content/editor/CodeMirror-0.8/js/undo.js - shindig - Git at Google

 /**
  * Storage and control for undo information within a CodeMirror
  * editor. 'Why on earth is such a complicated mess required for
  * that?', I hear you ask. The goal, in implementing this, was to make
  * the complexity of storing and reverting undo information depend
  * only on the size of the edited or restored content, not on the size
  * of the whole document. This makes it necessary to use a kind of
  * 'diff' system, which, when applied to a DOM tree, causes some
  * complexity and hackery.
  *
  * In short, the editor 'touches' BR elements as it parses them, and
  * the UndoHistory stores these. When nothing is touched in commitDelay
  * milliseconds, the changes are committed: It goes over all touched
  * nodes, throws out the ones that did not change since last commit or
  * are no longer in the document, and assembles the rest into zero or
  * more 'chains' -- arrays of adjacent lines. Links back to these
  * chains are added to the BR nodes, while the chain that previously
  * spanned these nodes is added to the undo history. Undoing a change
  * means taking such a chain off the undo history, restoring its
  * content (text is saved per line) and linking it back into the
  * document.
  */

 // A history object needs to know about the DOM container holding the
 // document, the maximum amount of undo levels it should store, the
 // delay (of no input) after which it commits a set of changes, and,
 // unfortunately, the 'parent' window -- a window that is not in
 // designMode, and on which setTimeout works in every browser.
 function UndoHistory(container, maxDepth, commitDelay, editor) {
   this.container = container;
   this.maxDepth = maxDepth; this.commitDelay = commitDelay;
   this.editor = editor; this.parent = editor.parent;
   // This line object represents the initial, empty editor.
   var initial = {text: "", from: null, to: null};
   // As the borders between lines are represented by BR elements, the
   // start of the first line and the end of the last one are
   // represented by null. Since you can not store any properties
   // (links to line objects) in null, these properties are used in
   // those cases.
   this.first = initial; this.last = initial;
   // Similarly, a 'historyTouched' property is added to the BR in
   // front of lines that have already been touched, and 'firstTouched'
   // is used for the first line.
   this.firstTouched = false;
   // History is the set of committed changes, touched is the set of
   // nodes touched since the last commit.
   this.history = []; this.redoHistory = []; this.touched = [];
 }

 UndoHistory.prototype = {
   // Schedule a commit (if no other touches come in for commitDelay
   // milliseconds).
   scheduleCommit: function() {
     var self = this;
     this.parent.clearTimeout(this.commitTimeout);
     this.commitTimeout = this.parent.setTimeout(function(){self.tryCommit();}, this.commitDelay);
   },

   // Mark a node as touched. Null is a valid argument.
   touch: function(node) {
     this.setTouched(node);
     this.scheduleCommit();
   },

   // Undo the last change.
   undo: function() {
     // Make sure pending changes have been committed.
     this.commit();

     if (this.history.length) {
       // Take the top diff from the history, apply it, and store its
       // shadow in the redo history.
       var item = this.history.pop();
       this.redoHistory.push(this.updateTo(item, "applyChain"));
       this.notifyEnvironment();
       return this.chainNode(item);
     }
   },

   // Redo the last undone change.
   redo: function() {
     this.commit();
     if (this.redoHistory.length) {
       // The inverse of undo, basically.
       var item = this.redoHistory.pop();
       this.addUndoLevel(this.updateTo(item, "applyChain"));
       this.notifyEnvironment();
       return this.chainNode(item);
     }
   },

   clear: function() {
     this.history = [];
     this.redoHistory = [];
   },

   // Ask for the size of the un/redo histories.
   historySize: function() {
     return {undo: this.history.length, redo: this.redoHistory.length};
   },

   // Push a changeset into the document.
   push: function(from, to, lines) {
     var chain = [];
     for (var i = 0; i < lines.length; i++) {
       var end = (i == lines.length - 1) ? to : this.container.ownerDocument.createElement("BR");
       chain.push({from: from, to: end, text: cleanText(lines[i])});
       from = end;
     }
     this.pushChains([chain], from == null && to == null);
     this.notifyEnvironment();
   },

   pushChains: function(chains, doNotHighlight) {
     this.commit(doNotHighlight);
     this.addUndoLevel(this.updateTo(chains, "applyChain"));
     this.redoHistory = [];
   },

   // Retrieve a DOM node from a chain (for scrolling to it after undo/redo).
   chainNode: function(chains) {
     for (var i = 0; i < chains.length; i++) {
       var start = chains[i][0], node = start && (start.from || start.to);
       if (node) return node;
     }
   },

