Application: gvSIG desktop » gvSIG projections

package org.gvsig.proj.swing.impl.tree;

import java.util.ArrayList;

import javax.swing.tree.TreeNode;

/**

 * Loads the children of a loaded group

 *  

 * @author Cesar Martinez Izquierdo

 */

public interface GroupLoader {

        /**

         * Start loading the children, which can happen immediately or

         * be done asynchronously

         */

        void execute();

        /**

         * Attempts to cancel the loading process

         * @return

         */

        void cancel();

        /**

         * Whether the loading process has been cancelled

         * 

         * @return

         */

        boolean isCancelled();

        /**

         * Creates an instance of a node to be displayed as temporary child

         * while data is loading 

         * 

         * @return A TreeNode instance or null if no loading node is needed

         */

        TreeNode createLoadingNode();

}