Transferable
+ * to and from Swing components. The Transferable is used to
+ * represent data that is exchanged via a cut, copy, or paste
+ * to/from a clipboard. It is also used in drag-and-drop operations
+ * to represent a drag from a component, and a drop to a component.
+ * Swing provides functionality that automatically supports cut, copy,
+ * and paste keyboard bindings that use the functionality provided by
+ * an implementation of this class. Swing also provides functionality
+ * that automatically supports drag and drop that uses the functionality
+ * provided by an implementation of this class. The Swing developer can
+ * concentrate on specifying the semantics of a transfer primarily by setting
+ * the transferHandler property on a Swing component.
+ *
+ * This class is implemented to provide a default behavior of transferring
+ * a component property simply by specifying the name of the property in
+ * the constructor. For example, to transfer the foreground color from
+ * one component to another either via the clipboard or a drag and drop operation
+ * a TransferHandler can be constructed with the string "foreground". The
+ * built in support will use the color returned by getForeground as the source
+ * of the transfer, and setForeground for the target of a transfer.
+ *
+ * Please see
+ *
+ * How to Use Drag and Drop and Data Transfer,
+ * a section in The Java Tutorial, for more information.
+ *
+ *
+ * @author Timothy Prinzing
+ * @author Shannon Hickey
+ * @since 1.4
+ */
+@SuppressWarnings("serial")
+public class TransferHandler implements Serializable {
+
+ /**
+ * An int representing no transfer action.
+ */
+ public static final int NONE = DnDConstants.ACTION_NONE;
+
+ /**
+ * An int representing a "copy" transfer action.
+ * This value is used when data is copied to a clipboard
+ * or copied elsewhere in a drag and drop operation.
+ */
+ public static final int COPY = DnDConstants.ACTION_COPY;
+
+ /**
+ * An int representing a "move" transfer action.
+ * This value is used when data is moved to a clipboard (i.e. a cut)
+ * or moved elsewhere in a drag and drop operation.
+ */
+ public static final int MOVE = DnDConstants.ACTION_MOVE;
+
+ /**
+ * An int representing a source action capability of either
+ * "copy" or "move".
+ */
+ public static final int COPY_OR_MOVE = DnDConstants.ACTION_COPY_OR_MOVE;
+
+ /**
+ * An int representing a "link" transfer action.
+ * This value is used to specify that data should be linked in a drag
+ * and drop operation.
+ *
+ * @see java.awt.dnd.DnDConstants#ACTION_LINK
+ * @since 1.6
+ */
+ public static final int LINK = DnDConstants.ACTION_LINK;
+
+ /**
+ * An interface to tag things with a {@code getTransferHandler} method.
+ */
+ interface HasGetTransferHandler {
+
+ /** Returns the {@code TransferHandler}.
+ *
+ * @return The {@code TransferHandler} or {@code null}
+ */
+ public TransferHandler getTransferHandler();
+ }
+
+ /**
+ * Represents a location where dropped data should be inserted.
+ * This is a base class that only encapsulates a point.
+ * Components supporting drop may provide subclasses of this
+ * containing more information.
+ *
+ * Developers typically shouldn't create instances of, or extend, this
+ * class. Instead, these are something provided by the DnD
+ * implementation by TransferSupport instances and by
+ * components with a getDropLocation() method.
+ *
+ * @see javax.swing.TransferHandler.TransferSupport#getDropLocation
+ * @since 1.6
+ */
+ public static class DropLocation {
+ private final Point dropPoint;
+
+ /**
+ * Constructs a drop location for the given point.
+ *
+ * @param dropPoint the drop point, representing the mouse's
+ * current location within the component.
+ * @throws IllegalArgumentException if the point
+ * is null
+ */
+ protected DropLocation(Point dropPoint) {
+ if (dropPoint == null) {
+ throw new IllegalArgumentException("Point cannot be null");
+ }
+
+ this.dropPoint = new Point(dropPoint);
+ }
+
+ /**
+ * Returns the drop point, representing the mouse's
+ * current location within the component.
+ *
+ * @return the drop point.
+ */
+ public final Point getDropPoint() {
+ return new Point(dropPoint);
+ }
+
+ /**
+ * Returns a string representation of this drop location.
+ * This method is intended to be used for debugging purposes,
+ * and the content and format of the returned string may vary
+ * between implementations.
+ *
+ * @return a string representation of this drop location
+ */
+ public String toString() {
+ return getClass().getName() + "[dropPoint=" + dropPoint + "]";
+ }
+ };
+
+ /**
+ * This class encapsulates all relevant details of a clipboard
+ * or drag and drop transfer, and also allows for customizing
+ * aspects of the drag and drop experience.
+ *
+ * The main purpose of this class is to provide the information + * needed by a developer to determine the suitability of a + * transfer or to import the data contained within. But it also + * doubles as a controller for customizing properties during drag + * and drop, such as whether or not to show the drop location, + * and which drop action to use. + *
+ * Developers typically need not create instances of this
+ * class. Instead, they are something provided by the DnD
+ * implementation to certain methods in TransferHandler.
+ *
+ * @see #canImport(TransferHandler.TransferSupport)
+ * @see #importData(TransferHandler.TransferSupport)
+ * @since 1.6
+ */
+ public final static class TransferSupport {
+ private boolean isDrop;
+ private Component component;
+
+ private boolean showDropLocationIsSet;
+ private boolean showDropLocation;
+
+ private int dropAction = -1;
+
+ /**
+ * The source is a {@code DropTargetDragEvent} or
+ * {@code DropTargetDropEvent} for drops,
+ * and a {@code Transferable} otherwise
+ */
+ private Object source;
+
+ private DropLocation dropLocation;
+
+ /**
+ * Create a TransferSupport with isDrop()
+ * true for the given component, event, and index.
+ *
+ * @param component the target component
+ * @param event a DropTargetEvent
+ */
+ private TransferSupport(Component component,
+ DropTargetEvent event) {
+
+ isDrop = true;
+ setDNDVariables(component, event);
+ }
+
+ /**
+ * Create a TransferSupport with isDrop()
+ * false for the given component and
+ * Transferable.
+ *
+ * @param component the target component
+ * @param transferable the transferable
+ * @throws NullPointerException if either parameter
+ * is null
+ */
+ public TransferSupport(Component component, Transferable transferable) {
+ if (component == null) {
+ throw new NullPointerException("component is null");
+ }
+
+ if (transferable == null) {
+ throw new NullPointerException("transferable is null");
+ }
+
+ isDrop = false;
+ this.component = component;
+ this.source = transferable;
+ }
+
+ /**
+ * Allows for a single instance to be reused during DnD.