   // Clear the undo history, make the current document the start
   // position.
   reset: function() {
     this.history = []; this.redoHistory = [];
   },

   textAfter: function(br) {
     return this.after(br).text;
   },

   nodeAfter: function(br) {
     return this.after(br).to;
   },

   nodeBefore: function(br) {
     return this.before(br).from;
   },

   // Commit unless there are pending dirty nodes.
   tryCommit: function() {
     if (!window.UndoHistory) return; // Stop when frame has been unloaded
     if (this.editor.highlightDirty()) this.commit(true);
     else this.scheduleCommit();
   },

   // Check whether the touched nodes hold any changes, if so, commit
   // them.
   commit: function(doNotHighlight) {
     this.parent.clearTimeout(this.commitTimeout);
     // Make sure there are no pending dirty nodes.
     if (!doNotHighlight) this.editor.highlightDirty(true);
     // Build set of chains.
     var chains = this.touchedChains(), self = this;

     if (chains.length) {
       this.addUndoLevel(this.updateTo(chains, "linkChain"));
       this.redoHistory = [];
       this.notifyEnvironment();
     }
   },

   // [ end of public interface ]

   // Update the document with a given set of chains, return its
   // shadow. updateFunc should be "applyChain" or "linkChain". In the
   // second case, the chains are taken to correspond the the current
   // document, and only the state of the line data is updated. In the
   // first case, the content of the chains is also pushed iinto the
   // document.
   updateTo: function(chains, updateFunc) {
     var shadows = [], dirty = [];
     for (var i = 0; i < chains.length; i++) {
       shadows.push(this.shadowChain(chains[i]));
       dirty.push(this[updateFunc](chains[i]));
     }
     if (updateFunc == "applyChain")
       this.notifyDirty(dirty);
     return shadows;
   },

   // Notify the editor that some nodes have changed.
   notifyDirty: function(nodes) {
     forEach(nodes, method(this.editor, "addDirtyNode"))
     this.editor.scheduleHighlight();
   },

   notifyEnvironment: function() {
     if (this.onChange) this.onChange();
     // Used by the line-wrapping line-numbering code.
     if (window.frameElement && window.frameElement.CodeMirror.updateNumbers)
       window.frameElement.CodeMirror.updateNumbers();
   },

   // Link a chain into the DOM nodes (or the first/last links for null
   // nodes).
   linkChain: function(chain) {
     for (var i = 0; i < chain.length; i++) {
       var line = chain[i];
       if (line.from) line.from.historyAfter = line;
       else this.first = line;
       if (line.to) line.to.historyBefore = line;
       else this.last = line;
     }
   },

   // Get the line object after/before a given node.
   after: function(node) {
     return node ? node.historyAfter : this.first;
   },
   before: function(node) {
     return node ? node.historyBefore : this.last;
   },

   // Mark a node as touched if it has not already been marked.
   setTouched: function(node) {
     if (node) {
       if (!node.historyTouched) {
         this.touched.push(node);
         node.historyTouched = true;
       }
     }
     else {
       this.firstTouched = true;
     }
   },

   // Store a new set of undo info, throw away info if there is more of
   // it than allowed.
   addUndoLevel: function(diffs) {
     this.history.push(diffs);
     if (this.history.length > this.maxDepth)
       this.history.shift();
   },

   // Build chains from a set of touched nodes.
   touchedChains: function() {
     var self = this;

     // The temp system is a crummy hack to speed up determining
     // whether a (currently touched) node has a line object associated
     // with it. nullTemp is used to store the object for the first
     // line, other nodes get it stored in their historyTemp property.
     var nullTemp = null;
     function temp(node) {return node ? node.historyTemp : nullTemp;}
     function setTemp(node, line) {
       if (node) node.historyTemp = line;
       else nullTemp = line;
     }

     function buildLine(node) {
       var text = [];
       for (var cur = node ? node.nextSibling : self.container.firstChild;
            cur && !isBR(cur); cur = cur.nextSibling)
         if (cur.currentText) text.push(cur.currentText);
       return {from: node, to: cur, text: cleanText(text.join(""))};
     }

