/*
* Copyright (c) 1997, 2015, 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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package java.awt.dnd;
import java.awt.Component;
import java.awt.Cursor;
import java.awt.GraphicsEnvironment;
import java.awt.HeadlessException;
import java.awt.Image;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.datatransfer.FlavorMap;
import java.awt.datatransfer.SystemFlavorMap;
import java.awt.datatransfer.Transferable;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.security.AccessController;
import java.util.EventListener;
import sun.awt.AWTAccessor;
import sun.awt.AWTAccessor.DragSourceContextAccessor;
import sun.awt.dnd.SunDragSourceContextPeer;
import sun.security.action.GetIntegerAction;
/**
* The {@code DragSource} is the entity responsible
* for the initiation of the Drag
* and Drop operation, and may be used in a number of scenarios:
* <UL>
* <LI>1 default instance per JVM for the lifetime of that JVM.
* <LI>1 instance per class of potential Drag Initiator object (e.g
* TextField). [implementation dependent]
* <LI>1 per instance of a particular
* {@code Component}, or application specific
* object associated with a {@code Component}
* instance in the GUI. [implementation dependent]
* <LI>Some other arbitrary association. [implementation dependent]
*</UL>
*
* Once the {@code DragSource} is
* obtained, a {@code DragGestureRecognizer} should
* also be obtained to associate the {@code DragSource}
* with a particular
* {@code Component}.
* <P>
* The initial interpretation of the user's gesture,
* and the subsequent starting of the drag operation
* are the responsibility of the implementing
* {@code Component}, which is usually
* implemented by a {@code DragGestureRecognizer}.
*<P>
* When a drag gesture occurs, the
* {@code DragSource}'s
* startDrag() method shall be
* invoked in order to cause processing
* of the user's navigational
* gestures and delivery of Drag and Drop
* protocol notifications. A
* {@code DragSource} shall only
* permit a single Drag and Drop operation to be
* current at any one time, and shall
* reject any further startDrag() requests
* by throwing an {@code IllegalDnDOperationException}
* until such time as the extant operation is complete.
* <P>
* The startDrag() method invokes the
* createDragSourceContext() method to
* instantiate an appropriate
* {@code DragSourceContext}
* and associate the {@code DragSourceContextPeer}
* with that.
* <P>
* If the Drag and Drop System is
* unable to initiate a drag operation for
* some reason, the startDrag() method throws
* a {@code java.awt.dnd.InvalidDnDOperationException}
* to signal such a condition. Typically this
* exception is thrown when the underlying platform
* system is either not in a state to
* initiate a drag, or the parameters specified are invalid.
* <P>
* Note that during the drag, the
* set of operations exposed by the source
* at the start of the drag operation may not change
* until the operation is complete.
* The operation(s) are constant for the
* duration of the operation with respect to the
* {@code DragSource}.
*
* @since 1.2
*/
public class DragSource implements Serializable {
private static final long serialVersionUID = 6236096958971414066L;
/*
* load a system default cursor
*/
private static Cursor load(String name) {
if (GraphicsEnvironment.isHeadless()) {
return null;
}
try {
return (Cursor)Toolkit.getDefaultToolkit().getDesktopProperty(name);
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException("failed to load system cursor: " + name + " : " + e.getMessage());
}
}
/**
* The default {@code Cursor} to use with a copy operation indicating
* that a drop is currently allowed. {@code null} if
* {@code GraphicsEnvironment.isHeadless()} returns {@code true}.
*
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public static final Cursor DefaultCopyDrop =
load("DnD.Cursor.CopyDrop");
/**
* The default {@code Cursor} to use with a move operation indicating
* that a drop is currently allowed. {@code null} if
* {@code GraphicsEnvironment.isHeadless()} returns {@code true}.
*
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public static final Cursor DefaultMoveDrop =
load("DnD.Cursor.MoveDrop");
/**
* The default {@code Cursor} to use with a link operation indicating
* that a drop is currently allowed. {@code null} if
* {@code GraphicsEnvironment.isHeadless()} returns {@code true}.
