-util.js

"use strict";
var getDocument = require("can-globals/document/document");

function eliminate(array, item) {
	var index = array.indexOf(item);
	if (index >= 0) {
		array.splice(index, 1);
	}
}
function wasNotInSet(item, set) {
	var inSet = set.has(item);
	if(inSet === false) {
		set.add(item);
	}
	return !inSet;
}


function contains(parent, child){
	if(child && child.nodeType === Node.TEXT_NODE) {
		return contains(parent, child.parentNode);
	}
	if(parent.contains) {
		return parent.contains(child);
	}
	if(parent.nodeType === Node.DOCUMENT_NODE && parent.documentElement) {
		return contains(parent.documentElement, child);
	} else {
		child = child.parentNode;
		if(child === parent) {
			return true;
		}
		return false;
	}
}

function isDocumentElement (node) {
	return getDocument().documentElement === node;
}

function isFragment (node) {
	return !!(node && node.nodeType === 11);
}

function isElementNode (node) {
	return !!(node && node.nodeType === 1);
}

function getChildren (parentNode) {
	var nodes = [];
	var node = parentNode.firstChild;
	while (node) {
		nodes.push(node);
		node = node.nextSibling;
	}
	return nodes;
}

function getParents (node) {
	var nodes;
	if (isFragment(node)) {
		nodes = getChildren(node);
	} else {
		nodes = [node];
	}
	return nodes;
}


function getNodesLegacyB(node) {
	var skip, tmp;

	var depth = 0;

	var items = isFragment(node) ? [] : [node];
	if(node.firstChild == null) {
		return items;
	}

	// Always start with the initial element.
	do {
		if ( !skip && (tmp = node.firstChild) ) {
			depth++;
			items.push(tmp);
		} else if ( tmp = node.nextSibling ) {
			skip = false;
			items.push(tmp);
		} else {
			// Skipped or no first child and no next sibling, so traverse upwards,
			tmp = node.parentNode;
			// and decrement the depth.
			depth--;
			// Enable skipping, so that in the next loop iteration, the children of
			// the now-current node (parent node) aren't processed again.
			skip = true;
		}

		// Instead of setting node explicitly in each conditional block, use the
		// tmp var and set it here.
		node = tmp;

		// Stop if depth comes back to 0 (or goes below zero, in conditions where
		// the passed node has neither children nore next siblings).
	} while ( depth > 0 );

	return items;
}

// IE11 requires a filter parameter for createTreeWalker
// it also must be an object with an `acceptNode` property
function treeWalkerFilterFunction() {
	return NodeFilter.FILTER_ACCEPT;
}
var treeWalkerFilter = treeWalkerFilterFunction;
treeWalkerFilter.acceptNode = treeWalkerFilterFunction;

function getNodesWithTreeWalker(rootNode) {
	var result = isFragment(rootNode) ? [] : [rootNode];

	// IE11 throws if createTreeWalker is called on a non-ElementNode
	var walker = isElementNode(rootNode) && getDocument().createTreeWalker(
		rootNode,
		NodeFilter.SHOW_TEXT | NodeFilter.SHOW_ELEMENT | NodeFilter.SHOW_COMMENT,
		treeWalkerFilter,
		false
	);

	var node;
	while(node = walker && walker.nextNode()) {
		result.push(node);
	}
	return result;
}

function getAllNodes (node) {
	if( getDocument().createTreeWalker !== undefined ) {
		return getNodesWithTreeWalker(node);
	} else {
		return getNodesLegacyB(node);
	}
}

function subscription (fn) {
	return function _subscription () {
		var disposal = fn.apply(this, arguments);
		var isDisposed = false;
		return function _disposal () {
			if (isDisposed) {
				var fnName = fn.name || fn.displayName || 'an anonymous function';
				var message = 'Disposal function returned by ' + fnName + ' called more than once.';
				throw new Error(message);
			}
			disposal.apply(this, arguments);
			isDisposed = true;
		};
	};
}

module.exports = {
	eliminate: eliminate,
	getDocument: getDocument,
	isDocumentElement: isDocumentElement,
	isFragment: isFragment,
	getParents: getParents,
	getAllNodes: getAllNodes,
	getChildren: getChildren,
	subscription: subscription,
	wasNotInSet: wasNotInSet,
	contains: contains
};