     // Filter out unchanged lines and nodes that are no longer in the
     // document. Build up line objects for remaining nodes.
     var lines = [];
     if (self.firstTouched) self.touched.push(null);
     forEach(self.touched, function(node) {
       if (node && node.parentNode != self.container) return;

       if (node) node.historyTouched = false;
       else self.firstTouched = false;

       var line = buildLine(node), shadow = self.after(node);
       if (!shadow || shadow.text != line.text || shadow.to != line.to) {
         lines.push(line);
         setTemp(node, line);
       }
     });

     // Get the BR element after/before the given node.
     function nextBR(node, dir) {
       var link = dir + "Sibling", search = node[link];
       while (search && !isBR(search))
         search = search[link];
       return search;
     }

     // Assemble line objects into chains by scanning the DOM tree
     // around them.
     var chains = []; self.touched = [];
     forEach(lines, function(line) {
       // Note that this makes the loop skip line objects that have
       // been pulled into chains by lines before them.
       if (!temp(line.from)) return;

       var chain = [], curNode = line.from, safe = true;
       // Put any line objects (referred to by temp info) before this
       // one on the front of the array.
       while (true) {
         var curLine = temp(curNode);
         if (!curLine) {
           if (safe) break;
           else curLine = buildLine(curNode);
         }
         chain.unshift(curLine);
         setTemp(curNode, null);
         if (!curNode) break;
         safe = self.after(curNode);
         curNode = nextBR(curNode, "previous");
       }
       curNode = line.to; safe = self.before(line.from);
       // Add lines after this one at end of array.
       while (true) {
         if (!curNode) break;
         var curLine = temp(curNode);
         if (!curLine) {
           if (safe) break;
           else curLine = buildLine(curNode);
         }
         chain.push(curLine);
         setTemp(curNode, null);
         safe = self.before(curNode);
         curNode = nextBR(curNode, "next");
       }
       chains.push(chain);
     });

     return chains;
   },

   // Find the 'shadow' of a given chain by following the links in the
   // DOM nodes at its start and end.
   shadowChain: function(chain) {
     var shadows = [], next = this.after(chain[0].from), end = chain[chain.length - 1].to;
     while (true) {
       shadows.push(next);
       var nextNode = next.to;
       if (!nextNode || nextNode == end)
         break;
       else
         next = nextNode.historyAfter || this.before(end);
       // (The this.before(end) is a hack -- FF sometimes removes
       // properties from BR nodes, in which case the best we can hope
       // for is to not break.)
     }
     return shadows;
   },

   // Update the DOM tree to contain the lines specified in a given
   // chain, link this chain into the DOM nodes.
   applyChain: function(chain) {
     // Some attempt is made to prevent the cursor from jumping
     // randomly when an undo or redo happens. It still behaves a bit
     // strange sometimes.
     var cursor = select.cursorPos(this.container, false), self = this;

     // Remove all nodes in the DOM tree between from and to (null for
     // start/end of container).
     function removeRange(from, to) {
       var pos = from ? from.nextSibling : self.container.firstChild;
       while (pos != to) {
         var temp = pos.nextSibling;
         removeElement(pos);
         pos = temp;
       }
     }

     var start = chain[0].from, end = chain[chain.length - 1].to;
     // Clear the space where this change has to be made.
     removeRange(start, end);

     // Insert the content specified by the chain into the DOM tree.
     for (var i = 0; i < chain.length; i++) {
       var line = chain[i];
       // The start and end of the space are already correct, but BR
       // tags inside it have to be put back.
       if (i > 0)
         self.container.insertBefore(line.from, end);

       // Add the text.
       var node = makePartSpan(fixSpaces(line.text), this.container.ownerDocument);
       self.container.insertBefore(node, end);
       // See if the cursor was on this line. Put it back, adjusting
       // for changed line length, if it was.
       if (cursor && cursor.node == line.from) {
         var cursordiff = 0;
         var prev = this.after(line.from);
         if (prev && i == chain.length - 1) {
           // Only adjust if the cursor is after the unchanged part of
           // the line.
           for (var match = 0; match < cursor.offset &&
                line.text.charAt(match) == prev.text.charAt(match); match++);
           if (cursor.offset > match)
             cursordiff = line.text.length - prev.text.length;
         }
         select.setCursorPos(this.container, {node: line.from, offset: Math.max(0, cursor.offset + cursordiff)});
       }
       // Cursor was in removed line, this is last new line.
       else if (cursor && (i == chain.length - 1) && cursor.node && cursor.node.parentNode != this.container) {
         select.setCursorPos(this.container, {node: line.from, offset: line.text.length});
       }
     }

