Class DragGestureRecognizer
- All Implemented Interfaces:
- Serializable
- Direct Known Subclasses:
- MouseDragGestureRecognizer
DragGestureRecognizer is an
 abstract base class for the specification
 of a platform-dependent listener that can be associated with a particular
 Component in order to
 identify platform-dependent drag initiating gestures.
 
 The appropriate DragGestureRecognizer
 subclass instance is obtained from the
 DragSource associated with
 a particular Component, or from the Toolkit object via its
 createDragGestureRecognizer()
 method.
 
 Once the DragGestureRecognizer
 is associated with a particular Component
 it will register the appropriate listener interfaces on that
 Component
 in order to track the input events delivered to the Component.
 
 Once the DragGestureRecognizer identifies a sequence of events
 on the Component as a drag initiating gesture, it will notify
 its unicast DragGestureListener by
 invoking its
 gestureRecognized()
 method.
 
 When a concrete DragGestureRecognizer
 instance detects a drag initiating
 gesture on the Component it is associated with,
 it fires a DragGestureEvent to
 the DragGestureListener registered on
 its unicast event source for DragGestureListener
 events. This DragGestureListener is responsible
 for causing the associated
 DragSource to start the Drag and Drop operation (if
 appropriate).
- See Also:
- 
Field SummaryFieldsModifier and TypeFieldDescriptionprotected ComponentTheComponentassociated with thisDragGestureRecognizer.protected DragGestureListenerTheDragGestureListenerassociated with thisDragGestureRecognizer.protected DragSourceTheDragSourceassociated with thisDragGestureRecognizer.protected ArrayList<InputEvent> The list of events (in order) that theDragGestureRecognizer"recognized" as a "gesture" that triggers a drag.protected intAnintrepresenting the type(s) of action(s) used in this Drag and Drop operation.
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Constructor SummaryConstructorsModifierConstructorDescriptionprotectedConstruct a newDragGestureRecognizergiven theDragSourceto be used in this Drag and Drop operation.protectedConstruct a newDragGestureRecognizergiven theDragSourceto be used in this Drag and Drop operation, and theComponentthisDragGestureRecognizershould "observe" for drag initiating gestures.protectedDragGestureRecognizer(DragSource ds, Component c, int sa) Construct a newDragGestureRecognizergiven theDragSourceto be used in this Drag and Drop operation, theComponentthisDragGestureRecognizershould "observe" for drag initiating gestures, and the action(s) supported for this Drag and Drop operation.protectedDragGestureRecognizer(DragSource ds, Component c, int sa, DragGestureListener dgl) Construct a newDragGestureRecognizergiven theDragSourceto be used in this Drag and Drop operation, theComponentthisDragGestureRecognizershould "observe" for drag initiating gestures, the action(s) supported for this Drag and Drop operation, and theDragGestureListenerto notify once a drag initiating gesture has been detected.
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Method SummaryModifier and TypeMethodDescriptionvoidRegister a newDragGestureListener.protected voidappendEvent(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.protected voidfireDragGestureRecognized(int dragAction, Point p) Notify the DragGestureListener that a Drag and Drop initiating gesture has occurred.This method returns theComponentthat is to be "observed" by theDragGestureRecognizerfor drag initiating gestures.This method returns theDragSourcethisDragGestureRecognizerwill use in order to process the Drag and Drop operation.intThis method returns an int representing the type of action(s) this Drag and Drop operation will support.This method returns the first event in the series of events that initiated the Drag and Drop operation.protected abstract voidregister this DragGestureRecognizer's Listeners with the Component subclasses must override this methodvoidunregister the current DragGestureListenervoidReset the Recognizer, if its currently recognizing a gesture, ignore it.voidset the Component that the DragGestureRecognizer is associated with registerListeners() and unregisterListeners() are called as a side effect as appropriate.voidsetSourceActions(int actions) This method sets the permitted source drag action(s) for this Drag and Drop operation.protected abstract voidunregister this DragGestureRecognizer's Listeners with the Component subclasses must override this method
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Field Details- 
dragSourceTheDragSourceassociated with thisDragGestureRecognizer.
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componentTheComponentassociated with thisDragGestureRecognizer.
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dragGestureListenerTheDragGestureListenerassociated with thisDragGestureRecognizer.
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sourceActionsprotected int sourceActionsAnintrepresenting the type(s) of action(s) used in this Drag and Drop operation.
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eventsThe list of events (in order) that theDragGestureRecognizer"recognized" as a "gesture" that triggers a drag.
 
