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class:DragSourceContext [NONE]
  • All Implemented Interfaces:
    DragSourceListener, DragSourceMotionListener, Serializable, EventListener 
    public class DragSourceContext
extends Object
implements DragSourceListener, DragSourceMotionListener, Serializable
    The DragSourceContext class is responsible for managing the initiator side of the Drag and Drop protocol. In particular, it is responsible for managing drag event notifications to the DragSourceListeners and DragSourceMotionListeners, and providing the Transferable representing the source data for the drag operation.

    Note that the DragSourceContext itself implements the DragSourceListener and DragSourceMotionListener interfaces. This is to allow the platform peer (the DragSourceContextPeer instance) created by the DragSource to notify the DragSourceContext of state changes in the ongoing operation. This allows the DragSourceContext object to interpose itself between the platform and the listeners provided by the initiator of the drag operation.

    By default, DragSourceContext sets the cursor as appropriate for the current state of the drag and drop operation. For example, if the user has chosen the move action , and the pointer is over a target that accepts the move action, the default move cursor is shown. When the pointer is over an area that does not accept the transfer, the default "no drop" cursor is shown.

    This default handling mechanism is disabled when a custom cursor is set by the setCursor(java.awt.Cursor) method. When the default handling is disabled, it becomes the responsibility of the developer to keep the cursor up to date, by listening to the DragSource events and calling the setCursor() method. Alternatively, you can provide custom cursor behavior by providing custom implementations of the DragSource and the DragSourceContext classes.

    Since:
    1.2
    See Also:
    DragSourceListener, DragSourceMotionListener, DnDConstants, Serialized Form

field:DEFAULT [NONE]

  • DEFAULT

    protected static final int DEFAULT
    An int used by updateCurrentCursor() indicating that the Cursor should change to the default (no drop) Cursor.
    See Also:
    Constant Field Values

field:ENTER [NONE]

  • ENTER

    protected static final int ENTER
    An int used by updateCurrentCursor() indicating that the Cursor has entered a DropTarget.
    See Also:
    Constant Field Values

field:OVER [NONE]

  • OVER

    protected static final int OVER
    An int used by updateCurrentCursor() indicating that the Cursor is over a DropTarget.
    See Also:
    Constant Field Values

field:CHANGED [NONE]

  • CHANGED

    protected static final int CHANGED
    An int used by updateCurrentCursor() indicating that the user operation has changed.
    See Also:
    Constant Field Values

constructor:<init>(java.awt.dnd.DragGestureEvent,java.awt.Cursor,java.awt.Image,java.awt.Point,java.awt.datatransfer.Transferable,java.awt.dnd.DragSourceListener) [NONE]

  • DragSourceContext

    public DragSourceContext​(DragGestureEvent trigger,
                         Cursor dragCursor,
                         Image dragImage,
                         Point offset,
                         Transferable t,
                         DragSourceListener dsl)
    Called from DragSource, this constructor creates a new DragSourceContext given the DragSourceContextPeer for this Drag, the DragGestureEvent that triggered the Drag, the initial Cursor to use for the Drag, an (optional) Image to display while the Drag is taking place, the offset of the Image origin from the hotspot at the instant of the triggering event, the Transferable subject data, and the DragSourceListener to use during the Drag and Drop operation.
    If DragSourceContextPeer is nullNullPointerException is thrown.
    If DragGestureEvent is nullNullPointerException is thrown.
    If Cursor is null no exception is thrown and the default drag cursor behavior is activated for this drag operation.
    If Image is null no exception is thrown.
    If Image is not null and the offset is null NullPointerException is thrown.
    If Transferable is nullNullPointerException is thrown.
    If DragSourceListener is null no exception is thrown.
    Parameters:
    trigger - the triggering event
    dragCursor - the initial Cursor for this drag operation or null for the default cursor handling; see class level documentation for more details on the cursor handling mechanism during drag and drop
    dragImage - the Image to drag (or null)
    offset - the offset of the image origin from the hotspot at the instant of the triggering event
    t - the Transferable
    dsl - the DragSourceListener
    Throws:
    IllegalArgumentException - if the Component associated with the trigger event is null.
    IllegalArgumentException - if the DragSource for the trigger event is null.
    IllegalArgumentException - if the drag action for the trigger event is DnDConstants.ACTION_NONE.
    IllegalArgumentException - if the source actions for the DragGestureRecognizer associated with the trigger event are equal to DnDConstants.ACTION_NONE.
    NullPointerException - if dscp, trigger, or t are null, or if dragImage is non-null and offset is null

method:getDragSource() [NONE]

  • getDragSource

    public DragSource getDragSource()
    Returns the DragSource that instantiated this DragSourceContext.
    Returns:
    the DragSource that instantiated this DragSourceContext

method:getComponent() [NONE]

  • getComponent

    public Component getComponent()
    Returns the Component associated with this DragSourceContext.
    Returns:
    the Component that started the drag

method:getTrigger() [NONE]

  • getTrigger

    public DragGestureEvent getTrigger()
    Returns the DragGestureEvent that initially triggered the drag.
    Returns:
    the Event that triggered the drag

method:getSourceActions() [NONE]

