Java™ Platform
Standard Ed. 6

javax.swing
Interface ListCellRenderer

All Known Implementing Classes:
BasicComboBoxRenderer, BasicComboBoxRenderer.UIResource, DefaultListCellRenderer, DefaultListCellRenderer.UIResource, MetalFileChooserUI.FileRenderer, MetalFileChooserUI.FilterComboBoxRenderer

public interface ListCellRenderer

Identifies components that can be used as "rubber stamps" to paint the cells in a JList. For example, to use a JLabel as a ListCellRenderer, you would write something like this:

 class MyCellRenderer extends JLabel implements ListCellRenderer {
     public MyCellRenderer() {
         setOpaque(true);
     }

     public Component getListCellRendererComponent(JList list,
                                                   Object value,
                                                   int index,
                                                   boolean isSelected,
                                                   boolean cellHasFocus) {

         setText(value.toString());

         Color background;
         Color foreground;

         // check if this cell represents the current DnD drop location
         JList.DropLocation dropLocation = list.getDropLocation();
         if (dropLocation != null
                 && !dropLocation.isInsert()
                 && dropLocation.getIndex() == index) {

             background = Color.BLUE;
             foreground = Color.WHITE;

         // check if this cell is selected
         } else if (isSelected) {
             background = Color.RED;
             foreground = Color.WHITE;

         // unselected, and not the DnD drop location
         } else {
             background = Color.WHITE;
             foreground = Color.BLACK;
         };

         setBackground(background);
         setForeground(foreground);

         return this;
     }
 }
 

See Also:
JList, DefaultListCellRenderer

Method Summary
 Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus)
          Return a component that has been configured to display the specified value.
 

Method Detail

getListCellRendererComponent

Component getListCellRendererComponent(JList list,
                                       Object value,
                                       int index,
                                       boolean isSelected,
                                       boolean cellHasFocus)
Return a component that has been configured to display the specified value. That component's paint method is then called to "render" the cell. If it is necessary to compute the dimensions of a list because the list cells do not have a fixed size, this method is called to generate a component on which getPreferredSize can be invoked.

Parameters:
list - The JList we're painting.
value - The value returned by list.getModel().getElementAt(index).
index - The cells index.
isSelected - True if the specified cell was selected.
cellHasFocus - True if the specified cell has the focus.
Returns:
A component whose paint() method will render the specified value.
See Also:
JList, ListSelectionModel, ListModel

Java™ Platform
Standard Ed. 6

Submit a bug or feature
For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright 2008 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.


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