/* * Copyright (c) 1997, 2006, 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 * or visit www.oracle.com if you need additional information or have any * questions. */ package java.awt.dnd; import java.awt.event.InputEvent; /** * The DragSourceDragEvent is * delivered from the DragSourceContextPeer, * via the DragSourceContext, to the DragSourceListener * registered with that DragSourceContext and with its associated * DragSource. *

* The DragSourceDragEvent reports the target drop action * and the user drop action that reflect the current state of * the drag operation. *

* Target drop action is one of DnDConstants that represents * the drop action selected by the current drop target if this drop action is * supported by the drag source or DnDConstants.ACTION_NONE if this * drop action is not supported by the drag source. *

* User drop action depends on the drop actions supported by the drag * source and the drop action selected by the user. The user can select a drop * action by pressing modifier keys during the drag operation: *

 *   Ctrl + Shift -> ACTION_LINK
 *   Ctrl         -> ACTION_COPY
 *   Shift        -> ACTION_MOVE
 * 
* If the user selects a drop action, the user drop action is one of * DnDConstants that represents the selected drop action if this * drop action is supported by the drag source or * DnDConstants.ACTION_NONE if this drop action is not supported * by the drag source. *

* If the user doesn't select a drop action, the set of * DnDConstants that represents the set of drop actions supported * by the drag source is searched for DnDConstants.ACTION_MOVE, * then for DnDConstants.ACTION_COPY, then for * DnDConstants.ACTION_LINK and the user drop action is the * first constant found. If no constant is found the user drop action * is DnDConstants.ACTION_NONE. * * @since 1.2 * */ public class DragSourceDragEvent extends DragSourceEvent { private static final long serialVersionUID = 481346297933902471L; /** * Constructs a DragSourceDragEvent. * This class is typically * instantiated by the DragSourceContextPeer * rather than directly * by client code. * The coordinates for this DragSourceDragEvent * are not specified, so getLocation will return * null for this event. *

* The arguments dropAction and action should * be one of DnDConstants that represents a single action. * The argument modifiers should be either a bitwise mask * of old java.awt.event.InputEvent.*_MASK constants or a * bitwise mask of extended java.awt.event.InputEvent.*_DOWN_MASK * constants. * This constructor does not throw any exception for invalid dropAction, * action and modifiers. * * @param dsc the DragSourceContext that is to manage * notifications for this event. * @param dropAction the user drop action. * @param action the target drop action. * @param modifiers the modifier keys down during event (shift, ctrl, * alt, meta) * Either extended _DOWN_MASK or old _MASK modifiers * should be used, but both models should not be mixed * in one event. Use of the extended modifiers is * preferred. * * @throws IllegalArgumentException if dsc is null. * * @see java.awt.event.InputEvent * @see DragSourceEvent#getLocation */ public DragSourceDragEvent(DragSourceContext dsc, int dropAction, int action, int modifiers) { super(dsc); targetActions = action; gestureModifiers = modifiers; this.dropAction = dropAction; if ((modifiers & ~(JDK_1_3_MODIFIERS | JDK_1_4_MODIFIERS)) != 0) { invalidModifiers = true; } else if ((getGestureModifiers() != 0) && (getGestureModifiersEx() == 0)) { setNewModifiers(); } else if ((getGestureModifiers() == 0) && (getGestureModifiersEx() != 0)) { setOldModifiers(); } else { invalidModifiers = true; } } /** * Constructs a DragSourceDragEvent given the specified * DragSourceContext, user drop action, target drop action, * modifiers and coordinates. *

* The arguments dropAction and action should * be one of DnDConstants that represents a single action. * The argument modifiers should be either a bitwise mask * of old java.awt.event.InputEvent.*_MASK constants or a * bitwise mask of extended java.awt.event.InputEvent.*_DOWN_MASK * constants. * This constructor does not throw any exception for invalid dropAction, * action and modifiers. * * @param dsc the DragSourceContext associated with this * event. * @param dropAction the user drop action. * @param action the target drop action. * @param modifiers the modifier keys down during event (shift, ctrl, * alt, meta) * Either extended _DOWN_MASK or old _MASK modifiers * should be used, but both models should not be mixed * in one event. Use of the extended modifiers is * preferred. * @param x the horizontal coordinate for the cursor location * @param y the vertical coordinate for the cursor location * * @throws IllegalArgumentException if dsc is null. * * @see java.awt.event.InputEvent * @since 1.4 */ public DragSourceDragEvent(DragSourceContext dsc, int dropAction, int action, int modifiers, int x, int y) { super(dsc, x, y); targetActions = action; gestureModifiers = modifiers; this.dropAction = dropAction; if ((modifiers & ~(JDK_1_3_MODIFIERS | JDK_1_4_MODIFIERS)) != 0) { invalidModifiers = true; } else if ((getGestureModifiers() != 0) && (getGestureModifiersEx() == 0)) { setNewModifiers(); } else if ((getGestureModifiers() == 0) && (getGestureModifiersEx() != 0)) { setOldModifiers(); } else { invalidModifiers = true; } } /** * This method returns the target drop action. * * @return the target drop action. */ public int getTargetActions() { return targetActions; } private static final int JDK_1_3_MODIFIERS = InputEvent.SHIFT_DOWN_MASK - 1; private static final int JDK_1_4_MODIFIERS = ((InputEvent.ALT_GRAPH_DOWN_MASK << 1) - 1) & ~JDK_1_3_MODIFIERS; /** * This method returns an int representing * the current state of the input device modifiers * associated with the user's gesture. Typically these * would be mouse buttons or keyboard modifiers. *