+ *
+ * @param component the target component
+ * @param event a DropTargetEvent
+ */
+ private void setDNDVariables(Component component,
+ DropTargetEvent event) {
+
+ assert isDrop;
+
+ this.component = component;
+ this.source = event;
+ dropLocation = null;
+ dropAction = -1;
+ showDropLocationIsSet = false;
+
+ if (source == null) {
+ return;
+ }
+
+ assert source instanceof DropTargetDragEvent ||
+ source instanceof DropTargetDropEvent;
+
+ Point p = source instanceof DropTargetDragEvent
+ ? ((DropTargetDragEvent)source).getLocation()
+ : ((DropTargetDropEvent)source).getLocation();
+
+ if (SunToolkit.isInstanceOf(component, "javax.swing.text.JTextComponent")) {
+ dropLocation = SwingAccessor.getJTextComponentAccessor().
+ dropLocationForPoint((JTextComponent)component, p);
+ } else if (component instanceof JComponent) {
+ dropLocation = ((JComponent)component).dropLocationForPoint(p);
+ }
+
+ /*
+ * The drop location may be null at this point if the component
+ * doesn't return custom drop locations. In this case, a point-only
+ * drop location will be created lazily when requested.
+ */
+ }
+
+ /**
+ * Returns whether or not this TransferSupport
+ * represents a drop operation.
+ *
+ * @return true if this is a drop operation,
+ * false otherwise.
+ */
+ public boolean isDrop() {
+ return isDrop;
+ }
+
+ /**
+ * Returns the target component of this transfer.
+ *
+ * @return the target component
+ */
+ public Component getComponent() {
+ return component;
+ }
+
+ /**
+ * Checks that this is a drop and throws an
+ * {@code IllegalStateException} if it isn't.
+ *
+ * @throws IllegalStateException if {@code isDrop} is false.
+ */
+ private void assureIsDrop() {
+ if (!isDrop) {
+ throw new IllegalStateException("Not a drop");
+ }
+ }
+
+ /**
+ * Returns the current (non-{@code null}) drop location for the component,
+ * when this {@code TransferSupport} represents a drop.
+ *
+ * Note: For components with built-in drop support, this location + * will be a subclass of {@code DropLocation} of the same type + * returned by that component's {@code getDropLocation} method. + *
+ * This method is only for use with drag and drop transfers. + * Calling it when {@code isDrop()} is {@code false} results + * in an {@code IllegalStateException}. + * + * @return the drop location + * @throws IllegalStateException if this is not a drop + * @see #isDrop() + */ + public DropLocation getDropLocation() { + assureIsDrop(); + + if (dropLocation == null) { + /* + * component didn't give us a custom drop location, + * so lazily create a point-only location + */ + Point p = source instanceof DropTargetDragEvent + ? ((DropTargetDragEvent)source).getLocation() + : ((DropTargetDropEvent)source).getLocation(); + + dropLocation = new DropLocation(p); + } + + return dropLocation; + } + + /** + * Sets whether or not the drop location should be visually indicated + * for the transfer - which must represent a drop. This is applicable to + * those components that automatically + * show the drop location when appropriate during a drag and drop + * operation). By default, the drop location is shown only when the + * {@code TransferHandler} has said it can accept the import represented + * by this {@code TransferSupport}. With this method you can force the + * drop location to always be shown, or always not be shown. + *
+ * This method is only for use with drag and drop transfers. + * Calling it when {@code isDrop()} is {@code false} results + * in an {@code IllegalStateException}. + * + * @param showDropLocation whether or not to indicate the drop location + * @throws IllegalStateException if this is not a drop + * @see #isDrop() + */ + public void setShowDropLocation(boolean showDropLocation) { + assureIsDrop(); + + this.showDropLocation = showDropLocation; + this.showDropLocationIsSet = true; + } + + /** + * Sets the drop action for the transfer - which must represent a drop + * - to the given action, + * instead of the default user drop action. The action must be + * supported by the source's drop actions, and must be one + * of {@code COPY}, {@code MOVE} or {@code LINK}. + *
+ * This method is only for use with drag and drop transfers. + * Calling it when {@code isDrop()} is {@code false} results + * in an {@code IllegalStateException}. + * + * @param dropAction the drop action + * @throws IllegalStateException if this is not a drop + * @throws IllegalArgumentException if an invalid action is specified + * @see #getDropAction + * @see #getUserDropAction + * @see #getSourceDropActions + * @see #isDrop() + */ + public void setDropAction(int dropAction) { + assureIsDrop(); + + int action = dropAction & getSourceDropActions(); + + if (!(action == COPY || action == MOVE || action == LINK)) { + throw new IllegalArgumentException("unsupported drop action: " + dropAction); + } + + this.dropAction = dropAction; + } + + /** + * Returns the action chosen for the drop, when this + * {@code TransferSupport} represents a drop. + *
+ * Unless explicitly chosen by way of {@code setDropAction}, + * this returns the user drop action provided by + * {@code getUserDropAction}. + *
+ * You may wish to query this in {@code TransferHandler}'s + * {@code importData} method to customize processing based + * on the action. + *
+ * This method is only for use with drag and drop transfers. + * Calling it when {@code isDrop()} is {@code false} results + * in an {@code IllegalStateException}. + * + * @return the action chosen for the drop + * @throws IllegalStateException if this is not a drop + * @see #setDropAction + * @see #getUserDropAction + * @see #isDrop() + */ + public int getDropAction() { + return dropAction == -1 ? getUserDropAction() : dropAction; + } + + /** + * Returns the user drop action for the drop, when this + * {@code TransferSupport} represents a drop. + *
+ * The user drop action is chosen for a drop as described in the + * documentation for {@link java.awt.dnd.DropTargetDragEvent} and + * {@link java.awt.dnd.DropTargetDropEvent}. A different action + * may be chosen as the drop action by way of the {@code setDropAction} + * method. + *
+ * You may wish to query this in {@code TransferHandler}'s + * {@code canImport} method when determining the suitability of a + * drop or when deciding on a drop action to explicitly choose. + *
+ * This method is only for use with drag and drop transfers. + * Calling it when {@code isDrop()} is {@code false} results + * in an {@code IllegalStateException}. + * + * @return the user drop action + * @throws IllegalStateException if this is not a drop + * @see #setDropAction + * @see #getDropAction + * @see #isDrop() + */ + public int getUserDropAction() { + assureIsDrop(); + + return (source instanceof DropTargetDragEvent) + ? ((DropTargetDragEvent)source).getDropAction() + : ((DropTargetDropEvent)source).getDropAction(); + } + + /** + * Returns the drag source's supported drop actions, when this + * {@code TransferSupport} represents a drop. + *
+ * The source actions represent the set of actions supported by the + * source of this transfer, and are represented as some bitwise-OR + * combination of {@code COPY}, {@code MOVE} and {@code LINK}. + * You may wish to query this in {@code TransferHandler}'s + * {@code canImport} method when determining the suitability of a drop + * or when deciding on a drop action to explicitly choose. To determine + * if a particular action is supported by the source, bitwise-AND + * the action with the source drop actions, and then compare the result + * against the original action. For example: + *
+ * boolean copySupported = (COPY & getSourceDropActions()) == COPY; + *+ *
+ * This method is only for use with drag and drop transfers.
