diff --git a/src/timeline/Timeline.js b/src/timeline/Timeline.js
index 82e69e92..33b0571d 100644
--- a/src/timeline/Timeline.js
+++ b/src/timeline/Timeline.js
@@ -355,6 +355,7 @@ Timeline.prototype.setGroups = function(groups) {
 
     // create new GroupSet
     this.groupSet = new GroupSet(this.labelPanel, options);
+    this.groupSet.on('change', this.rootPanel.repaint.bind(this.rootPanel, 'changes'));
     this.groupSet.setRange(this.range);
     this.groupSet.setItems(this.itemsData);
     this.groupSet.setGroups(this.groupsData);
@@ -373,6 +374,7 @@ Timeline.prototype.setGroups = function(groups) {
     this.itemSet = new ItemSet(options);
     this.itemSet.setRange(this.range);
     this.itemSet.setItems(this.itemsData);
+    this.itemSet.on('change', me.rootPanel.repaint.bind(me.rootPanel));
     this.contentPanel.appendChild(this.itemSet);
   }
 };
diff --git a/src/timeline/component/Component.js b/src/timeline/component/Component.js
index 412b76cd..b8737264 100644
--- a/src/timeline/component/Component.js
+++ b/src/timeline/component/Component.js
@@ -14,6 +14,9 @@ function Component () {
   this.height = 0;
 }
 
+// Turn the Component into an event emitter
+Emitter(Component.prototype);
+
 /**
  * Set parameters for the frame. Parameters will be merged in current parameter
  * set.
@@ -72,9 +75,11 @@ Component.prototype.getFrame = function getFrame() {
 
 /**
  * Repaint the component
+ * @return {boolean} Returns true if the component is resized
  */
 Component.prototype.repaint = function repaint() {
   // should be implemented by the component
+  return false;
 };
 
 /**
@@ -104,3 +109,18 @@ Component.prototype.show = function show() {
     return false;
   }
 };
+
+/**
+ * Test whether the component is resized since the last time _isResized() was
+ * called.
+ * @return {Boolean} Returns true if the component is resized
+ * @private
+ */
+Component.prototype._isResized = function _isResized() {
+  var resized = (this._previousWidth !== this.width || this._previousHeight !== this.height);
+
+  this._previousWidth = this.width;
+  this._previousHeight = this.height;
+
+  return resized;
+};
diff --git a/src/timeline/component/CurrentTime.js b/src/timeline/component/CurrentTime.js
index a39e3330..d141afeb 100644
--- a/src/timeline/component/CurrentTime.js
+++ b/src/timeline/component/CurrentTime.js
@@ -32,7 +32,7 @@ CurrentTime.prototype.getContainer = function () {
 
 /**
  * Repaint the component
- * @return {Boolean} changed
+ * @return {boolean} Returns true if the component is resized
  */
 CurrentTime.prototype.repaint = function () {
   var bar = this.frame,
diff --git a/src/timeline/component/CustomTime.js b/src/timeline/component/CustomTime.js
index 09a55575..f75fec73 100644
--- a/src/timeline/component/CustomTime.js
+++ b/src/timeline/component/CustomTime.js
@@ -20,8 +20,6 @@ function CustomTime (options) {
 
 CustomTime.prototype = new Component();
 
-Emitter(CustomTime.prototype);
-
 CustomTime.prototype.setOptions = Component.prototype.setOptions;
 
 /**
@@ -35,7 +33,7 @@ CustomTime.prototype.getContainer = function () {
 
 /**
  * Repaint the component
- * @return {Boolean} changed
+ * @return {boolean} Returns true if the component is resized
  */
 CustomTime.prototype.repaint = function () {
   var bar = this.frame,
diff --git a/src/timeline/component/Group.js b/src/timeline/component/Group.js
index c166d4ce..78a3d2ec 100644
--- a/src/timeline/component/Group.js
+++ b/src/timeline/component/Group.js
@@ -63,6 +63,7 @@ Group.prototype.setItems = function setItems(items) {
 
     var itemSetOptions = Object.create(this.options);
     this.itemSet = new ItemSet(itemSetOptions);
+    this.itemSet.on('change', this.emit.bind(this, 'change')); // propagate change event
     if (this.range) this.itemSet.setRange(this.range);
     this.contentPanel.appendChild(this.itemSet);
 
