JDK8/Java8源码在线阅读
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*
* This code is distributed in the hope that it will be useful, but WITHOUT
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* 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).
*
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*
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package sun.awt.dnd;
import java.awt.Component;
import java.awt.Point;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.awt.dnd.DnDConstants;
import java.awt.dnd.DropTarget;
import java.awt.dnd.DropTargetContext;
import java.awt.dnd.DropTargetListener;
import java.awt.dnd.DropTargetEvent;
import java.awt.dnd.DropTargetDragEvent;
import java.awt.dnd.DropTargetDropEvent;
import java.awt.dnd.InvalidDnDOperationException;
import java.awt.dnd.peer.DropTargetContextPeer;
import java.util.HashSet;
import java.util.Map;
import java.util.Arrays;
import sun.util.logging.PlatformLogger;
import java.io.IOException;
import java.io.InputStream;
import sun.awt.AppContext;
import sun.awt.SunToolkit;
import sun.awt.datatransfer.DataTransferer;
import sun.awt.datatransfer.ToolkitThreadBlockedHandler;
import sun.security.util.SecurityConstants;
/**
* <p>
* The SunDropTargetContextPeer class is the generic class responsible for handling
* the interaction between a windowing systems DnD system and Java.
* </p>
*
* @since JDK1.3.1
*
*/
public abstract class SunDropTargetContextPeer implements DropTargetContextPeer, Transferable {
/*
* A boolean constant that requires the peer to wait until the
* SunDropTargetEvent is processed and return the status back
* to the native code.
*/
public static final boolean DISPATCH_SYNC = true;
private DropTarget currentDT;
private DropTargetContext currentDTC;
private long[] currentT;
private int currentA; // target actions
private int currentSA; // source actions
private int currentDA; // current drop action
private int previousDA;
private long nativeDragContext;
private Transferable local;
private boolean dragRejected = false;
protected int dropStatus = STATUS_NONE;
protected boolean dropComplete = false;
// The flag is used to monitor whether the drop action is
// handled by a user. That allows to distinct during
// which operation getTransferData() method is invoked.
boolean dropInProcess = false;
/*
* global lock
*/
protected static final Object _globalLock = new Object();
private static final PlatformLogger dndLog = PlatformLogger.getLogger("sun.awt.dnd.SunDropTargetContextPeer");
/*
* a primitive mechanism for advertising intra-JVM Transferables
*/
protected static Transferable currentJVMLocalSourceTransferable = null;
public static void setCurrentJVMLocalSourceTransferable(Transferable t) throws InvalidDnDOperationException {
synchronized(_globalLock) {
if (t != null && currentJVMLocalSourceTransferable != null) {
throw new InvalidDnDOperationException();
} else {
currentJVMLocalSourceTransferable = t;
}
}
}
/**
* obtain the transferable iff the operation is in the same VM
*/
private static Transferable getJVMLocalSourceTransferable() {
return currentJVMLocalSourceTransferable;
}
/*
* constants used by dropAccept() or dropReject()
*/
protected final static int STATUS_NONE = 0; // none pending
protected final static int STATUS_WAIT = 1; // drop pending
protected final static int STATUS_ACCEPT = 2;
protected final static int STATUS_REJECT = -1;
/**
* create the peer
*/
public SunDropTargetContextPeer() {
super();
}
/**
* @return the DropTarget associated with this peer
*/
public DropTarget getDropTarget() { return currentDT; }
/**
* @param actions set the current actions
*/
public synchronized void setTargetActions(int actions) {
currentA = actions &
(DnDConstants.ACTION_COPY_OR_MOVE | DnDConstants.ACTION_LINK);
}
/**
* @return the current target actions
*/
public int getTargetActions() {
return currentA;
}
/**
* get the Transferable associated with the drop
*/
public Transferable getTransferable() {
return this;
}
/**
* @return current DataFlavors available
*/
// NOTE: This method may be called by privileged threads.
