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package java.awt.dnd;

import java.awt.Insets;
import java.awt.Point;


During DnD operations it is possible that a user may wish to drop the
subject of the operation on a region of a scrollable GUI control that is
not currently visible to the user.


In such situations it is desirable that the GUI control detect this
and institute a scroll operation in order to make obscured region(s)
visible to the user. This feature is known as autoscrolling.

 If a GUI control is both an active DropTarget and is also scrollable, it can receive notifications of autoscrolling gestures by the user from the DnD system by implementing this interface. 
 An autoscrolling gesture is initiated by the user by keeping the drag cursor motionless with a border region of the Component, referred to as the "autoscrolling region", for a predefined period of time, this will result in repeated scroll requests to the Component until the drag Cursor resumes its motion. 
Since:1.2
/**
 * During DnD operations it is possible that a user may wish to drop the
 * subject of the operation on a region of a scrollable GUI control that is
 * not currently visible to the user.
 * <p>
 * In such situations it is desirable that the GUI control detect this
 * and institute a scroll operation in order to make obscured region(s)
 * visible to the user. This feature is known as autoscrolling.
 * <p>
 * If a GUI control is both an active {@code DropTarget}
 * and is also scrollable, it
 * can receive notifications of autoscrolling gestures by the user from
 * the DnD system by implementing this interface.
 * <p>
 * An autoscrolling gesture is initiated by the user by keeping the drag
 * cursor motionless with a border region of the {@code Component},
 * referred to as
 * the "autoscrolling region", for a predefined period of time, this will
 * result in repeated scroll requests to the {@code Component}
 * until the drag {@code Cursor} resumes its motion.
 *
 * @since 1.2
 */

public interface Autoscroll {

    
This method returns the Insets describing the autoscrolling region or border relative to the geometry of the implementing Component. 
 This value is read once by the DropTarget upon entry of the drag Cursor into the associated Component. 
Returns:the Insets
/**
     * This method returns the {@code Insets} describing
     * the autoscrolling region or border relative
     * to the geometry of the implementing Component.
     * <P>
     * This value is read once by the {@code DropTarget}
     * upon entry of the drag {@code Cursor}
     * into the associated {@code Component}.
     *
     * @return the Insets
     */

    public Insets getAutoscrollInsets();

    
notify the Component to autoscroll 
Params:
  • cursorLocn – A Point indicating the location of the cursor that triggered this operation.
/**
     * notify the {@code Component} to autoscroll
     *
     * @param cursorLocn A {@code Point} indicating the
     * location of the cursor that triggered this operation.
     */

    public void autoscroll(Point cursorLocn);

}