| /* |
| * Copyright (c) 1996, 2017, 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.datatransfer; |
| |
| import java.io.IOException; |
| import java.util.Arrays; |
| import java.util.HashSet; |
| import java.util.Objects; |
| import java.util.Set; |
| |
| import sun.datatransfer.DataFlavorUtil; |
| |
| /** |
| * A class that implements a mechanism to transfer data using cut/copy/paste |
| * operations. |
| * <p> |
| * {@link FlavorListener}s may be registered on an instance of the Clipboard |
| * class to be notified about changes to the set of {@link DataFlavor}s |
| * available on this clipboard (see {@link #addFlavorListener}). |
| * |
| * @author Amy Fowler |
| * @author Alexander Gerasimov |
| * @see java.awt.Toolkit#getSystemClipboard |
| * @see java.awt.Toolkit#getSystemSelection |
| * @since 1.1 |
| */ |
| public class Clipboard { |
| |
| String name; |
| |
| /** |
| * The owner of the clipboard. |
| */ |
| protected ClipboardOwner owner; |
| |
| /** |
| * Contents of the clipboard. |
| */ |
| protected Transferable contents; |
| |
| /** |
| * An aggregate of flavor listeners registered on this local clipboard. |
| * |
| * @since 1.5 |
| */ |
| private Set<FlavorListener> flavorListeners; |
| |
| /** |
| * A set of {@code DataFlavor}s that is available on this local clipboard. |
| * It is used for tracking changes of {@code DataFlavor}s available on this |
| * clipboard. |
| * |
| * @since 1.5 |
| */ |
| private Set<DataFlavor> currentDataFlavors; |
| |
| /** |
| * Creates a clipboard object. |
| * |
| * @param name for the clipboard |
| * @see java.awt.Toolkit#getSystemClipboard |
| */ |
| public Clipboard(String name) { |
| this.name = name; |
| } |
| |
| /** |
| * Returns the name of this clipboard object. |
| * |
| * @return the name of this clipboard object |
| * @see java.awt.Toolkit#getSystemClipboard |
| */ |
| public String getName() { |
| return name; |
| } |
| |
| /** |
| * Sets the current contents of the clipboard to the specified transferable |
| * object and registers the specified clipboard owner as the owner of the |
| * new contents. |
| * <p> |
| * If there is an existing owner different from the argument {@code owner}, |
| * that owner is notified that it no longer holds ownership of the clipboard |
| * contents via an invocation of {@code ClipboardOwner.lostOwnership()} on |
| * that owner. An implementation of {@code setContents()} is free not to |
| * invoke {@code lostOwnership()} directly from this method. For example, |
| * {@code lostOwnership()} may be invoked later on a different thread. The |
| * same applies to {@code FlavorListener}s registered on this clipboard. |
| * <p> |
| * The method throws {@code IllegalStateException} if the clipboard is |
| * currently unavailable. For example, on some platforms, the system |
| * clipboard is unavailable while it is accessed by another application. |
| * |
| * @param contents the transferable object representing the clipboard |
| * content |
| * @param owner the object which owns the clipboard content |
| * @throws IllegalStateException if the clipboard is currently unavailable |
| * @see java.awt.Toolkit#getSystemClipboard |
| */ |
| public synchronized void setContents(Transferable contents, ClipboardOwner owner) { |
| final ClipboardOwner oldOwner = this.owner; |
| final Transferable oldContents = this.contents; |
| |
| this.owner = owner; |
| this.contents = contents; |
| |
| if (oldOwner != null && oldOwner != owner) { |
| DataFlavorUtil.getDesktopService().invokeOnEventThread(() -> |
| oldOwner.lostOwnership(Clipboard.this, oldContents)); |
| } |
| fireFlavorsChanged(); |
| } |
| |
| /** |
| * Returns a transferable object representing the current contents of the |
| * clipboard. If the clipboard currently has no contents, it returns |
| * {@code null}. The parameter Object requestor is not currently used. The |
| * method throws {@code IllegalStateException} if the clipboard is currently |
| * unavailable. For example, on some platforms, the system clipboard is |
| * unavailable while it is accessed by another application. |
| * |
| * @param requestor the object requesting the clip data (not used) |
| * @return the current transferable object on the clipboard |
| * @throws IllegalStateException if the clipboard is currently unavailable |
| * @see java.awt.Toolkit#getSystemClipboard |
| */ |
| public synchronized Transferable getContents(Object requestor) { |
| return contents; |
| } |
| |
| /** |
| * Returns an array of {@code DataFlavor}s in which the current contents of |
| * this clipboard can be provided. If there are no {@code DataFlavor}s |
| * available, this method returns a zero-length array. |
| * |
| * @return an array of {@code DataFlavor}s in which the current contents of |
| * this clipboard can be provided |
| * @throws IllegalStateException if this clipboard is currently unavailable |
| * @since 1.5 |
| */ |
| public DataFlavor[] getAvailableDataFlavors() { |
| Transferable cntnts = getContents(null); |
| if (cntnts == null) { |
| return new DataFlavor[0]; |
| } |
| return cntnts.getTransferDataFlavors(); |
| } |
| |
| /** |
| * Returns whether or not the current contents of this clipboard can be |
| * provided in the specified {@code DataFlavor}. |
