File	Doc	Category	Size	Date	Package
DragGestureRecognizer.java	API Doc	Java SE 5 API	14810	Fri Aug 26 14:56:48 BST 2005	java.awt.dnd

DragGestureRecognizer

• java.lang.Object

Fields Summary
private static final long	serialVersionUID
protected DragSource	dragSource The DragSource associated with this DragGestureRecognizer.
protected Component	component The Component associated with this DragGestureRecognizer.
protected transient DragGestureListener	dragGestureListener The DragGestureListener associated with this DragGestureRecognizer.
protected int	sourceActions An int representing the type(s) of action(s) used in this Drag and Drop operation.
protected ArrayList	events The list of events (in order) that the DragGestureRecognizer "recognized" as a "gesture" that triggers a drag.

Constructors Summary
protected DragGestureRecognizer(DragSource ds, Component c, int sa, DragGestureListener dgl) Construct a new DragGestureRecognizer given the DragSource to be used in this Drag and Drop operation, the Component this DragGestureRecognizer should "observe" for drag initiating gestures, the action(s) supported for this Drag and Drop operation, and the DragGestureListener to notify once a drag initiating gesture has been detected. param ds the DragSource this DragGestureRecognizer will use to process the Drag and Drop operation param c the Component this DragGestureRecognizer should "observe" the event stream to, in order to detect a drag initiating gesture. If this value is null, the DragGestureRecognizer is not associated with any Component. param sa the set (logical OR) of the DnDConstants that this Drag and Drop operation will support param dgl the DragGestureRecognizer to notify when a drag gesture is detected throws IllegalArgumentException if ds is null. super(); if (ds == null) throw new IllegalArgumentException("null DragSource"); dragSource = ds; component = c; sourceActions = sa & (DnDConstants.ACTION_COPY_OR_MOVE | DnDConstants.ACTION_LINK); try { if (dgl != null) addDragGestureListener(dgl); } catch (TooManyListenersException tmle) { // cant happen ... }
protected DragGestureRecognizer(DragSource ds, Component c, int sa) Construct a new DragGestureRecognizer given the DragSource to be used in this Drag and Drop operation, the Component this DragGestureRecognizer should "observe" for drag initiating gestures, and the action(s) supported for this Drag and Drop operation. param ds the DragSource this DragGestureRecognizer will use to process the Drag and Drop operation param c the Component this DragGestureRecognizer should "observe" the event stream to, in order to detect a drag initiating gesture. If this value is null, the DragGestureRecognizer is not associated with any Component. param sa the set (logical OR) of the DnDConstants that this Drag and Drop operation will support throws IllegalArgumentException if ds is null. this(ds, c, sa, null);
protected DragGestureRecognizer(DragSource ds, Component c) Construct a new DragGestureRecognizer given the DragSource to be used in this Drag and Drop operation, and the Component this DragGestureRecognizer should "observe" for drag initiating gestures. param ds the DragSource this DragGestureRecognizer will use to process the Drag and Drop operation param c the Component this DragGestureRecognizer should "observe" the event stream to, in order to detect a drag initiating gesture. If this value is null, the DragGestureRecognizer is not associated with any Component. throws IllegalArgumentException if ds is null. this(ds, c, DnDConstants.ACTION_NONE);
protected DragGestureRecognizer(DragSource ds) Construct a new DragGestureRecognizer given the DragSource to be used in this Drag and Drop operation. param ds the DragSource this DragGestureRecognizer will use to process the Drag and Drop operation throws IllegalArgumentException if ds is null. this(ds, null);

