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package org.biopcd.widgets;

import java.awt.datatransfer.Transferable;
import java.awt.dnd.DragSourceDragEvent;
import java.awt.dnd.DragSourceMotionListener;
import javax.swing.JComponent;
import javax.swing.TransferHandler;

/**
 * Widget transfer handler - used for dragging and dropping Widgets
 **
 * Acknowledgement - Bryan E. Smith - bryanesmith@gmail.com
 * Thanks for providing sample Java drag&drop code that helped
 * me with writing the underlying framework
 **
 * @author Graham Alvare
 * @author Brian Fristensky
 */
public class WidgetTransferHandler extends TransferHandler
        implements DragSourceMotionListener {

    /**
     * Creates a new WidgetTransferHandler object.
     */
    public WidgetTransferHandler() {
        super();
    }

    /**
     * <p>This creates the Transferable object. In our case,
     *    RandomDragAndDropPanel implements Transferable,
     *    so this requires only a type cast.</p>
     * @param  cmp The component to make transferable.
     * @return     The transferable object coresponding to 'cmp'.
     */
    @Override()
    public Transferable createTransferable(JComponent cmp) {

        //System.out.println("Step 3 of 7: Casting the RandomDragAndDropPanel"
        //                 + "as Transferable. The Transferable"
        //                 + "RandomDragAndDropPanel will be queried for"
        //                 + "acceptable DataFlavors as it enters drop targets,"
        //                 + "as well as eventually present the target with the"
        //                 + "Object it transfers.");

        // TaskInstancePanel implements Transferable
        if (cmp instanceof Transferable) {
            return (Transferable) cmp;
        }

        // Not found
        return null;
    }

    public void dragMouseMoved(DragSourceDragEvent dsde) {}

    /**
     * <p>This is queried to see whether the component can be copied,
     *    moved, both or neither. We are only concerned with copying.</p>
     * @param  cmp The component to get source actions for.
     * @return     The source action integer for the component.
     */
    @Override()
    public int getSourceActions(JComponent cmp) {

        // System.out.println("Step 2 of 7: Returning the acceptable"
        //                  + "TransferHandler action.  Our"
        //                  + "RandomDragAndDropPanel accepts Copy only.");

        if (cmp instanceof Widget) {
            System.out.println("move");
            return TransferHandler.MOVE;
        } else if (cmp instanceof Transferable) {
            System.out.println("copy");
            return TransferHandler.COPY;
        }

        return TransferHandler.NONE;
    }
} // DragAndDropTransferHandler