vaadin-framework/documentation/gwt/gwt-styling.asciidoc

---
title: Styling a Widget
order: 8
layout: page
---

[[gwt.styling]]
= Styling a Widget

To make your widget look stylish, you need to style it. There are two basic ways
to define CSS styles for a component: in the widget sources and in a theme. A
default style should be defined in the widget sources, and different themes can
then modify the style.

[[gwt.styling.class]]
== Determining the CSS Class

The CSS class of a widget element is normally defined in the widget class and
set with [methodname]#setStyleName()#. A widget should set the styles for its
sub-elements as it desires.

For example, you could style a composite widget with an overall style and with
separate styles for the sub-widgets as follows:

[source, java]
----
public class MyPickerWidget extends ComplexPanel {
    public static final String CLASSNAME = "mypicker";

    private final TextBox textBox = new TextBox();
    private final PushButton button = new PushButton("...");

    public MyPickerWidget() {
        setElement(Document.get().createDivElement());
        setStylePrimaryName(CLASSNAME);

        textBox.setStylePrimaryName(CLASSNAME + "-field");
        button.setStylePrimaryName(CLASSNAME + "-button");

        add(textBox, getElement());
        add(button, getElement());

        button.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent event) {
              Window.alert("Calendar picker not yet supported!");
            }
        });
    }
}
----

In addition, all Vaadin components get the [literal]#++v-widget++# class. If it
extends an existing Vaadin or GWT widget, it will inherit CSS classes from that
as well.


[[gwt.styling.default]]
== Default Stylesheet

A client-side module, which is normally a widget set, can include stylesheets.
They must be placed under the [filename]#public# folder under the folder of the
widget set, a described in
<<../clientside/clientside-module#clientside.module.stylesheet,"Specifying
a Stylesheet">>.

For example, you could style the widget described above as follows:


----
.mypicker {
	white-space: nowrap;
}

.mypicker-button {
	display: inline-block;
	border: 1px solid black;
	padding: 3px;
	width: 15px;
	text-align: center;
}
----

Notice that some size settings may require more complex handling and calculating
the sizes dynamically.