//Variable selection changed
    //Add or remove data row
    private void CheckedItemsChanged(object sender, CollectionItemsChangedEventArgs<IndexedItem<StringValue>> checkedItems) {

      foreach (IndexedItem<StringValue> item in checkedItems.Items) {
        string variableName = item.Value.Value;

        //variable is displayed -> remove
        if (VariableIsDisplayed(variableName)) {
          dataTable.Rows.Remove(variableName);
          dataTable.SelectedRows.Remove(variableName);
          dataTablePerVariable.Remove(dataTablePerVariable.Find(x => (x.Name == variableName)));
          //variable isnt't displayed -> add
        } else {
          DataRow row = GetDataRow(variableName);
          DataRow selectedRow = GetSelectedDataRow(variableName);
          dataTable.Rows.Add(row);

          PreprocessingDataTable pdt = new PreprocessingDataTable(variableName);
          pdt.Rows.Add(row);
          dataTablePerVariable.Add(pdt);

          //update selection
          if (selectedRow != null) {
            dataTable.SelectedRows.Add(selectedRow);
            pdt.SelectedRows.Add(selectedRow);
          }
        }
      }

      // update chart if not in all in one mode
      if (Content != null && !Content.AllInOneMode)
        GenerateChart();

    }

 private void JobsOnChanged(object sender, CollectionItemsChangedEventArgs<IndexedItem<Job>> e) {
   foreach (var job in e.OldItems)
     job.Value.TasksChanged -= JobOnTasksChanged;
   foreach (var job in e.Items)
     job.Value.TasksChanged += JobOnTasksChanged;
   FillGanttChart();
 }

 private void Content_ItemsAdded(object sender, CollectionItemsChangedEventArgs<IRun> e) {
   if (suppressUpdates) return;
   if (InvokeRequired) {
     Invoke(new CollectionItemsChangedEventHandler<IRun>(Content_ItemsAdded), sender, e);
     return;
   }
   UpdateDataTableComboBox(); // will trigger AddRuns
 }

 private void Content_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<IRun> e) {
   if (suppressUpdates) return;
   if (InvokeRequired) {
     Invoke(new CollectionItemsChangedEventHandler<IRun>(Content_ItemsRemoved), sender, e);
     return;
   }
   UpdateDataTableComboBox();
   RemoveRuns(e.Items);
 }

 private void Runs_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<IRun> e) {
   if (Optimizer != null) Optimizer.Runs.RemoveRange(e.Items);
 }

 private void Runs_CollectionReset(object sender, CollectionItemsChangedEventArgs<IRun> e) {
   if (Optimizer != null) Optimizer.Runs.RemoveRange(e.OldItems);
   foreach (IRun run in e.Items) {
     IItem item;
     run.Results.TryGetValue("Execution Time", out item);
     TimeSpanValue executionTime = item as TimeSpanValue;
     if (executionTime != null) ExecutionTime += executionTime.Value;
   }
 }

 private void Runs_ItemsAdded(object sender, CollectionItemsChangedEventArgs<IRun> e) {
   foreach (IRun run in e.Items) {
     IItem item;
     run.Results.TryGetValue("Execution Time", out item);
     TimeSpanValue executionTime = item as TimeSpanValue;
     if (executionTime != null) {
       if (Optimizer.ExecutionState == ExecutionState.Started)
         runsExecutionTime += executionTime.Value;
       else
         ExecutionTime += executionTime.Value;
     }
   }
 }

 private void Content_CollectionReset(object sender, CollectionItemsChangedEventArgs<IRun> e) {
   DeregisterRunEvents(e.OldItems);
   RegisterRunEvents(e.Items);
   if (!suppressUpdates) UpdateAll();
 }

 private void Optimizer_Runs_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<IRun> e) {
   Runs.RemoveRange(e.Items);
 }

 private void convertersList_Changed(object sender, CollectionItemsChangedEventArgs<IndexedItem<IItemToSolutionMessageConverter>> e) {
   BuildDispatcher();
 }

    private void rows_CollectionReset(object sender, CollectionItemsChangedEventArgs<DataRow> e) {
      foreach (DataRow row in e.OldItems)
        this.DeregisterRowEvents(row);
      foreach (DataRow row in e.Items)
        this.RegisterRowEvents(row);

      if (e.OldItems.Count() != e.Items.Count())
        this.OnColumnsChanged();
      this.OnColumnNamesChanged();
      this.OnReset();
    }

 private void AnalyzerOperators_ItemsAdded(object sender, CollectionItemsChangedEventArgs<IndexedItem<IAnalyzer>> e) {
   foreach (var analyzer in e.Items) {
     foreach (var parameter in analyzer.Value.Parameters.OfType<IScopeTreeLookupParameter>()) {
       parameter.Depth = 2;
     }
   }
 }

 private void Runs_CollectionReset(object sender, CollectionItemsChangedEventArgs<IRun> e) {
   runsCounter = runs.Count;
 }

 private void Content_CollectionReset(object sender, CollectionItemsChangedEventArgs<IRun> e) {
   if (suppressUpdates) return;
   if (InvokeRequired) Invoke((Action<object, CollectionItemsChangedEventArgs<IRun>>)Content_CollectionReset, sender, e);
   else {
     UpdateComboboxes();
     RebuildDataTableAsync();
   }
 }

 private void ConnectionInfos_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<IConnectionInfo> e) {
   foreach (IConnectionInfo connectionInfo in e.Items)
     this.RemoveConnectionInfo(connectionInfo);
 }

 private void HiveTasks_CollectionReset(object sender, CollectionItemsChangedEventArgs<HiveTask> e) {
   if (InvokeRequired)
     Invoke(new CollectionItemsChangedEventHandler<HiveTask>(HiveTasks_CollectionReset), sender, e);
   else {
     SetEnabledStateOfControls();
   }
 }

 private void SelectedRows_ItemsReplaced(object sender, CollectionItemsChangedEventArgs<DataRow> e) {
   if (InvokeRequired)
     Invoke(new CollectionItemsChangedEventHandler<DataRow>(Rows_ItemsReplaced), sender, e);
   else {
     RemoveSelectedDataRows(e.OldItems);
     AddSelectedDataRows(e.Items);
   }
 }

 private void Values_CollectionReset(object sender, CollectionItemsChangedEventArgs<IndexedItem<double>> e) {
   this.OnReset();
 }

 private void Content_ItemsAdded(object sender, CollectionItemsChangedEventArgs<IRun> e) {
   RegisterRunEvents(e.Items);
   if (!suppressUpdates) UpdateComboBoxes();
 }

 private void Rows_ItemsAdded(object sender, CollectionItemsChangedEventArgs<DataRow> e) {
   if (InvokeRequired)
     Invoke(new CollectionItemsChangedEventHandler<DataRow>(Rows_ItemsAdded), sender, e);
   else {
     AddDataRows(e.Items);
   }
 }