JdtViewerDropAdapter (Eclipse 3.5.2 Javadoc and Source)

java.lang.Object
- org.eclipse.swt.dnd.DropTargetAdapter
- - org.eclipse.jdt.internal.ui.dnd.JdtViewerDropAdapter

All Implemented Interfaces:

EventListener, DropTargetListener, SWTEventListener

Direct Known Subclasses:

FileTransferDropAdapter, SelectionTransferDropAdapter, WorkingSetDropAdapter
```
public abstract class JdtViewerDropAdapter
extends DropTargetAdapter
```
This adapter class provides generic drag-and-drop support for a viewer.
Subclasses must implement the following methods:
- validateDrop - identifies valid drop targets in viewer
- performDrop - carries out a drop into a viewer
The setFeedbackEnabled method can be called to turn on and off visual insertion feedback (on by default).

THIS IS (ALMOST) A ONE-TO-ONE COPY OF PLATFORMS ViewerDropAdapter REFERE THERE FIRST IF YOU NEED TO FIX SOMETHING.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`LOCATION_AFTER` Constant describing the position of the cursor relative to the target object.
`static int`	`LOCATION_BEFORE` Constant describing the position of the cursor relative to the target object.
`static int`	`LOCATION_NONE` Constant describing the position of the cursor relative to the target object.
`static int`	`LOCATION_ON` Constant describing the position of the cursor relative to the target object.

Constructor Summary

Constructors
Modifier Constructor and Description

protected JdtViewerDropAdapter(Viewer viewer)
Creates a new drop adapter for the given viewer.

Constructors
Modifier	Constructor and Description
`protected`	`JdtViewerDropAdapter(Viewer viewer)` Creates a new drop adapter for the given viewer.

Method Summary

Methods
Modifier and Type	Method and Description
`protected int`	`determineLocation(DropTargetEvent event)` Returns the position of the given event's coordinates relative to its target.
`protected int`	`determineOperation(Object target, int operation, TransferData transferType, int operations)` Determine the operation which should be executed given the target and the operation requested by the user.
`protected Object`	`determineTarget(DropTargetEvent event)` Returns the target item of the given drop event.
`void`	`dragEnter(DropTargetEvent event)` This implementation of `dragEnter` permits the default operation defined in `event.detail`to be performed on the current data type defined in `event.currentDataType`.
`void`	`dragOperationChanged(DropTargetEvent event)` This implementation of `dragOperationChanged` permits the default operation defined in `event.detail`to be performed on the current data type defined in `event.currentDataType`.
`void`	`dragOver(DropTargetEvent event)` This implementation of `dragOver` permits the default operation defined in `event.detail`to be performed on the current data type defined in `event.currentDataType`.
`void`	`drop(DropTargetEvent event)` This implementation of `drop` does nothing.
`void`	`dropAccept(DropTargetEvent event)` This implementation of `dropAccept` permits the default operation defined in `event.detail`to be performed on the current data type defined in `event.currentDataType`.
`protected Rectangle`	`getBounds(Item item)` Returns the bounds of the given SWT tree or table item.
`protected int`	`getCurrentLocation()` Returns a constant describing the position of the mouse relative to the target (before, on, or after the target.
`protected int`	`getCurrentOperation()` Returns the current operation.
`protected Object`	`getCurrentTarget()` Returns the target object currently under the mouse.
`boolean`	`getFeedbackEnabled()` Returns whether visible insertion feedback should be presented to the user.
`protected Object`	`getSelectedObject()` Returns the object currently selected by the viewer.
`protected Viewer`	`getViewer()`
`protected void`	`handleException(Throwable exception, DropTargetEvent event)` Deprecated. this method should not be used. Exception handling has been removed from DropTargetAdapter methods overridden by this class. Handles any exception that occurs during callback, including rethrowing behavior. [Issue: Implementation prints stack trace and eats exception to avoid crashing VA/J. Consider conditionalizing the implementation to do one thing in VAJ and something more reasonable in other operating environments. ]
`abstract boolean`	`performDrop(Object data)` Performs any work associated with the drop.
`void`	`setExpandEnabled(boolean value)` Sets whether auto expanding should be provided during dragging.
`void`	`setFeedbackEnabled(boolean value)` Sets whether visible insertion feedback should be presented to the user.
`void`	`setScrollEnabled(boolean value)` Sets whether auto scrolling should be provided during dragging.
`void`	`setScrollExpandEnabled(boolean value)` Sets whether auto scrolling and expanding should be provided during dragging.
`void`	`setSelectionFeedbackEnabled(boolean value)` Sets whether selection feedback should be provided during dragging.
`abstract boolean`	`validateDrop(Object target, int operation, TransferData transferType)` Validates dropping on the given object.

Methods inherited from class org.eclipse.swt.dnd.DropTargetAdapter
dragLeave

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - LOCATION_BEFORE
```
public static final int LOCATION_BEFORE
```
    Constant describing the position of the cursor relative to the target object. This means the mouse is positioned slightly before the target.
    
