com.allen_sauer.gwt.dnd.client.drop
Class AbstractInsertPanelDropController

java.lang.Object
  com.allen_sauer.gwt.dnd.client.drop.AbstractDropController
      com.allen_sauer.gwt.dnd.client.drop.AbstractPositioningDropController
          com.allen_sauer.gwt.dnd.client.drop.AbstractInsertPanelDropController

All Implemented Interfaces:

DropController

Direct Known Subclasses:

FlowPanelDropController, HorizontalPanelDropController, VerticalPanelDropController

public abstract class AbstractInsertPanelDropController
extends AbstractPositioningDropController

A DropController for InsertPanel drop targets.

Field Summary

protected int	dropIndex
protected com.google.gwt.user.client.ui.InsertPanel	dropTarget Our drop target.

Constructor Summary

AbstractInsertPanelDropController(com.google.gwt.user.client.ui.InsertPanel dropTarget)

Method Summary

protected abstract LocationWidgetComparator	getLocationWidgetComparator() Required implementation method which provides the desired comparator strategy.
protected abstract com.google.gwt.user.client.ui.Widget	newPositioner(DragContext context) Called by onEnter(DragContext) to create a new positioner widget for this InsertPanel drop target.
void	onDrop(DragContext context) Called when the draggable widget or its proxy is dropped on our drop target.
void	onEnter(DragContext context) Called when the draggable widget or its proxy engages our drop target.
void	onLeave(DragContext context) Called when the reference widget stops engaging our drop target by leaving the area of the page occupied by our drop target, or after DropController.onDrop(DragContext) to allow for any cleanup.
void	onMove(DragContext context) Called with each mouse movement while the reference widget is engaging our drop target.
void	onPreviewDrop(DragContext context) Called just prior to DropController.onDrop(DragContext) to allow the drop operation to be cancelled by throwing a VetoDragException.

Methods inherited from class com.allen_sauer.gwt.dnd.client.drop.AbstractDropController

getDropTarget

Methods inherited from class java.lang.Object

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

Field Detail

dropTarget

protected final com.google.gwt.user.client.ui.InsertPanel dropTarget

Our drop target.

dropIndex

protected int dropIndex

Constructor Detail

AbstractInsertPanelDropController

public AbstractInsertPanelDropController(com.google.gwt.user.client.ui.InsertPanel dropTarget)

Parameters:

dropTarget - the insert panel drop target

See Also:

FlowPanelDropController.FlowPanelDropController(com.google.gwt.user.client.ui.FlowPanel)

Method Detail

onDrop

public void onDrop(DragContext context)

Description copied from interface: DropController

Called when the draggable widget or its proxy is dropped on our drop target. Implementing classes must attach the draggable widget to our drop target in a suitable manner.

Specified by:

onDrop in interface DropController

Overrides:

onDrop in class AbstractDropController

Parameters:

context - the current drag context

See Also:

DropController.onPreviewDrop(DragContext)

onEnter

public void onEnter(DragContext context)

Description copied from interface: DropController

Called when the draggable widget or its proxy engages our drop target. This occurs when the widget area and the drop target area intersect and there are no drop targets which are descendants of our drop target which also intersect with the widget. If there are, the widget engages with the descendant drop target instead.

Specified by:

onEnter in interface DropController

Overrides:

onEnter in class AbstractDropController

Parameters:

context - the current drag context

See Also:

DropController.onLeave(DragContext)

onLeave

public void onLeave(DragContext context)

Description copied from interface: DropController

Called when the reference widget stops engaging our drop target by leaving the area of the page occupied by our drop target, or after DropController.onDrop(DragContext) to allow for any cleanup.

Specified by:

onLeave in interface DropController

Overrides:

onLeave in class AbstractDropController

Parameters:

context - the current drag context

See Also:

DropController.onEnter(DragContext)

onMove

public void onMove(DragContext context)

Description copied from interface: DropController

Called with each mouse movement while the reference widget is engaging our drop target. DropController.onEnter(DragContext) is called before this method is called.

Specified by:

onMove in interface DropController

Overrides:

onMove in class AbstractDropController

Parameters:

context - the current drag context

See Also:

DropController.onEnter(DragContext), DropController.onLeave(DragContext)

onPreviewDrop

public void onPreviewDrop(DragContext context)
                   throws VetoDragException

Description copied from interface: DropController

Called just prior to DropController.onDrop(DragContext) to allow the drop operation to be cancelled by throwing a VetoDragException.

Specified by:

onPreviewDrop in interface DropController

Overrides:

onPreviewDrop in class AbstractDropController

Parameters:

context - the current drag context

Throws:

VetoDragException - if the proposed operation is unacceptable

getLocationWidgetComparator

protected abstract LocationWidgetComparator getLocationWidgetComparator()

Required implementation method which provides the desired comparator strategy.

Returns:

the comparator strategy to be used

newPositioner

protected abstract com.google.gwt.user.client.ui.Widget newPositioner(DragContext context)

Called by onEnter(DragContext) to create a new positioner widget for this InsertPanel drop target. Override this method to customize the look and feel of your positioner. The positioner widget may not have any CSS borders or margins, although there are no such restrictions on the children of the positioner widget. If borders and/or margins are desired, wrap that widget in a SimplePanel with a 0px border and margin.

Parameters:

context - The current drag context.

Returns:

a new positioner widget