To change the appearance of TriggerFieldCell and ComboBoxCell throughout your app, you'll need to do the following:
- Create an appearance that implements TriggerFieldCellAppearance
- Add a rebind rule to your module XML file
It sounds like you already have the first half done. At this point, add a rebind rule to your module XML file:
This will replace the appearance of all TriggerFieldCells and their subclasses.
<when-type-is class="com.sencha.gxt.cell.core.client.form.TriggerFieldCell.TriggerFieldAppearance" />
To replace the appearance of a single instance of a ComboBoxCell, you will need to subclass ComboBoxCell and set the value of the appearance field inherited from TriggerFieldCell. This can probably be done easily enough using an anonymous inner class.
That being said, I've filed an API review ticket against the team to see whether ComboBoxCell should indeed have a constructor that accepts an appearance. This review will give us a chance to take a moment to ensure that the current design is what we intended. I'll post a reply here if we decide to make any changes.