Package org.eclipse.ui.navigator

Class CommonDragAdapterAssistant

java.lang.Object

org.eclipse.ui.navigator.CommonDragAdapterAssistant

Direct Known Subclasses:

ResourceDragAdapterAssistant

public abstract class CommonDragAdapterAssistant
extends Object

Assist the CommonDragAdapter by providing new TransferTypes and the logic to handle setting up the transfer data. Clients must extend this class as part of the org.eclipse.ui.navigator.viewer/dragAssistant extension. By default, the Common Navigator supports LocalSelectionTransfer and PluginTransfer.

Clients may extend this class.

Since:

3.2

See Also:

INavigatorDnDService, CommonDragAdapter, CommonDropAdapter, CommonDropAdapterAssistant, CommonViewer, Drag and Drop: Adding Drag and Drop to an SWT Application, Drag and Drop in the Eclipse UI (Custom Transfer Types)

Constructor Summary

Constructors

Constructor	Description
CommonDragAdapterAssistant()

Method Summary

Modifier and Type	Method	Description
void	dragFinished(DragSourceEvent anEvent, IStructuredSelection aSelection)	Allows the drag assistant to do any necessary cleanup after the drop operation is done.
void	dragStart(DragSourceEvent anEvent, IStructuredSelection aSelection)	Allows the drag assistant indicate it wants to participate in the drag operation.
INavigatorContentService	getContentService()
Shell	getShell()
abstract Transfer[]	getSupportedTransferTypes()	Extra TransferTypes allow the Navigator to generate different kinds of payloads for DND clients.
void	setContentService(INavigatorContentService aContentService)	Accept and remember the content service this assistant is associated with.
abstract boolean	setDragData(DragSourceEvent anEvent, IStructuredSelection aSelection)	Set the value of the Event.data field using the given selection.

Methods inherited from class java.lang.Object

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

Constructor Detail

CommonDragAdapterAssistant

public CommonDragAdapterAssistant()

Method Detail

getSupportedTransferTypes

public abstract Transfer[] getSupportedTransferTypes()

Extra TransferTypes allow the Navigator to generate different kinds of payloads for DND clients. By default, the CommonDragAdapter supports LocalSelectionTransfer and PluginTransfer.

CommonDragAdapterAssistants can extend the available TransferTypes that a Common Navigator Viewer can generate. Clients should return the set of Transfer Types they support. When a drop event occurs, the available drag assistants will be searched for a enabled assistants for the DragSourceEvent. Only if the drop event occurs will setDragData(DragSourceEvent, IStructuredSelection) be called. If the drop event is cancelled, setDragData(DragSourceEvent, IStructuredSelection) will not be called.

Returns:

The added transfer types. (e.g. FileTransfer.getInstance()).

setDragData

public abstract boolean setDragData(DragSourceEvent anEvent,
                                    IStructuredSelection aSelection)

Set the value of the Event.data field using the given selection. Clients will only have an opportunity to set the drag data if they have returned a matching Transfer Type from getSupportedTransferTypes() for the DragSourceEvent.dataType.

Clients will only have an opportunity to set the data when the drop event occurs. If the drop operation is cancelled, then this method will not be called.

Parameters:

anEvent - The event object should have its Event.data field set to a value that matches a supported TransferData type.

aSelection - The current selection from the viewer.

Returns:

True if the data could be set; false otherwise.

dragStart

public void dragStart(DragSourceEvent anEvent,
                      IStructuredSelection aSelection)

Allows the drag assistant indicate it wants to participate in the drag operation. This is called at DragSourceListener.dragStart(DragSourceEvent) time.

Parameters:

anEvent - The event object should return doit = true if it wants to participate in the drag and set doit = false if it does not want to further participate.

aSelection - The current selection from the viewer.

Since:

3.4

dragFinished

public void dragFinished(DragSourceEvent anEvent,
                         IStructuredSelection aSelection)

Allows the drag assistant to do any necessary cleanup after the drop operation is done. This is called at DragSourceListener.dragFinished(DragSourceEvent) time. This is called on the same assistant that was called for the set data.

Parameters:

anEvent - The event object should have its Event.data field set to a value that matches a supported TransferData type.

aSelection - The current selection from the viewer.

Since:

3.4

setContentService

public final void setContentService(INavigatorContentService aContentService)

Accept and remember the content service this assistant is associated with.

Parameters:

aContentService - associated content service

getContentService

public INavigatorContentService getContentService()

Returns:

The associated content service.

getShell

public final Shell getShell()

Returns:

The shell for the viewer this assistant is associated with or the shell of the active workbench window.