* If the modifiers passed to the constructor * are invalid, this method returns them unchanged. * * @return the current state of the input device modifiers */ public int getGestureModifiers() { return invalidModifiers ? gestureModifiers : gestureModifiers & JDK_1_3_MODIFIERS; } /** * This method returns an int representing * the current state of the input device extended modifiers * associated with the user's gesture. * See {@link InputEvent#getModifiersEx} *

* If the modifiers passed to the constructor * are invalid, this method returns them unchanged. * * @return the current state of the input device extended modifiers * @since 1.4 */ public int getGestureModifiersEx() { return invalidModifiers ? gestureModifiers : gestureModifiers & JDK_1_4_MODIFIERS; } /** * This method returns the user drop action. * * @return the user drop action. */ public int getUserAction() { return dropAction; } /** * This method returns the logical intersection of * the target drop action and the set of drop actions supported by * the drag source. * * @return the logical intersection of the target drop action and * the set of drop actions supported by the drag source. */ public int getDropAction() { return targetActions & getDragSourceContext().getSourceActions(); } /* * fields */ /** * The target drop action. * * @serial */ private int targetActions = DnDConstants.ACTION_NONE; /** * The user drop action. * * @serial */ private int dropAction = DnDConstants.ACTION_NONE; /** * The state of the input device modifiers associated with the user * gesture. * * @serial */ private int gestureModifiers = 0; /** * Indicates whether the gestureModifiers are invalid. * * @serial */ private boolean invalidModifiers; /** * Sets new modifiers by the old ones. * The mouse modifiers have higher priority than overlaying key * modifiers. */ private void setNewModifiers() { if ((gestureModifiers & InputEvent.BUTTON1_MASK) != 0) { gestureModifiers |= InputEvent.BUTTON1_DOWN_MASK; } if ((gestureModifiers & InputEvent.BUTTON2_MASK) != 0) { gestureModifiers |= InputEvent.BUTTON2_DOWN_MASK; } if ((gestureModifiers & InputEvent.BUTTON3_MASK) != 0) { gestureModifiers |= InputEvent.BUTTON3_DOWN_MASK; } if ((gestureModifiers & InputEvent.SHIFT_MASK) != 0) { gestureModifiers |= InputEvent.SHIFT_DOWN_MASK; } if ((gestureModifiers & InputEvent.CTRL_MASK) != 0) { gestureModifiers |= InputEvent.CTRL_DOWN_MASK; } if ((gestureModifiers & InputEvent.ALT_GRAPH_MASK) != 0) { gestureModifiers |= InputEvent.ALT_GRAPH_DOWN_MASK; } } /** * Sets old modifiers by the new ones. */ private void setOldModifiers() { if ((gestureModifiers & InputEvent.BUTTON1_DOWN_MASK) != 0) { gestureModifiers |= InputEvent.BUTTON1_MASK; } if ((gestureModifiers & InputEvent.BUTTON2_DOWN_MASK) != 0) { gestureModifiers |= InputEvent.BUTTON2_MASK; } if ((gestureModifiers & InputEvent.BUTTON3_DOWN_MASK) != 0) { gestureModifiers |= InputEvent.BUTTON3_MASK; } if ((gestureModifiers & InputEvent.SHIFT_DOWN_MASK) != 0) { gestureModifiers |= InputEvent.SHIFT_MASK; } if ((gestureModifiers & InputEvent.CTRL_DOWN_MASK) != 0) { gestureModifiers |= InputEvent.CTRL_MASK; } if ((gestureModifiers & InputEvent.ALT_GRAPH_DOWN_MASK) != 0) { gestureModifiers |= InputEvent.ALT_GRAPH_MASK; } } }