oracle.javatools.editor.plugins
Class DropTargetPlugin

java.lang.Object
  oracle.javatools.editor.plugins.DropTargetPlugin

All Implemented Interfaces:

java.awt.dnd.DropTargetListener, java.beans.PropertyChangeListener, java.util.EventListener, EditorPlugin

Direct Known Subclasses:

DragDropPlugin

public class DropTargetPlugin
extends java.lang.Object
implements java.awt.dnd.DropTargetListener, EditorPlugin

The DropTargetPlugin is an editor plugin which adds drop support to the BasicEditorPane so that it can accept drop operations for Drag-n-Drop. This does not provide support for initiating a drag operation from the editor however.

Field Summary

protected static EditDescriptor	DROP_DESCRIPTOR The edit (undo) descriptor for a drop operation.
protected static int	DROP_RECT_WIDTH The width of the drop rectangle to paint - since drawRect() is used, a width of 1 is a thickness of 2.
protected java.awt.dnd.DropTarget	dropTarget The drop target associated with the editor.
protected BasicEditorPane	editor The editor that this plugin is installed into.
protected java.awt.Rectangle	lastDropRect The last drop rectangle that was painted.
protected static java.awt.datatransfer.DataFlavor	PLAIN_FLAVOR The plain text flavor to use.
protected static java.awt.datatransfer.DataFlavor	STRING_FLAVOR The string flavor to use.

Constructor Summary

DropTargetPlugin()
Constructs a new DropTargetPlugin instance that adds drop capability to the editor for text drops.

Method Summary

protected void	cancelDragEvent(java.awt.dnd.DropTargetEvent event) Utility method to handle case where the drop is cancelled because the drag has left the component.
protected void	clearDropLocation() Utility method to force a repaint of the last drop location that was painted (if any.)
void	deinstall(BasicEditorPane editor) Called when the plugin is being removed from the BasicEditorPane (for example when the editor is closed.) This is used to notify plugins that they should unregister any listeners that were attached.
void	dragEnter(java.awt.dnd.DropTargetDragEvent event) Called when a drag operation has encountered the DropTarget.
void	dragExit(java.awt.dnd.DropTargetEvent event) The drag operation has departed the DropTarget without dropping.
void	dragOver(java.awt.dnd.DropTargetDragEvent event) Called when a drag operation is ongoing on the DropTarget.
void	drop(java.awt.dnd.DropTargetDropEvent event) The drag operation has terminated with a drop on this DropTarget.
void	dropActionChanged(java.awt.dnd.DropTargetDragEvent event) Called if the user has modified the current drop gesture.
protected BasicDocument	getDocument() Fetch the document of the editor.
protected java.awt.Rectangle	getDropRectangle(java.awt.Point location) Utility method to fetch the rectangle corresponding to a given location.
protected java.awt.datatransfer.DataFlavor	getPreferredDataFlavor(java.awt.datatransfer.Transferable transferable) Utility method to choose the data flavor to use for the transfer based on the transferable in the drag/drop operation.
protected java.awt.datatransfer.DataFlavor[]	getSupportedFlavors() Fetch the DataFlavors that can be accepted by this drop target.
protected java.lang.String	getTransferText(java.awt.datatransfer.Transferable transferable) Utility method to fetch the text to drop based on the transferable in the drag and drop operation
protected void	handleDragEvent(java.awt.dnd.DropTargetDragEvent event) Utility method to handle the various drag events that occur prior to the actual drop.
protected void	handleDropEvent(java.awt.dnd.DropTargetDropEvent event) Utility method to handle the actual drop event that occurred.
void	install(BasicEditorPane editor) Called when this plugin is being installed into the BasicEditorPane.
protected boolean	isDataFlavorSupported(java.awt.dnd.DropTargetDragEvent event) Utility method to check if the data flavor of the transferable in the drag and drop operation is supported by us.
protected boolean	isDataFlavorSupported(java.awt.dnd.DropTargetDropEvent event) Utility method to check if the data flavor of the transferable in the drag and drop operation is supported by us.
protected boolean	isDropActionSupported(int requestedAction) Utility method to check if the requested drop operation (i.e., COPY) is supported.
protected void	paintDropLocation(java.awt.Point newLocation) Utility method to request a repaint of the new drop location specified by the given location.
void	propertyChange(java.beans.PropertyChangeEvent event) This method gets called when a bound property is changed.

Methods inherited from class java.lang.Object

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

Field Detail

editor

protected BasicEditorPane editor

The editor that this plugin is installed into.

dropTarget

protected java.awt.dnd.DropTarget dropTarget

The drop target associated with the editor.

lastDropRect

protected java.awt.Rectangle lastDropRect

The last drop rectangle that was painted.

DROP_RECT_WIDTH

protected static final int DROP_RECT_WIDTH

The width of the drop rectangle to paint - since drawRect() is used, a width of 1 is a thickness of 2.

See Also:

Constant Field Values

STRING_FLAVOR

protected static final java.awt.datatransfer.DataFlavor STRING_FLAVOR

The string flavor to use.

PLAIN_FLAVOR

protected static final java.awt.datatransfer.DataFlavor PLAIN_FLAVOR

The plain text flavor to use.

DROP_DESCRIPTOR

protected static final EditDescriptor DROP_DESCRIPTOR

The edit (undo) descriptor for a drop operation.

Constructor Detail

DropTargetPlugin

public DropTargetPlugin()

Constructs a new DropTargetPlugin instance that adds drop capability to the editor for text drops.

Method Detail

install

public void install(BasicEditorPane editor)

Called when this plugin is being installed into the BasicEditorPane.