+ * Calling it when {@code isDrop()} is {@code false} results
+ * in an {@code IllegalStateException}.
+ *
+ * @return the drag source's supported drop actions
+ * @throws IllegalStateException if this is not a drop
+ * @see #isDrop()
+ */
+ public int getSourceDropActions() {
+ assureIsDrop();
+
+ return (source instanceof DropTargetDragEvent)
+ ? ((DropTargetDragEvent)source).getSourceActions()
+ : ((DropTargetDropEvent)source).getSourceActions();
+ }
+
+ /**
+ * Returns the data flavors for this transfer.
+ *
+ * @return the data flavors for this transfer
+ */
+ public DataFlavor[] getDataFlavors() {
+ if (isDrop) {
+ if (source instanceof DropTargetDragEvent) {
+ return ((DropTargetDragEvent)source).getCurrentDataFlavors();
+ } else {
+ return ((DropTargetDropEvent)source).getCurrentDataFlavors();
+ }
+ }
+
+ return ((Transferable)source).getTransferDataFlavors();
+ }
+
+ /**
+ * Returns whether or not the given data flavor is supported.
+ *
+ * @param df the DataFlavor to test
+ * @return whether or not the given flavor is supported.
+ */
+ public boolean isDataFlavorSupported(DataFlavor df) {
+ if (isDrop) {
+ if (source instanceof DropTargetDragEvent) {
+ return ((DropTargetDragEvent)source).isDataFlavorSupported(df);
+ } else {
+ return ((DropTargetDropEvent)source).isDataFlavorSupported(df);
+ }
+ }
+
+ return ((Transferable)source).isDataFlavorSupported(df);
+ }
+
+ /**
+ * Returns the Transferable associated with this transfer.
+ *
+ * Note: Unless it is necessary to fetch the Transferable
+ * directly, use one of the other methods on this class to inquire about
+ * the transfer. This may perform better than fetching the
+ * Transferable and asking it directly.
+ *
+ * @return the Transferable associated with this transfer
+ */
+ public Transferable getTransferable() {
+ if (isDrop) {
+ if (source instanceof DropTargetDragEvent) {
+ return ((DropTargetDragEvent)source).getTransferable();
+ } else {
+ return ((DropTargetDropEvent)source).getTransferable();
+ }
+ }
+
+ return (Transferable)source;
+ }
+ }
+
+
+ /**
+ * Returns an {@code Action} that performs cut operations to the
+ * clipboard. When performed, this action operates on the {@code JComponent}
+ * source of the {@code ActionEvent} by invoking {@code exportToClipboard},
+ * with a {@code MOVE} action, on the component's {@code TransferHandler}.
+ *
+ * @return an {@code Action} for performing cuts to the clipboard
+ */
+ public static Action getCutAction() {
+ return cutAction;
+ }
+
+ /**
+ * Returns an {@code Action} that performs copy operations to the
+ * clipboard. When performed, this action operates on the {@code JComponent}
+ * source of the {@code ActionEvent} by invoking {@code exportToClipboard},
+ * with a {@code COPY} action, on the component's {@code TransferHandler}.
+ *
+ * @return an {@code Action} for performing copies to the clipboard
+ */
+ public static Action getCopyAction() {
+ return copyAction;
+ }
+
+ /**
+ * Returns an {@code Action} that performs paste operations from the
+ * clipboard. When performed, this action operates on the {@code JComponent}
+ * source of the {@code ActionEvent} by invoking {@code importData},
+ * with the clipboard contents, on the component's {@code TransferHandler}.
+ *
+ * @return an {@code Action} for performing pastes from the clipboard
+ */
+ public static Action getPasteAction() {
+ return pasteAction;
+ }
+
+
+ /**
+ * Constructs a transfer handler that can transfer a Java Bean property
+ * from one component to another via the clipboard or a drag and drop
+ * operation.
+ *
+ * @param property the name of the property to transfer; this can
+ * be null if there is no property associated with the transfer
+ * handler (a subclass that performs some other kind of transfer, for example)
+ */
+ public TransferHandler(String property) {
+ propertyName = property;
+ }
+
+ /**
+ * Convenience constructor for subclasses.
+ */
+ protected TransferHandler() {
+ this(null);
+ }
+
+
+ /**
+ * image for the {@code startDrag} method
+ *
+ * @see java.awt.dnd.DragGestureEvent#startDrag(Cursor dragCursor, Image dragImage, Point imageOffset, Transferable transferable, DragSourceListener dsl)
+ */
+ private Image dragImage;
+
+ /**
+ * anchor offset for the {@code startDrag} method
+ *
+ * @see java.awt.dnd.DragGestureEvent#startDrag(Cursor dragCursor, Image dragImage, Point imageOffset, Transferable transferable, DragSourceListener dsl)
+ */
+ private Point dragImageOffset;
+
+ /**
+ * Sets the drag image parameter. The image has to be prepared
+ * for rendering by the moment of the call. The image is stored
+ * by reference because of some performance reasons.
+ *
+ * @param img an image to drag
+ */
+ public void setDragImage(Image img) {
+ dragImage = img;
+ }
+
+ /**
+ * Returns the drag image. If there is no image to drag,
+ * the returned value is {@code null}.
+ *
+ * @return the reference to the drag image
+ */
+ public Image getDragImage() {
+ return dragImage;
+ }
+
+ /**
+ * Sets an anchor offset for the image to drag.
+ * It can not be {@code null}.
+ *
+ * @param p a {@code Point} object that corresponds
+ * to coordinates of an anchor offset of the image
+ * relative to the upper left corner of the image
+ */
+ public void setDragImageOffset(Point p) {
+ dragImageOffset = new Point(p);
+ }
+
+ /**
+ * Returns an anchor offset for the image to drag.
+ *
+ * @return a {@code Point} object that corresponds
+ * to coordinates of an anchor offset of the image
+ * relative to the upper left corner of the image.
+ * The point {@code (0,0)} returns by default.
+ */
+ public Point getDragImageOffset() {
+ if (dragImageOffset == null) {
+ return new Point(0,0);
+ }
+ return new Point(dragImageOffset);
+ }
+
+ /**
+ * Causes the Swing drag support to be initiated. This is called by
+ * the various UI implementations in the javax.swing.plaf.basic
+ * package if the dragEnabled property is set on the component.
