/** * Add a change handler. * <p> * Called when a FormItem's value is about to change as the result of user interaction. This method fires after the user * performed an action that would change the value of this field, but before the element itself is changed. <P> Returning * false cancels the change. Note that if what you want to do is <b>transform</b> the user's input, for example, * automatically change separator characters to a standard separator character, you should implement {@link * com.smartgwt.client.widgets.form.fields.FormItem#setInputTransformer transformInput} rather than using a combination of * change() and setValue() to accomplish the same thing. Returning false from <code>change</code> is intended for * rejecting input entirely, such as typing invalid characters. <p> Note that if you ask the form for the current value in * this handler, you will get the old value because the change has not yet been committed. The new value is available as a * parameter to this method. * * @param handler the change handler * @return {@link HandlerRegistration} used to remove this handler */ public HandlerRegistration addChangeHandler(com.smartgwt.client.widgets.form.fields.events.ChangeHandler handler) { if(getHandlerCount(com.smartgwt.client.widgets.form.fields.events.ChangeEvent.getType()) == 0) setupChangeEvent(); return doAddHandler(handler, com.smartgwt.client.widgets.form.fields.events.ChangeEvent.getType()); }