Widget Types

While Widget is pretty straightforward as far as the interface is concerned, there are several intermediate implementations to make it easier to define the widget.

Class	Description
`AbstractWidget`	Implements `getProperties()`, `getSources()`, and `titleProperty()`
`SingleTypeWidget<T>`	Adds properties for widgets that only support a single data type
`AnnotatedWidget`	Adds default implementations for `getName()` and `getDataTypes()` for widgets with a `@Description` annotation
`SingleSourceWidget`	For widgets with only a single source (by default, widgets support multiple sources)
`SimpleAnnotatedWidget<T>`	Combines `SingleTypeWidget<T>`, `AnnotatedWidget`, and `SingleSourceWidget`

There are also two annotations to help define widgets:

Name	Description
`@ParametrizedController`	Allows widgets to be FXML controllers for JavaFX views defined via FXML
`@Description`	Lets the name and supported data types be defined in a single line

AbstractWidget

This class implements getProperties(), getSources(), addSource(), and titleProperty(). It also defines a method exportProperties(Property<?>...) method so subclasses can easy add custom widget properties, or properties for the JavaFX components in the widget. Most of the widgets in the base plugin use this.

SingleTypeWidget

A type of widget that only supports a single data type. This interface is parametrized and has methods for setting or getting the data, as well as a method for getting the (single) data type of the widget.

AnnotatedWidget

This interface implements getDataTypes() and getName() by looking at the @Description annotation on the implementing class. This requires the annotation to be present, or the widget will not be able to be loaded and used.

// No @Description annotation!
public class WrongImplementation implements AnnotatedWidget {
  // ...
}

@Description(name = ..., dataTypes = ...)
public class CorrectImplementation implements AnnotatedWidget {
  // ...
}

SingleSourceWidget

A type of widget that only uses a single source.

SimpleAnnotatedWidget

A combination of SingleTypeWidget<T>, AnnotatedWidget, and SingleSourceWidget. Most widgets in the base plugin extend from this class. This also has a protected field called dataOrDefault that lets subclasses use a default data value if the widget doesn’t have a source, or if the source is providing null.

@ParametrizedController

This annotation can be placed on a widget class to let shuffleboard know that it’s an FXML controller for a JavaFX view defined via FXML. The annotation takes a single parameter that defines where the FXML file in relation to the class on which it is placed. For example, a widget in the directory src/main/java/com/acme that is an FXML controller for a FXML file in src/main/resources/com/acme can use the annotation as either

@ParametrizedController("MyWidget.fxml")

or as

@ParametrizedController("/com/acme/MyWidget.fxml")

@Description

This allows widgets to have their name and supported data types defined by a single annotation, when used alongside AnnotatedWidget.