. * @children: points to the first child of the #GNode. The other * children are accessed by using the @next pointer of each * child. * * The #GNode struct represents one node in a * N-ary Tree. fields **/ /** * g_node_push_allocator: * @dummy: the #GAllocator to use when allocating #GNode elements. * * Sets the allocator to use to allocate #GNode elements. Use * g_node_pop_allocator() to restore the previous allocator. * * Note that this function is not available if GLib has been compiled * with * * Deprecated:2.10: It does nothing, since #GNode has been converted to * the slice * allocator **/ void g_node_push_allocator (gpointer dummy) { /* present for binary compat only */ } /** * g_node_pop_allocator: * * Restores the previous #GAllocator, used when allocating #GNode * elements. * * Note that this function is not available if GLib has been compiled * with * * Deprecated:2.10: It does nothing, since #GNode has been converted to * the slice * allocator **/ void g_node_pop_allocator (void) { /* present for binary compat only */ } #define g_node_alloc0() g_slice_new0 (GNode) #define g_node_free(node) g_slice_free (GNode, node) /* --- functions --- */ /** * g_node_new: * @data: the data of the new node * * Creates a new #GNode containing the given data. * Used to create the first node in a tree. * * Returns: a new #GNode */ GNode* g_node_new (gpointer data) { GNode *node = g_node_alloc0 (); node->data = data; return node; } static void g_nodes_free (GNode *node) { while (node) { GNode *next = node->next; if (node->children) g_nodes_free (node->children); g_node_free (node); node = next; } } /** * g_node_destroy: * @root: the root of the tree/subtree to destroy * * Removes @root and its children from the tree, freeing any memory * allocated. */ void g_node_destroy (GNode *root) { g_return_if_fail (root != NULL); if (!G_NODE_IS_ROOT (root)) g_node_unlink (root); g_nodes_free (root); } /** * g_node_unlink: * @node: the #GNode to unlink, which becomes the root of a new tree * * Unlinks a #GNode from a tree, resulting in two separate trees. */ void g_node_unlink (GNode *node) { g_return_if_fail (node != NULL); if (node->prev) node->prev->next = node->next; else if (node->parent) node->parent->children = node->next; node->parent = NULL; if (node->next) { node->next->prev = node->prev; node->next = NULL; } node->prev = NULL; } /** * g_node_copy_deep: * @node: a #GNode * @copy_func: the function which is called to copy the data inside each node, * or %NULL to use the original data. * @data: data to pass to @copy_func * * Recursively copies a #GNode and its data. * * Return value: a new #GNode containing copies of the data in @node. * * Since: 2.4 **/ GNode* g_node_copy_deep (GNode *node, GCopyFunc copy_func, gpointer data) { GNode *new_node = NULL; if (copy_func == NULL) return g_node_copy (node); if (node) { GNode *child, *new_child; new_node = g_node_new (copy_func (node->data, data)); for (child = g_node_last_child (node); child; child = child->prev) { new_child = g_node_copy_deep (child, copy_func, data); g_node_prepend (new_node, new_child); } } return new_node; } /** * g_node_copy: * @node: a #GNode * * Recursively copies a #GNode (but does not deep-copy the data inside the * nodes, see g_node_copy_deep() if you need that). * * Returns: a new #GNode containing the same data pointers */ GNode* g_node_copy (GNode *node) { GNode *new_node = NULL; if (node) { GNode *child; new_node = g_node_new (node->data); for (child = g_node_last_child (node); child; child = child->prev) g_node_prepend (new_node, g_node_copy (child)); } return new_node; } /** * g_node_insert: * @parent: the #GNode to place @node under * @position: the position to place @node at, with respect to its siblings * If