Package com.simsilica.lemur.dnd

Class AbstractDragAndDropListener

java.lang.Object

com.simsilica.lemur.dnd.AbstractDragAndDropListener

All Implemented Interfaces:

DragAndDropListener

public abstract class AbstractDragAndDropListener
extends Object
implements DragAndDropListener

Base class that DragAndDropListeners can extend to provide default implementations for some methods. Implementors must provide onDragDetected(), onDragOver(), onDrop(), onDragDone() at a minimum.

Constructor Summary

Constructors

Constructor	Description
AbstractDragAndDropListener()

Method Summary

Modifier and Type	Method	Description
abstract Draggable	onDragDetected(DragEvent event)	Called when the drag gesture is first detected by the drag container.
abstract void	onDragDone(DragEvent event)	Called on listeners on the SOUCE container when the drag operation is completed, regardless of whether the drop was successful.
void	onDragEnter(DragEvent event)	Default implementation does nothing.
void	onDragExit(DragEvent event)	Default implementation does nothing.
abstract void	onDragOver(DragEvent event)	Called for all draggable motion over the drag-and-drop container to which this listener is listening.
abstract void	onDrop(DragEvent event)	Called on listeners on the TARGET container when a drag operation is completed and the drag status at the time was DragStatus.ValidTarget.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

AbstractDragAndDropListener

public AbstractDragAndDropListener()

Method Details

onDragDetected

public abstract Draggable onDragDetected(DragEvent event)

Description copied from interface: DragAndDropListener

Called when the drag gesture is first detected by the drag container. It is up to the implementation to return a proper Draggable or not depending on if the drag operation is valid at the event's location. Return null if no drag operation should commence.

Specified by:

onDragDetected in interface DragAndDropListener

onDragEnter

public void onDragEnter(DragEvent event)

Default implementation does nothing.

Specified by:

onDragEnter in interface DragAndDropListener

onDragExit

public void onDragExit(DragEvent event)

Default implementation does nothing.

Specified by:

onDragExit in interface DragAndDropListener

onDragOver

public abstract void onDragOver(DragEvent event)

Description copied from interface: DragAndDropListener

Called for all draggable motion over the drag-and-drop container to which this listener is listening.

Specified by:

onDragOver in interface DragAndDropListener

onDrop

public abstract void onDrop(DragEvent event)

Description copied from interface: DragAndDropListener

Called on listeners on the TARGET container when a drag operation is completed and the drag status at the time was DragStatus.ValidTarget. It is up to the listeners to decide if the drag was successful or failed by setting the session's drag status. By default, drop operations succeed unless the listeners set the status to DragStatus.InvalidTarget.

Specified by:

onDrop in interface DragAndDropListener

onDragDone

public abstract void onDragDone(DragEvent event)

Description copied from interface: DragAndDropListener

Called on listeners on the SOUCE container when the drag operation is completed, regardless of whether the drop was successful. This allows the source container to either refresh undropped item or clean its view up now that the item is gone 'for real'.

Specified by:

onDragDone in interface DragAndDropListener