@@ -113,10 +114,10 @@ Group.prototype.getSelection = function getSelection() {
 
 /**
  * Repaint the group
- * @return {Boolean} changed
+ * @return {boolean} Returns true if the component is resized
  */
 Group.prototype.repaint = function repaint() {
-  this.itemSet.repaint();
+  var resized = this.itemSet.repaint();
 
   this.top    = this.itemSet ? this.itemSet.top : 0;
   this.height = this.itemSet ? this.itemSet.height : 0;
@@ -133,4 +134,6 @@ Group.prototype.repaint = function repaint() {
     this.props.label.width = 0;
     this.props.label.height = 0;
   }
+
+  return resized;
 };
diff --git a/src/timeline/component/GroupSet.js b/src/timeline/component/GroupSet.js
index d3a90d1e..60594c38 100644
--- a/src/timeline/component/GroupSet.js
+++ b/src/timeline/component/GroupSet.js
@@ -79,6 +79,7 @@ GroupSet.prototype.setItems = function setItems(items) {
   for (var id in this.groups) {
     if (this.groups.hasOwnProperty(id)) {
       var group = this.groups[id];
+      // TODO: every group will emit a change event, causing a lot of unnecessary repaints. improve this.
       group.setItems(items);
     }
   }
@@ -147,6 +148,8 @@ GroupSet.prototype.setGroups = function setGroups(groups) {
     ids = this.groupsData.getIds();
     this._onAdd(ids);
   }
+
+  this.emit('change');
 };
 
 /**
@@ -244,6 +247,8 @@ GroupSet.prototype.repaint = function repaint() {
       groups = this.groups,
       groupsData = this.groupsData;
 
+  this.queue = {}; // clear old queue, we have a copy here
+
   // show/hide added/changed/removed groups
   var ids = Object.keys(queue);
   if (ids.length) {
@@ -262,15 +267,18 @@ GroupSet.prototype.repaint = function repaint() {
             });
 
             group = new Group(me, me.labelPanel, id, groupOptions);
+            group.on('change', me.emit.bind(me, 'change')); // propagate change event
             group.setRange(me.range);
             group.setItems(me.itemsData); // attach items data
             groups[id] = group;
+
+            // Note: it is important to add the binding after group.setItems
+            // is executed, because that will start an infinite loop
+            // as this call will already triger a
           }
 
           // TODO: update group data
           group.data = groupsData.get(id);
-
-          delete queue[id];
           break;
 
         case 'remove':
@@ -279,8 +287,6 @@ GroupSet.prototype.repaint = function repaint() {
             delete groups[id];
           }
 
-          // update lists
-          delete queue[id];
           break;
 
         default:
@@ -306,7 +312,7 @@ GroupSet.prototype.repaint = function repaint() {
 
   // repaint all groups in order
   this.groupIds.forEach(function (id) {
-    group = groups[id].repaint();
+    groups[id].repaint();
   });
 
   // reposition the labels and calculate the maximum label width
@@ -479,6 +485,8 @@ GroupSet.prototype._toQueue = function _toQueue(ids, action) {
   ids.forEach(function (id) {
     queue[id] = action;
   });
+
+  this.emit('change');
 };
 
 /**
diff --git a/src/timeline/component/ItemSet.js b/src/timeline/component/ItemSet.js
index bf37050a..74881565 100644
--- a/src/timeline/component/ItemSet.js
+++ b/src/timeline/component/ItemSet.js
@@ -45,6 +45,7 @@ function ItemSet(options) {
   this.selection = [];  // list with the ids of all selected nodes
   this.queue = {};      // queue with id/actions: 'add', 'update', 'delete'
   this.stack = new Stack(Object.create(this.options));
+  this.stackDirty = true; // if true, all items will be restacked on next repaint
   this.conversion = null;
 
   this.touchParams = {}; // stores properties while dragging
@@ -164,11 +165,9 @@ ItemSet.prototype._deselect = function _deselect(id) {
 
 /**
  * Repaint the component
- * @param {boolean} [force=false] If true, all items will be re-stacked.
- *                                If false (default), only items having a
- *                                top===null will be re-stacked
+ * @return {boolean} Returns true if the component is resized
  */
-ItemSet.prototype.repaint = function repaint(force) {
+ItemSet.prototype.repaint = function repaint() {
   var asSize = util.option.asSize,
       asString = util.option.asString,
       options = this.options,
@@ -225,7 +224,6 @@ ItemSet.prototype.repaint = function repaint(force) {
   var visibleInterval = this.range.end - this.range.start;
   var zoomed = (this.visibleInterval != visibleInterval);
   this.visibleInterval = visibleInterval;
-  force = force || zoomed;
 
   /* TODO: implement+fix smarter way to update visible items
   // find the first visible item
@@ -293,7 +291,9 @@ ItemSet.prototype.repaint = function repaint(force) {
 
   // reposition visible items vertically
   //this.stack.order(this.visibleItems); // TODO: solve ordering issue
+  var force = this.stackDirty || zoomed; // force re-stacking of all items if true
   this.stack.stack(this.visibleItems, force);
+  this.stackDirty = false;
   for (var i = 0, ii = this.visibleItems.length; i < ii; i++) {
     this.visibleItems[i].repositionY();
   }
@@ -340,7 +340,7 @@ ItemSet.prototype.repaint = function repaint(force) {
   this.dom.axis.style.top    = (orientation == 'top') ? '0' : '';
   this.dom.axis.style.bottom = (orientation == 'top') ? '' : '0';
 
