sku-pg/doc/ide/static/closure-library/closure/goog/structs/treenode.js

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// Copyright 2010 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

/**
 * @fileoverview Generic tree node data structure with arbitrary number of child
 * nodes.
 *
*
 */

goog.provide('goog.structs.TreeNode');

goog.require('goog.array');
goog.require('goog.asserts');
goog.require('goog.structs.Node');



/**
 * Generic tree node data structure with arbitrary number of child nodes.
 * It is possible to create a dynamic tree structure by overriding
 * {@link #getParent} and {@link #getChildren} in a subclass. All other getters
 * will automatically work.
 *
 * @param {*} key Key.
 * @param {*} value Value.
 * @constructor
 * @extends {goog.structs.Node}
 */
goog.structs.TreeNode = function(key, value) {
  goog.structs.Node.call(this, key, value);
};
goog.inherits(goog.structs.TreeNode, goog.structs.Node);


/**
 * Constant for empty array to avoid unnecessary allocations.
 * @private
 */
goog.structs.TreeNode.EMPTY_ARRAY_ = [];


/**
 * Reference to the parent node or null if it has no parent.
 * @type {goog.structs.TreeNode}
 * @private
 */
goog.structs.TreeNode.prototype.parent_ = null;


/**
 * Child nodes or null in case of leaf node.
 * @type {Array.<!goog.structs.TreeNode>}
 * @private
 */
goog.structs.TreeNode.prototype.children_ = null;


/**
 * @return {!goog.structs.TreeNode} Clone of the tree node without its parent
 *     and child nodes. The key and the value are copied by reference.
 */
goog.structs.TreeNode.prototype.clone = function() {
  return new goog.structs.TreeNode(this.getKey(), this.getValue());
};


/**
 * @return {!goog.structs.TreeNode} Clone of the subtree with this node as root.
 */
goog.structs.TreeNode.prototype.deepClone = function() {
  var clone = this.clone();
  this.forEachChild(function(child) {
    clone.addChild(child.deepClone());
  });
  return clone;
};


/**
 * @return {goog.structs.TreeNode} Parent node or null if it has no parent.
 */
goog.structs.TreeNode.prototype.getParent = function() {
  return this.parent_;
};


/**
 * @return {boolean} Whether the node is a leaf node.
 */
goog.structs.TreeNode.prototype.isLeaf = function() {
  return this.getChildren().length == 0;
};


/**
 * @return {!Array.<!goog.structs.TreeNode>} Immutable child nodes.
 */
goog.structs.TreeNode.prototype.getChildren = function() {
  return this.children_ || goog.structs.TreeNode.EMPTY_ARRAY_;
};


/**
 * Gets the child node of this node at the given index.
 * @param {number} index Child index.
 * @return {goog.structs.TreeNode} The node at the given index or null if not
 *     found.
 */
goog.structs.TreeNode.prototype.getChildAt = function(index) {
  return this.getChildren()[index] || null;
};


/**
 * @return {number} The number of ancestors of the node.
 */
goog.structs.TreeNode.prototype.getDepth = function() {
  var depth = 0;
  var node = this;
  while (node.getParent()) {
    depth++;
    node = node.getParent();
  }
  return depth;
};


/**
 * @return {!Array.<!goog.structs.TreeNode>} All ancestor nodes in bottom-up
 *     order.
 */
goog.structs.TreeNode.prototype.getAncestors = function() {
  var ancestors = [];
  var node = this.getParent();
  while (node) {
    ancestors.push(node);
    node = node.getParent();
  }
  return ancestors;
};


/**
 * @return {!goog.structs.TreeNode} The root of the tree structure, i.e. the
 *     farthest ancestor of the node or the node itself if it has no parents.
 */
goog.structs.TreeNode.prototype.getRoot = function() {
  var root = this;
  while (root.getParent()) {
    root = root.getParent();
  }
  return root;
};


/**
 * Tells whether this node is the ancestor of the given node.
 * @param {!goog.structs.TreeNode} node A node.
 * @return {boolean} Whether this node is the ancestor of {@code node}.
 */
goog.structs.TreeNode.prototype.contains = function(node) {
  do {
    node = node.getParent();
  } while (node && node != this);
  return Boolean(node);
};


/**
 * Traverses all child nodes.
 * @param {function(!goog.structs.TreeNode, number,
 *     !Array.<!goog.structs.TreeNode>)} f Callback function. It takes the
 *     node, its index and the array of all child nodes as arguments.
 * @param {Object=} opt_this The object to be used as the value of {@code this}
 *     within {@code f}.
 */
goog.structs.TreeNode.prototype.forEachChild = function(f, opt_this) {
  goog.array.forEach(this.getChildren(), f, opt_this);
};


/**
 * Traverses all child nodes recursively.
 * @param {function(!goog.structs.TreeNode)} f Callback function. It takes the
 *     node as argument.
 * @param {Object=} opt_this The object to be used as the value of {@code this}
 *     within {@code f}.
 */
goog.structs.TreeNode.prototype.forEachDescendant = function(f, opt_this) {
  goog.array.forEach(this.getChildren(), function(child) {
    f.call(opt_this, child);
    child.forEachDescendant(f, opt_this);
  });
};


/**
 * Sets the parent node of this node. The callers must ensure that the parent
 * node and only that has this node among its children.
 * @param {goog.structs.TreeNode} parent The parent to set. If null, the node
 *     will be detached from the tree.
 * @protected
 */
goog.structs.TreeNode.prototype.setParent = function(parent) {
  this.parent_ = parent;
};


/**
 * Appends a child node to this node.
 * @param {!goog.structs.TreeNode} child Orphan child node.
 */
goog.structs.TreeNode.prototype.addChild = function(child) {
  this.addChildAt(child, this.children_ ? this.children_.length : 0);
};


/**
 * Inserts a child node at the given index.
 * @param {!goog.structs.TreeNode} child Orphan child node.
 * @param {number} index The position to insert at.
 */
goog.structs.TreeNode.prototype.addChildAt = function(child, index) {
  goog.asserts.assert(!child.getParent());
  child.setParent(this);
  this.children_ = this.children_ || [];
  goog.asserts.assert(index >= 0 && index <= this.children_.length);
  goog.array.insertAt(this.children_, child, index);
};


/**
 * Removes the child node at the given index.
 * @param {number} index The position to remove from.
 * @return {goog.structs.TreeNode} The removed node if any.
 */
goog.structs.TreeNode.prototype.removeChildAt = function(index) {
  var child = this.children_ && this.children_[index];
  if (child) {
    child.setParent(null);
    goog.array.removeAt(this.children_, index);
    if (this.children_.length == 0) {
      delete this.children_;
    }
    return child;
  }
  return null;
};


/**
 * Removes the given child node of this node.
 * @param {goog.structs.TreeNode} child The node to remove.
 * @return {goog.structs.TreeNode} The removed node if any.
 */
goog.structs.TreeNode.prototype.removeChild = function(child) {
  return this.removeChildAt(goog.array.indexOf(this.getChildren(), child));
};


/**
 * Removes all child nodes of this node.
 */
goog.structs.TreeNode.prototype.removeChildren = function() {
  if (this.children_) {
    goog.array.forEach(this.children_, function(child) {
      child.setParent(null);
    });
  }
  delete this.children_;
};