Methods Summary
public synchronized void	addDragGestureListener(java.awt.dnd.DragGestureListener dgl) Register a new DragGestureListener. param dgl the DragGestureListener to register with this DragGestureRecognizer. throws java.util.TooManyListenersException if a DragGestureListener has already been added. if (dragGestureListener != null) throw new TooManyListenersException(); else { dragGestureListener = dgl; if (component != null) registerListeners(); }
protected synchronized void	appendEvent(java.awt.event.InputEvent awtie) Listeners registered on the Component by this Recognizer shall record all Events that are recognized as part of the series of Events that go to comprise a Drag and Drop initiating gesture via this API. This method is used by a DragGestureRecognizer implementation to add an InputEvent subclass (that it believes is one in a series of events that comprise a Drag and Drop operation) to the array of events that this DragGestureRecognizer maintains internally. param awtie the InputEvent to add to this DragGestureRecognizer's internal array of events. Note that null is not a valid value, and will be ignored. events.add(awtie);
protected synchronized void	fireDragGestureRecognized(int dragAction, java.awt.Point p) Notify the DragGestureListener that a Drag and Drop initiating gesture has occurred. Then reset the state of the Recognizer. param dragAction The action initially selected by the users gesture param p The point (in Component coords) where the gesture originated try { if (dragGestureListener != null) { dragGestureListener.dragGestureRecognized(new DragGestureEvent(this, dragAction, p, events)); } } finally { events.clear(); }
public synchronized java.awt.Component	getComponent() This method returns the Component that is to be "observed" by the DragGestureRecognizer for drag initiating gestures. return The Component this DragGestureRecognizer is associated with return component;
public java.awt.dnd.DragSource	getDragSource() This method returns the DragSource this DragGestureRecognizer will use in order to process the Drag and Drop operation. return the DragSource return dragSource;
public synchronized int	getSourceActions() This method returns an int representing the type of action(s) this Drag and Drop operation will support. return the currently permitted source action(s) return sourceActions;
public java.awt.event.InputEvent	getTriggerEvent() This method returns the first event in the series of events that initiated the Drag and Drop operation. return the initial event that triggered the drag gesture return events.isEmpty() ? null : (InputEvent)events.get(0);
private void	readObject(java.io.ObjectInputStream s) Deserializes this DragGestureRecognizer. This method first performs default deserialization for all non-transient fields. This object's DragGestureListener is then deserialized as well by using the next object in the stream. since 1.4 s.defaultReadObject(); dragGestureListener = (DragGestureListener)s.readObject();
protected abstract void	registerListeners() register this DragGestureRecognizer's Listeners with the Component subclasses must override this method
public synchronized void	removeDragGestureListener(java.awt.dnd.DragGestureListener dgl) unregister the current DragGestureListener param dgl the DragGestureListener to unregister from this DragGestureRecognizer throws IllegalArgumentException if dgl is not (equal to) the currently registered DragGestureListener. if (dragGestureListener == null || !dragGestureListener.equals(dgl)) throw new IllegalArgumentException(); else { dragGestureListener = null; if (component != null) unregisterListeners(); }
public void	resetRecognizer() Reset the Recognizer, if its currently recognizing a gesture, ignore it. events.clear();
public synchronized void	setComponent(java.awt.Component c) set the Component that the DragGestureRecognizer is associated with registerListeners() and unregisterListeners() are called as a side effect as appropriate. param c The Component or null if (component != null && dragGestureListener != null) unregisterListeners(); component = c; if (component != null && dragGestureListener != null) registerListeners();
public synchronized void	setSourceActions(int actions) This method sets the permitted source drag action(s) for this Drag and Drop operation. param actions the permitted source drag action(s) sourceActions = actions & (DnDConstants.ACTION_COPY_OR_MOVE | DnDConstants.ACTION_LINK);
protected abstract void	unregisterListeners() unregister this DragGestureRecognizer's Listeners with the Component subclasses must override this method
private void	writeObject(java.io.ObjectOutputStream s) Serializes this DragGestureRecognizer. This method first performs default serialization. Then, this object's DragGestureListener is written out if and only if it can be serialized. If not, null is written instead. serialData The default serializable fields, in alphabetical order, followed by either a DragGestureListener, or null. since 1.4 s.defaultWriteObject(); s.writeObject(SerializationTester.test(dragGestureListener) ? dragGestureListener : null);