Creating a TextField only for digits

There are two ways to get valid input from the user using a textbox. Validate it after confirmation on the server side or during writing text on the client side. In this recipe, we will create a custom text field that validates the input during pressing keys. It will allow only digit keys.

How to do it...

Carry out the following steps to create a text field that accepts only digit keystrokes from zero to nine:

1. We create a Vaadin project with the main UI class named Demo as follows:

   public class Demo extends UI {…}

2. We open the context menu on the project and choose New | Other…. A wizard opens. In the wizard, we select Vaadin Widget and click on the Next button.

3. On the next page we set some properties. Package will be com.packtpub.vaadin.widget. The name of our new component will be IntegerTextField and we set the superclass to com.vaadin.ui.TextField. After filling the properties, we click on the Finish button.

4. Eclipse will generate a skeleton of a simple custom...