-  return false;
+  return this._isResized();
 };
 
 /**
@@ -505,7 +505,9 @@ ItemSet.prototype._onUpdate = function _onUpdate(ids) {
   });
 
   this._order();
-  this.repaint();
+
+  this.stackDirty = true; // force re-stacking of all items next repaint
+  this.emit('change');
 };
 
 /**
@@ -534,9 +536,9 @@ ItemSet.prototype._onRemove = function _onRemove(ids) {
   });
 
   if (count) {
-    var force = true; // force restacking of all items
     this._order();
-    this.repaint(force);
+    this.stackDirty = true; // force re-stacking of all items next repaint
+    this.emit('change');
   }
 };
 
@@ -682,8 +684,8 @@ ItemSet.prototype._onDrag = function (event) {
 
     // TODO: implement dragging from one group to another
 
-    var force = true; // force restacking of all items
-    this.repaint(force); // TODO: must repaint the rootPanel instead
+    this.stackDirty = true; // force re-stacking of all items next repaint
+    this.emit('change');
 
     event.stopPropagation();
   }
@@ -726,8 +728,9 @@ ItemSet.prototype._onDragEnd = function (event) {
             // restore original values
             if ('start' in props) props.item.data.start = props.start;
             if ('end' in props)   props.item.data.end   = props.end;
-            var force = true; // force restacking of all items
-            me.repaint(force);
+
+            this.stackDirty = true; // force re-stacking of all items next repaint
+            this.emit('change');
           }
         });
       }
diff --git a/src/timeline/component/Panel.js b/src/timeline/component/Panel.js
index 12f2cf27..d7c02bb2 100644
--- a/src/timeline/component/Panel.js
+++ b/src/timeline/component/Panel.js
@@ -75,6 +75,7 @@ Panel.prototype.removeChild = function (child) {
 
 /**
  * Repaint the component
+ * @return {boolean} Returns true if the component was resized since previous repaint
  */
 Panel.prototype.repaint = function () {
   var asString = util.option.asString,
@@ -97,20 +98,25 @@ Panel.prototype.repaint = function () {
   frame.className = 'vpanel' + (options.className ? (' ' + asString(options.className)) : '');
 
   // repaint the child components
-  this._repaintChilds();
+  var childsResized = this._repaintChilds();
 
   // update frame size
   this._updateSize();
+
+  return this._isResized() || childsResized;
 };
 
 /**
  * Repaint all childs of the panel
+ * @return {boolean} Returns true if the component is resized
  * @private
  */
 Panel.prototype._repaintChilds = function () {
+  var resized = false;
   for (var i = 0, ii = this.childs.length; i < ii; i++) {
-    this.childs[i].repaint();
+    resized = this.childs[i].repaint() || resized;
   }
+  return resized;
 };
 
 /**
diff --git a/src/timeline/component/RootPanel.js b/src/timeline/component/RootPanel.js
index 41ae7bfc..d8f61901 100644
--- a/src/timeline/component/RootPanel.js
+++ b/src/timeline/component/RootPanel.js
@@ -18,9 +18,6 @@ function RootPanel(container, options) {
 
 RootPanel.prototype = new Panel();
 
-// turn RootPanel into an event emitter
-Emitter(RootPanel.prototype);
-
 /**
  * Set options. Will extend the current options.
  * @param {Object} [options]    Available parameters:
@@ -48,7 +45,7 @@ RootPanel.prototype.setOptions = function (options) {
 };
 
 /**
- * Repaint the component
+ * Repaint the root panel
  */
 RootPanel.prototype.repaint = function () {
   // create frame
@@ -87,11 +84,18 @@ RootPanel.prototype.repaint = function () {
   this.frame.className = className;
 
   // repaint the child components
-  this._repaintChilds();
+  var childsResized = this._repaintChilds();
 
   // update frame size
   this.frame.style.maxHeight = util.option.asSize(this.options.maxHeight, '');
   this._updateSize();
+
+  // if the root panel or any of its childs is resized, repaint again,
+  // as other components may need to be resized accordingly
+  var resized = this._isResized() || childsResized;
+  if (resized) {
+    setTimeout(this.repaint.bind(this), 0);
+  }
 };
 
 /**
diff --git a/src/timeline/component/TimeAxis.js b/src/timeline/component/TimeAxis.js
index d4cf9045..17df2f37 100644
--- a/src/timeline/component/TimeAxis.js
+++ b/src/timeline/component/TimeAxis.js
@@ -59,6 +59,7 @@ TimeAxis.prototype.setRange = function (range) {
 
 /**
  * Repaint the component
+ * @return {boolean} Returns true if the component is resized
  */
 TimeAxis.prototype.repaint = function () {
   var asSize = util.option.asSize,
@@ -137,6 +138,8 @@ TimeAxis.prototype.repaint = function () {
       parent.appendChild(frame)
     }
   }
+
+  return this._isResized();
 };
 
 /**