  • getSourceActions

    public int getSourceActions()
    Returns a bitwise mask of DnDConstants that represent the set of drop actions supported by the drag source for the drag operation associated with this DragSourceContext.
    Returns:
    the drop actions supported by the drag source

method:setCursor(java.awt.Cursor) [NONE]

  • setCursor

    public void setCursor​(Cursor c)
    Sets the custom cursor for this drag operation to the specified Cursor. If the specified Cursor is null, the default drag cursor behavior is activated for this drag operation, otherwise it is deactivated.
    Parameters:
    c - the initial Cursor for this drag operation, or null for the default cursor handling; see class level documentation for more details on the cursor handling during drag and drop

method:getCursor() [NONE]

  • getCursor

    public Cursor getCursor()
    Returns the current custom drag Cursor.
    Returns:
    the current custom drag Cursor, if it was set otherwise returns null.
    See Also:
    setCursor(java.awt.Cursor)

method:addDragSourceListener(java.awt.dnd.DragSourceListener) [NONE]

  • addDragSourceListener

    public void addDragSourceListener​(DragSourceListener dsl)
                           throws TooManyListenersException
    Add a DragSourceListener to this DragSourceContext if one has not already been added. If a DragSourceListener already exists, this method throws a TooManyListenersException.
    Parameters:
    dsl - the DragSourceListener to add. Note that while null is not prohibited, it is not acceptable as a parameter.
    Throws:
    TooManyListenersException - if a DragSourceListener has already been added

method:removeDragSourceListener(java.awt.dnd.DragSourceListener) [NONE]

  • removeDragSourceListener

    public void removeDragSourceListener​(DragSourceListener dsl)
    Removes the specified DragSourceListener from this DragSourceContext.
    Parameters:
    dsl - the DragSourceListener to remove; note that while null is not prohibited, it is not acceptable as a parameter

method:transferablesFlavorsChanged() [NONE]

  • transferablesFlavorsChanged

    public void transferablesFlavorsChanged()
    Notifies the peer that the Transferable's DataFlavors have changed.

method:dragEnter(java.awt.dnd.DragSourceDragEvent) [NONE]

  • dragEnter

    public void dragEnter​(DragSourceDragEvent dsde)
    Calls dragEnter on the DragSourceListeners registered with this DragSourceContext and with the associated DragSource, and passes them the specified DragSourceDragEvent.
    Specified by:
    dragEnter in interface DragSourceListener
    Parameters:
    dsde - the DragSourceDragEvent

method:dragOver(java.awt.dnd.DragSourceDragEvent) [NONE]

  • dragOver

    public void dragOver​(DragSourceDragEvent dsde)
    Calls dragOver on the DragSourceListeners registered with this DragSourceContext and with the associated DragSource, and passes them the specified DragSourceDragEvent.
    Specified by:
    dragOver in interface DragSourceListener
    Parameters:
    dsde - the DragSourceDragEvent

method:dragExit(java.awt.dnd.DragSourceEvent) [NONE]

  • dragExit

    public void dragExit​(DragSourceEvent dse)
    Calls dragExit on the DragSourceListeners registered with this DragSourceContext and with the associated DragSource, and passes them the specified DragSourceEvent.
    Specified by:
    dragExit in interface DragSourceListener
    Parameters:
    dse - the DragSourceEvent

method:dropActionChanged(java.awt.dnd.DragSourceDragEvent) [NONE]

  • dropActionChanged

    public void dropActionChanged​(DragSourceDragEvent dsde)
    Calls dropActionChanged on the DragSourceListeners registered with this DragSourceContext and with the associated DragSource, and passes them the specified DragSourceDragEvent.
    Specified by:
    dropActionChanged in interface DragSourceListener
    Parameters:
    dsde - the DragSourceDragEvent

method:dragDropEnd(java.awt.dnd.DragSourceDropEvent) [NONE]

  • dragDropEnd

    public void dragDropEnd​(DragSourceDropEvent dsde)
    Calls dragDropEnd on the DragSourceListeners registered with this DragSourceContext and with the associated DragSource, and passes them the specified DragSourceDropEvent.
    Specified by:
    dragDropEnd in interface DragSourceListener
    Parameters:
    dsde - the DragSourceDropEvent

method:dragMouseMoved(java.awt.dnd.DragSourceDragEvent) [NONE]

  • dragMouseMoved

    public void dragMouseMoved​(DragSourceDragEvent dsde)
    Calls dragMouseMoved on the DragSourceMotionListeners registered with the DragSource associated with this DragSourceContext, and them passes the specified DragSourceDragEvent.
    Specified by:
    dragMouseMoved in interface DragSourceMotionListener
    Parameters:
    dsde - the DragSourceDragEvent
    Since:
    1.4

method:getTransferable() [NONE]

  • getTransferable

    public Transferable getTransferable()
    Returns the Transferable associated with this DragSourceContext.
    Returns:
    the Transferable

method:updateCurrentCursor(int,int,int) [NONE]

  • updateCurrentCursor

    protected void updateCurrentCursor​(int sourceAct,
                                   int targetAct,
                                   int status)
    If the default drag cursor behavior is active, this method sets the default drag cursor for the specified actions supported by the drag source, the drop target action, and status, otherwise this method does nothing.
    Parameters:
    sourceAct - the actions supported by the drag source
    targetAct - the drop target action
    status - one of the fields DEFAULT, ENTER, OVER, CHANGED

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