| /* |
| * Copyright (c) 1997, 2007, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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| * questions. |
| */ |
| |
| package java.awt.dnd; |
| |
| import java.util.EventListener; |
| |
| import java.awt.dnd.DropTargetDragEvent; |
| import java.awt.dnd.DropTargetDropEvent; |
| |
| /** |
| * The {@code DropTargetListener} interface |
| * is the callback interface used by the |
| * {@code DropTarget} class to provide |
| * notification of DnD operations that involve |
| * the subject {@code DropTarget}. Methods of |
| * this interface may be implemented to provide |
| * "drag under" visual feedback to the user throughout |
| * the Drag and Drop operation. |
| * <p> |
| * Create a listener object by implementing the interface and then register it |
| * with a {@code DropTarget}. When the drag enters, moves over, or exits |
| * the operable part of the drop site for that {@code DropTarget}, when |
| * the drop action changes, and when the drop occurs, the relevant method in |
| * the listener object is invoked, and the {@code DropTargetEvent} is |
| * passed to it. |
| * <p> |
| * The operable part of the drop site for the {@code DropTarget} is |
| * the part of the associated {@code Component}'s geometry that is not |
| * obscured by an overlapping top-level window or by another |
| * {@code Component} higher in the Z-order that has an associated active |
| * {@code DropTarget}. |
| * <p> |
| * During the drag, the data associated with the current drag operation can be |
| * retrieved by calling {@code getTransferable()} on |
| * {@code DropTargetDragEvent} instances passed to the listener's |
| * methods. |
| * <p> |
| * Note that {@code getTransferable()} on the |
| * {@code DropTargetDragEvent} instance should only be called within the |
| * respective listener's method and all the necessary data should be retrieved |
| * from the returned {@code Transferable} before that method returns. |
| * |
| * @since 1.2 |
| */ |
| |
| public interface DropTargetListener extends EventListener { |
| |
| /** |
| * Called while a drag operation is ongoing, when the mouse pointer enters |
| * the operable part of the drop site for the {@code DropTarget} |
| * registered with this listener. |
| * |
| * @param dtde the {@code DropTargetDragEvent} |
| */ |
| |
| void dragEnter(DropTargetDragEvent dtde); |
| |
| /** |
| * Called when a drag operation is ongoing, while the mouse pointer is still |
| * over the operable part of the drop site for the {@code DropTarget} |
| * registered with this listener. |
| * |
| * @param dtde the {@code DropTargetDragEvent} |
| */ |
| |
| void dragOver(DropTargetDragEvent dtde); |
| |
| /** |
| * Called if the user has modified |
| * the current drop gesture. |
| * |
| * @param dtde the {@code DropTargetDragEvent} |
| */ |
| |
| void dropActionChanged(DropTargetDragEvent dtde); |
| |
| /** |
| * Called while a drag operation is ongoing, when the mouse pointer has |
| * exited the operable part of the drop site for the |
| * {@code DropTarget} registered with this listener. |
| * |
| * @param dte the {@code DropTargetEvent} |
| */ |
| |
| void dragExit(DropTargetEvent dte); |
| |
| /** |
| * Called when the drag operation has terminated with a drop on |
| * the operable part of the drop site for the {@code DropTarget} |
| * registered with this listener. |
| * <p> |
| * This method is responsible for undertaking |
| * the transfer of the data associated with the |
| * gesture. The {@code DropTargetDropEvent} |
| * provides a means to obtain a {@code Transferable} |
| * object that represents the data object(s) to |
| * be transferred.<P> |
| * From this method, the {@code DropTargetListener} |
| * shall accept or reject the drop via the |
| * acceptDrop(int dropAction) or rejectDrop() methods of the |
| * {@code DropTargetDropEvent} parameter. |
| * <P> |
| * Subsequent to acceptDrop(), but not before, |
| * {@code DropTargetDropEvent}'s getTransferable() |
| * method may be invoked, and data transfer may be |
| * performed via the returned {@code Transferable}'s |
| * getTransferData() method. |
| * <P> |
| * At the completion of a drop, an implementation |
| * of this method is required to signal the success/failure |
| * of the drop by passing an appropriate |
| * {@code boolean} to the {@code DropTargetDropEvent}'s |
| * dropComplete(boolean success) method. |
| * <P> |
| * Note: The data transfer should be completed before the call to the |
| * {@code DropTargetDropEvent}'s dropComplete(boolean success) method. |
| * After that, a call to the getTransferData() method of the |
| * {@code Transferable} returned by |
| * {@code DropTargetDropEvent.getTransferable()} is guaranteed to |
| * succeed only if the data transfer is local; that is, only if |
| * {@code DropTargetDropEvent.isLocalTransfer()} returns |
| * {@code true}. Otherwise, the behavior of the call is |
| * implementation-dependent. |
| * |
| * @param dtde the {@code DropTargetDropEvent} |
| */ |
| |
| void drop(DropTargetDropEvent dtde); |
| } |