JEP 205: New Controls for JavaFX

Summary

Add a spinner control, a formatted-text control, and a standard set of alert dialogs to JavaFX.

Motivation

JavaFX needs to be complete and comprehensive, otherwise adoption is compromised. A spinner is a standard UI control that appears in many different applications. Business applications need formatted-text controls to validate input. Most application need to warn the user occasionally, or request "ok/cancel" confirmations. In order to be complete and compelling, comprehensive UI applications require this functionality.

Description

Adding new controls to JavaFX follows a standard implementation template. Each JavaFX control consists of the control itself and the public API it provides, a behavior class that handles input events and similar functionality, and a skin class for the final presentation. The skin class is configured using CSS, and standard CSS classes are defined so that the control can be manipulated from a CSS file.

A spinner is a well-known UI control which can be thought of as a kind of combo box. Using a spinner, a single value can be selected from a list of values. Values are often chosen using up- and down-arrow affordances. Spinner controls typically display and manipulate numeric values but can also display strings which often represent the elements of an enumeration.

A filtered-text control is often (but not necessarily) implemented as subclass of a single-line text field. This allows the editing features of the control to be inherited while adding API to restrict and format the characters that can be displayed and typed. Filtered-text provides the basis for complex formatting. For example, it is possible to implemented formatting masks such as (###) ###-#### that might specify a phone number.

Standard alert dialogs are common on the desktop and provide a well-understood interaction pattern. Alerts notify the user that something has happened. Typically, they consist of an icon that indicates the severity of the notification (i.e., warning, error, or information). On some platforms alerts are implemented as top-level windows, modal to their parent; on other platforms they are attached to the parent window frame and slide in when requested.

Testing

JavaFX has standard set of unit test for testing controls. There are also full-scale examples such as Ensemble that provide sample code for each control. SceneBuilder is a large JavaFX application that allows programmers to drag and drop controls from a palette. The controls described here will be added to the existing frameworks and will be tested using the standard JavaFX SQE process.