Range performance fixes

src/range.coffee

@@ -189,13 +189,23 @@ class Range.NormalizedRange
   #
   # Returns updated self or null.
   limit: (bounds) ->
-    nodes = $.grep this.textNodes(), (node) ->
-      node.parentNode == bounds or $.contains(bounds, node.parentNode)
+    if @commonAncestor == bounds or $.contains(bounds, @commonAncestor)
+      return this
 
-    return null unless nodes.length
+    if not $.contains(@commonAncestor, bounds)
+      return null
 
-    @start = nodes[0]
-    @end   = nodes[nodes.length - 1]
+    document = bounds.ownerDocument
+
+    if not $.contains(bounds, @start)
+      walker = document.createTreeWalker(bounds, NodeFilter.SHOW_TEXT)
+      @start = walker.firstChild()
+
+    if not $.contains(bounds, @end)
+      walker = document.createTreeWalker(bounds, NodeFilter.SHOW_TEXT)
+      @end = walker.lastChild()
+
+    return null unless @start and @end
 
     startParents = $(@start).parents()
     for parent in $(@end).parents()

src/util.coffee

@@ -60,27 +60,13 @@ Util.getLastTextNodeUpTo = (n) ->
 #
 # Returns a new jQuery collection of text nodes.
 Util.getTextNodes = (jq) ->
-  getTextNodes = (node) ->
-    if node and node.nodeType != Util.NodeTypes.TEXT_NODE
-      nodes = []
+  getTextNodes = (root) ->
+    document = root.ownerDocument
+    walker = document.createTreeWalker(root, NodeFilter.SHOW_TEXT)
+    nodes = (node while node = walker.nextNode())
+    return nodes
 
-      # If not a comment then traverse children collecting text nodes.
-      # We traverse the child nodes manually rather than using the .childNodes
-      # property because IE9 does not update the .childNodes property after
-      # .splitText() is called on a child text node.
-      if node.nodeType != Util.NodeTypes.COMMENT_NODE
-        # Start at the last child and walk backwards through siblings.
-        node = node.lastChild
-        while node
-          nodes.push getTextNodes(node)
-          node = node.previousSibling
-
-      # Finally reverse the array so that nodes are in the correct order.
-      return nodes.reverse()
-    else
-      return node
-
-  jq.map -> Util.flatten(getTextNodes(this))
+  jq.map -> getTextNodes(this)
 
 Util.getGlobal = -> (-> this)()
 
@@ -96,20 +82,6 @@ Util.contains = (parent, child) ->
     node = node.parentNode
   return false
 
-# Public: Flatten a nested array structure
-#
-# Returns an array
-Util.flatten = (array) ->
-  flatten = (ary) ->
-    flat = []
-
-    for el in ary
-      flat = flat.concat(if el and $.isArray(el) then flatten(el) else el)
-
-    return flat
-
-  flatten(array)
-
 
 # Export Util object
 module.exports = Util

test/spec/range_spec.coffee

@@ -155,25 +155,47 @@ describe 'Range', ->
       headText = null
       paraText = null
       paraText2 = null
+      paraText3 = null
+      para2Text = null
       para = null
       root = null
 
       beforeEach ->
         headText  = document.createTextNode("My Heading")
         paraText  = document.createTextNode("My paragraph")
-        paraText2 = document.createTextNode(" continues")
+        paraText2 = document.createTextNode(" conti")
+        paraText3 = document.createTextNode("nues")
+        para2Text = document.createTextNode("Another paragraph begins")
 
         head = document.createElement('h1')
         head.appendChild(headText)
         para = document.createElement('p')
         para.appendChild(paraText)
-        para.appendChild(paraText2)
+        span = document.createElement('span')
+        span.appendChild(paraText2)
+        span.appendChild(paraText3)
+        para.appendChild(span)
+        para2 = document.createElement('p')
+        para2.appendChild(para2Text)
 
         root = document.createElement('div')
         root.appendChild(head)
         root.appendChild(para)
+        root.appendChild(para2)
 
-      it "should exclude any nodes not within the bounding element.", ->
+      it "should be a no-op if all nodes are within the bounding element.", ->
+        range = new Range.NormalizedRange({
+          commonAncestor: para
+          start: paraText
+          end: paraText2
+        })
+
+        range = range.limit(para)
+        assert.equal(range.commonAncestor, para)
+        assert.equal(range.start, paraText)
+        assert.equal(range.end, paraText2)
+
+      it "should exclude any nodes to the left of the bounding element.", ->
         range = new Range.NormalizedRange({
           commonAncestor: root
           start: headText
@@ -185,6 +207,30 @@ describe 'Range', ->
         assert.equal(range.start, paraText)
         assert.equal(range.end, paraText2)
 
+      it "should exclude any nodes to the right of the bounding element.", ->
+        range = new Range.NormalizedRange({
+          commonAncestor: root
+          start: paraText
+          end: para2Text
+        })
+
+        range = range.limit(para)
+        assert.equal(range.commonAncestor, para)
+        assert.equal(range.start, paraText)
+        assert.equal(range.end, paraText3)
+
+      it "should exclude any nodes on either side of the bounding element.", ->
+        range = new Range.NormalizedRange({
+          commonAncestor: root
+          start: headText
+          end: para2Text
+        })
+
+        range = range.limit(para)
+        assert.equal(range.commonAncestor, para)
+        assert.equal(range.start, paraText)
+        assert.equal(range.end, paraText3)
+
       it "should return null if no nodes fall within the bounds", ->
         otherDiv = document.createElement('div')
         range = new Range.NormalizedRange({

test/spec/util_spec.coffee

@@ -2,11 +2,6 @@ h = require('helpers')
 $ = require('jquery')
 Util = require('../../src/util')
 
-describe 'Util.flatten()', ->
-  it "flattens the contents of an Array", ->
-    flattened = Util.flatten([[1,2], 'lorem ipsum', [{}]])
-    assert.deepEqual(flattened, [1, 2, 'lorem ipsum', {}])
-
 describe 'Util.getTextNodes()', ->
   $fix = null