*
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public static final Cursor DefaultLinkDrop =
load("DnD.Cursor.LinkDrop");
/**
* The default {@code Cursor} to use with a copy operation indicating
* that a drop is currently not allowed. {@code null} if
* {@code GraphicsEnvironment.isHeadless()} returns {@code true}.
*
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public static final Cursor DefaultCopyNoDrop =
load("DnD.Cursor.CopyNoDrop");
/**
* The default {@code Cursor} to use with a move operation indicating
* that a drop is currently not allowed. {@code null} if
* {@code GraphicsEnvironment.isHeadless()} returns {@code true}.
*
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public static final Cursor DefaultMoveNoDrop =
load("DnD.Cursor.MoveNoDrop");
/**
* The default {@code Cursor} to use with a link operation indicating
* that a drop is currently not allowed. {@code null} if
* {@code GraphicsEnvironment.isHeadless()} returns {@code true}.
*
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public static final Cursor DefaultLinkNoDrop =
load("DnD.Cursor.LinkNoDrop");
private static final DragSource dflt =
(GraphicsEnvironment.isHeadless()) ? null : new DragSource();
/**
* Internal constants for serialization.
*/
static final String dragSourceListenerK = "dragSourceL";
static final String dragSourceMotionListenerK = "dragSourceMotionL";
/**
* Gets the {@code DragSource} object associated with
* the underlying platform.
*
* @return the platform DragSource
* @exception HeadlessException if GraphicsEnvironment.isHeadless()
* returns true
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public static DragSource getDefaultDragSource() {
if (GraphicsEnvironment.isHeadless()) {
throw new HeadlessException();
} else {
return dflt;
}
}
/**
* Reports
* whether or not drag
* {@code Image} support
* is available on the underlying platform.
*
* @return if the Drag Image support is available on this platform
*/
public static boolean isDragImageSupported() {
Toolkit t = Toolkit.getDefaultToolkit();
Boolean supported;
try {
supported = (Boolean)Toolkit.getDefaultToolkit().getDesktopProperty("DnD.isDragImageSupported");
return supported.booleanValue();
} catch (Exception e) {
return false;
}
}
/**
* Creates a new {@code DragSource}.
*
* @exception HeadlessException if GraphicsEnvironment.isHeadless()
* returns true
* @see java.awt.GraphicsEnvironment#isHeadless
*/
public DragSource() throws HeadlessException {
if (GraphicsEnvironment.isHeadless()) {
throw new HeadlessException();
}
}
/**
* Start a drag, given the {@code DragGestureEvent}
* that initiated the drag, the initial
* {@code Cursor} to use,
* the {@code Image} to drag,
* the offset of the {@code Image} origin
* from the hotspot of the {@code Cursor} at
* the instant of the trigger,
* the {@code Transferable} subject data
* of the drag, the {@code DragSourceListener},
* and the {@code FlavorMap}.
*
* @param trigger the {@code DragGestureEvent} that initiated the drag
* @param dragCursor the initial {@code Cursor} for this drag operation
* or {@code null} for the default cursor handling;
* see <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a>
* for more details on the cursor handling mechanism during drag and drop
* @param dragImage the image to drag or {@code null}
* @param imageOffset the offset of the {@code Image} origin from the hotspot
* of the {@code Cursor} at the instant of the trigger
* @param transferable the subject data of the drag
* @param dsl the {@code DragSourceListener}
* @param flavorMap the {@code FlavorMap} to use, or {@code null}
*
* @throws java.awt.dnd.InvalidDnDOperationException
* if the Drag and Drop
* system is unable to initiate a drag operation, or if the user
* attempts to start a drag while an existing drag operation
* is still executing
*/
public void startDrag(DragGestureEvent trigger,
Cursor dragCursor,
Image dragImage,
Point imageOffset,
Transferable transferable,
DragSourceListener dsl,
FlavorMap flavorMap) throws InvalidDnDOperationException {
SunDragSourceContextPeer.setDragDropInProgress(true);
try {
if (flavorMap != null) this.flavorMap = flavorMap;
DragSourceContext dsc = createDragSourceContext(trigger, dragCursor,
dragImage,
imageOffset,
transferable, dsl);
if (dsc == null) {
throw new InvalidDnDOperationException();
}
DragSourceContextAccessor acc = AWTAccessor.getDragSourceContextAccessor();
acc.getPeer(dsc).startDrag(dsc, dsc.getCursor(), dragImage, imageOffset); // may throw
} catch (RuntimeException e) {
SunDragSourceContextPeer.setDragDropInProgress(false);
throw e;
}
}
/**
* Start a drag, given the {@code DragGestureEvent}
* that initiated the drag, the initial
* {@code Cursor} to use,
* the {@code Transferable} subject data
* of the drag, the {@code DragSourceListener},
* and the {@code FlavorMap}.
