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package javax.swing.plaf;

import javax.swing.JList;
import java.awt.Point;
import java.awt.Rectangle;



The JList pluggable look and feel delegate. 
Author:Hans Muller
/**
 * The {@code JList} pluggable look and feel delegate.
 *
 * @author Hans Muller
 */

public abstract class ListUI extends ComponentUI
{
    
Constructor for subclasses to call.

/**
     * Constructor for subclasses to call.
     */
    protected ListUI() {}

    
Returns the cell index in the specified JList closest to the given location in the list's coordinate system. To determine if the cell actually contains the specified location, compare the point against the cell's bounds, as provided by getCellBounds. This method returns -1 if the list's model is empty. 
Params:
  • list – the list
  • location – the coordinates of the point
Throws:
Returns:the cell index closest to the given location, or -1
/**
     * Returns the cell index in the specified {@code JList} closest to the
     * given location in the list's coordinate system. To determine if the
     * cell actually contains the specified location, compare the point against
     * the cell's bounds, as provided by {@code getCellBounds}.
     * This method returns {@code -1} if the list's model is empty.
     *
     * @param list the list
     * @param location the coordinates of the point
     * @return the cell index closest to the given location, or {@code -1}
     * @throws NullPointerException if {@code location} is null
     */
    public abstract int locationToIndex(JList<?> list, Point location);


    
Returns the origin in the given JList, of the specified item, in the list's coordinate system. Returns null if the index isn't valid. 
Params:
  • list – the list
  • index – the cell index
Returns:the origin of the cell, or null
/**
     * Returns the origin in the given {@code JList}, of the specified item,
     * in the list's coordinate system.
     * Returns {@code null} if the index isn't valid.
     *
     * @param list the list
     * @param index the cell index
     * @return the origin of the cell, or {@code null}
     */
    public abstract Point indexToLocation(JList<?> list, int index);


    
Returns the bounding rectangle, in the given list's coordinate system,
for the range of cells specified by the two indices.
The indices can be supplied in any order.

 If the smaller index is outside the list's range of cells, this method returns null. If the smaller index is valid, but the larger index is outside the list's range, the bounds of just the first index is returned. Otherwise, the bounds of the valid range is returned. 
Params:
  • list – the list
  • index1 – the first index in the range
  • index2 – the second index in the range
Returns:the bounding rectangle for the range of cells, or null
/**
     * Returns the bounding rectangle, in the given list's coordinate system,
     * for the range of cells specified by the two indices.
     * The indices can be supplied in any order.
     * <p>
     * If the smaller index is outside the list's range of cells, this method
     * returns {@code null}. If the smaller index is valid, but the larger
     * index is outside the list's range, the bounds of just the first index
     * is returned. Otherwise, the bounds of the valid range is returned.
     *
     * @param list the list
     * @param index1 the first index in the range
     * @param index2 the second index in the range
     * @return the bounding rectangle for the range of cells, or {@code null}
     */
    public abstract Rectangle getCellBounds(JList<?> list, int index1, int index2);
}