     // Anchor the chain in the DOM tree.
     this.linkChain(chain);
     return start;
   }
 };
	/**
	* Storage and control for undo information within a CodeMirror
	* editor. 'Why on earth is such a complicated mess required for
	* that?', I hear you ask. The goal, in implementing this, was to make
	* the complexity of storing and reverting undo information depend
	* only on the size of the edited or restored content, not on the size
	* of the whole document. This makes it necessary to use a kind of
	* 'diff' system, which, when applied to a DOM tree, causes some
	* complexity and hackery.
	*
	* In short, the editor 'touches' BR elements as it parses them, and
	* the UndoHistory stores these. When nothing is touched in commitDelay
	* milliseconds, the changes are committed: It goes over all touched
	* nodes, throws out the ones that did not change since last commit or
	* are no longer in the document, and assembles the rest into zero or
	* more 'chains' -- arrays of adjacent lines. Links back to these
	* chains are added to the BR nodes, while the chain that previously
	* spanned these nodes is added to the undo history. Undoing a change
	* means taking such a chain off the undo history, restoring its
	* content (text is saved per line) and linking it back into the
	* document.
	*/

	// A history object needs to know about the DOM container holding the
	// document, the maximum amount of undo levels it should store, the
	// delay (of no input) after which it commits a set of changes, and,
	// unfortunately, the 'parent' window -- a window that is not in
	// designMode, and on which setTimeout works in every browser.
	function UndoHistory(container, maxDepth, commitDelay, editor) {
	this.container = container;
	this.maxDepth = maxDepth; this.commitDelay = commitDelay;
	this.editor = editor; this.parent = editor.parent;
	// This line object represents the initial, empty editor.
	var initial = {text: "", from: null, to: null};
	// As the borders between lines are represented by BR elements, the
	// start of the first line and the end of the last one are
	// represented by null. Since you can not store any properties
	// (links to line objects) in null, these properties are used in
	// those cases.
	this.first = initial; this.last = initial;
	// Similarly, a 'historyTouched' property is added to the BR in
	// front of lines that have already been touched, and 'firstTouched'
	// is used for the first line.
	this.firstTouched = false;
	// History is the set of committed changes, touched is the set of
	// nodes touched since the last commit.
	this.history = []; this.redoHistory = []; this.touched = [];
	}

	UndoHistory.prototype = {
	// Schedule a commit (if no other touches come in for commitDelay
	// milliseconds).
	scheduleCommit: function() {
	var self = this;
	this.parent.clearTimeout(this.commitTimeout);
	this.commitTimeout = this.parent.setTimeout(function(){self.tryCommit();}, this.commitDelay);
	},

	// Mark a node as touched. Null is a valid argument.
	touch: function(node) {
	this.setTouched(node);
	this.scheduleCommit();
	},

	// Undo the last change.
	undo: function() {
	// Make sure pending changes have been committed.
	this.commit();

	if (this.history.length) {
	// Take the top diff from the history, apply it, and store its
	// shadow in the redo history.
	var item = this.history.pop();
	this.redoHistory.push(this.updateTo(item, "applyChain"));
	this.notifyEnvironment();
	return this.chainNode(item);
	}
	},

	// Redo the last undone change.
	redo: function() {
	this.commit();
	if (this.redoHistory.length) {
	// The inverse of undo, basically.
	var item = this.redoHistory.pop();
	this.addUndoLevel(this.updateTo(item, "applyChain"));
	this.notifyEnvironment();
	return this.chainNode(item);
	}
	},

	clear: function() {
	this.history = [];
	this.redoHistory = [];
	},

	// Ask for the size of the un/redo histories.
	historySize: function() {
	return {undo: this.history.length, redo: this.redoHistory.length};
	},

	// Push a changeset into the document.
	push: function(from, to, lines) {
	var chain = [];
	for (var i = 0; i < lines.length; i++) {
	var end = (i == lines.length - 1) ? to : this.container.ownerDocument.createElement("BR");
	chain.push({from: from, to: end, text: cleanText(lines[i])});
	from = end;
	}
	this.pushChains([chain], from == null && to == null);
	this.notifyEnvironment();
	},

	pushChains: function(chains, doNotHighlight) {
	this.commit(doNotHighlight);
	this.addUndoLevel(this.updateTo(chains, "applyChain"));
	this.redoHistory = [];
	},

	// Retrieve a DOM node from a chain (for scrolling to it after undo/redo).
	chainNode: function(chains) {
	for (var i = 0; i < chains.length; i++) {
	var start = chains[i][0], node = start && (start.from \|\| start.to);
	if (node) return node;
	}
	},