position is -1, @node is inserted as the last child of @parent * @node: the #GNode to insert * * Inserts a #GNode beneath the parent at the given position. * * Returns: the inserted #GNode */ GNode* g_node_insert (GNode *parent, gint position, GNode *node) { g_return_val_if_fail (parent != NULL, node); g_return_val_if_fail (node != NULL, node); g_return_val_if_fail (G_NODE_IS_ROOT (node), node); if (position > 0) return g_node_insert_before (parent, g_node_nth_child (parent, position), node); else if (position == 0) return g_node_prepend (parent, node); else /* if (position < 0) */ return g_node_append (parent, node); } /** * g_node_insert_before: * @parent: the #GNode to place @node under * @sibling: the sibling #GNode to place @node before. * If sibling is %NULL, the node is inserted as the last child of @parent. * @node: the #GNode to insert * * Inserts a #GNode beneath the parent before the given sibling. * * Returns: the inserted #GNode */ GNode* g_node_insert_before (GNode *parent, GNode *sibling, GNode *node) { g_return_val_if_fail (parent != NULL, node); g_return_val_if_fail (node != NULL, node); g_return_val_if_fail (G_NODE_IS_ROOT (node), node); if (sibling) g_return_val_if_fail (sibling->parent == parent, node); node->parent = parent; if (sibling) { if (sibling->prev) { node->prev = sibling->prev; node->prev->next = node; node->next = sibling; sibling->prev = node; } else { node->parent->children = node; node->next = sibling; sibling->prev = node; } } else { if (parent->children) { sibling = parent->children; while (sibling->next) sibling = sibling->next; node->prev = sibling; sibling->next = node; } else node->parent->children = node; } return node; } /** * g_node_insert_after: * @parent: the #GNode to place @node under * @sibling: the sibling #GNode to place @node after. * If sibling is %NULL, the node is inserted as the first child of @parent. * @node: the #GNode to insert * * Inserts a #GNode beneath the parent after the given sibling. * * Returns: the inserted #GNode */ GNode* g_node_insert_after (GNode *parent, GNode *sibling, GNode *node) { g_return_val_if_fail (parent != NULL, node); g_return_val_if_fail (node != NULL, node); g_return_val_if_fail (G_NODE_IS_ROOT (node), node); if (sibling) g_return_val_if_fail (sibling->parent == parent, node); node->parent = parent; if (sibling) { if (sibling->next) { sibling->next->prev = node; } node->next = sibling->next; node->prev = sibling; sibling->next = node; } else { if (parent->children) { node->next = parent->children; parent->children->prev = node; } parent->children = node; } return node; } /** * g_node_prepend: * @parent: the #GNode to place the new #GNode under * @node: the #GNode to insert * * Inserts a #GNode as the first child of the given parent. * * Returns: the inserted #GNode */ GNode* g_node_prepend (GNode *parent, GNode *node) { g_return_val_if_fail (parent != NULL, node); return g_node_insert_before (parent, parent->children, node); } /** * g_node_get_root: * @node: a #GNode * * Gets the root of a tree. * * Returns: the root of the tree */ GNode* g_node_get_root (GNode *node) { g_return_val_if_fail (node != NULL, NULL); while (node->parent) node = node->parent; return node; } /** * g_node_is_ancestor: * @node: a #GNode * @descendant: a #GNode * * Returns %TRUE if @node is an ancestor of @descendant. * This is true if node is the parent of @descendant, * or if node is the grandparent of @descendant etc. * * Returns: %TRUE if @node is an ancestor of @descendant */ gboolean g_node_is_ancestor (GNode *node, GNode *descendant) { g_return_val_if_fail (node != NULL, FALSE); g_return_val_if_fail (descendant != NULL, FALSE); while (descendant) { if (descendant->parent == node) return TRUE; descendant = descendant->parent; } return FALSE; } /** * g_node_depth: * @node: a #GNode * * Gets the depth of a #GNode. * * If @node is %NULL the depth is 0. The root node has a depth of 1. * For the children of the root node the depth is 2. And so on. * * Returns: the depth of the #GNode */ guint g_node_depth (GNode *node) { guint depth = 0; while (node) { depth++; node = node->parent; } return depth; } /** * g_node_reverse_children: * @node: a #GNode. * * Reverses the order of the children of a #GNode. * (It doesn't change the order of the grandchildren.) */ void g_node_reverse_children (GNode *node) { GNode *child; GNode *last; g_return_if_fail (node != NULL); child = node->children; last = NULL; while (child) { last = child; child = last->next; last->next = last->prev; last->prev = child; } node->children = last; } /** * g_node_max_height: * @root: a #GNode * * Gets the maximum height of all branches beneath a #GNode. * This is the maximum distance from the #GNode to all leaf nodes. * * If @root is %NULL, 0 is returned. If @root has no children, * 1 is returned. If @root has children, 2 is returned. And so on. * * Returns: the maximum height of the tree beneath @root */ guint g_node_max_height (GNode *root) { GNode *child; guint max_height = 0; if (!root) return 0; child = root->children; while (child) { guint tmp_height; tmp_height = g_node_max_height (child); if (tmp_height > max_height) max_height = tmp_height; child = child->next; } return max_height + 1; } static gboolean g_node_traverse_pre_order (GNode *node, GTraverseFlags flags, GNodeTraverseFunc func, gpointer data) { if (node->children) { GNode *child; if ((flags & G_TRAVERSE_NON_LEAFS) && func (node, data)) return TRUE; child = node->children; while (child) { GNode *current; current = child; child = current->next; if (g_node_traverse_pre_order (current, flags, func, data)) return TRUE; } } else if ((flags & G_TRAVERSE_LEAFS) && func (node, data)) return TRUE; return FALSE; } static gboolean g_node_depth_traverse_pre_order (GNode *node, GTraverseFlags flags, guint depth, GNodeTraverseFunc func, gpointer data) { if (node->children) { GNode *child; if ((flags & G_TRAVERSE_NON_LEAFS) && func (node, data)) return TRUE; depth--; if (!depth) return FALSE; child = node->children; while (child) { GNode *current; current = child; child = current->next; if (g_node_depth_traverse_pre_order (current, flags, depth, func, data)) return TRUE; } } else if ((flags & G_TRAVERSE_LEAFS) && func (node, data)) return TRUE; return FALSE; } static gboolean g_node_traverse_post_order (GNode *node, GTraverseFlags flags, GNodeTraverseFunc func, gpointer data) { if (node->children) { GNode *child; child = node->children; while (child) { GNode *current; current = child; child = current->next; if (g_node_traverse_post_order (current, flags, func, data)) return TRUE; } if ((flags & G_TRAVERSE_NON_LEAFS) && func (node, data)) return TRUE; } else if ((flags & G_TRAVERSE_LEAFS) && func (node, data)) return TRUE; return FALSE; } static gboolean g_node_depth_traverse_post_order (GNode *node, GTraverseFlags flags, guint depth, GNodeTraverseFunc func, gpointer data) { if (node->children) { depth--; if (depth) { GNode *child; child = node->children; while (child) { GNode *current; current = child; child = current->next; if (g_node_depth_traverse_post_order (current, flags, depth, func, data)) return TRUE; } } if ((flags & G_TRAVERSE_NON_LEAFS) && func (node, data)) return TRUE; } else if ((flags & G_TRAVERSE_LEAFS) && func (node, data)) return TRUE; return FALSE; } static gboolean g_node_traverse_in_order (GNode *node, GTraverseFlags flags, GNodeTraverseFunc func, gpointer data) { if (node->children) { GNode *child; GNode *current; child = node->children; current = child; child = current->next; if (g_node_traverse_in_order (current, flags, func, data)) return TRUE; if ((flags & G_TRAVERSE_NON_LEAFS) && func (node, data)) return TRUE; while (child) { current = child; child = current->next; if (g_node_traverse_in_order (current, flags, func, data)) return TRUE; } } else if ((flags & G_TRAVERSE_LEAFS) && func (node, data)) return TRUE; return FALSE; } static gboolean g_node_depth_traverse_in_order (GNode *node, GTraverseFlags flags, guint depth, GNodeTraverseFunc func, gpointer data) { if (node->children) { depth--; if (depth) { GNode *child; GNode *current; child = node->children; current = child; child = current->next; if (g_node_depth_traverse_in_order (current, flags, depth, func, data)) return TRUE; if ((flags & G_TRAVERSE_NON_LEAFS) && func (node, data)) return TRUE; while (child) { current = child; child = current->next; if (g_node_depth_traverse_in_order (current, flags, depth, func, data)) return TRUE; } } else if ((flags & G_TRAVERSE_NON_LEAFS) && func (node, data)) return TRUE; } else if ((flags & G_TRAVERSE_LEAFS) && func (node, data)) return TRUE; return FALSE; } static gboolean g_node_traverse_level (GNode *node, GTraverseFlags flags, guint level, GNodeTraverseFunc func, gpointer data, gboolean *more_levels) { if (level == 0) { if (node->children) { *more_levels = TRUE; return (flags & G_TRAVERSE_NON_LEAFS) && func (node, data); } else { return (flags & G_TRAVERSE_LEAFS) && func (node, data); } } else { node = node->children; while (node) { if (g_node_traverse_level (node, flags, level - 1, func, data, more_levels)) return TRUE; node = node->next; } } return FALSE; } static gboolean g_node_depth_traverse_level (GNode *node, GTraverseFlags flags, guint depth, GNodeTraverseFunc func, gpointer data) { guint level; gboolean more_levels; level = 0; while (level != depth) { more_levels = FALSE; if (g_node_traverse_level (node, flags, level, func, data, &more_levels)) return TRUE; if (!more_levels) break; level++; } return FALSE; } /** * g_node_traverse: * @root: the root #GNode of the tree to traverse * @order: the order in which nodes are visited - %G_IN_ORDER, * %G_PRE_ORDER, %G_POST_ORDER, or %G_LEVEL_ORDER. * @flags: which types of children are to be visited, one of * %G_TRAVERSE_ALL, %G_TRAVERSE_LEAVES and %G_TRAVERSE_NON_LEAVES * @max_depth: the maximum depth of the traversal. Nodes below this * depth will not be visited. If max_depth is -1 all nodes in * the tree are visited. If depth is 1, only the root is visited. * If depth is 2, the root and its children are visited. And so on. * @func: the function to call for each visited #GNode * @data: user data to pass to the function * * Traverses a tree starting at the given root #GNode. * It calls the given function for each node visited. * The traversal can be halted at any point by returning %TRUE from @func. */ /** * GTraverseFlags: * @G_TRAVERSE_LEAVES: only leaf nodes should be visited. This name has * been introduced in 2.6, for older version use * %G_TRAVERSE_LEAFS. * @G_TRAVERSE_NON_LEAVES: only non-leaf nodes should be visited. This * name has been introduced in 2.6, for older * version use %G_TRAVERSE_NON_LEAFS. * @G_TRAVERSE_ALL: all nodes should be visited. * @G_TRAVERSE_MASK: a mask of all traverse flags. * @G_TRAVERSE_LEAFS: identical to %G_TRAVERSE_LEAVES. * @G_TRAVERSE_NON_LEAFS: identical to %G_TRAVERSE_NON_LEAVES. * * Specifies which nodes are visited during several of the tree * functions, including g_node_traverse() and g_node_find(). **/ /** * GNodeTraverseFunc: * @node: a #GNode. * @data: user data passed to g_node_traverse(). * @Returns: %TRUE to stop the traversal. * * Specifies the type of function passed to g_node_traverse(). The * function is called with each of the nodes