Add onUpdate option (experimental, not documented yet)

Author: marijnh

lib/codemirror.js

@@ -790,7 +790,7 @@ var CodeMirror = (function() {
     // Uses a set of changes plus the current scroll position to
     // determine which DOM updates have to be made, and makes the
     // updates.
-    function updateDisplay(changes) {
+    function updateDisplay(changes, suppressCallback) {
       if (!scroller.clientWidth) {
         showingFrom = showingTo = displayOffset = 0;
         return;
@@ -865,6 +865,8 @@ var CodeMirror = (function() {
       gutter.style.display = gutterDisplay;
       if (different || gutterDirty) updateGutter();
       updateCursor();
+      if (!suppressCallback && options.onUpdate) options.onUpdate(instance);
+      return true;
     }
 
     function computeIntact(intact, changes) {
@@ -1650,9 +1652,9 @@ var CodeMirror = (function() {
       changes = []; selectionChanged = false; callbacks = [];
     }
     function endOperation() {
-      var reScroll = false;
+      var reScroll = false, updated;
       if (selectionChanged) reScroll = !scrollCursorIntoView();
-      if (changes.length) updateDisplay(changes);
+      if (changes.length) updated = updateDisplay(changes, true);
       else {
         if (selectionChanged) updateCursor();
         if (gutterDirty) updateGutter();
@@ -1675,6 +1677,7 @@ var CodeMirror = (function() {
       if (tc && options.onChange && instance)
         options.onChange(instance, tc);
       for (var i = 0; i < cbs.length; ++i) cbs[i](instance);
+      if (updated && options.onUpdate) options.onUpdate(instance);
     }
     var nestedOperation = 0;
     function operation(f) {