*
* @param trigger the {@code DragGestureEvent} that
* initiated the drag
* @param dragCursor the initial {@code Cursor} for this drag operation
* or {@code null} for the default cursor handling;
* see <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a>
* for more details on the cursor handling mechanism during drag and drop
* @param transferable the subject data of the drag
* @param dsl the {@code DragSourceListener}
* @param flavorMap the {@code FlavorMap} to use or {@code null}
*
* @throws java.awt.dnd.InvalidDnDOperationException
* if the Drag and Drop
* system is unable to initiate a drag operation, or if the user
* attempts to start a drag while an existing drag operation
* is still executing
*/
public void startDrag(DragGestureEvent trigger,
Cursor dragCursor,
Transferable transferable,
DragSourceListener dsl,
FlavorMap flavorMap) throws InvalidDnDOperationException {
startDrag(trigger, dragCursor, null, null, transferable, dsl, flavorMap);
}
/**
* Start a drag, given the {@code DragGestureEvent}
* that initiated the drag, the initial {@code Cursor}
* to use,
* the {@code Image} to drag,
* the offset of the {@code Image} origin
* from the hotspot of the {@code Cursor}
* at the instant of the trigger,
* the subject data of the drag, and
* the {@code DragSourceListener}.
*
* @param trigger the {@code DragGestureEvent} that initiated the drag
* @param dragCursor the initial {@code Cursor} for this drag operation
* or {@code null} for the default cursor handling;
* see <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a>
* for more details on the cursor handling mechanism during drag and drop
* @param dragImage the {@code Image} to drag or {@code null}
* @param dragOffset the offset of the {@code Image} origin from the hotspot
* of the {@code Cursor} at the instant of the trigger
* @param transferable the subject data of the drag
* @param dsl the {@code DragSourceListener}
*
* @throws java.awt.dnd.InvalidDnDOperationException
* if the Drag and Drop
* system is unable to initiate a drag operation, or if the user
* attempts to start a drag while an existing drag operation
* is still executing
*/
public void startDrag(DragGestureEvent trigger,
Cursor dragCursor,
Image dragImage,
Point dragOffset,
Transferable transferable,
DragSourceListener dsl) throws InvalidDnDOperationException {
startDrag(trigger, dragCursor, dragImage, dragOffset, transferable, dsl, null);
}
/**
* Start a drag, given the {@code DragGestureEvent}
* that initiated the drag, the initial
* {@code Cursor} to
* use,
* the {@code Transferable} subject data
* of the drag, and the {@code DragSourceListener}.
*
* @param trigger the {@code DragGestureEvent} that initiated the drag
* @param dragCursor the initial {@code Cursor} for this drag operation
* or {@code null} for the default cursor handling;
* see <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a> class
* for more details on the cursor handling mechanism during drag and drop
* @param transferable the subject data of the drag
* @param dsl the {@code DragSourceListener}
*
* @throws java.awt.dnd.InvalidDnDOperationException
* if the Drag and Drop
* system is unable to initiate a drag operation, or if the user
* attempts to start a drag while an existing drag operation
* is still executing
*/
public void startDrag(DragGestureEvent trigger,
Cursor dragCursor,
Transferable transferable,
DragSourceListener dsl) throws InvalidDnDOperationException {
startDrag(trigger, dragCursor, null, null, transferable, dsl, null);
}
/**
* Creates the {@code DragSourceContext} to handle the current drag
* operation.
