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---
title: Creating a Custom Widget
order: 5
layout: page
---
[[clientside.widget]]
= Creating a Custom Widget
Creating a new Vaadin component usually begins from making a client-side widget,
which is later integrated with a server-side counterpart to enable server-side
development. In addition, you can also choose to make pure client-side widgets,
a possibility which we also describe later in this section.
[[clientside.widget.simple]]
== A Basic Widget
All widgets extend the [classname]#Widget# class or some of its subclasses. You
can extend any core GWT or supplementary Vaadin widgets. Perhaps typically, an
abstraction such as [classname]#Composite#. The basic GWT widget component
hierarchy is illustrated in <<figure.clientside.widgets>>. Please see the GWT
API documentation for a complete description of the widget classes.
[[figure.clientside.widgets]]
.GWT Widget Base Class Hierarchy
image::img/gwt-widgets-hi.png[]
For example, we could extend the [classname]#Label# widget to display some
custom text.
----
package com.example.myapp.client;
import com.google.gwt.user.client.ui.Label;
public class MyWidget extends Label {
public static final String CLASSNAME = "mywidget";
public MyWidget() {
setStyleName(CLASSNAME);
setText("This is MyWidget");
}
}
----
The above example is largely what the Eclipse plugin generates as a widget stub.
It is a good practice to set a distinctive style class for the widget, to allow
styling it with CSS.
The client-side source code __must__ be contained in a [filename]#client#
package under the package of the descriptor file, which is covered later.
[[clientside.widget.using]]
== Using the Widget
You can use a custom widget just like you would use any widget, possibly
integrating it with a server-side component, or in pure client-side modules such
as the following:
----
public class MyEntryPoint implements EntryPoint {
@Override
public void onModuleLoad() {
// Use the custom widget
final MyWidget mywidget = new MyWidget();
RootPanel.get().add(mywidget);
}
}
----
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