    See Also:
    getCurrentLocation(), Constant Field Values
  - LOCATION_AFTER
```
public static final int LOCATION_AFTER
```
    Constant describing the position of the cursor relative to the target object. This means the mouse is positioned slightly after the target.
    
    See Also:
    getCurrentLocation(), Constant Field Values
  - LOCATION_ON
```
public static final int LOCATION_ON
```
    Constant describing the position of the cursor relative to the target object. This means the mouse is positioned directly on the target.
    
    See Also:
    getCurrentLocation(), Constant Field Values
  - LOCATION_NONE
```
public static final int LOCATION_NONE
```
    Constant describing the position of the cursor relative to the target object. This means the mouse is not positioned over or near any valid target.
    
    See Also:
    getCurrentLocation(), Constant Field Values
- Constructor Detail
  - JdtViewerDropAdapter
```
protected JdtViewerDropAdapter(Viewer viewer)
```
    Creates a new drop adapter for the given viewer.
    
    Parameters:
    viewer - the viewer
- Method Detail
  - determineLocation
```
protected int determineLocation(DropTargetEvent event)
```
    Returns the position of the given event's coordinates relative to its target. The position is determined to be before, after, or on the item, based on some threshold value.
    
    Parameters:
    event - the event
    
    Returns:
    one of the LOCATION_* constants defined in this class
  - determineTarget
```
protected Object determineTarget(DropTargetEvent event)
```
    Returns the target item of the given drop event.
    
    Parameters:
    event - the event
    
    Returns:
    The target of the drop, may be null.
  - dragEnter
```
public void dragEnter(DropTargetEvent event)
```
    Description copied from class: DropTargetAdapter
    
    This implementation of dragEnter permits the default operation defined in event.detailto be performed on the current data type defined in event.currentDataType. For additional information see DropTargetListener.dragEnter.
    
    Specified by:
    
    dragEnter in interface DropTargetListener
    
    Overrides:
    
    dragEnter in class DropTargetAdapter
    
    Parameters:
    event - the information associated with the drag enter event
    See Also:
    DropTargetEvent
  - dragOperationChanged
```
public void dragOperationChanged(DropTargetEvent event)
```
    Description copied from class: DropTargetAdapter
    
    This implementation of dragOperationChanged permits the default operation defined in event.detailto be performed on the current data type defined in event.currentDataType. For additional information see DropTargetListener.dragOperationChanged.
    
    Specified by:
    
    dragOperationChanged in interface DropTargetListener
    
    Overrides:
    
    dragOperationChanged in class DropTargetAdapter
    
    Parameters:
    event - the information associated with the drag operation changed event
    See Also:
    DropTargetEvent
  - dragOver
```
public void dragOver(DropTargetEvent event)
```
    Description copied from class: DropTargetAdapter
    
    This implementation of dragOver permits the default operation defined in event.detailto be performed on the current data type defined in event.currentDataType. For additional information see DropTargetListener.dragOver.
    
    Specified by:
    
    dragOver in interface DropTargetListener
    
    Overrides:
    
    dragOver in class DropTargetAdapter
    
    Parameters:
    event - the information associated with the drag over event
    See Also:
    DropTargetEvent
  - drop
```
public void drop(DropTargetEvent event)
```
    Description copied from class: DropTargetAdapter
    
    This implementation of drop does nothing. For additional information see DropTargetListener.drop.
    
    Specified by:
    
    drop in interface DropTargetListener
    
    Overrides:
    
    drop in class DropTargetAdapter
    
    Parameters:
    event - the information associated with the drop event
    See Also:
    DropTargetEvent
  - dropAccept
```
public void dropAccept(DropTargetEvent event)
```
    Description copied from class: DropTargetAdapter
    
    This implementation of dropAccept permits the default operation defined in event.detailto be performed on the current data type defined in event.currentDataType. For additional information see DropTargetListener.dropAccept.
    
    Specified by:
    
    dropAccept in interface DropTargetListener
    
    Overrides:
    
    dropAccept in class DropTargetAdapter
    
    Parameters:
    event - the information associated with the drop accept event
    See Also:
    DropTargetEvent
  - getBounds
```
protected Rectangle getBounds(Item item)
```
    Returns the bounds of the given SWT tree or table item.
    
    Parameters:
    item - the SWT Item
    
    Returns:
    the bounds, or null if it is not a known type of item
  - getCurrentLocation
```
protected int getCurrentLocation()
```
    Returns a constant describing the position of the mouse relative to the target (before, on, or after the target.
    
    Returns:
    one of the LOCATION_* constants defined in this type
  - getCurrentOperation
```
protected int getCurrentOperation()
```
    Returns the current operation.
    
    Returns:
    a DROP_* constant from class DND
    See Also:
    DND.DROP_COPY, DND.DROP_MOVE, DND.DROP_LINK, DND.DROP_NONE
  - getCurrentTarget
```
protected Object getCurrentTarget()
```
    Returns the target object currently under the mouse.
    