* <p>
* To incorporate a new {@code DragSourceContext}
* subclass, subclass {@code DragSource} and
* override this method.
* <p>
* If {@code dragImage} is {@code null}, no image is used
* to represent the drag over feedback for this drag operation, but
* {@code NullPointerException} is not thrown.
* <p>
* If {@code dsl} is {@code null}, no drag source listener
* is registered with the created {@code DragSourceContext},
* but {@code NullPointerException} is not thrown.
*
* @param dgl The {@code DragGestureEvent} that triggered the
* drag
* @param dragCursor The initial {@code Cursor} for this drag operation
* or {@code null} for the default cursor handling;
* see <a href="DragSourceContext.html#defaultCursor">DragSourceContext</a> class
* for more details on the cursor handling mechanism during drag and drop
* @param dragImage The {@code Image} to drag or {@code null}
* @param imageOffset The offset of the {@code Image} origin from the
* hotspot of the cursor at the instant of the trigger
* @param t The subject data of the drag
* @param dsl The {@code DragSourceListener}
*
* @return the {@code DragSourceContext}
*
* @throws NullPointerException if {@code dscp} is {@code null}
* @throws NullPointerException if {@code dgl} is {@code null}
* @throws NullPointerException if {@code dragImage} is not
* {@code null} and {@code imageOffset} is {@code null}
* @throws NullPointerException if {@code t} is {@code null}
* @throws IllegalArgumentException if the {@code Component}
* associated with the trigger event is {@code null}.
* @throws IllegalArgumentException if the {@code DragSource} for the
* trigger event is {@code null}.
* @throws IllegalArgumentException if the drag action for the
* trigger event is {@code DnDConstants.ACTION_NONE}.
* @throws IllegalArgumentException if the source actions for the
* {@code DragGestureRecognizer} associated with the trigger
* event are equal to {@code DnDConstants.ACTION_NONE}.
*/
protected DragSourceContext createDragSourceContext(DragGestureEvent dgl,
Cursor dragCursor,
Image dragImage,
Point imageOffset,
Transferable t,
DragSourceListener dsl) {
return new DragSourceContext(dgl, dragCursor, dragImage, imageOffset, t, dsl);
}
/**
* This method returns the
* {@code FlavorMap} for this {@code DragSource}.
*
* @return the {@code FlavorMap} for this {@code DragSource}
*/
public FlavorMap getFlavorMap() { return flavorMap; }
/**
* Creates a new {@code DragGestureRecognizer}
* that implements the specified
* abstract subclass of
* {@code DragGestureRecognizer}, and
* sets the specified {@code Component}
* and {@code DragGestureListener} on
* the newly created object.
*
* @param <T> the type of {@code DragGestureRecognizer} to create
* @param recognizerAbstractClass the requested abstract type
* @param actions the permitted source drag actions
* @param c the {@code Component} target
* @param dgl the {@code DragGestureListener} to notify
*
* @return the new {@code DragGestureRecognizer} or {@code null}
* if the {@code Toolkit.createDragGestureRecognizer} method
* has no implementation available for
* the requested {@code DragGestureRecognizer}
* subclass and returns {@code null}
*/
public <T extends DragGestureRecognizer> T
createDragGestureRecognizer(Class<T> recognizerAbstractClass,
Component c, int actions,
DragGestureListener dgl)
{
return Toolkit.getDefaultToolkit().createDragGestureRecognizer(recognizerAbstractClass, this, c, actions, dgl);
}
/**
* Creates a new {@code DragGestureRecognizer}
* that implements the default
* abstract subclass of {@code DragGestureRecognizer}
* for this {@code DragSource},
* and sets the specified {@code Component}
* and {@code DragGestureListener} on the
* newly created object.
*
* For this {@code DragSource}
* the default is {@code MouseDragGestureRecognizer}.
