Module java.desktop
Package java.awt.dnd

Class DropTargetDragEvent

  • All Implemented Interfaces:
    Serializable
    public class DropTargetDragEvent
extends DropTargetEvent
    The DropTargetDragEvent is delivered to a DropTargetListener via its dragEnter() and dragOver() methods.

    The DropTargetDragEvent reports the source drop actions and the user drop action that reflect the current state of the drag operation.

    Source drop actions is a bitwise mask of DnDConstants that represents the set of drop actions supported by the drag source for this drag operation.

    User drop action depends on the drop actions supported by the drag source and the drop action selected by the user. The user can select a drop action by pressing modifier keys during the drag operation: 

       Ctrl + Shift -> ACTION_LINK
   Ctrl         -> ACTION_COPY
   Shift        -> ACTION_MOVE
    If the user selects a drop action, the user drop action is one of DnDConstants that represents the selected drop action if this drop action is supported by the drag source or DnDConstants.ACTION_NONE if this drop action is not supported by the drag source.

    If the user doesn't select a drop action, the set of DnDConstants that represents the set of drop actions supported by the drag source is searched for DnDConstants.ACTION_MOVE, then for DnDConstants.ACTION_COPY, then for DnDConstants.ACTION_LINK and the user drop action is the first constant found. If no constant is found the user drop action is DnDConstants.ACTION_NONE.

    Since:
    1.2
    See Also:
    Serialized Form

    • Constructor Detail

      • DropTargetDragEvent

        public DropTargetDragEvent​(DropTargetContext dtc,
                           Point cursorLocn,
                           int dropAction,
                           int srcActions)
        Construct a DropTargetDragEvent given the DropTargetContext for this operation, the location of the "Drag" Cursor's hotspot in the Component's coordinates, the user drop action, and the source drop actions.
        Parameters:
        dtc - The DropTargetContext for this operation
        cursorLocn - The location of the "Drag" Cursor's hotspot in Component coordinates
        dropAction - The user drop action
        srcActions - The source drop actions
        Throws:
        NullPointerException - if cursorLocn is null
        IllegalArgumentException - if dropAction is not one of DnDConstants.
        IllegalArgumentException - if srcActions is not a bitwise mask of DnDConstants.
        IllegalArgumentException - if dtc is null.

    • Method Detail

      • getLocation

        public Point getLocation()
        This method returns a Point indicating the Cursor's current location within the Component's coordinates.
        Returns:
        the current cursor location in Component's coords.

      • getCurrentDataFlavors

        public DataFlavor[] getCurrentDataFlavors()
        This method returns the current DataFlavors from the DropTargetContext.
        Returns:
        current DataFlavors from the DropTargetContext

      • getCurrentDataFlavorsAsList

        public List<DataFlavor> getCurrentDataFlavorsAsList()
        This method returns the current DataFlavors as a java.util.List
        Returns:
        a java.util.List of the Current DataFlavors

      • isDataFlavorSupported

        public boolean isDataFlavorSupported​(DataFlavor df)
        This method returns a boolean indicating if the specified DataFlavor is supported.
        Parameters:
        df - the DataFlavor to test
        Returns:
        if a particular DataFlavor is supported

      • getSourceActions

        public int getSourceActions()
        This method returns the source drop actions.
        Returns:
        the source drop actions

      • getDropAction

        public int getDropAction()
        This method returns the user drop action.
        Returns:
        the user drop action

      • getTransferable

        public Transferable getTransferable()
        This method returns the Transferable object that represents the data associated with the current drag operation.
        Returns:
        the Transferable associated with the drag operation
        Throws:
        InvalidDnDOperationException - if the data associated with the drag operation is not available
        Since:
        1.5

      • acceptDrag

        public void acceptDrag​(int dragOperation)
        Accepts the drag. This method should be called from a DropTargetListeners dragEnter, dragOver, and dropActionChanged methods if the implementation wishes to accept an operation from the srcActions other than the one selected by the user as represented by the dropAction.
        Parameters:
        dragOperation - the operation accepted by the target

      • rejectDrag

        public void rejectDrag()
        Rejects the drag as a result of examining either the dropAction or the available DataFlavor types.