com.allen_sauer.gwt.dnd.client

Class PickupDragController

java.lang.Object

com.allen_sauer.gwt.dnd.client.AbstractDragController

com.allen_sauer.gwt.dnd.client.PickupDragController

All Implemented Interfaces:

DragController, FiresDragEvents

Direct Known Subclasses:

FlexTableRowDragController

public class PickupDragController
extends AbstractDragController

Field Summary

Fields inherited from class com.allen_sauer.gwt.dnd.client.AbstractDragController

context

Constructor Summary

Constructors

Constructor and Description
PickupDragController(com.google.gwt.user.client.ui.AbsolutePanel boundaryPanel, boolean allowDroppingOnBoundaryPanel) Create a new pickup-and-move style drag controller.

Method Summary

Methods

Modifier and Type	Method and Description
void	dragEnd() Callback method for MouseDragHandler.
void	dragMove() Callback method for MouseDragHandler.
void	dragStart() Callback method for MouseDragHandler when a drag operation is initiated for this drag controller.
boolean	getBehaviorBoundaryPanelDrop() Whether or not dropping on the boundary panel is permitted.
boolean	getBehaviorDragProxy() Determine whether or not this controller automatically creates a drag proxy for each drag operation.
java.lang.Iterable<com.google.gwt.user.client.ui.Widget>	getSelectedWidgets() Retrieve currently selected widgets.
protected BoundaryDropController	newBoundaryDropController(com.google.gwt.user.client.ui.AbsolutePanel boundaryPanel, boolean allowDroppingOnBoundaryPanel) Create a new BoundaryDropController to manage our boundary panel as a drop target.
protected com.google.gwt.user.client.ui.Widget	newDragProxy(DragContext context) Called by dragStart() to allow subclasses to provide their own drag proxies.
void	previewDragEnd() Callback method for MouseDragHandler.
void	registerDropController(DropController dropController) Register a new DropController, representing a new drop target, with this drag controller.
void	resetCache() Reset the internal drop controller (drop target) cache which is initialized primarily by AbstractDragController.dragStart().
protected void	restoreSelectedWidgetsLocation() Restore the selected widgets to their original location.
protected void	restoreSelectedWidgetsStyle() Restore the selected widgets with their original style.
protected void	saveSelectedWidgetsLocationAndStyle() Save the selected widgets' current location in case they much be restored due to a cancelled drop.
void	setBehaviorBoundaryPanelDrop(boolean allowDroppingOnBoundaryPanel) Set whether or not widgets may be dropped anywhere on the boundary panel.
void	setBehaviorDragProxy(boolean dragProxyEnabled) Set whether or not this controller should automatically create a drag proxy for each drag operation.
void	unregisterDropController(DropController dropController) Unregister a DropController from this drag controller.
void	unregisterDropControllers() Unregister all DropControllers from this drag controller.

Methods inherited from class com.allen_sauer.gwt.dnd.client.AbstractDragController

addDragHandler, clearSelection, getBehaviorCancelDocumentSelections, getBehaviorConstrainedToBoundaryPanel, getBehaviorDragStartSensitivity, getBehaviorMultipleSelection, getBehaviorScrollIntoView, getBoundaryPanel, makeDraggable, makeDraggable, makeNotDraggable, previewDragStart, removeDragHandler, setBehaviorCancelDocumentSelections, setBehaviorConstrainedToBoundaryPanel, setBehaviorDragStartSensitivity, setBehaviorMultipleSelection, setBehaviorScrollIntoView, setConstrainWidgetToBoundaryPanel, toggleSelection

Methods inherited from class java.lang.Object

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

Constructor Detail

PickupDragController

public PickupDragController(com.google.gwt.user.client.ui.AbsolutePanel boundaryPanel,
                    boolean allowDroppingOnBoundaryPanel)

Create a new pickup-and-move style drag controller. Allows widgets or a suitable proxy to be temporarily picked up and moved around the specified boundary panel.

Note: An implicit BoundaryDropController is created and registered automatically.

Parameters:

boundaryPanel - the desired boundary panel or RootPanel.get() (read http://code.google.com/p/gwt-dnd/wiki/GettingStarted) if entire document body is to be the boundary

allowDroppingOnBoundaryPanel - whether or not boundary panel should allow dropping

Method Detail

dragEnd

public void dragEnd()

Description copied from interface: DragController

Callback method for MouseDragHandler.

