Interface ListCellRenderer<E>

Type Parameters:

E - the type of values this renderer can be used for

All Known Implementing Classes:

BasicComboBoxRenderer, BasicComboBoxRenderer.UIResource, DefaultListCellRenderer, DefaultListCellRenderer.UIResource, MetalFileChooserUI.FileRenderer, MetalFileChooserUI.FilterComboBoxRenderer

public interface ListCellRenderer<E>

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<Object> {
    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;
    }
}

Since:

1.2

See Also:

• JList
• DefaultListCellRenderer

Method Summary

Modifier and Type	Method	Description
Component	getListCellRendererComponent(JList<? extends E> list, E value, int index, boolean isSelected, boolean cellHasFocus)	Return a component that has been configured to display the specified value.

Method Details

getListCellRendererComponent

Component getListCellRendererComponent(JList<? extends E> list,
 E 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