    Returns:
    the current target object
  - getFeedbackEnabled
```
public boolean getFeedbackEnabled()
```
    Returns whether visible insertion feedback should be presented to the user.
    Typical insertion feedback is the horizontal insertion bars that appear between adjacent items while dragging.
    
    Returns:
    true if visual feedback is desired, and false if not
  - getSelectedObject
```
protected Object getSelectedObject()
```
    Returns the object currently selected by the viewer.
    
    Returns:
    the selected object, or null if either no object or multiple objects are selected
  - getViewer
```
protected Viewer getViewer()
```
    Returns:
    the viewer to which this drop support has been added.
  - handleException
```
protected void handleException(Throwable exception,
                   DropTargetEvent event)
```
    Deprecated. this method should not be used. Exception handling has been removed from DropTargetAdapter methods overridden by this class. Handles any exception that occurs during callback, including rethrowing behavior.
    [Issue: Implementation prints stack trace and eats exception to avoid crashing VA/J. Consider conditionalizing the implementation to do one thing in VAJ and something more reasonable in other operating environments. ]
    
    Parameters:
    exception - the exception
    event - the event
  - performDrop
```
public abstract boolean performDrop(Object data)
```
    Performs any work associated with the drop.
    Subclasses must implement this method to provide drop behavior.
    
    Parameters:
    data - the drop data
    
    Returns:
    true if the drop was successful, and false otherwise
  - setFeedbackEnabled
```
public void setFeedbackEnabled(boolean value)
```
    Sets whether visible insertion feedback should be presented to the user.
    Typical insertion feedback is the horizontal insertion bars that appear between adjacent items while dragging.
    
    Parameters:
    value - true if visual feedback is desired, and false if not
  - setSelectionFeedbackEnabled
```
public void setSelectionFeedbackEnabled(boolean value)
```
    Sets whether selection feedback should be provided during dragging.
    
    Parameters:
    value - true if selection feedback is desired, and false if not
    Since:
    
    3.2
  - setScrollExpandEnabled
```
public void setScrollExpandEnabled(boolean value)
```
    Sets whether auto scrolling and expanding should be provided during dragging.
    
    Parameters:
    value - true if scrolling and expanding is desired, and false if not
    Since:
    
    2.0
  - setExpandEnabled
```
public void setExpandEnabled(boolean value)
```
    Sets whether auto expanding should be provided during dragging.
    
    Parameters:
    value - true if expanding is desired, and false if not
    Since:
    
    3.4
  - setScrollEnabled
```
public void setScrollEnabled(boolean value)
```
    Sets whether auto scrolling should be provided during dragging.
    
    Parameters:
    value - true if scrolling is desired, and false if not
    Since:
    
    3.4
  - validateDrop
```
public abstract boolean validateDrop(Object target,
                   int operation,
                   TransferData transferType)
```
    Validates dropping on the given object. This method is called whenever some aspect of the drop operation changes.
    Subclasses must implement this method to define which drops make sense.
    
    Parameters:
    target - the object that the mouse is currently hovering over, or null if the mouse is hovering over empty space
    operation - the current drag operation (copy, move, etc.)
    transferType - the current transfer type
    
    Returns:
    true if the drop is valid, and false otherwise
  - determineOperation
```
protected int determineOperation(Object target,
                     int operation,
                     TransferData transferType,
                     int operations)
```
    Determine the operation which should be executed given the target and the operation requested by the user. This method is called whenever some aspect of the drop operation changes. The operation is one of DND#DROP_DEFAULT, DND#DROP_COPY, DND#DROP_MOVE, DND#DROP_LINK.
    The method returns the operation valid in the given context. The result is one of DND#DROP_NONE, DND#DROP_COPY, DND#DROP_MOVE, DND#DROP_LINK, DND#DROP_DEFAULT.
    
    Subclasses can overwrite this method to define which operation does make sense in the given context.
    
    Parameters:
    target - the object that the mouse is currently hovering over, or null if the mouse is hovering over empty space
    operation - the current drag operation (copy, move, etc.)
    transferType - the current transfer type
    operations - a bitwise OR'ing of the operations that the DragSource can support
    
    Returns:
    the operation which will be executed if no modifier key is pressed by the user
    See Also:
    DND.DROP_NONE, DND.DROP_MOVE, DND.DROP_COPY, DND.DROP_LINK

Class JdtViewerDropAdapter [ source ]

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.eclipse.swt.dnd.DropTargetAdapter

Methods inherited from class java.lang.Object

Field Detail

LOCATION_BEFORE

LOCATION_AFTER

LOCATION_ON

LOCATION_NONE

Constructor Detail

JdtViewerDropAdapter

Method Detail

determineLocation

determineTarget

dragEnter

dragOperationChanged

dragOver

drop

dropAccept

getBounds

getCurrentLocation

getCurrentOperation

getCurrentTarget

getFeedbackEnabled

getSelectedObject

getViewer

handleException

performDrop

setFeedbackEnabled

setSelectionFeedbackEnabled

setScrollExpandEnabled

setExpandEnabled

setScrollEnabled

validateDrop

determineOperation