Arithmetic field extension
FieldArithmetics is an extension add-on that evaluates simple calculations on the client-side before the field value is sent to the server side. in addition to the basic operations: +, -, /, *. (plus, minus, division, multiplication) it also has limited support for ^ (power operator), parenthesis and locale (thousand and decimal separators) auto guessing.
Field types it can extend are: TextField, TextArea and various Stepper add-on's fields.
This add-on uses a custom EventDispatcher that must be registered to the GWT event system before the Vaadin debug windows is opened or the extension will not work when the debug window is open. Because of this, make sure the add-on widget set must be inherited before the Vaadin DefaultWidgetset.
E.g. edit your gwt.xml to look something like this:
<inherits name="org.vaadin.addons.jonni.fieldarithmetics.WidgetSet" />
<inherits name="com.vaadin.DefaultWidgetSet" />