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* accompanied this code).
*
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package javax.swing;
import java.awt.Component;
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;
}
}
Author: Hans Muller Type parameters: - <E> – the type of values this renderer can be used for
See Also:
/**
* 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:
* <pre>
* {@code
* 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;
* }
* }
* }
* </pre>
*
* @param <E> the type of values this renderer can be used for
*
* @see JList
* @see DefaultListCellRenderer
*
* @author Hans Muller
*/
public interface ListCellRenderer<E>
{
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.
Params: - 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.
See Also: Returns: A component whose paint() method will render the specified value.
/**
* Return a component that has been configured to display the specified
* value. That component's <code>paint</code> 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 <code>getPreferredSize</code>
* can be invoked.
*
* @param list The JList we're painting.
* @param value The value returned by list.getModel().getElementAt(index).
* @param index The cells index.
* @param isSelected True if the specified cell was selected.
* @param cellHasFocus True if the specified cell has the focus.
* @return A component whose paint() method will render the specified value.
*
* @see JList
* @see ListSelectionModel
* @see ListModel
*/
Component getListCellRendererComponent(
JList<? extends E> list,
E value,
int index,
boolean isSelected,
boolean cellHasFocus);
}