// DO NOT INVOKE CLIENT CODE ON THIS THREAD!
public DataFlavor[] getTransferDataFlavors() {
final Transferable localTransferable = local;
if (localTransferable != null) {
return localTransferable.getTransferDataFlavors();
} else {
return DataTransferer.getInstance().getFlavorsForFormatsAsArray
(currentT, DataTransferer.adaptFlavorMap
(currentDT.getFlavorMap()));
}
}
/**
* @return if the flavor is supported
*/
public boolean isDataFlavorSupported(DataFlavor df) {
Transferable localTransferable = local;
if (localTransferable != null) {
return localTransferable.isDataFlavorSupported(df);
} else {
return DataTransferer.getInstance().getFlavorsForFormats
(currentT, DataTransferer.adaptFlavorMap
(currentDT.getFlavorMap())).
containsKey(df);
}
}
/**
* @return the data
*/
public Object getTransferData(DataFlavor df)
throws UnsupportedFlavorException, IOException,
InvalidDnDOperationException
{
SecurityManager sm = System.getSecurityManager();
try {
if (!dropInProcess && sm != null) {
sm.checkPermission(SecurityConstants.AWT.ACCESS_CLIPBOARD_PERMISSION);
}
} catch (Exception e) {
Thread currentThread = Thread.currentThread();
currentThread.getUncaughtExceptionHandler().uncaughtException(currentThread, e);
return null;
}
Long lFormat = null;
Transferable localTransferable = local;
if (localTransferable != null) {
return localTransferable.getTransferData(df);
}
if (dropStatus != STATUS_ACCEPT || dropComplete) {
throw new InvalidDnDOperationException("No drop current");
}
Map flavorMap = DataTransferer.getInstance().getFlavorsForFormats
(currentT, DataTransferer.adaptFlavorMap
(currentDT.getFlavorMap()));
lFormat = (Long)flavorMap.get(df);
if (lFormat == null) {
throw new UnsupportedFlavorException(df);
}
if (df.isRepresentationClassRemote() &&
currentDA != DnDConstants.ACTION_LINK) {
throw new InvalidDnDOperationException("only ACTION_LINK is permissable for transfer of java.rmi.Remote objects");
}
final long format = lFormat.longValue();
Object ret = getNativeData(format);
if (ret instanceof byte[]) {
try {
return DataTransferer.getInstance().
translateBytes((byte[])ret, df, format, this);
} catch (IOException e) {
throw new InvalidDnDOperationException(e.getMessage());
}
} else if (ret instanceof InputStream) {
try {
return DataTransferer.getInstance().
translateStream((InputStream)ret, df, format, this);
} catch (IOException e) {
throw new InvalidDnDOperationException(e.getMessage());
}
} else {
throw new IOException("no native data was transfered");
}
}
protected abstract Object getNativeData(long format)
throws IOException;
/**
* @return if the transfer is a local one
*/
public boolean isTransferableJVMLocal() {
return local != null || getJVMLocalSourceTransferable() != null;
}
private int handleEnterMessage(final Component component,
final int x, final int y,
final int dropAction,
final int actions, final long[] formats,
final long nativeCtxt) {
return postDropTargetEvent(component, x, y, dropAction, actions,
formats, nativeCtxt,
SunDropTargetEvent.MOUSE_ENTERED,
SunDropTargetContextPeer.DISPATCH_SYNC);
}
/**
* actual processing on EventQueue Thread
*/
protected void processEnterMessage(SunDropTargetEvent event) {
Component c = (Component)event.getSource();
DropTarget dt = c.getDropTarget();
Point hots = event.getPoint();
local = getJVMLocalSourceTransferable();
if (currentDTC != null) { // some wreckage from last time
currentDTC.removeNotify();
currentDTC = null;
}
if (c.isShowing() && dt != null && dt.isActive()) {
currentDT = dt;
currentDTC = currentDT.getDropTargetContext();
currentDTC.addNotify(this);
currentA = dt.getDefaultActions();
try {
((DropTargetListener)dt).dragEnter(new DropTargetDragEvent(currentDTC,
hots,
currentDA,
currentSA));
} catch (Exception e) {
e.printStackTrace();
currentDA = DnDConstants.ACTION_NONE;
}
} else {
currentDT = null;
currentDTC = null;
currentDA = DnDConstants.ACTION_NONE;
currentSA = DnDConstants.ACTION_NONE;
currentA = DnDConstants.ACTION_NONE;
}
}
/**
* upcall to handle exit messages
*/
private void handleExitMessage(final Component component,
final long nativeCtxt) {
/*
* Even though the return value is irrelevant for this event, it is
* dispatched synchronously to fix 4393148 properly.
