title: GWT - Handler for lost focus on widgets in flextable
body: <p>I'm currently coding in GWT, for the first time, and it's going well so far. I'm having a problem with EventHandlers though. I have a FlexTable which has 2 columns, 1 for labels, and 1 for TextBox/ListBox fields. When a user insert datas into the textbox  and leaves the textBox again, I want to write the contents to an object. That is quite easy, But, I can't figure out how to make the ActionHandler for it? It works fine with an OnClick event, but I want something like on focus from the FocusListener, but it's deprecated...! So what I need in a GWT, onLostFocus EventHandler of some type. </p>