J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1997-2004 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package java.awt.dnd; |
| 27 | |
| 28 | import java.awt.Point; |
| 29 | |
| 30 | import java.awt.datatransfer.DataFlavor; |
| 31 | import java.awt.datatransfer.Transferable; |
| 32 | |
| 33 | import java.util.List; |
| 34 | |
| 35 | /** |
| 36 | * The <code>DropTargetDragEvent</code> is delivered to a |
| 37 | * <code>DropTargetListener</code> via its |
| 38 | * dragEnter() and dragOver() methods. |
| 39 | * <p> |
| 40 | * The <code>DropTargetDragEvent</code> reports the <i>source drop actions</i> |
| 41 | * and the <i>user drop action</i> that reflect the current state of |
| 42 | * the drag operation. |
| 43 | * <p> |
| 44 | * <i>Source drop actions</i> is a bitwise mask of <code>DnDConstants</code> |
| 45 | * that represents the set of drop actions supported by the drag source for |
| 46 | * this drag operation. |
| 47 | * <p> |
| 48 | * <i>User drop action</i> depends on the drop actions supported by the drag |
| 49 | * source and the drop action selected by the user. The user can select a drop |
| 50 | * action by pressing modifier keys during the drag operation: |
| 51 | * <pre> |
| 52 | * Ctrl + Shift -> ACTION_LINK |
| 53 | * Ctrl -> ACTION_COPY |
| 54 | * Shift -> ACTION_MOVE |
| 55 | * </pre> |
| 56 | * If the user selects a drop action, the <i>user drop action</i> is one of |
| 57 | * <code>DnDConstants</code> that represents the selected drop action if this |
| 58 | * drop action is supported by the drag source or |
| 59 | * <code>DnDConstants.ACTION_NONE</code> if this drop action is not supported |
| 60 | * by the drag source. |
| 61 | * <p> |
| 62 | * If the user doesn't select a drop action, the set of |
| 63 | * <code>DnDConstants</code> that represents the set of drop actions supported |
| 64 | * by the drag source is searched for <code>DnDConstants.ACTION_MOVE</code>, |
| 65 | * then for <code>DnDConstants.ACTION_COPY</code>, then for |
| 66 | * <code>DnDConstants.ACTION_LINK</code> and the <i>user drop action</i> is the |
| 67 | * first constant found. If no constant is found the <i>user drop action</i> |
| 68 | * is <code>DnDConstants.ACTION_NONE</code>. |
| 69 | * |
| 70 | * @since 1.2 |
| 71 | */ |
| 72 | |
| 73 | public class DropTargetDragEvent extends DropTargetEvent { |
| 74 | |
| 75 | private static final long serialVersionUID = -8422265619058953682L; |
| 76 | |
| 77 | /** |
| 78 | * Construct a <code>DropTargetDragEvent</code> given the |
| 79 | * <code>DropTargetContext</code> for this operation, |
| 80 | * the location of the "Drag" <code>Cursor</code>'s hotspot |
| 81 | * in the <code>Component</code>'s coordinates, the |
| 82 | * user drop action, and the source drop actions. |
| 83 | * <P> |
| 84 | * @param dtc The DropTargetContext for this operation |
| 85 | * @param cursorLocn The location of the "Drag" Cursor's |
| 86 | * hotspot in Component coordinates |
| 87 | * @param dropAction The user drop action |
| 88 | * @param srcActions The source drop actions |
| 89 | * |
| 90 | * @throws NullPointerException if cursorLocn is null |
| 91 | * @throws <code>IllegalArgumentException</code> if dropAction is not one of |
| 92 | * <code>DnDConstants</code>. |
| 93 | * @throws <code>IllegalArgumentException</code> if srcActions is not |
| 94 | * a bitwise mask of <code>DnDConstants</code>. |
| 95 | * @throws <code>IllegalArgumentException</code> if dtc is <code>null</code>. |
| 96 | */ |
| 97 | |
| 98 | public DropTargetDragEvent(DropTargetContext dtc, Point cursorLocn, int dropAction, int srcActions) { |
| 99 | super(dtc); |
| 100 | |
| 101 | if (cursorLocn == null) throw new NullPointerException("cursorLocn"); |
| 102 | |
| 103 | if (dropAction != DnDConstants.ACTION_NONE && |
| 104 | dropAction != DnDConstants.ACTION_COPY && |
| 105 | dropAction != DnDConstants.ACTION_MOVE && |
| 106 | dropAction != DnDConstants.ACTION_LINK |
| 107 | ) throw new IllegalArgumentException("dropAction" + dropAction); |
| 108 | |
| 109 | if ((srcActions & ~(DnDConstants.ACTION_COPY_OR_MOVE | DnDConstants.ACTION_LINK)) != 0) throw new IllegalArgumentException("srcActions"); |
| 110 | |
| 111 | location = cursorLocn; |
| 112 | actions = srcActions; |