*/
postDropTargetEvent(component, 0, 0, DnDConstants.ACTION_NONE,
DnDConstants.ACTION_NONE, null, nativeCtxt,
SunDropTargetEvent.MOUSE_EXITED,
SunDropTargetContextPeer.DISPATCH_SYNC);
}
/**
*
*/
protected void processExitMessage(SunDropTargetEvent event) {
Component c = (Component)event.getSource();
DropTarget dt = c.getDropTarget();
DropTargetContext dtc = null;
if (dt == null) {
currentDT = null;
currentT = null;
if (currentDTC != null) {
currentDTC.removeNotify();
}
currentDTC = null;
return;
}
if (dt != currentDT) {
if (currentDTC != null) {
currentDTC.removeNotify();
}
currentDT = dt;
currentDTC = dt.getDropTargetContext();
currentDTC.addNotify(this);
}
dtc = currentDTC;
if (dt.isActive()) try {
((DropTargetListener)dt).dragExit(new DropTargetEvent(dtc));
} catch (Exception e) {
e.printStackTrace();
} finally {
currentA = DnDConstants.ACTION_NONE;
currentSA = DnDConstants.ACTION_NONE;
currentDA = DnDConstants.ACTION_NONE;
currentDT = null;
currentT = null;
currentDTC.removeNotify();
currentDTC = null;
local = null;
dragRejected = false;
}
}
private int handleMotionMessage(final Component component,
final int x, final int y,
final int dropAction,
final int actions, final long[] formats,
final long nativeCtxt) {
return postDropTargetEvent(component, x, y, dropAction, actions,
formats, nativeCtxt,
SunDropTargetEvent.MOUSE_DRAGGED,
SunDropTargetContextPeer.DISPATCH_SYNC);
}
/**
*
*/
protected void processMotionMessage(SunDropTargetEvent event,
boolean operationChanged) {
Component c = (Component)event.getSource();
Point hots = event.getPoint();
int id = event.getID();
DropTarget dt = c.getDropTarget();
DropTargetContext dtc = null;
if (c.isShowing() && (dt != null) && dt.isActive()) {
if (currentDT != dt) {
if (currentDTC != null) {
currentDTC.removeNotify();
}
currentDT = dt;
currentDTC = null;
}
dtc = currentDT.getDropTargetContext();
if (dtc != currentDTC) {
if (currentDTC != null) {
currentDTC.removeNotify();
}
currentDTC = dtc;
currentDTC.addNotify(this);
}
currentA = currentDT.getDefaultActions();
try {
DropTargetDragEvent dtde = new DropTargetDragEvent(dtc,
hots,
currentDA,
currentSA);
DropTargetListener dtl = (DropTargetListener)dt;
if (operationChanged) {
dtl.dropActionChanged(dtde);
} else {
dtl.dragOver(dtde);
}
if (dragRejected) {
currentDA = DnDConstants.ACTION_NONE;
}
} catch (Exception e) {
e.printStackTrace();
currentDA = DnDConstants.ACTION_NONE;
}
} else {
currentDA = DnDConstants.ACTION_NONE;
}
}
/**
* upcall to handle the Drop message
*/
private void handleDropMessage(final Component component,
final int x, final int y,
final int dropAction, final int actions,
final long[] formats,
final long nativeCtxt) {
postDropTargetEvent(component, x, y, dropAction, actions,
formats, nativeCtxt,
SunDropTargetEvent.MOUSE_DROPPED,
!SunDropTargetContextPeer.DISPATCH_SYNC);
}
/**
*
*/
protected void processDropMessage(SunDropTargetEvent event) {
Component c = (Component)event.getSource();
Point hots = event.getPoint();
DropTarget dt = c.getDropTarget();
dropStatus = STATUS_WAIT; // drop pending ACK