	// Clear the undo history, make the current document the start
	// position.
	reset: function() {
	this.history = []; this.redoHistory = [];
	},

	textAfter: function(br) {
	return this.after(br).text;
	},

	nodeAfter: function(br) {
	return this.after(br).to;
	},

	nodeBefore: function(br) {
	return this.before(br).from;
	},

	// Commit unless there are pending dirty nodes.
	tryCommit: function() {
	if (!window.UndoHistory) return; // Stop when frame has been unloaded
	if (this.editor.highlightDirty()) this.commit(true);
	else this.scheduleCommit();
	},

	// Check whether the touched nodes hold any changes, if so, commit
	// them.
	commit: function(doNotHighlight) {
	this.parent.clearTimeout(this.commitTimeout);
	// Make sure there are no pending dirty nodes.
	if (!doNotHighlight) this.editor.highlightDirty(true);
	// Build set of chains.
	var chains = this.touchedChains(), self = this;

	if (chains.length) {
	this.addUndoLevel(this.updateTo(chains, "linkChain"));
	this.redoHistory = [];
	this.notifyEnvironment();
	}
	},

	// [ end of public interface ]

	// Update the document with a given set of chains, return its
	// shadow. updateFunc should be "applyChain" or "linkChain". In the
	// second case, the chains are taken to correspond the the current
	// document, and only the state of the line data is updated. In the
	// first case, the content of the chains is also pushed iinto the
	// document.
	updateTo: function(chains, updateFunc) {
	var shadows = [], dirty = [];
	for (var i = 0; i < chains.length; i++) {
	shadows.push(this.shadowChain(chains[i]));
	dirty.push(this[updateFunc](chains[i]));
	}
	if (updateFunc == "applyChain")
	this.notifyDirty(dirty);
	return shadows;
	},

	// Notify the editor that some nodes have changed.
	notifyDirty: function(nodes) {
	forEach(nodes, method(this.editor, "addDirtyNode"))
	this.editor.scheduleHighlight();
	},

	notifyEnvironment: function() {
	if (this.onChange) this.onChange();
	// Used by the line-wrapping line-numbering code.
	if (window.frameElement && window.frameElement.CodeMirror.updateNumbers)
	window.frameElement.CodeMirror.updateNumbers();
	},

	// Link a chain into the DOM nodes (or the first/last links for null
	// nodes).
	linkChain: function(chain) {
	for (var i = 0; i < chain.length; i++) {
	var line = chain[i];
	if (line.from) line.from.historyAfter = line;
	else this.first = line;
	if (line.to) line.to.historyBefore = line;
	else this.last = line;
	}
	},

	// Get the line object after/before a given node.
	after: function(node) {
	return node ? node.historyAfter : this.first;
	},
	before: function(node) {
	return node ? node.historyBefore : this.last;
	},

	// Mark a node as touched if it has not already been marked.
	setTouched: function(node) {
	if (node) {
	if (!node.historyTouched) {
	this.touched.push(node);
	node.historyTouched = true;
	}
	}
	else {
	this.firstTouched = true;
	}
	},

	// Store a new set of undo info, throw away info if there is more of
	// it than allowed.
	addUndoLevel: function(diffs) {
	this.history.push(diffs);
	if (this.history.length > this.maxDepth)
	this.history.shift();
	},

	// Build chains from a set of touched nodes.
	touchedChains: function() {
	var self = this;

	// The temp system is a crummy hack to speed up determining
	// whether a (currently touched) node has a line object associated
	// with it. nullTemp is used to store the object for the first
	// line, other nodes get it stored in their historyTemp property.
	var nullTemp = null;
	function temp(node) {return node ? node.historyTemp : nullTemp;}
	function setTemp(node, line) {
	if (node) node.historyTemp = line;
	else nullTemp = line;
	}

	function buildLine(node) {
	var text = [];
	for (var cur = node ? node.nextSibling : self.container.firstChild;
	cur && !isBR(cur); cur = cur.nextSibling)
	if (cur.currentText) text.push(cur.currentText);
	return {from: node, to: cur, text: cleanText(text.join(""))};
	}

	// Filter out unchanged lines and nodes that are no longer in the
	// document. Build up line objects for remaining nodes.
	var lines = [];
	if (self.firstTouched) self.touched.push(null);
	forEach(self.touched, function(node) {
	if (node && node.parentNode != self.container) return;

	if (node) node.historyTouched = false;
	else self.firstTouched = false;

	var line = buildLine(node), shadow = self.after(node);
	if (!shadow \|\| shadow.text != line.text \|\| shadow.to != line.to) {
	lines.push(line);
	setTemp(node, line);
	}
	});