| 113 | this.dropAction = dropAction; |
| 114 | } |
| 115 | |
| 116 | /** |
| 117 | * This method returns a <code>Point</code> |
| 118 | * indicating the <code>Cursor</code>'s current |
| 119 | * location within the <code>Component'</code>s |
| 120 | * coordinates. |
| 121 | * <P> |
| 122 | * @return the current cursor location in |
| 123 | * <code>Component</code>'s coords. |
| 124 | */ |
| 125 | |
| 126 | public Point getLocation() { |
| 127 | return location; |
| 128 | } |
| 129 | |
| 130 | |
| 131 | /** |
| 132 | * This method returns the current <code>DataFlavor</code>s from the |
| 133 | * <code>DropTargetContext</code>. |
| 134 | * <P> |
| 135 | * @return current DataFlavors from the DropTargetContext |
| 136 | */ |
| 137 | |
| 138 | public DataFlavor[] getCurrentDataFlavors() { |
| 139 | return getDropTargetContext().getCurrentDataFlavors(); |
| 140 | } |
| 141 | |
| 142 | /** |
| 143 | * This method returns the current <code>DataFlavor</code>s |
| 144 | * as a <code>java.util.List</code> |
| 145 | * <P> |
| 146 | * @return a <code>java.util.List</code> of the Current <code>DataFlavor</code>s |
| 147 | */ |
| 148 | |
| 149 | public List<DataFlavor> getCurrentDataFlavorsAsList() { |
| 150 | return getDropTargetContext().getCurrentDataFlavorsAsList(); |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * This method returns a <code>boolean</code> indicating |
| 155 | * if the specified <code>DataFlavor</code> is supported. |
| 156 | * <P> |
| 157 | * @param df the <code>DataFlavor</code> to test |
| 158 | * <P> |
| 159 | * @return if a particular DataFlavor is supported |
| 160 | */ |
| 161 | |
| 162 | public boolean isDataFlavorSupported(DataFlavor df) { |
| 163 | return getDropTargetContext().isDataFlavorSupported(df); |
| 164 | } |
| 165 | |
| 166 | /** |
| 167 | * This method returns the source drop actions. |
| 168 | * |
| 169 | * @return the source drop actions |
| 170 | */ |
| 171 | public int getSourceActions() { return actions; } |
| 172 | |
| 173 | /** |
| 174 | * This method returns the user drop action. |
| 175 | * |
| 176 | * @return the user drop action |
| 177 | */ |
| 178 | public int getDropAction() { return dropAction; } |
| 179 | |
| 180 | /** |
| 181 | * This method returns the Transferable object that represents |
| 182 | * the data associated with the current drag operation. |
| 183 | * |
| 184 | * @return the Transferable associated with the drag operation |
| 185 | * @throws InvalidDnDOperationException if the data associated with the drag |
| 186 | * operation is not available |
| 187 | * |
| 188 | * @since 1.5 |
| 189 | */ |
| 190 | public Transferable getTransferable() { |
| 191 | return getDropTargetContext().getTransferable(); |
| 192 | } |
| 193 | |
| 194 | /** |
| 195 | * Accepts the drag. |
| 196 | * |
| 197 | * This method should be called from a |
| 198 | * <code>DropTargetListeners</code> <code>dragEnter</code>, |
| 199 | * <code>dragOver</code>, and <code>dropActionChanged</code> |
| 200 | * methods if the implementation wishes to accept an operation |
| 201 | * from the srcActions other than the one selected by |
| 202 | * the user as represented by the <code>dropAction</code>. |
| 203 | * |
| 204 | * @param dragOperation the operation accepted by the target |
| 205 | */ |
| 206 | public void acceptDrag(int dragOperation) { |
| 207 | getDropTargetContext().acceptDrag(dragOperation); |
| 208 | } |
| 209 | |
| 210 | /** |
| 211 | * Rejects the drag as a result of examining either the |
| 212 | * <code>dropAction</code> or the available <code>DataFlavor</code> |
| 213 | * types. |
| 214 | */ |
| 215 | public void rejectDrag() { |
| 216 | getDropTargetContext().rejectDrag(); |
| 217 | } |
| 218 | |
| 219 | /* |
| 220 | * fields |
| 221 | */ |
| 222 | |
| 223 | /** |
| 224 | * The location of the drag cursor's hotspot in Component coordinates. |
| 225 | * |
| 226 | * @serial |
| 227 | */ |
| 228 | private Point location; |
| 229 | |
| 230 | /** |
| 231 | * The source drop actions. |
| 232 | * |
| 233 | * @serial |
| 234 | */ |
| 235 | private int actions; |
| 236 | |
| 237 | /** |
| 238 | * The user drop action. |
| 239 | * |
| 240 | * @serial |
| 241 | */ |
| 242 | private int dropAction; |
| 243 | } |