dropComplete = false;
if (c.isShowing() && dt != null && dt.isActive()) {
DropTargetContext dtc = dt.getDropTargetContext();
currentDT = dt;
if (currentDTC != null) {
currentDTC.removeNotify();
}
currentDTC = dtc;
currentDTC.addNotify(this);
currentA = dt.getDefaultActions();
synchronized(_globalLock) {
if ((local = getJVMLocalSourceTransferable()) != null)
setCurrentJVMLocalSourceTransferable(null);
}
dropInProcess = true;
try {
((DropTargetListener)dt).drop(new DropTargetDropEvent(dtc,
hots,
currentDA,
currentSA,
local != null));
} finally {
if (dropStatus == STATUS_WAIT) {
rejectDrop();
} else if (dropComplete == false) {
dropComplete(false);
}
dropInProcess = false;
}
} else {
rejectDrop();
}
}
protected int postDropTargetEvent(final Component component,
final int x, final int y,
final int dropAction,
final int actions,
final long[] formats,
final long nativeCtxt,
final int eventID,
final boolean dispatchType) {
AppContext appContext = SunToolkit.targetToAppContext(component);
EventDispatcher dispatcher =
new EventDispatcher(this, dropAction, actions, formats, nativeCtxt,
dispatchType);
SunDropTargetEvent event =
new SunDropTargetEvent(component, eventID, x, y, dispatcher);
if (dispatchType == SunDropTargetContextPeer.DISPATCH_SYNC) {
DataTransferer.getInstance().getToolkitThreadBlockedHandler().lock();
}
// schedule callback
SunToolkit.postEvent(appContext, event);
eventPosted(event);
if (dispatchType == SunDropTargetContextPeer.DISPATCH_SYNC) {
while (!dispatcher.isDone()) {
DataTransferer.getInstance().getToolkitThreadBlockedHandler().enter();
}
DataTransferer.getInstance().getToolkitThreadBlockedHandler().unlock();
// return target's response
return dispatcher.getReturnValue();
} else {
return 0;
}
}
/**
* acceptDrag
*/
public synchronized void acceptDrag(int dragOperation) {
if (currentDT == null) {
throw new InvalidDnDOperationException("No Drag pending");
}
currentDA = mapOperation(dragOperation);
if (currentDA != DnDConstants.ACTION_NONE) {
dragRejected = false;
}
}
/**
* rejectDrag
*/
public synchronized void rejectDrag() {
if (currentDT == null) {
throw new InvalidDnDOperationException("No Drag pending");
}
currentDA = DnDConstants.ACTION_NONE;
dragRejected = true;
}
/**
* acceptDrop
*/
public synchronized void acceptDrop(int dropOperation) {
if (dropOperation == DnDConstants.ACTION_NONE)
throw new IllegalArgumentException("invalid acceptDrop() action");
if (dropStatus == STATUS_WAIT || dropStatus == STATUS_ACCEPT) {
currentDA = currentA = mapOperation(dropOperation & currentSA);
dropStatus = STATUS_ACCEPT;
dropComplete = false;
} else {
throw new InvalidDnDOperationException("invalid acceptDrop()");
}
}
/**
* reject Drop
*/
public synchronized void rejectDrop() {
if (dropStatus != STATUS_WAIT) {
throw new InvalidDnDOperationException("invalid rejectDrop()");
}
dropStatus = STATUS_REJECT;
/*
* Fix for 4285634.
* The target rejected the drop means that it doesn't perform any
* drop action. This change is to make Solaris behavior consistent
* with Win32.