+ * This can be called by custom UI
+ * implementations to use the Swing drag support. This method can also be called
+ * by a Swing extension written as a subclass of JComponent
+ * to take advantage of the Swing drag support.
+ *
+ * The transfer will not necessarily have been completed at the
+ * return of this call (i.e. the call does not block waiting for the drop).
+ * The transfer will take place through the Swing implementation of the
+ * java.awt.dnd mechanism, requiring no further effort
+ * from the developer. The exportDone method will be called
+ * when the transfer has completed.
+ *
+ * @param comp the component holding the data to be transferred;
+ * provided to enable sharing of TransferHandlers
+ * @param e the event that triggered the transfer
+ * @param action the transfer action initially requested;
+ * either {@code COPY}, {@code MOVE} or {@code LINK};
+ * the DnD system may change the action used during the
+ * course of the drag operation
+ */
+ public void exportAsDrag(JComponent comp, InputEvent e, int action) {
+ int srcActions = getSourceActions(comp);
+
+ // only mouse events supported for drag operations
+ if (!(e instanceof MouseEvent)
+ // only support known actions
+ || !(action == COPY || action == MOVE || action == LINK)
+ // only support valid source actions
+ || (srcActions & action) == 0) {
+
+ action = NONE;
+ }
+
+ if (action != NONE && !GraphicsEnvironment.isHeadless()) {
+ if (recognizer == null) {
+ recognizer = new SwingDragGestureRecognizer(new DragHandler());
+ }
+ recognizer.gestured(comp, (MouseEvent)e, srcActions, action);
+ } else {
+ exportDone(comp, null, NONE);
+ }
+ }
+
+ /**
+ * Causes a transfer from the given component to the
+ * given clipboard. This method is called by the default cut and
+ * copy actions registered in a component's action map.
+ *
+ * The transfer will take place using the java.awt.datatransfer
+ * mechanism, requiring no further effort from the developer. Any data
+ * transfer will be complete and the exportDone
+ * method will be called with the action that occurred, before this method
+ * returns. Should the clipboard be unavailable when attempting to place
+ * data on it, the IllegalStateException thrown by
+ * {@link Clipboard#setContents(Transferable, ClipboardOwner)} will
+ * be propagated through this method. However,
+ * exportDone will first be called with an action
+ * of NONE for consistency.
+ *
+ * @param comp the component holding the data to be transferred;
+ * provided to enable sharing of TransferHandlers
+ * @param clip the clipboard to transfer the data into
+ * @param action the transfer action requested; this should
+ * be a value of either COPY or MOVE;
+ * the operation performed is the intersection of the transfer
+ * capabilities given by getSourceActions and the requested action;
+ * the intersection may result in an action of NONE
+ * if the requested action isn't supported
+ * @throws IllegalStateException if the clipboard is currently unavailable
+ * @see Clipboard#setContents(Transferable, ClipboardOwner)
+ */
+ public void exportToClipboard(JComponent comp, Clipboard clip, int action)
+ throws IllegalStateException {
+
+ if ((action == COPY || action == MOVE)
+ && (getSourceActions(comp) & action) != 0) {
+
+ Transferable t = createTransferable(comp);
+ if (t != null) {
+ try {
+ clip.setContents(t, null);
+ exportDone(comp, t, action);
+ return;
+ } catch (IllegalStateException ise) {
+ exportDone(comp, t, NONE);
+ throw ise;
+ }
+ }
+ }
+
+ exportDone(comp, null, NONE);
+ }
+
+ /**
+ * Causes a transfer to occur from a clipboard or a drag and
+ * drop operation. The Transferable to be
+ * imported and the component to transfer to are contained
+ * within the TransferSupport.
+ *
+ * While the drag and drop implementation calls {@code canImport} + * to determine the suitability of a transfer before calling this + * method, the implementation of paste does not. As such, it cannot + * be assumed that the transfer is acceptable upon a call to + * this method for paste. It is recommended that {@code canImport} be + * explicitly called to cover this case. + *
+ * Note: The TransferSupport object passed to this method
+ * is only valid for the duration of the method call. It is undefined
+ * what values it may contain after this method returns.
+ *
+ * @param support the object containing the details of
+ * the transfer, not null.
+ * @return true if the data was inserted into the component,
+ * false otherwise
+ * @throws NullPointerException if support is {@code null}
+ * @see #canImport(TransferHandler.TransferSupport)
+ * @since 1.6
+ */
+ public boolean importData(TransferSupport support) {
+ return support.getComponent() instanceof JComponent
+ ? importData((JComponent)support.getComponent(), support.getTransferable())
+ : false;
+ }
+
+ /**
+ * Causes a transfer to a component from a clipboard or a
+ * DND drop operation. The Transferable represents
+ * the data to be imported into the component.
+ *
+ * Note: Swing now calls the newer version of importData
+ * that takes a TransferSupport, which in turn calls this
+ * method (if the component in the {@code TransferSupport} is a
+ * {@code JComponent}). Developers are encouraged to call and override the
+ * newer version as it provides more information (and is the only
+ * version that supports use with a {@code TransferHandler} set directly
+ * on a {@code JFrame} or other non-{@code JComponent}).
+ *
+ * @param comp the component to receive the transfer;
+ * provided to enable sharing of TransferHandlers
+ * @param t the data to import
+ * @return true if the data was inserted into the component, false otherwise
+ * @see #importData(TransferHandler.TransferSupport)
+ */
+ public boolean importData(JComponent comp, Transferable t) {
+ PropertyDescriptor prop = getPropertyDescriptor(comp);
+ if (prop != null) {
+ Method writer = prop.getWriteMethod();
+ if (writer == null) {
+ // read-only property. ignore
+ return false;
+ }
+ Class[] params = writer.getParameterTypes();
+ if (params.length != 1) {
+ // zero or more than one argument, ignore
+ return false;
+ }
+ DataFlavor flavor = getPropertyDataFlavor(params[0], t.getTransferDataFlavors());
+ if (flavor != null) {
+ try {
+ Object value = t.getTransferData(flavor);
+ Object[] args = { value };
+ MethodUtil.invoke(writer, comp, args);
+ return true;
+ } catch (Exception ex) {
+ System.err.println("Invocation failed");
+ // invocation code
+ }
+ }
+ }
+ return false;
+ }
+
+ /**
+ * This method is called repeatedly during a drag and drop operation
+ * to allow the developer to configure properties of, and to return
+ * the acceptability of transfers; with a return value of {@code true}
+ * indicating that the transfer represented by the given
+ * {@code TransferSupport} (which contains all of the details of the
+ * transfer) is acceptable at the current time, and a value of {@code false}
+ * rejecting the transfer.