*
* @param c the {@code Component} target for the recognizer
* @param actions the permitted source actions
* @param dgl the {@code DragGestureListener} to notify
*
* @return the new {@code DragGestureRecognizer} or {@code null}
* if the {@code Toolkit.createDragGestureRecognizer} method
* has no implementation available for
* the requested {@code DragGestureRecognizer}
* subclass and returns {@code null}
*/
public DragGestureRecognizer createDefaultDragGestureRecognizer(Component c, int actions, DragGestureListener dgl) {
return Toolkit.getDefaultToolkit().createDragGestureRecognizer(MouseDragGestureRecognizer.class, this, c, actions, dgl);
}
/**
* Adds the specified {@code DragSourceListener} to this
* {@code DragSource} to receive drag source events during drag
* operations initiated with this {@code DragSource}.
* If a {@code null} listener is specified, no action is taken and no
* exception is thrown.
*
* @param dsl the {@code DragSourceListener} to add
*
* @see #removeDragSourceListener
* @see #getDragSourceListeners
* @since 1.4
*/
public void addDragSourceListener(DragSourceListener dsl) {
if (dsl != null) {
synchronized (this) {
listener = DnDEventMulticaster.add(listener, dsl);
}
}
}
/**
* Removes the specified {@code DragSourceListener} from this
* {@code DragSource}.
* If a {@code null} listener is specified, no action is taken and no
* exception is thrown.
* If the listener specified by the argument was not previously added to
* this {@code DragSource}, no action is taken and no exception
* is thrown.
*
* @param dsl the {@code DragSourceListener} to remove
*
* @see #addDragSourceListener
* @see #getDragSourceListeners
* @since 1.4
*/
public void removeDragSourceListener(DragSourceListener dsl) {
if (dsl != null) {
synchronized (this) {
listener = DnDEventMulticaster.remove(listener, dsl);
}
}
}
/**
* Gets all the {@code DragSourceListener}s
* registered with this {@code DragSource}.
*
* @return all of this {@code DragSource}'s
* {@code DragSourceListener}s or an empty array if no
* such listeners are currently registered
*
* @see #addDragSourceListener
* @see #removeDragSourceListener
* @since 1.4
*/
public DragSourceListener[] getDragSourceListeners() {
return getListeners(DragSourceListener.class);
}
/**
* Adds the specified {@code DragSourceMotionListener} to this
* {@code DragSource} to receive drag motion events during drag
* operations initiated with this {@code DragSource}.
* If a {@code null} listener is specified, no action is taken and no
* exception is thrown.
*
* @param dsml the {@code DragSourceMotionListener} to add
*
* @see #removeDragSourceMotionListener
* @see #getDragSourceMotionListeners
* @since 1.4
*/
public void addDragSourceMotionListener(DragSourceMotionListener dsml) {
if (dsml != null) {
synchronized (this) {
motionListener = DnDEventMulticaster.add(motionListener, dsml);
}
}
}
/**
* Removes the specified {@code DragSourceMotionListener} from this
* {@code DragSource}.
* If a {@code null} listener is specified, no action is taken and no
* exception is thrown.
* If the listener specified by the argument was not previously added to
* this {@code DragSource}, no action is taken and no exception
* is thrown.
*
* @param dsml the {@code DragSourceMotionListener} to remove
*
* @see #addDragSourceMotionListener
* @see #getDragSourceMotionListeners
* @since 1.4
*/
public void removeDragSourceMotionListener(DragSourceMotionListener dsml) {
if (dsml != null) {
synchronized (this) {
motionListener = DnDEventMulticaster.remove(motionListener, dsml);
}
}
}
/**
* Gets all of the {@code DragSourceMotionListener}s
* registered with this {@code DragSource}.
*
* @return all of this {@code DragSource}'s
* {@code DragSourceMotionListener}s or an empty array if no
* such listeners are currently registered
*
* @see #addDragSourceMotionListener
* @see #removeDragSourceMotionListener
* @since 1.4
*/
public DragSourceMotionListener[] getDragSourceMotionListeners() {
return getListeners(DragSourceMotionListener.class);
}
/**
* Gets all the objects currently registered as
* <code><em>Foo</em>Listener</code>s upon this {@code DragSource}.
* <code><em>Foo</em>Listener</code>s are registered using the
* <code>add<em>Foo</em>Listener</code> method.