visited, together with the * user data passed to g_node_traverse(). If the function returns * %TRUE, then the traversal is stopped. **/ void g_node_traverse (GNode *root, GTraverseType order, GTraverseFlags flags, gint depth, GNodeTraverseFunc func, gpointer data) { g_return_if_fail (root != NULL); g_return_if_fail (func != NULL); g_return_if_fail (order <= G_LEVEL_ORDER); g_return_if_fail (flags <= G_TRAVERSE_MASK); g_return_if_fail (depth == -1 || depth > 0); switch (order) { case G_PRE_ORDER: if (depth < 0) g_node_traverse_pre_order (root, flags, func, data); else g_node_depth_traverse_pre_order (root, flags, depth, func, data); break; case G_POST_ORDER: if (depth < 0) g_node_traverse_post_order (root, flags, func, data); else g_node_depth_traverse_post_order (root, flags, depth, func, data); break; case G_IN_ORDER: if (depth < 0) g_node_traverse_in_order (root, flags, func, data); else g_node_depth_traverse_in_order (root, flags, depth, func, data); break; case G_LEVEL_ORDER: g_node_depth_traverse_level (root, flags, depth, func, data); break; } } static gboolean g_node_find_func (GNode *node, gpointer data) { gpointer *d = data; if (*d != node->data) return FALSE; *(++d) = node; return TRUE; } /** * g_node_find: * @root: the root #GNode of the tree to search * @order: the order in which nodes are visited - %G_IN_ORDER, * %G_PRE_ORDER, %G_POST_ORDER, or %G_LEVEL_ORDER * @flags: which types of children are to be searched, one of * %G_TRAVERSE_ALL, %G_TRAVERSE_LEAVES and %G_TRAVERSE_NON_LEAVES * @data: the data to find * * Finds a #GNode in a tree. * * Returns: the found #GNode, or %NULL if the data is not found */ GNode* g_node_find (GNode *root, GTraverseType order, GTraverseFlags flags, gpointer data) { gpointer d[2]; g_return_val_if_fail (root != NULL, NULL); g_return_val_if_fail (order <= G_LEVEL_ORDER, NULL); g_return_val_if_fail (flags <= G_TRAVERSE_MASK, NULL); d[0] = data; d[1] = NULL; g_node_traverse (root, order, flags, -1, g_node_find_func, d); return d[1]; } static void g_node_count_func (GNode *node, GTraverseFlags flags, guint *n) { if (node->children) { GNode *child; if (flags & G_TRAVERSE_NON_LEAFS) (*n)++; child = node->children; while (child) { g_node_count_func (child, flags, n); child = child->next; } } else if (flags & G_TRAVERSE_LEAFS) (*n)++; } /** * g_node_n_nodes: * @root: a #GNode * @flags: which types of children are to be counted, one of * %G_TRAVERSE_ALL, %G_TRAVERSE_LEAVES and %G_TRAVERSE_NON_LEAVES * * Gets the number of nodes in a tree. * * Returns: the number of nodes in the tree */ guint g_node_n_nodes (GNode *root, GTraverseFlags flags) { guint n = 0; g_return_val_if_fail (root != NULL, 0); g_return_val_if_fail (flags <= G_TRAVERSE_MASK, 0); g_node_count_func (root, flags, &n); return n; } /** * g_node_last_child: * @node: a #GNode (must not be %NULL) * * Gets the last child of a #GNode. * * Returns: the last child of @node, or %NULL if @node has no children */ GNode* g_node_last_child (GNode *node) { g_return_val_if_fail (node != NULL, NULL); node = node->children; if (node) while (node->next) node = node->next; return node; } /** * g_node_nth_child: * @node: a #GNode * @n: the index of the desired child * * Gets a child of a #GNode, using the given index. * The first child is at index 0. If the index is * too big, %NULL is returned. * * Returns: the child of @node at index @n */ GNode* g_node_nth_child (GNode *node, guint n) { g_return_val_if_fail (node != NULL, NULL); node = node->children; if (node) while ((n-- > 0) && node) node = node->next; return node; } /** * g_node_n_children: * @node: a #GNode * * Gets the number of children of a #GNode. * * Returns: the number of children of @node */ guint g_node_n_children (GNode *node) { guint n = 0; g_return_val_if_fail (node != NULL, 0); node = node->children; while (node) { n++; node = node->next; } return n; } /** * g_node_find_child: * @node: a #GNode * @flags: which types of children are to be searched, one of * %G_TRAVERSE_ALL, %G_TRAVERSE_LEAVES and %G_TRAVERSE_NON_LEAVES * @data: the data to find * * Finds the first child of a #GNode with the given data. * * Returns: the found child #GNode, or %NULL if the data is not found */ GNode* g_node_find_child (GNode *node, GTraverseFlags flags, gpointer data) { g_return_val_if_fail (node != NULL, NULL); g_return_val_if_fail (flags <= G_TRAVERSE_MASK, NULL); node = node->children; while (node) { if (node->data == data) { if (G_NODE_IS_LEAF (node)) { if (flags & G_TRAVERSE_LEAFS) return node; } else { if (flags & G_TRAVERSE_NON_LEAFS) return node; } } node = node->next; } return NULL; } /** * g_node_child_position: * @node: a #GNode * @child: a child of @node * * Gets the position of a #GNode with respect to its siblings. * @child must be a child of @node. The first child is numbered 0, * the second 1, and so on. * * Returns: the position of @child with respect to its siblings */ gint g_node_child_position (GNode *node, GNode *child) { guint n = 0; g_return_val_if_fail (node != NULL, -1); g_return_val_if_fail (child != NULL, -1); g_return_val_if_fail (child->parent == node, -1); node = node->children; while (node) { if (node == child) return n; n++; node = node->next; } return -1; } /** * g_node_child_index: * @node: a #GNode * @data: the data to find * * Gets the position of the first child of a #GNode * which contains the given data. * * Returns: the index of the child of @node which contains * @data, or -1 if the data is not found */ gint g_node_child_index (GNode *node, gpointer data) { guint n = 0; g_return_val_if_fail (node != NULL, -1); node = node->children; while (node) { if (node->data == data) return n; n++; node = node->next; } return -1; } /** * g_node_first_sibling: * @node: a #GNode * * Gets the first sibling of a #GNode. * This could possibly be the node itself. * * Returns: the first sibling of @node */ GNode* g_node_first_sibling (GNode *node) { g_return_val_if_fail (node != NULL, NULL); if (node->parent) return node->parent->children; while (node->prev) node = node->prev; return node; } /** * g_node_last_sibling: * @node: a #GNode * * Gets the last sibling of a #GNode. * This could possibly be the node itself. * * Returns: the last sibling of @node */ GNode* g_node_last_sibling (GNode *node) { g_return_val_if_fail (node != NULL, NULL); while (node->next) node = node->next; return node; } /** * g_node_children_foreach: * @node: a #GNode * @flags: which types of children are to be visited, one of * %G_TRAVERSE_ALL, %G_TRAVERSE_LEAVES and %G_TRAVERSE_NON_LEAVES * @func: the function to call for each visited node * @data: user data to pass to the function * * Calls a function for each of the children of a #GNode. * Note that it doesn't descend beneath the child nodes. */ /** * GNodeForeachFunc: * @node: a #GNode. * @data: user data passed to g_node_children_foreach(). * * Specifies the type of function passed to g_node_children_foreach(). * The function is called with each child node, together with the user * data passed to g_node_children_foreach(). **/ void g_node_children_foreach (GNode *node, GTraverseFlags flags, GNodeForeachFunc func, gpointer data) { g_return_if_fail (node != NULL); g_return_if_fail (flags <= G_TRAVERSE_MASK); g_return_if_fail (func != NULL); node = node->children; while (node) { GNode *current; current = node; node = current->next; if (G_NODE_IS_LEAF (current)) { if (flags & G_TRAVERSE_LEAFS) func (current, data); } else { if (flags & G_TRAVERSE_NON_LEAFS) func (current, data); } } }