| * |
| * @param flavor the requested {@code DataFlavor} for the contents |
| * @return {@code true} if the current contents of this clipboard can be |
| * provided in the specified {@code DataFlavor}; {@code false} |
| * otherwise |
| * @throws NullPointerException if {@code flavor} is {@code null} |
| * @throws IllegalStateException if this clipboard is currently unavailable |
| * @since 1.5 |
| */ |
| public boolean isDataFlavorAvailable(DataFlavor flavor) { |
| if (flavor == null) { |
| throw new NullPointerException("flavor"); |
| } |
| |
| Transferable cntnts = getContents(null); |
| if (cntnts == null) { |
| return false; |
| } |
| return cntnts.isDataFlavorSupported(flavor); |
| } |
| |
| /** |
| * Returns an object representing the current contents of this clipboard in |
| * the specified {@code DataFlavor}. The class of the object returned is |
| * defined by the representation class of {@code flavor}. |
| * |
| * @param flavor the requested {@code DataFlavor} for the contents |
| * @return an object representing the current contents of this clipboard in |
| * the specified {@code DataFlavor} |
| * @throws NullPointerException if {@code flavor} is {@code null} |
| * @throws IllegalStateException if this clipboard is currently unavailable |
| * @throws UnsupportedFlavorException if the requested {@code DataFlavor} is |
| * not available |
| * @throws IOException if the data in the requested {@code DataFlavor} can |
| * not be retrieved |
| * @see DataFlavor#getRepresentationClass |
| * @since 1.5 |
| */ |
| public Object getData(DataFlavor flavor) |
| throws UnsupportedFlavorException, IOException { |
| if (flavor == null) { |
| throw new NullPointerException("flavor"); |
| } |
| |
| Transferable cntnts = getContents(null); |
| if (cntnts == null) { |
| throw new UnsupportedFlavorException(flavor); |
| } |
| return cntnts.getTransferData(flavor); |
| } |
| |
| /** |
| * Registers the specified {@code FlavorListener} to receive |
| * {@code FlavorEvent}s from this clipboard. If {@code listener} is |
| * {@code null}, no exception is thrown and no action is performed. |
| * |
| * @param listener the listener to be added |
| * @see #removeFlavorListener |
| * @see #getFlavorListeners |
| * @see FlavorListener |
| * @see FlavorEvent |
| * @since 1.5 |
| */ |
| public synchronized void addFlavorListener(FlavorListener listener) { |
| if (listener == null) { |
| return; |
| } |
| |
| if (flavorListeners == null) { |
| flavorListeners = new HashSet<>(); |
| currentDataFlavors = getAvailableDataFlavorSet(); |
| } |
| |
| flavorListeners.add(listener); |
| } |
| |
| /** |
| * Removes the specified {@code FlavorListener} so that it no longer |
| * receives {@code FlavorEvent}s from this {@code Clipboard}. This method |
| * performs no function, nor does it throw an exception, if the listener |
| * specified by the argument was not previously added to this |
| * {@code Clipboard}. If {@code listener} is {@code null}, no exception is |
| * thrown and no action is performed. |
| * |
| * @param listener the listener to be removed |
| * @see #addFlavorListener |
| * @see #getFlavorListeners |
| * @see FlavorListener |
| * @see FlavorEvent |
| * @since 1.5 |
| */ |
| public synchronized void removeFlavorListener(FlavorListener listener) { |
| if (listener == null || flavorListeners == null) { |
| return; |
| } |
| flavorListeners.remove(listener); |
| } |
| |
| /** |
| * Returns an array of all the {@code FlavorListener}s currently registered |
| * on this {@code Clipboard}. |
| * |
| * @return all of this clipboard's {@code FlavorListener}s or an empty array |
| * if no listeners are currently registered |
| * @see #addFlavorListener |
| * @see #removeFlavorListener |
| * @see FlavorListener |
| * @see FlavorEvent |
| * @since 1.5 |
| */ |
| public synchronized FlavorListener[] getFlavorListeners() { |
| return flavorListeners == null ? new FlavorListener[0] : |
| flavorListeners.toArray(new FlavorListener[flavorListeners.size()]); |
| } |
| |
| /** |
| * Checks change of the {@code DataFlavor}s and, if necessary, notifies all |
| * listeners that have registered interest for notification on |
| * {@code FlavorEvent}s. |
| * |
| * @since 1.5 |
| */ |
| private void fireFlavorsChanged() { |
| if (flavorListeners == null) { |
| return; |
| } |
| |
| Set<DataFlavor> prevDataFlavors = currentDataFlavors; |
| currentDataFlavors = getAvailableDataFlavorSet(); |
| if (Objects.equals(prevDataFlavors, currentDataFlavors)) { |
| return; |
| } |
| flavorListeners.forEach(listener -> |
| DataFlavorUtil.getDesktopService().invokeOnEventThread(() -> |
| listener.flavorsChanged(new FlavorEvent(Clipboard.this)))); |
| } |
| |
| /** |
| * Returns a set of {@code DataFlavor}s currently available on this |
| * clipboard. |
| * |
| * @return a set of {@code DataFlavor}s currently available on this |
| * clipboard |
| * @since 1.5 |
| */ |
| private Set<DataFlavor> getAvailableDataFlavorSet() { |
| Set<DataFlavor> set = new HashSet<>(); |
| Transferable contents = getContents(null); |
| if (contents != null) { |
| DataFlavor[] flavors = contents.getTransferDataFlavors(); |
| if (flavors != null) { |
| set.addAll(Arrays.asList(flavors)); |
| } |
| } |
| return set; |
| } |
| } |