*
* @param <T> the type of listener objects
* @param listenerType the type of listeners requested; this parameter
* should specify an interface that descends from
* {@code java.util.EventListener}
* @return an array of all objects registered as
* <code><em>Foo</em>Listener</code>s on this
* {@code DragSource}, or an empty array if no such listeners
* have been added
* @exception ClassCastException if {@code listenerType}
* doesn't specify a class or interface that implements
* {@code java.util.EventListener}
*
* @see #getDragSourceListeners
* @see #getDragSourceMotionListeners
* @since 1.4
*/
public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
EventListener l = null;
if (listenerType == DragSourceListener.class) {
l = listener;
} else if (listenerType == DragSourceMotionListener.class) {
l = motionListener;
}
return DnDEventMulticaster.getListeners(l, listenerType);
}
/**
* This method calls {@code dragEnter} on the
* {@code DragSourceListener}s registered with this
* {@code DragSource}, and passes them the specified
* {@code DragSourceDragEvent}.
*
* @param dsde the {@code DragSourceDragEvent}
*/
void processDragEnter(DragSourceDragEvent dsde) {
DragSourceListener dsl = listener;
if (dsl != null) {
dsl.dragEnter(dsde);
}
}
/**
* This method calls {@code dragOver} on the
* {@code DragSourceListener}s registered with this
* {@code DragSource}, and passes them the specified
* {@code DragSourceDragEvent}.
*
* @param dsde the {@code DragSourceDragEvent}
*/
void processDragOver(DragSourceDragEvent dsde) {
DragSourceListener dsl = listener;
if (dsl != null) {
dsl.dragOver(dsde);
}
}
/**
* This method calls {@code dropActionChanged} on the
* {@code DragSourceListener}s registered with this
* {@code DragSource}, and passes them the specified
* {@code DragSourceDragEvent}.
*
* @param dsde the {@code DragSourceDragEvent}
*/
void processDropActionChanged(DragSourceDragEvent dsde) {
DragSourceListener dsl = listener;
if (dsl != null) {
dsl.dropActionChanged(dsde);
}
}
/**
* This method calls {@code dragExit} on the
* {@code DragSourceListener}s registered with this
* {@code DragSource}, and passes them the specified
* {@code DragSourceEvent}.
*
* @param dse the {@code DragSourceEvent}
*/
void processDragExit(DragSourceEvent dse) {
DragSourceListener dsl = listener;
if (dsl != null) {
dsl.dragExit(dse);
}
}
/**
* This method calls {@code dragDropEnd} on the
* {@code DragSourceListener}s registered with this
* {@code DragSource}, and passes them the specified
* {@code DragSourceDropEvent}.
*
* @param dsde the {@code DragSourceEvent}
*/
void processDragDropEnd(DragSourceDropEvent dsde) {
DragSourceListener dsl = listener;
if (dsl != null) {
dsl.dragDropEnd(dsde);
}
}
/**
* This method calls {@code dragMouseMoved} on the
* {@code DragSourceMotionListener}s registered with this
* {@code DragSource}, and passes them the specified
* {@code DragSourceDragEvent}.
*
* @param dsde the {@code DragSourceEvent}
*/
void processDragMouseMoved(DragSourceDragEvent dsde) {
DragSourceMotionListener dsml = motionListener;
if (dsml != null) {
dsml.dragMouseMoved(dsde);
}
}
/**
* Serializes this {@code DragSource}. This method first performs
* default serialization. Next, it writes out this object's
* {@code FlavorMap} if and only if it can be serialized. If not,
* {@code null} is written instead. Next, it writes out
* {@code Serializable} listeners registered with this
* object. Listeners are written in a {@code null}-terminated sequence
* of 0 or more pairs. The pair consists of a {@code String} and an
* {@code Object}; the {@code String} indicates the type of the
* {@code Object} and is one of the following:
* <ul>
* <li>{@code dragSourceListenerK} indicating a
* {@code DragSourceListener} object;
* <li>{@code dragSourceMotionListenerK} indicating a
* {@code DragSourceMotionListener} object.