+ *
+ * For those components that automatically display a drop location during + * drag and drop, accepting the transfer, by default, tells them to show + * the drop location. This can be changed by calling + * {@code setShowDropLocation} on the {@code TransferSupport}. + *
+ * By default, when the transfer is accepted, the chosen drop action is that + * picked by the user via their drag gesture. The developer can override + * this and choose a different action, from the supported source + * actions, by calling {@code setDropAction} on the {@code TransferSupport}. + *
+ * On every call to {@code canImport}, the {@code TransferSupport} contains + * fresh state. As such, any properties set on it must be set on every + * call. Upon a drop, {@code canImport} is called one final time before + * calling into {@code importData}. Any state set on the + * {@code TransferSupport} during that last call will be available in + * {@code importData}. + *
+ * This method is not called internally in response to paste operations. + * As such, it is recommended that implementations of {@code importData} + * explicitly call this method for such cases and that this method + * be prepared to return the suitability of paste operations as well. + *
+ * Note: The TransferSupport object passed to this method
+ * is only valid for the duration of the method call. It is undefined
+ * what values it may contain after this method returns.
+ *
+ * @param support the object containing the details of
+ * the transfer, not null.
+ * @return true if the import can happen,
+ * false otherwise
+ * @throws NullPointerException if support is {@code null}
+ * @see #importData(TransferHandler.TransferSupport)
+ * @see javax.swing.TransferHandler.TransferSupport#setShowDropLocation
+ * @see javax.swing.TransferHandler.TransferSupport#setDropAction
+ * @since 1.6
+ */
+ public boolean canImport(TransferSupport support) {
+ return support.getComponent() instanceof JComponent
+ ? canImport((JComponent)support.getComponent(), support.getDataFlavors())
+ : false;
+ }
+
+ /**
+ * Indicates whether a component will accept an import of the given
+ * set of data flavors prior to actually attempting to import it.
+ *
+ * Note: Swing now calls the newer version of canImport
+ * that takes a TransferSupport, which in turn calls this
+ * method (only if the component in the {@code TransferSupport} is a
+ * {@code JComponent}). Developers are encouraged to call and override the
+ * newer version as it provides more information (and is the only
+ * version that supports use with a {@code TransferHandler} set directly
+ * on a {@code JFrame} or other non-{@code JComponent}).
+ *
+ * @param comp the component to receive the transfer;
+ * provided to enable sharing of TransferHandlers
+ * @param transferFlavors the data formats available
+ * @return true if the data can be inserted into the component, false otherwise
+ * @see #canImport(TransferHandler.TransferSupport)
+ */
+ public boolean canImport(JComponent comp, DataFlavor[] transferFlavors) {
+ PropertyDescriptor prop = getPropertyDescriptor(comp);
+ if (prop != null) {
+ Method writer = prop.getWriteMethod();
+ if (writer == null) {
+ // read-only property. ignore
+ return false;
+ }
+ Class[] params = writer.getParameterTypes();
+ if (params.length != 1) {
+ // zero or more than one argument, ignore
+ return false;
+ }
+ DataFlavor flavor = getPropertyDataFlavor(params[0], transferFlavors);
+ if (flavor != null) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Returns the type of transfer actions supported by the source;
+ * any bitwise-OR combination of {@code COPY}, {@code MOVE}
+ * and {@code LINK}.
+ *
+ * Some models are not mutable, so a transfer operation of {@code MOVE}
+ * should not be advertised in that case. Returning {@code NONE}
+ * disables transfers from the component.
+ *
+ * @param c the component holding the data to be transferred;
+ * provided to enable sharing of TransferHandlers
+ * @return {@code COPY} if the transfer property can be found,
+ * otherwise returns NONE
+ */
+ public int getSourceActions(JComponent c) {
+ PropertyDescriptor prop = getPropertyDescriptor(c);
+ if (prop != null) {
+ return COPY;
+ }
+ return NONE;
+ }
+
+ /**
+ * Returns an object that establishes the look of a transfer. This is
+ * useful for both providing feedback while performing a drag operation and for
+ * representing the transfer in a clipboard implementation that has a visual
+ * appearance. The implementation of the Icon interface should
+ * not alter the graphics clip or alpha level.
+ * The icon implementation need not be rectangular or paint all of the
+ * bounding rectangle and logic that calls the icons paint method should
+ * not assume the all bits are painted. null is a valid return value
+ * for this method and indicates there is no visual representation provided.
+ * In that case, the calling logic is free to represent the
+ * transferable however it wants.
+ *
+ * The default Swing logic will not do an alpha blended drag animation if
+ * the return is null.
+ *
+ * @param t the data to be transferred; this value is expected to have been
+ * created by the createTransferable method
+ * @return null, indicating
+ * there is no default visual representation
+ */
+ public Icon getVisualRepresentation(Transferable t) {
+ return null;
+ }
+
+ /**
+ * Creates a Transferable to use as the source for
+ * a data transfer. Returns the representation of the data to
+ * be transferred, or null if the component's
+ * property is null
+ *
+ * @param c the component holding the data to be transferred;
+ * provided to enable sharing of TransferHandlers
+ * @return the representation of the data to be transferred, or
+ * null if the property associated with c
+ * is null
+ *
+ */
+ protected Transferable createTransferable(JComponent c) {
+ PropertyDescriptor property = getPropertyDescriptor(c);
+ if (property != null) {
+ return new PropertyTransferable(property, c);
+ }
+ return null;
+ }
+
+ /**
+ * Invoked after data has been exported. This method should remove
+ * the data that was transferred if the action was MOVE.
+ *
+ * This method is implemented to do nothing since MOVE
+ * is not a supported action of this implementation
+ * (getSourceActions does not include MOVE).
+ *
+ * @param source the component that was the source of the data
+ * @param data The data that was transferred or possibly null
+ * if the action is NONE.
+ * @param action the actual action that was performed
+ */
+ protected void exportDone(JComponent source, Transferable data, int action) {
+ }
+
+ /**
+ * Fetches the property descriptor for the property assigned to this transfer
+ * handler on the given component (transfer handler may be shared). This
+ * returns null if the property descriptor can't be found
+ * or there is an error attempting to fetch the property descriptor.
+ */
+ private PropertyDescriptor getPropertyDescriptor(JComponent comp) {
+ if (propertyName == null) {
+ return null;
+ }
+ Class k = comp.getClass();
+ BeanInfo bi;
+ try {
+ bi = Introspector.getBeanInfo(k);
+ } catch (IntrospectionException ex) {
+ return null;
+ }
+ PropertyDescriptor props[] = bi.getPropertyDescriptors();
+ for (int i=0; i < props.length; i++) {
+ if (propertyName.equals(props[i].getName())) {
+ Method reader = props[i].getReadMethod();
+
+ if (reader != null) {
+ Class[] params = reader.getParameterTypes();
+
+ if (params == null || params.length == 0) {
+ // found the desired descriptor
+ return props[i];
+ }
+ }
+ }
+ }
+ return null;
+ }
+
+ /**
+ * Fetches the data flavor from the array of possible flavors that
+ * has data of the type represented by property type. Null is
+ * returned if there is no match.