Specified by:

install in interface EditorPlugin

Parameters:

editor - the editor pane

deinstall

public void deinstall(BasicEditorPane editor)

Called when the plugin is being removed from the BasicEditorPane (for example when the editor is closed.) This is used to notify plugins that they should unregister any listeners that were attached.

Specified by:

deinstall in interface EditorPlugin

Parameters:

editor - the editor pane

propertyChange

public void propertyChange(java.beans.PropertyChangeEvent event)

This method gets called when a bound property is changed.

Specified by:

propertyChange in interface java.beans.PropertyChangeListener

Parameters:

event - A PropertyChangeEvent object describing the event source and the property that has changed.

dragEnter

public void dragEnter(java.awt.dnd.DropTargetDragEvent event)

Called when a drag operation has encountered the DropTarget.

Specified by:

dragEnter in interface java.awt.dnd.DropTargetListener

Parameters:

event - the DropTargetDragEvent that occurred

dragOver

public void dragOver(java.awt.dnd.DropTargetDragEvent event)

Called when a drag operation is ongoing on the DropTarget.

Specified by:

dragOver in interface java.awt.dnd.DropTargetListener

Parameters:

event - the DropTargetDragEvent that occurred

dropActionChanged

public void dropActionChanged(java.awt.dnd.DropTargetDragEvent event)

Called if the user has modified the current drop gesture.

Specified by:

dropActionChanged in interface java.awt.dnd.DropTargetListener

Parameters:

event - the DropTargetDragEvent that occurred

dragExit

public void dragExit(java.awt.dnd.DropTargetEvent event)

The drag operation has departed the DropTarget without dropping.

Specified by:

dragExit in interface java.awt.dnd.DropTargetListener

Parameters:

event - the DropTargetEvent that occurred

drop

public void drop(java.awt.dnd.DropTargetDropEvent event)

The drag operation has terminated with a drop on this DropTarget. This method is responsible for undertaking the transfer of the data associated with the gesture. The DropTargetDropEvent provides a means to obtain a Transferable object that represents the data object(s) to be transfered.

From this method, the DropTargetListener shall accept or reject the drop via the acceptDrop(int dropAction) or rejectDrop() methods of the DropTargetDropEvent parameter.

Subsequent to acceptDrop(), but not before, DropTargetDropEvent's getTransferable() method may be invoked, and data transfer may be performed via the returned Transferable's getTransferData() method.

At the completion of a drop, an implementation of this method is required to signal the success/failure of the drop by passing an appropriate boolean to the DropTargetDropEvent's dropComplete(boolean success) method.

Note: The actual processing of the data transfer is not required to finish before this method returns. It may be deferred until later.

Specified by:

drop in interface java.awt.dnd.DropTargetListener

Parameters:

event - the DropTargetDropEvent that occurred

getDocument

protected BasicDocument getDocument()

Fetch the document of the editor.

Returns:

the editor document

getDropRectangle

protected java.awt.Rectangle getDropRectangle(java.awt.Point location)

Utility method to fetch the rectangle corresponding to a given location. This can be used to paint a drop location for example.

Parameters:

location - the location to get the rectangle for

Returns:

a rectangle for the given offset location

clearDropLocation

protected void clearDropLocation()

Utility method to force a repaint of the last drop location that was painted (if any.)

paintDropLocation

protected void paintDropLocation(java.awt.Point newLocation)

Utility method to request a repaint of the new drop location specified by the given location.

Parameters:

newLocation - the new location to paint

cancelDragEvent

protected void cancelDragEvent(java.awt.dnd.DropTargetEvent event)

Utility method to handle case where the drop is cancelled because the drag has left the component. This gives us a chance to clean up anything we need to.

Parameters:

event - the event that occurred

handleDropEvent

protected void handleDropEvent(java.awt.dnd.DropTargetDropEvent event)

Utility method to handle the actual drop event that occurred.

Parameters:

event - the actual drop event that occurred

getTransferText

protected java.lang.String getTransferText(java.awt.datatransfer.Transferable transferable)

Utility method to fetch the text to drop based on the transferable in the drag and drop operation

Parameters:

transferable - the transferable involved

Returns:

the text contained in the transferable

getPreferredDataFlavor

protected java.awt.datatransfer.DataFlavor getPreferredDataFlavor(java.awt.datatransfer.Transferable transferable)

Utility method to choose the data flavor to use for the transfer based on the transferable in the drag/drop operation.

Parameters:

transferable - the transferable involved

Returns:

the preferred data flavor

handleDragEvent

protected void handleDragEvent(java.awt.dnd.DropTargetDragEvent event)

Utility method to handle the various drag events that occur prior to the actual drop.

Parameters:

event - the event that occurred

isDropActionSupported

protected boolean isDropActionSupported(int requestedAction)

Utility method to check if the requested drop operation (i.e., COPY) is supported.

Parameters:

requestedAction - the requested drag/drop operation

Returns:

if the requested drag/drop operation is supported

isDataFlavorSupported

protected boolean isDataFlavorSupported(java.awt.dnd.DropTargetDragEvent event)

Utility method to check if the data flavor of the transferable in the drag and drop operation is supported by us.

Parameters:

event - the drag event that occurred

Returns:

if this is a supported data flavor

isDataFlavorSupported

protected boolean isDataFlavorSupported(java.awt.dnd.DropTargetDropEvent event)

Utility method to check if the data flavor of the transferable in the drag and drop operation is supported by us.

Parameters:

event - the drag event that occurred

Returns:

if this is a supported data flavor

getSupportedFlavors

protected java.awt.datatransfer.DataFlavor[] getSupportedFlavors()

Fetch the DataFlavors that can be accepted by this drop target. The order of the DataFlavors indicates preference by this target.

Returns:

an array of the data flavors supported by this target