* </ul>
*
* @serialData Either a {@code FlavorMap} instance, or
* {@code null}, followed by a {@code null}-terminated
* sequence of 0 or more pairs; the pair consists of a
* {@code String} and an {@code Object}; the
* {@code String} indicates the type of the {@code Object}
* and is one of the following:
* <ul>
* <li>{@code dragSourceListenerK} indicating a
* {@code DragSourceListener} object;
* <li>{@code dragSourceMotionListenerK} indicating a
* {@code DragSourceMotionListener} object.
* </ul>.
* @since 1.4
*/
private void writeObject(ObjectOutputStream s) throws IOException {
s.defaultWriteObject();
s.writeObject(SerializationTester.test(flavorMap) ? flavorMap : null);
DnDEventMulticaster.save(s, dragSourceListenerK, listener);
DnDEventMulticaster.save(s, dragSourceMotionListenerK, motionListener);
s.writeObject(null);
}
/**
* Deserializes this {@code DragSource}. This method first performs
* default deserialization. Next, this object's {@code FlavorMap} is
* deserialized by using the next object in the stream.
* If the resulting {@code FlavorMap} is {@code null}, this
* object's {@code FlavorMap} is set to the default FlavorMap for
* this thread's {@code ClassLoader}.
* Next, this object's listeners are deserialized by reading a
* {@code null}-terminated sequence of 0 or more key/value pairs
* from the stream:
* <ul>
* <li>If a key object is a {@code String} equal to
* {@code dragSourceListenerK}, a {@code DragSourceListener} is
* deserialized using the corresponding value object and added to this
* {@code DragSource}.
* <li>If a key object is a {@code String} equal to
* {@code dragSourceMotionListenerK}, a
* {@code DragSourceMotionListener} is deserialized using the
* corresponding value object and added to this {@code DragSource}.
* <li>Otherwise, the key/value pair is skipped.
* </ul>
*
* @see java.awt.datatransfer.SystemFlavorMap#getDefaultFlavorMap
* @since 1.4
*/
private void readObject(ObjectInputStream s)
throws ClassNotFoundException, IOException {
s.defaultReadObject();
// 'flavorMap' was written explicitly
flavorMap = (FlavorMap)s.readObject();
// Implementation assumes 'flavorMap' is never null.
if (flavorMap == null) {
flavorMap = SystemFlavorMap.getDefaultFlavorMap();
}
Object keyOrNull;
while (null != (keyOrNull = s.readObject())) {
String key = ((String)keyOrNull).intern();
if (dragSourceListenerK == key) {
addDragSourceListener((DragSourceListener)(s.readObject()));
} else if (dragSourceMotionListenerK == key) {
addDragSourceMotionListener(
(DragSourceMotionListener)(s.readObject()));
} else {
// skip value for unrecognized key
s.readObject();
}
}
}
/**
* Returns the drag gesture motion threshold. The drag gesture motion threshold
* defines the recommended behavior for {@link MouseDragGestureRecognizer}s.
* <p>
* If the system property {@code awt.dnd.drag.threshold} is set to
* a positive integer, this method returns the value of the system property;
* otherwise if a pertinent desktop property is available and supported by
* the implementation of the Java platform, this method returns the value of
* that property; otherwise this method returns some default value.
* The pertinent desktop property can be queried using
* {@code java.awt.Toolkit.getDesktopProperty("DnD.gestureMotionThreshold")}.
*
* @return the drag gesture motion threshold
* @see MouseDragGestureRecognizer
* @since 1.5
*/
public static int getDragThreshold() {
int ts = AccessController.doPrivileged(
new GetIntegerAction("awt.dnd.drag.threshold", 0)).intValue();
if (ts > 0) {
return ts;
} else {
Integer td = (Integer)Toolkit.getDefaultToolkit().
getDesktopProperty("DnD.gestureMotionThreshold");
if (td != null) {
return td.intValue();
}
}
return 5;
}
/*
* fields
*/
private transient FlavorMap flavorMap = SystemFlavorMap.getDefaultFlavorMap();
private transient DragSourceListener listener;
private transient DragSourceMotionListener motionListener;
}