net.sf.jguiraffe.gui.builder.window.ctrl

Class FormValidationTriggerFocus

java.lang.Object

net.sf.jguiraffe.gui.builder.window.ctrl.FormValidationTriggerFocus

All Implemented Interfaces:

EventListener, FormEventListener, FormFocusListener, FormValidationTrigger

public class FormValidationTriggerFocus
extends Object
implements FormValidationTrigger, FormFocusListener

A specialized FormValidationTrigger implementation that triggers a validation operation whenever the user leaves an input field.

This validation trigger implementation registers itself as focus listener on all input components of the form to monitor. Whenever it receives a focus lost event, it triggers a validation operation.

This way the user gets fast feedback about invalid input. Invalid fields can be marked while editing the form, and fresh validation error messages can be displayed. Because validation happens only if the user switches to another input field, the number of validations (a UI updates related to validation) is limited. So this FormValidationTrigger is a good compromise between real-time validation feedback and annoying the user with permanent validation messages.

Implementation note: This class is not thread-safe. An instance should be associated with a single FormController only and not be reused.

Version:

$Id: FormValidationTriggerFocus.java 205 2012-01-29 18:29:57Z oheger $

Author:

Oliver Heger

Constructor Summary

Constructors

Constructor and Description
FormValidationTriggerFocus()

Method Summary

Modifier and Type	Method and Description
void	focusGained(FormFocusEvent e) Notifies this object that an input component gained focus.
void	focusLost(FormFocusEvent e) Notifies this object that an input component lost focus.
FormController	getFormController() Returns a reference to the associated FormController.
void	initTrigger(FormController controller) Initializes this FormValidationTrigger.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FormValidationTriggerFocus

public FormValidationTriggerFocus()

Method Detail

getFormController

public final FormController getFormController()

Returns a reference to the associated FormController.

Returns:

the FormController

initTrigger

public void initTrigger(FormController controller)

Initializes this FormValidationTrigger. This implementation stores the FormController reference and registers itself as global focus listener. Thus it can intercept every change in the focus of the associated input form.

Specified by:

initTrigger in interface FormValidationTrigger

Parameters:

controller - the FormController

focusGained

public void focusGained(FormFocusEvent e)

Notifies this object that an input component gained focus. This implementation does nothing.

Specified by:

focusGained in interface FormFocusListener

Parameters:

e - the focus event

focusLost

public void focusLost(FormFocusEvent e)

Notifies this object that an input component lost focus. This implementation triggers the FormController to perform another validation.

Specified by:

focusLost in interface FormFocusListener

Parameters:

e - the focus event