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Constructor Details- 
DragGestureRecognizerConstruct a newDragGestureRecognizergiven theDragSourceto be used in this Drag and Drop operation, theComponentthisDragGestureRecognizershould "observe" for drag initiating gestures, the action(s) supported for this Drag and Drop operation, and theDragGestureListenerto notify once a drag initiating gesture has been detected.- Parameters:
- ds- the- DragSourcethis- DragGestureRecognizerwill use to process the Drag and Drop operation
- c- the- Componentthis- DragGestureRecognizershould "observe" the event stream to, in order to detect a drag initiating gesture. If this value is- null, the- DragGestureRecognizeris not associated with any- Component.
- sa- the set (logical OR) of the- DnDConstantsthat this Drag and Drop operation will support
- dgl- the- DragGestureRecognizerto notify when a drag gesture is detected
- Throws:
- IllegalArgumentException- if ds is- null.
 
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DragGestureRecognizerConstruct a newDragGestureRecognizergiven theDragSourceto be used in this Drag and Drop operation, theComponentthisDragGestureRecognizershould "observe" for drag initiating gestures, and the action(s) supported for this Drag and Drop operation.- Parameters:
- ds- the- DragSourcethis- DragGestureRecognizerwill use to process the Drag and Drop operation
- c- the- Componentthis- DragGestureRecognizershould "observe" the event stream to, in order to detect a drag initiating gesture. If this value is- null, the- DragGestureRecognizeris not associated with any- Component.
- sa- the set (logical OR) of the- DnDConstantsthat this Drag and Drop operation will support
- Throws:
- IllegalArgumentException- if ds is- null.
 
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DragGestureRecognizerConstruct a newDragGestureRecognizergiven theDragSourceto be used in this Drag and Drop operation, and theComponentthisDragGestureRecognizershould "observe" for drag initiating gestures.- Parameters:
- ds- the- DragSourcethis- DragGestureRecognizerwill use to process the Drag and Drop operation
- c- the- Componentthis- DragGestureRecognizershould "observe" the event stream to, in order to detect a drag initiating gesture. If this value is- null, the- DragGestureRecognizeris not associated with any- Component.
- Throws:
- IllegalArgumentException- if ds is- null.
 
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DragGestureRecognizerConstruct a newDragGestureRecognizergiven theDragSourceto be used in this Drag and Drop operation.- Parameters:
- ds- the- DragSourcethis- DragGestureRecognizerwill use to process the Drag and Drop operation
- Throws:
- IllegalArgumentException- if ds is- null.
 
 
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Method Details- 
registerListenersprotected abstract void registerListeners()register this DragGestureRecognizer's Listeners with the Component subclasses must override this method
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unregisterListenersprotected abstract void unregisterListeners()unregister this DragGestureRecognizer's Listeners with the Component subclasses must override this method
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getDragSourceThis method returns theDragSourcethisDragGestureRecognizerwill use in order to process the Drag and Drop operation.- Returns:
- the DragSource
 
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getComponentThis method returns theComponentthat is to be "observed" by theDragGestureRecognizerfor drag initiating gestures.- Returns:
- The Component this DragGestureRecognizer is associated with
 
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setComponentset the Component that the DragGestureRecognizer is associated with registerListeners() and unregisterListeners() are called as a side effect as appropriate.- Parameters:
- c- The- Componentor- null
 
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getSourceActionspublic int getSourceActions()This method returns an int representing the type of action(s) this Drag and Drop operation will support.- Returns:
- the currently permitted source action(s)
 
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setSourceActionspublic void setSourceActions(int actions) This method sets the permitted source drag action(s) for this Drag and Drop operation.- Parameters:
- actions- the permitted source drag action(s)
 
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getTriggerEventThis method returns the first event in the series of events that initiated the Drag and Drop operation.- Returns:
- the initial event that triggered the drag gesture
 
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resetRecognizerpublic void resetRecognizer()Reset the Recognizer, if its currently recognizing a gesture, ignore it.
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addDragGestureListenerRegister a newDragGestureListener.- Parameters:
- dgl- the- DragGestureListenerto register with this- DragGestureRecognizer.
- Throws:
- TooManyListenersException- if a- DragGestureListenerhas already been added.
 
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removeDragGestureListenerunregister the current DragGestureListener- Parameters:
- dgl- the- DragGestureListenerto unregister from this- DragGestureRecognizer
- Throws:
- IllegalArgumentException- if dgl is not (equal to) the currently registered- DragGestureListener.
 
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fireDragGestureRecognizedNotify the DragGestureListener that a Drag and Drop initiating gesture has occurred. Then reset the state of the Recognizer.- Parameters:
- dragAction- The action initially selected by the users gesture
- p- The point (in Component coords) where the gesture originated
 
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appendEventListeners 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 DragGestureRecognizerimplementation to add anInputEventsubclass (that it believes is one in a series of events that comprise a Drag and Drop operation) to the array of events that thisDragGestureRecognizermaintains internally.- Parameters:
- awtie- the- InputEventto add to this- DragGestureRecognizer's internal array of events. Note that- nullis not a valid value, and will be ignored.
 
 
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