+ */
+ private DataFlavor getPropertyDataFlavor(Class k, DataFlavor[] flavors) {
+ for(int i = 0; i < flavors.length; i++) {
+ DataFlavor flavor = flavors[i];
+ if ("application".equals(flavor.getPrimaryType()) &&
+ "x-java-jvm-local-objectref".equals(flavor.getSubType()) &&
+ k.isAssignableFrom(flavor.getRepresentationClass())) {
+
+ return flavor;
+ }
+ }
+ return null;
+ }
+
+
+ private String propertyName;
+ private static SwingDragGestureRecognizer recognizer = null;
+
+ private static DropTargetListener getDropTargetListener() {
+ synchronized(DropHandler.class) {
+ DropHandler handler =
+ (DropHandler)AppContext.getAppContext().get(DropHandler.class);
+
+ if (handler == null) {
+ handler = new DropHandler();
+ AppContext.getAppContext().put(DropHandler.class, handler);
+ }
+
+ return handler;
+ }
+ }
+
+ static class PropertyTransferable implements Transferable {
+
+ PropertyTransferable(PropertyDescriptor p, JComponent c) {
+ property = p;
+ component = c;
+ }
+
+ // --- Transferable methods ----------------------------------------------
+
+ /**
+ * Returns an array of DataFlavor objects indicating the flavors the data
+ * can be provided in. The array should be ordered according to preference
+ * for providing the data (from most richly descriptive to least descriptive).
+ * @return an array of data flavors in which this data can be transferred
+ */
+ public DataFlavor[] getTransferDataFlavors() {
+ DataFlavor[] flavors = new DataFlavor[1];
+ Class propertyType = property.getPropertyType();
+ String mimeType = DataFlavor.javaJVMLocalObjectMimeType + ";class=" + propertyType.getName();
+ try {
+ flavors[0] = new DataFlavor(mimeType);
+ } catch (ClassNotFoundException cnfe) {
+ flavors = new DataFlavor[0];
+ }
+ return flavors;
+ }
+
+ /**
+ * Returns whether the specified data flavor is supported for
+ * this object.
+ * @param flavor the requested flavor for the data
+ * @return true if this DataFlavor is supported,
+ * otherwise false
+ */
+ public boolean isDataFlavorSupported(DataFlavor flavor) {
+ Class propertyType = property.getPropertyType();
+ if ("application".equals(flavor.getPrimaryType()) &&
+ "x-java-jvm-local-objectref".equals(flavor.getSubType()) &&
+ flavor.getRepresentationClass().isAssignableFrom(propertyType)) {
+
+ return true;
+ }
+ return false;
+ }
+
+ /**
+ * Returns an object which represents the data to be transferred. The class
+ * of the object returned is defined by the representation class of the flavor.
+ *
+ * @param flavor the requested flavor for the data
+ * @see DataFlavor#getRepresentationClass
+ * @exception IOException if the data is no longer available
+ * in the requested flavor.
+ * @exception UnsupportedFlavorException if the requested data flavor is
+ * not supported.
+ */
+ public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException {
+ if (! isDataFlavorSupported(flavor)) {
+ throw new UnsupportedFlavorException(flavor);
+ }
+ Method reader = property.getReadMethod();
+ Object value = null;
+ try {
+ value = MethodUtil.invoke(reader, component, (Object[])null);
+ } catch (Exception ex) {
+ throw new IOException("Property read failed: " + property.getName());
+ }
+ return value;
+ }
+
+ JComponent component;
+ PropertyDescriptor property;
+ }
+
+ /**
+ * This is the default drop target for drag and drop operations if
+ * one isn't provided by the developer. DropTarget
+ * only supports one DropTargetListener and doesn't
+ * function properly if it isn't set.
+ * This class sets the one listener as the linkage of drop handling
+ * to the TransferHandler, and adds support for
+ * additional listeners which some of the ComponentUI
+ * implementations install to manipulate a drop insertion location.
+ */
+ static class SwingDropTarget extends DropTarget implements UIResource {
+
+ SwingDropTarget(Component c) {
+ super(c, COPY_OR_MOVE | LINK, null);
+ try {
+ // addDropTargetListener is overridden
+ // we specifically need to add to the superclass
+ super.addDropTargetListener(getDropTargetListener());
+ } catch (TooManyListenersException tmle) {}
+ }
+
+ public void addDropTargetListener(DropTargetListener dtl) throws TooManyListenersException {
+ // Since the super class only supports one DropTargetListener,
+ // and we add one from the constructor, we always add to the
+ // extended list.
+ if (listenerList == null) {
+ listenerList = new EventListenerList();
+ }
+ listenerList.add(DropTargetListener.class, dtl);
+ }
+
+ public void removeDropTargetListener(DropTargetListener dtl) {
+ if (listenerList != null) {
+ listenerList.remove(DropTargetListener.class, dtl);
+ }
+ }
+
+ // --- DropTargetListener methods (multicast) --------------------------
+
+ public void dragEnter(DropTargetDragEvent e) {
+ super.dragEnter(e);
+ if (listenerList != null) {
+ Object[] listeners = listenerList.getListenerList();
+ for (int i = listeners.length-2; i>=0; i-=2) {
+ if (listeners[i]==DropTargetListener.class) {
+ ((DropTargetListener)listeners[i+1]).dragEnter(e);
+ }
+ }
+ }
+ }
+
+ public void dragOver(DropTargetDragEvent e) {
+ super.dragOver(e);
+ if (listenerList != null) {
+ Object[] listeners = listenerList.getListenerList();
+ for (int i = listeners.length-2; i>=0; i-=2) {
+ if (listeners[i]==DropTargetListener.class) {
+ ((DropTargetListener)listeners[i+1]).dragOver(e);
+ }
+ }
+ }
+ }
+
+ public void dragExit(DropTargetEvent e) {
+ super.dragExit(e);
+ if (listenerList != null) {
+ Object[] listeners = listenerList.getListenerList();
+ for (int i = listeners.length-2; i>=0; i-=2) {
+ if (listeners[i]==DropTargetListener.class) {
+ ((DropTargetListener)listeners[i+1]).dragExit(e);
+ }
+ }
+ }
+ if (!isActive()) {
+ // If the Drop target is inactive the dragExit will not be dispatched to the dtListener,
+ // so make sure that we clean up the dtListener anyway.
