TwinTrigger Question

In Ext JS 3.x, I used a 'twin trigger' combo box to implement a search field. The box displayed one or two triggers at a time, depending on whether there was data entered into the text field. I know how to create a twin trigger field in Ext JS 4, I just need to specify additional trigger classes, what I'm not clear on how to do is to selectively hide and show just one of the triggers. For example, when the field is first visible, I want the first trigger to be hidden (x-form-clear-trigger), but to show the second trigger (x-form-search-trigger). When the user enters text in the field I want to show the first trigger. When the user clicks the first trigger I want to clear the field and have the trigger disappear. I can capture all the events I need to make this work, I just don't know how to selectively turn a trigger on and off and have the layout look correct.



Any help would be appreciated.



Thanks.



Jim