	// Get the BR element after/before the given node.
	function nextBR(node, dir) {
	var link = dir + "Sibling", search = node[link];
	while (search && !isBR(search))
	search = search[link];
	return search;
	}

	// Assemble line objects into chains by scanning the DOM tree
	// around them.
	var chains = []; self.touched = [];
	forEach(lines, function(line) {
	// Note that this makes the loop skip line objects that have
	// been pulled into chains by lines before them.
	if (!temp(line.from)) return;

	var chain = [], curNode = line.from, safe = true;
	// Put any line objects (referred to by temp info) before this
	// one on the front of the array.
	while (true) {
	var curLine = temp(curNode);
	if (!curLine) {
	if (safe) break;
	else curLine = buildLine(curNode);
	}
	chain.unshift(curLine);
	setTemp(curNode, null);
	if (!curNode) break;
	safe = self.after(curNode);
	curNode = nextBR(curNode, "previous");
	}
	curNode = line.to; safe = self.before(line.from);
	// Add lines after this one at end of array.
	while (true) {
	if (!curNode) break;
	var curLine = temp(curNode);
	if (!curLine) {
	if (safe) break;
	else curLine = buildLine(curNode);
	}
	chain.push(curLine);
	setTemp(curNode, null);
	safe = self.before(curNode);
	curNode = nextBR(curNode, "next");
	}
	chains.push(chain);
	});

	return chains;
	},

	// Find the 'shadow' of a given chain by following the links in the
	// DOM nodes at its start and end.
	shadowChain: function(chain) {
	var shadows = [], next = this.after(chain[0].from), end = chain[chain.length - 1].to;
	while (true) {
	shadows.push(next);
	var nextNode = next.to;
	if (!nextNode \|\| nextNode == end)
	break;
	else
	next = nextNode.historyAfter \|\| this.before(end);
	// (The this.before(end) is a hack -- FF sometimes removes
	// properties from BR nodes, in which case the best we can hope
	// for is to not break.)
	}
	return shadows;
	},

	// Update the DOM tree to contain the lines specified in a given
	// chain, link this chain into the DOM nodes.
	applyChain: function(chain) {
	// Some attempt is made to prevent the cursor from jumping
	// randomly when an undo or redo happens. It still behaves a bit
	// strange sometimes.
	var cursor = select.cursorPos(this.container, false), self = this;

	// Remove all nodes in the DOM tree between from and to (null for
	// start/end of container).
	function removeRange(from, to) {
	var pos = from ? from.nextSibling : self.container.firstChild;
	while (pos != to) {
	var temp = pos.nextSibling;
	removeElement(pos);
	pos = temp;
	}
	}

	var start = chain[0].from, end = chain[chain.length - 1].to;
	// Clear the space where this change has to be made.
	removeRange(start, end);

	// Insert the content specified by the chain into the DOM tree.
	for (var i = 0; i < chain.length; i++) {
	var line = chain[i];
	// The start and end of the space are already correct, but BR
	// tags inside it have to be put back.
	if (i > 0)
	self.container.insertBefore(line.from, end);

	// Add the text.
	var node = makePartSpan(fixSpaces(line.text), this.container.ownerDocument);
	self.container.insertBefore(node, end);
	// See if the cursor was on this line. Put it back, adjusting
	// for changed line length, if it was.
	if (cursor && cursor.node == line.from) {
	var cursordiff = 0;
	var prev = this.after(line.from);
	if (prev && i == chain.length - 1) {
	// Only adjust if the cursor is after the unchanged part of
	// the line.
	for (var match = 0; match < cursor.offset &&
	line.text.charAt(match) == prev.text.charAt(match); match++);
	if (cursor.offset > match)
	cursordiff = line.text.length - prev.text.length;
	}
	select.setCursorPos(this.container, {node: line.from, offset: Math.max(0, cursor.offset + cursordiff)});
	}
	// Cursor was in removed line, this is last new line.
	else if (cursor && (i == chain.length - 1) && cursor.node && cursor.node.parentNode != this.container) {
	select.setCursorPos(this.container, {node: line.from, offset: line.text.length});
	}
	}

	// Anchor the chain in the DOM tree.
	this.linkChain(chain);
	return start;
	}
	};