GXT 3 ComboBox event handler for changing the field value on selection - Solution
comboInstance.addSelectionHandler(new SelectionHandler (){ @Override public void onSelection(SelectionEvent event) { //fire events if boolean fireEvents is true and value is new comboInstance.setValue(event.getSelectedItem(), true); } }); comboInstance.addValueChangeHandler(new ValueChangeHandler (){ @Override public void onValueChange(ValueChangeEvent event) { //TODO Enter the code or method call here you want carried out once the user makes a selection } }); For more background on the implementation of the event handlers on the ComboBox; http://www.sencha.com/forum/showthread.php?160547-%28Beta%29-ComboBox-issues&p=779655&viewfull=1#post779655