*/
currentDA = DnDConstants.ACTION_NONE;
dropComplete(false);
}
/**
* mapOperation
*/
private int mapOperation(int operation) {
int[] operations = {
DnDConstants.ACTION_MOVE,
DnDConstants.ACTION_COPY,
DnDConstants.ACTION_LINK,
};
int ret = DnDConstants.ACTION_NONE;
for (int i = 0; i < operations.length; i++) {
if ((operation & operations[i]) == operations[i]) {
ret = operations[i];
break;
}
}
return ret;
}
/**
* signal drop complete
*/
public synchronized void dropComplete(boolean success) {
if (dropStatus == STATUS_NONE) {
throw new InvalidDnDOperationException("No Drop pending");
}
if (currentDTC != null) currentDTC.removeNotify();
currentDT = null;
currentDTC = null;
currentT = null;
currentA = DnDConstants.ACTION_NONE;
synchronized(_globalLock) {
currentJVMLocalSourceTransferable = null;
}
dropStatus = STATUS_NONE;
dropComplete = true;
try {
doDropDone(success, currentDA, local != null);
} finally {
currentDA = DnDConstants.ACTION_NONE;
// The native context is invalid after the drop is done.
// Clear the reference to prohibit access.
nativeDragContext = 0;
}
}
protected abstract void doDropDone(boolean success,
int dropAction, boolean isLocal);
protected synchronized long getNativeDragContext() {
return nativeDragContext;
}
protected void eventPosted(SunDropTargetEvent e) {}
protected void eventProcessed(SunDropTargetEvent e, int returnValue,
boolean dispatcherDone) {}
protected static class EventDispatcher {
private final SunDropTargetContextPeer peer;
// context fields
private final int dropAction;
private final int actions;
private final long[] formats;
private long nativeCtxt;
private final boolean dispatchType;
private boolean dispatcherDone = false;
// dispatcher state fields
private int returnValue = 0;
// set of events to be dispatched by this dispatcher
private final HashSet eventSet = new HashSet(3);
static final ToolkitThreadBlockedHandler handler =
DataTransferer.getInstance().getToolkitThreadBlockedHandler();
EventDispatcher(SunDropTargetContextPeer peer,
int dropAction,
int actions,
long[] formats,
long nativeCtxt,
boolean dispatchType) {
this.peer = peer;
this.nativeCtxt = nativeCtxt;
this.dropAction = dropAction;
this.actions = actions;
this.formats =
(null == formats) ? null : Arrays.copyOf(formats, formats.length);
this.dispatchType = dispatchType;
}
void dispatchEvent(SunDropTargetEvent e) {
int id = e.getID();
switch (id) {
case SunDropTargetEvent.MOUSE_ENTERED:
dispatchEnterEvent(e);
break;
case SunDropTargetEvent.MOUSE_DRAGGED:
dispatchMotionEvent(e);
break;
case SunDropTargetEvent.MOUSE_EXITED:
dispatchExitEvent(e);
break;
case SunDropTargetEvent.MOUSE_DROPPED:
dispatchDropEvent(e);
break;
default:
throw new InvalidDnDOperationException();
}
}
private void dispatchEnterEvent(SunDropTargetEvent e) {
synchronized (peer) {
// store the drop action here to track operation changes
peer.previousDA = dropAction;
// setup peer context
peer.nativeDragContext = nativeCtxt;
peer.currentT = formats;
peer.currentSA = actions;
peer.currentDA = dropAction;
// To allow data retrieval.
peer.dropStatus = STATUS_ACCEPT;
peer.dropComplete = false;
try {
peer.processEnterMessage(e);
} finally {
peer.dropStatus = STATUS_NONE;
}
setReturnValue(peer.currentDA);
}
}
private void dispatchMotionEvent(SunDropTargetEvent e) {
synchronized (peer) {
boolean operationChanged = peer.previousDA != dropAction;
peer.previousDA = dropAction;
// setup peer context
peer.nativeDragContext = nativeCtxt;
peer.currentT = formats;
peer.currentSA = actions;
peer.currentDA = dropAction;
// To allow data retrieval.
peer.dropStatus = STATUS_ACCEPT;
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