+ DropTargetListener dtListener = getDropTargetListener();
+ if (dtListener != null && dtListener instanceof DropHandler) {
+ ((DropHandler)dtListener).cleanup(false);
+ }
+ }
+ }
+
+ public void drop(DropTargetDropEvent e) {
+ super.drop(e);
+ if (listenerList != null) {
+ Object[] listeners = listenerList.getListenerList();
+ for (int i = listeners.length-2; i>=0; i-=2) {
+ if (listeners[i]==DropTargetListener.class) {
+ ((DropTargetListener)listeners[i+1]).drop(e);
+ }
+ }
+ }
+ }
+
+ public void dropActionChanged(DropTargetDragEvent e) {
+ super.dropActionChanged(e);
+ if (listenerList != null) {
+ Object[] listeners = listenerList.getListenerList();
+ for (int i = listeners.length-2; i>=0; i-=2) {
+ if (listeners[i]==DropTargetListener.class) {
+ ((DropTargetListener)listeners[i+1]).dropActionChanged(e);
+ }
+ }
+ }
+ }
+
+ private EventListenerList listenerList;
+ }
+
+ private static class DropHandler implements DropTargetListener,
+ Serializable,
+ ActionListener {
+
+ private Timer timer;
+ private Point lastPosition;
+ private Rectangle outer = new Rectangle();
+ private Rectangle inner = new Rectangle();
+ private int hysteresis = 10;
+
+ private Component component;
+ private Object state;
+ private TransferSupport support =
+ new TransferSupport(null, (DropTargetEvent)null);
+
+ private static final int AUTOSCROLL_INSET = 10;
+
+ /**
+ * Update the geometry of the autoscroll region. The geometry is
+ * maintained as a pair of rectangles. The region can cause
+ * a scroll if the pointer sits inside it for the duration of the
+ * timer. The region that causes the timer countdown is the area
+ * between the two rectangles.
+ *
+ * This is implemented to use the visible area of the component + * as the outer rectangle, and the insets are fixed at 10. Should + * the component be smaller than a total of 20 in any direction, + * autoscroll will not occur in that direction. + */ + private void updateAutoscrollRegion(JComponent c) { + // compute the outer + Rectangle visible = c.getVisibleRect(); + outer.setBounds(visible.x, visible.y, visible.width, visible.height); + + // compute the insets + Insets i = new Insets(0, 0, 0, 0); + if (c instanceof Scrollable) { + int minSize = 2 * AUTOSCROLL_INSET; + + if (visible.width >= minSize) { + i.left = i.right = AUTOSCROLL_INSET; + } + + if (visible.height >= minSize) { + i.top = i.bottom = AUTOSCROLL_INSET; + } + } + + // set the inner from the insets + inner.setBounds(visible.x + i.left, + visible.y + i.top, + visible.width - (i.left + i.right), + visible.height - (i.top + i.bottom)); + } + + /** + * Perform an autoscroll operation. This is implemented to scroll by the + * unit increment of the Scrollable using scrollRectToVisible. If the + * cursor is in a corner of the autoscroll region, more than one axis will + * scroll. + */ + private void autoscroll(JComponent c, Point pos) { + if (c instanceof Scrollable) { + Scrollable s = (Scrollable) c; + if (pos.y < inner.y) { + // scroll upward + int dy = s.getScrollableUnitIncrement(outer, SwingConstants.VERTICAL, -1); + Rectangle r = new Rectangle(inner.x, outer.y - dy, inner.width, dy); + c.scrollRectToVisible(r); + } else if (pos.y > (inner.y + inner.height)) { + // scroll downard + int dy = s.getScrollableUnitIncrement(outer, SwingConstants.VERTICAL, 1); + Rectangle r = new Rectangle(inner.x, outer.y + outer.height, inner.width, dy); + c.scrollRectToVisible(r); + } + + if (pos.x < inner.x) { + // scroll left + int dx = s.getScrollableUnitIncrement(outer, SwingConstants.HORIZONTAL, -1); + Rectangle r = new Rectangle(outer.x - dx, inner.y, dx, inner.height); + c.scrollRectToVisible(r); + } else if (pos.x > (inner.x + inner.width)) { + // scroll right + int dx = s.getScrollableUnitIncrement(outer, SwingConstants.HORIZONTAL, 1); + Rectangle r = new Rectangle(outer.x + outer.width, inner.y, dx, inner.height); + c.scrollRectToVisible(r); + } + } + } + + /** + * Initializes the internal properties if they haven't been already + * inited. This is done lazily to avoid loading of desktop properties. + */ + private void initPropertiesIfNecessary() { + if (timer == null) { + Toolkit t = Toolkit.getDefaultToolkit(); + Integer prop; + + prop = (Integer) + t.getDesktopProperty("DnD.Autoscroll.interval"); + + timer = new Timer(prop == null ? 100 : prop.intValue(), this); + + prop = (Integer) + t.getDesktopProperty("DnD.Autoscroll.initialDelay"); + + timer.setInitialDelay(prop == null ? 100 : prop.intValue()); + + prop = (Integer) + t.getDesktopProperty("DnD.Autoscroll.cursorHysteresis"); + + if (prop != null) { + hysteresis = prop.intValue(); + } + } + } + + /** + * The timer fired, perform autoscroll if the pointer is within the + * autoscroll region. + *
+ * @param e the ActionEvent
+ */
+ public void actionPerformed(ActionEvent e) {
+ updateAutoscrollRegion((JComponent)component);
+ if (outer.contains(lastPosition) && !inner.contains(lastPosition)) {
+ autoscroll((JComponent)component, lastPosition);
+ }
+ }
+
+ // --- DropTargetListener methods -----------------------------------
+
+ private void setComponentDropLocation(TransferSupport support,
+ boolean forDrop) {
+
+ DropLocation dropLocation = (support == null)
+ ? null
+ : support.getDropLocation();
+
+ if (SunToolkit.isInstanceOf(component, "javax.swing.text.JTextComponent")) {
+ state = SwingAccessor.getJTextComponentAccessor().
+ setDropLocation((JTextComponent)component, dropLocation, state, forDrop);
+ } else if (component instanceof JComponent) {
+ state = ((JComponent)component).setDropLocation(dropLocation, state, forDrop);
+ }
+ }
+
+ private void handleDrag(DropTargetDragEvent e) {
+ TransferHandler importer =
+ ((HasGetTransferHandler)component).getTransferHandler();
+
+ if (importer == null) {
+ e.rejectDrag();
+ setComponentDropLocation(null, false);
+ return;
+ }
+
+ support.setDNDVariables(component, e);
+ boolean canImport = importer.canImport(support);
+
+ if (canImport) {
+ e.acceptDrag(support.getDropAction());
+ } else {
+ e.rejectDrag();
+ }
+
+ boolean showLocation = support.showDropLocationIsSet ?
