uk.ac.starlink.util.gui

Class CustomComboBoxRenderer<T>

java.lang.Object

uk.ac.starlink.util.gui.CustomComboBoxRenderer<T>

All Implemented Interfaces:

ListCellRenderer<T>

public class CustomComboBoxRenderer<T>
extends Object
implements ListCellRenderer<T>

Utility class which does the job of rendering items into a JComboBox when you just want to provide a different stringification of them than the one provided by the toString method.

You would use this class by providing an implementation of the mapValue(T) method and class by calling JComboBox.setRenderer(javax.swing.ListCellRenderer<? super E>) on an instance of the resulting subclass.

Author:

Mark Taylor (Starlink)

Constructor Summary

Constructors

Constructor and Description
CustomComboBoxRenderer() Constructs a renderer for which nulls are represented as blank.
CustomComboBoxRenderer(String nullTxt) Constructs a renderer with a custom null representation.

Method Summary

Modifier and Type	Method and Description
Component	getListCellRendererComponent(JList<? extends T> list, T value, int index, boolean isSelected, boolean hasFocus)
protected String	mapValue(T value) Turns a non-null object which might be found in the ComboBox itself into a string to be displayed by a standard combobox renderer.

Methods inherited from class java.lang.Object

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

Constructor Detail

CustomComboBoxRenderer

public CustomComboBoxRenderer()

Constructs a renderer for which nulls are represented as blank.

CustomComboBoxRenderer

public CustomComboBoxRenderer(String nullTxt)

Constructs a renderer with a custom null representation.

Parameters:

nullTxt - text to be displayed for null values

Method Detail

getListCellRendererComponent

public Component getListCellRendererComponent(JList<? extends T> list,
                                              T value,
                                              int index,
                                              boolean isSelected,
                                              boolean hasFocus)

Specified by:

getListCellRendererComponent in interface ListCellRenderer<T>

mapValue

protected String mapValue(T value)

Turns a non-null object which might be found in the ComboBox itself into a string to be displayed by a standard combobox renderer. The default implementation just uses the toString method.

This method will only be invoked if value is not null. In case of null, the nullTxt value supplied at construction tim will be used instead.

Parameters:

value - non-null value to map

Returns:

display string