/* * Copyright (c) 1996, 2014, 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 sun.datatransfer.DataFlavorUtil; import java.util.Objects; import java.util.Set; import java.util.HashSet; import java.util.Arrays; import java.io.IOException; /** * A class that implements a mechanism to transfer data using * cut/copy/paste operations. *
* {@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}).
*
* @see java.awt.Toolkit#getSystemClipboard
* @see java.awt.Toolkit#getSystemSelection
*
* @author Amy Fowler
* @author Alexander Gerasimov
*/
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
* If there is an existing owner different from the argument
*
* The method throws DataFlavor
s that is available on
* this local clipboard. It is used for tracking changes
* of DataFlavor
s available on this clipboard.
*
* @since 1.5
*/
private Setowner
, that owner is notified that it no longer
* holds ownership of the clipboard contents via an invocation
* of ClipboardOwner.lostOwnership()
on that owner.
* An implementation of setContents()
is free not
* to invoke lostOwnership()
directly from this method.
* For example, lostOwnership()
may be invoked later on
* a different thread. The same applies to FlavorListener
s
* registered on this clipboard.
* 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 null
. The parameter Object requestor is
* not currently used. The method throws
* 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 DataFlavor
s in which the current
* contents of this clipboard can be provided. If there are no
* DataFlavor
s available, this method returns a zero-length
* array.
*
* @return an array of 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 DataFlavor
.
*
* @param flavor the requested DataFlavor
for the contents
*
* @return true
if the current contents of this clipboard
* can be provided in the specified DataFlavor
;
* false
otherwise
*
* @throws NullPointerException if flavor
is 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 DataFlavor
.
* The class of the object returned is defined by the representation
* class of flavor
.
*
* @param flavor the requested DataFlavor
for the contents
*
* @return an object representing the current contents of this clipboard
* in the specified DataFlavor
*
* @throws NullPointerException if flavor
is null
* @throws IllegalStateException if this clipboard is currently unavailable
* @throws UnsupportedFlavorException if the requested DataFlavor
* is not available
* @throws IOException if the data in the requested 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 FlavorListener
to receive
* FlavorEvent
s from this clipboard.
* If listener
is 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 FlavorListener
so that it no longer
* receives FlavorEvent
s from this 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
* Clipboard
.
* If listener
is 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 FlavorListener
s currently
* registered on this Clipboard
.
*
* @return all of this clipboard's 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 DataFlavor
s and, if necessary,
* notifies all listeners that have registered interest for notification
* on FlavorEvent
s.
*
* @since 1.5
*/
private void fireFlavorsChanged() {
if (flavorListeners == null) {
return;
}
SetDataFlavor
s currently available
* on this clipboard.
*
* @return a set of DataFlavor
s currently available
* on this clipboard
*
* @since 1.5
*/
private Set