+ support.showDropLocation :
+ canImport;
+
+ setComponentDropLocation(showLocation ? support : null, false);
+ }
+
+ public void dragEnter(DropTargetDragEvent e) {
+ state = null;
+ component = e.getDropTargetContext().getComponent();
+
+ handleDrag(e);
+
+ if (component instanceof JComponent) {
+ lastPosition = e.getLocation();
+ updateAutoscrollRegion((JComponent)component);
+ initPropertiesIfNecessary();
+ }
+ }
+
+ public void dragOver(DropTargetDragEvent e) {
+ handleDrag(e);
+
+ if (!(component instanceof JComponent)) {
+ return;
+ }
+
+ Point p = e.getLocation();
+
+ if (Math.abs(p.x - lastPosition.x) > hysteresis
+ || Math.abs(p.y - lastPosition.y) > hysteresis) {
+ // no autoscroll
+ if (timer.isRunning()) timer.stop();
+ } else {
+ if (!timer.isRunning()) timer.start();
+ }
+
+ lastPosition = p;
+ }
+
+ public void dragExit(DropTargetEvent e) {
+ cleanup(false);
+ }
+
+ public void drop(DropTargetDropEvent e) {
+ TransferHandler importer =
+ ((HasGetTransferHandler)component).getTransferHandler();
+
+ if (importer == null) {
+ e.rejectDrop();
+ cleanup(false);
+ return;
+ }
+
+ support.setDNDVariables(component, e);
+ boolean canImport = importer.canImport(support);
+
+ if (canImport) {
+ e.acceptDrop(support.getDropAction());
+
+ boolean showLocation = support.showDropLocationIsSet ?
+ support.showDropLocation :
+ canImport;
+
+ setComponentDropLocation(showLocation ? support : null, false);
+
+ boolean success;
+
+ try {
+ success = importer.importData(support);
+ } catch (RuntimeException re) {
+ success = false;
+ }
+
+ e.dropComplete(success);
+ cleanup(success);
+ } else {
+ e.rejectDrop();
+ cleanup(false);
+ }
+ }
+
+ public void dropActionChanged(DropTargetDragEvent e) {
+ /*
+ * Work-around for Linux bug where dropActionChanged
+ * is called before dragEnter.
+ */
+ if (component == null) {
+ return;
+ }
+
+ handleDrag(e);
+ }
+
+ private void cleanup(boolean forDrop) {
+ setComponentDropLocation(null, forDrop);
+ if (component instanceof JComponent) {
+ ((JComponent)component).dndDone();
+ }
+
+ if (timer != null) {
+ timer.stop();
+ }
+
+ state = null;
+ component = null;
+ lastPosition = null;
+ }
+ }
+
+ /**
+ * This is the default drag handler for drag and drop operations that
+ * use the TransferHandler.
+ */
+ private static class DragHandler implements DragGestureListener, DragSourceListener {
+
+ private boolean scrolls;
+
+ // --- DragGestureListener methods -----------------------------------
+
+ /**
+ * a Drag gesture has been recognized
+ */
+ public void dragGestureRecognized(DragGestureEvent dge) {
+ JComponent c = (JComponent) dge.getComponent();
+ TransferHandler th = c.getTransferHandler();
+ Transferable t = th.createTransferable(c);
+ if (t != null) {
+ scrolls = c.getAutoscrolls();
+ c.setAutoscrolls(false);
+ try {
+ Image im = th.getDragImage();
+ if (im == null) {
+ dge.startDrag(null, t, this);
+ } else {
+ dge.startDrag(null, im, th.getDragImageOffset(), t, this);
+ }
+ return;
+ } catch (RuntimeException re) {
+ c.setAutoscrolls(scrolls);
+ }
+ }
+
+ th.exportDone(c, t, NONE);
+ }
+
+ // --- DragSourceListener methods -----------------------------------
+
+ /**
+ * as the hotspot enters a platform dependent drop site
+ */
+ public void dragEnter(DragSourceDragEvent dsde) {
+ }
+
+ /**
+ * as the hotspot moves over a platform dependent drop site
+ */
+ public void dragOver(DragSourceDragEvent dsde) {
+ }
+
+ /**
+ * as the hotspot exits a platform dependent drop site
+ */
+ public void dragExit(DragSourceEvent dsde) {
+ }
+
+ /**
+ * as the operation completes
+ */
+ public void dragDropEnd(DragSourceDropEvent dsde) {
+ DragSourceContext dsc = dsde.getDragSourceContext();
+ JComponent c = (JComponent)dsc.getComponent();
+ if (dsde.getDropSuccess()) {
+ c.getTransferHandler().exportDone(c, dsc.getTransferable(), dsde.getDropAction());
+ } else {
+ c.getTransferHandler().exportDone(c, dsc.getTransferable(), NONE);
+ }
+ c.setAutoscrolls(scrolls);
+ }
+
+ public void dropActionChanged(DragSourceDragEvent dsde) {
+ }
+ }
+
+ private static class SwingDragGestureRecognizer extends DragGestureRecognizer {
+
+ SwingDragGestureRecognizer(DragGestureListener dgl) {
+ super(DragSource.getDefaultDragSource(), null, NONE, dgl);
+ }
+
+ void gestured(JComponent c, MouseEvent e, int srcActions, int action) {
+ setComponent(c);
+ setSourceActions(srcActions);
+ appendEvent(e);
+ fireDragGestureRecognized(action, e.getPoint());
+ }
+
+ /**
+ * register this DragGestureRecognizer's Listeners with the Component
+ */
+ protected void registerListeners() {
+ }
+
+ /**
+ * unregister this DragGestureRecognizer's Listeners with the Component
+ *
+ * subclasses must override this method
+ */
+ protected void unregisterListeners() {
+ }
+
+ }
+
+ static final Action cutAction = new TransferAction("cut");
+ static final Action copyAction = new TransferAction("copy");
+ static final Action pasteAction = new TransferAction("paste");
+
+ static class TransferAction extends UIAction implements UIResource {
+
+ TransferAction(String name) {
+ super(name);
+ }
+
+ public boolean isEnabled(Object sender) {
+ if (sender instanceof JComponent
+ && ((JComponent)sender).getTransferHandler() == null) {
+ return false;
+ }
+
+ return true;
+ }
+
+ private static final JavaSecurityAccess javaSecurityAccess =
+ SharedSecrets.getJavaSecurityAccess();
+
+ public void actionPerformed(final ActionEvent e) {
+ final Object src = e.getSource();
+
+ final PrivilegedAction