[Bug] Significant performance issue on Chrome with DateItem in an editable ListGrid

[Fox]

Hi there,

We are currently working with the latest released version (4.0) of SmartGWT and have had the following issue reported by our customers. A full decoupled test case can be found below the explanation of the issue.

Situation
When editing a value in an editable ListGrid on a ListGridField that is of ListGridFieldType.DATE, upon pressing 'ok' on the pop-up date chooser there is a significant freeze on Chrome. The length of the freeze is directly proportional to the number of records currently in the grid. This is not an issue in Internet Explorer 9 or Firefox. This issue also occurs if you are providing DateItem instances via a ListGridEditorCustomizer, so the assumption would be it is a browser specific issue with the DateItem implementation rather than with ListGrid.

Test Case

import java.util.HashSet;

import com.smartgwt.client.types.ListGridFieldType;
import com.smartgwt.client.widgets.form.fields.DateItem;
import com.smartgwt.client.widgets.grid.ListGrid;
import com.smartgwt.client.widgets.grid.ListGridField;
import com.smartgwt.client.widgets.grid.ListGridRecord;

/**
 * Demonstrating the severe performance issues involved in loading an editable grid
 * relying on {@link DateItem} instances to handle cell editing in Chrome.
 * 
 * @author Liam
 *
 */
public class DateItemPerformance extends ListGrid {

   public DateItemPerformance() {
      super();
      setSize("100%", "100%");
      setCanEdit(true);
      initFields();
      setSpoofData();
   }
   
   protected void initFields() {
      ListGridField nameField = new ListGridField("name", "Name");
      nameField.setCanEdit(false);
      
      ListGridField dateField = new ListGridField("date", "Date");
      dateField.setType(ListGridFieldType.DATE);
      
      setFields(nameField, dateField);
   }
   
   protected void setSpoofData() {
      HashSet<ListGridRecord> records = new HashSet<ListGridRecord>();
      
      for (int i = 0; i < 100; i++) {
         ListGridRecord testRecord = new ListGridRecord();
         testRecord.setAttribute("name", "Test Record " + i);
         testRecord.setAttribute("date", System.currentTimeMillis());
         records.add(testRecord);
      }
      
      setData(records.toArray(new ListGridRecord[0]));
   }
}

[Isomorphic]

We've seen a similar report here which suggests a native bug in Chrome. You can use Chrome's developer tools to confirm that, during the odd delay, there's no JavaScript actually running; native code within the browser is running.

Currently, we don't plan to try to find a workaround (which would really involve searching blindly for a possible cause) and will wait for the problem to be fixed in Chrome itself.