add stuff for walking the tree

www/common/treesome.js

@@ -0,0 +1,215 @@
+define([], function () {
+    var tree = {};
+
+    tree.some = function (branch, predicate) {
+        // take the index of the last element in the current branch
+        var last = branch.childElementCount - 1;
+
+        // it might be a leaf node
+        if (last < 0) { return false; }
+
+        // otherwise it has children
+        while (last >= 0) {
+            // check from back to front
+
+            // check the node's children (depth first)
+            // if the predicate tests true, return true
+            if (tree.some(branch.children[last], predicate)) {
+                return true;
+            } // otherwise none of the nodes inside it matched.
+           
+            // check the node itself
+            if (predicate(branch.children[last], last)) {
+                return true;
+            }
+            last--;
+        }
+        return false;
+    };
+
+    tree.someIncludingText = function (branch, predicate) {
+        // take the index of the last element in the current branch
+        var last = branch.childNodes.length - 1;
+        
+        // it might be a leaf node
+        if (last < 0) { return false; }
+
+        // otherwise it has children
+        while (last >= 0) {
+            // check from back to front
+
+            // check the node's children (depth first)
+            // if the predicate tests true, return true
+            if (tree.someIncludingText(branch.childNodes[last], predicate)) {
+                return true;
+            } // otherwise none of the nodes inside it matched.
+           
+            // check the node itself
+            if (predicate(branch.childNodes[last], last)) {
+                return true;
+            }
+            last--;
+        }
+        return false;
+    };
+
+    tree.findSameHierarchy = function (list, ancestor) {
+        var i = 0;
+        var success = true;
+        var last = list.length - 1;
+        var el;
+
+        tree.someIncludingText(ancestor, function (e) {
+            // don't out of bounds
+            if (i > last) {
+                // unsuccessful
+                success = false;
+                return true;
+            }
+
+            if (list[i] === (e.tagName||e.nodeName)) {
+
+                if (i === last) {
+                    el = e;
+                    return true;
+                }
+                i++;
+            } else {
+                // hierarchy has changed, what should we do?
+                success = false;
+                return true; // terminate
+            }
+        });
+        return success? el: false;
+    };
+
+    var indexOfNode = tree.indexOfNode = function (el) {
+        if (!(el && el.parentNode)) {
+            console.log("No parentNode found!");
+        }
+        return Array.prototype.indexOf.call(el.parentNode.childNodes, el);
+    };
+
+    var siblingCount = tree.siblingCount = function (el) {
+        return el.parentNodes.childNodes.length;
+    };
+
+    var deepestNode = tree.deepestNode = function (el) {
+        var deepest = el.childNodes.length;
+        if (!deepest) { // no children
+            return el; // return the element
+        } else {
+            return deepestNode(el.childNodes[deepest - 1]);
+        }
+    };
+
+    var leftMostNode = tree.leftMostNode = function (el) {
+        var left = el.childNodes[0];
+        if (el.childNodes.length) {
+            return leftMostNode(el.childNodes[0]);
+        } else {
+            return el;
+        }
+    };
+
+    var previousNode = tree.previousNode = function (el, root) {
+        if (!el || el === root) { return null; }
+
+        var i = indexOfNode(el);
+        if (!el.parentNode) { return null; }
+        if (i === 0) {
+
+            if (root && el.parentNode === root.childNodes[0]) { return null; }
+            return deepestNode(previousNode(el.parentNode));
+        } else {
+            return el.parentNode.childNodes[i-1];
+        }
+    };
+
+    /* includes text elements */
+    var nextNode = tree.nextNode = function (el, root) {
+        if (!el || el === root) {
+            return null;
+        }
+        var i = indexOfNode(el) + 1, // the index of the next node
+            l = el.parentNode.childNodes.length;
+        if (i === l) { // out of bounds
+            return leftMostNode(nextNode(el.parentNode, root));
+        } else {
+            return el.parentNode.childNodes[i];
+        }
+    };
+
+    tree.recoverElement = function (el, root) {
+        var tags = tree.tagsUntilElement(el, root);
+        var found = tree.findSameHierarchy(tags, root);
+        var isSame = found === el;
+        console.log("found an equivalent node: %s", isSame);
+        return found;
+    };
+
+    tree.tagsUntilElement = function (el, ancestor) {
+        var list = [];
+        tree.someIncludingText(ancestor, function (e, index) {
+            list.push(e.tagName||e.nodeName);
+            return e === el;
+        });
+        return list;
+    };
+
+    tree.distanceFromEnd = function (el, ancestor) {
+        var i = 0, success = false;
+        // FIXME can't be trusted if element is not found.
+        tree.some(ancestor, function (e, index) {
+            return (++i, e === el);
+        });
+        return i;
+    };
+
+    tree.nthFromEnd = function (n, ancestor) {
+        var el = false, i = 0;
+        tree.some(ancestor, function (e) {
+            if (i > n) {
+                // terminate
+                return true;
+            } else {
+                return (++i === n) ?
+                ((el = e), true):
+                false;
+            }
+        });
+        return el;
+    };
+
+    tree.contains = function (el, ancestor) {
+        ancestor = ancestor || inner;
+        return el && ancestor.contains && ancestor.contains(el);
+    };
+
+    tree.check = function (el, ancestor) {
+        return tree.nthFromEnd(Tree.distanceFromEnd(el, ancestor), ancestor) === el;
+    };
+
+    // TODO see if we can use this
+    tree.getNext = function (node, parent) {
+        if (node.firstChild) { return node.nextSibling; }
+        do {
+            if(node.nextSibling) { return node.nextSibling; }
+            node = node.parentNode;
+        } while (node && node !== parent);
+    };
+
+    // FIXME remove
+    tree.flatten = function (el, ancestor, cursorContainer) {
+        var list = [];
+        for (var el = ancestor; el = tree.getNext(next, ancestor);) {
+            if (cf || el === cursorContainer) {
+                cf = true;
+                list.push(el.tagName);
+            }
+        }
+        return list;
+    };
+
+    return tree;
+});