Specified by:

dragEnd in interface DragController

Overrides:

dragEnd in class AbstractDragController

dragMove

public void dragMove()

Description copied from interface: DragController

Callback method for MouseDragHandler.

dragStart

public void dragStart()

Description copied from interface: DragController

Callback method for MouseDragHandler when a drag operation is initiated for this drag controller.

Specified by:

dragStart in interface DragController

Overrides:

dragStart in class AbstractDragController

getBehaviorBoundaryPanelDrop

public boolean getBehaviorBoundaryPanelDrop()

Whether or not dropping on the boundary panel is permitted.

Returns:

true if dropping on the boundary panel is allowed

getBehaviorDragProxy

public boolean getBehaviorDragProxy()

Determine whether or not this controller automatically creates a drag proxy for each drag operation.

Returns:

true if drag proxy behavior is enabled

getSelectedWidgets

public java.lang.Iterable<com.google.gwt.user.client.ui.Widget> getSelectedWidgets()

Retrieve currently selected widgets.

Returns:

iterator of currently selected widgets

previewDragEnd

public void previewDragEnd()
                    throws VetoDragException

Description copied from interface: DragController

Callback method for MouseDragHandler.

Specified by:

previewDragEnd in interface DragController

Overrides:

previewDragEnd in class AbstractDragController

Throws:

VetoDragException - if the proposed operation is unacceptable

registerDropController

public void registerDropController(DropController dropController)

Register a new DropController, representing a new drop target, with this drag controller.

Parameters:

dropController - the controller to register

See Also:

unregisterDropController(DropController)

resetCache

public void resetCache()

Description copied from interface: DragController

Reset the internal drop controller (drop target) cache which is initialized primarily by AbstractDragController.dragStart(). This method should be called when a drop target's size and/or location changes, or when drop target eligibility changes.

Specified by:

resetCache in interface DragController

Overrides:

resetCache in class AbstractDragController

setBehaviorBoundaryPanelDrop

public void setBehaviorBoundaryPanelDrop(boolean allowDroppingOnBoundaryPanel)

Set whether or not widgets may be dropped anywhere on the boundary panel. Set to false when you only want explicitly registered drop controllers to accept drops. Defaults to true.

Parameters:

allowDroppingOnBoundaryPanel - true to allow dropping

setBehaviorDragProxy

public void setBehaviorDragProxy(boolean dragProxyEnabled)

Set whether or not this controller should automatically create a drag proxy for each drag operation.

Parameters:

dragProxyEnabled - true to enable drag proxy behavior

unregisterDropController

public void unregisterDropController(DropController dropController)

Unregister a DropController from this drag controller.

Parameters:

dropController - the controller to register

See Also:

registerDropController(DropController), unregisterDropControllers()

unregisterDropControllers

public void unregisterDropControllers()

Unregister all DropControllers from this drag controller.

See Also:

registerDropController(DropController), unregisterDropController(DropController)

newBoundaryDropController

protected BoundaryDropController newBoundaryDropController(com.google.gwt.user.client.ui.AbsolutePanel boundaryPanel,
                                               boolean allowDroppingOnBoundaryPanel)

Create a new BoundaryDropController to manage our boundary panel as a drop target. To ensure that draggable widgets can only be dropped on registered drop targets, set allowDroppingOnBoundaryPanel to false.

Parameters:

boundaryPanel - the panel to which our drag-and-drop operations are constrained

allowDroppingOnBoundaryPanel - whether or not dropping is allowed on the boundary panel

Returns:

the new BoundaryDropController

newDragProxy

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

Called by dragStart() to allow subclasses to provide their own drag proxies.

Parameters:

context - the current drag context

Returns:

a new drag proxy

restoreSelectedWidgetsLocation

protected void restoreSelectedWidgetsLocation()

Restore the selected widgets to their original location.

See Also:

saveSelectedWidgetsLocationAndStyle(), restoreSelectedWidgetsStyle()

restoreSelectedWidgetsStyle

protected void restoreSelectedWidgetsStyle()

Restore the selected widgets with their original style.

See Also:

saveSelectedWidgetsLocationAndStyle(), restoreSelectedWidgetsLocation()

saveSelectedWidgetsLocationAndStyle

protected void saveSelectedWidgetsLocationAndStyle()

Save the selected widgets' current location in case they much be restored due to a cancelled drop.

See Also:

restoreSelectedWidgetsLocation()