Java javax.swing Class TransferHandler.TransferSupport（JDK8）

Constructor Detail

• TransferSupport

  public TransferSupport(Component component,
                         Transferable transferable)

  Create a TransferSupport with isDrop() false for the given component and Transferable.

  Parameters:

  component - the target component

  transferable - the transferable

  Throws:

  NullPointerException - if either parameter is null

Method Detail

• isDrop

  public boolean isDrop()

  Returns whether or not this TransferSupport represents a drop operation.

  Returns:

  true if this is a drop operation, false otherwise.

• getComponent

  public Component getComponent()

  Returns the target component of this transfer.

  Returns:

  the target component

• getDropLocation

  public TransferHandler.DropLocation getDropLocation()

  Returns the current (non-null) drop location for the component, when this TransferSupport represents a drop.

  Note: For components with built-in drop support, this location will be a subclass of DropLocation of the same type returned by that component's getDropLocation method.

  This method is only for use with drag and drop transfers. Calling it when isDrop() is false results in an IllegalStateException.

  Returns:

  the drop location

  Throws:

  IllegalStateException - if this is not a drop

  See Also:

  isDrop()

• setShowDropLocation

  public void setShowDropLocation(boolean showDropLocation)

  Sets whether or not the drop location should be visually indicated for the transfer - which must represent a drop. This is applicable to those components that automatically show the drop location when appropriate during a drag and drop operation). By default, the drop location is shown only when the TransferHandler has said it can accept the import represented by this TransferSupport. With this method you can force the drop location to always be shown, or always not be shown.

  This method is only for use with drag and drop transfers. Calling it when isDrop() is false results in an IllegalStateException.

  Parameters:

  showDropLocation - whether or not to indicate the drop location

  Throws:

  IllegalStateException - if this is not a drop

  See Also:

  isDrop()

• setDropAction

  public void setDropAction(int dropAction)

  Sets the drop action for the transfer - which must represent a drop - to the given action, instead of the default user drop action. The action must be supported by the source's drop actions, and must be one of COPY, MOVE or LINK.

  This method is only for use with drag and drop transfers. Calling it when isDrop() is false results in an IllegalStateException.

  Parameters:

  dropAction - the drop action

  Throws:

  IllegalStateException - if this is not a drop

  IllegalArgumentException - if an invalid action is specified

  See Also:

  getDropAction(), getUserDropAction(), getSourceDropActions(), isDrop()

• getDropAction

  public int getDropAction()

  Returns the action chosen for the drop, when this TransferSupport represents a drop.

  Unless explicitly chosen by way of setDropAction, this returns the user drop action provided by getUserDropAction.

  You may wish to query this in TransferHandler's importData method to customize processing based on the action.

  This method is only for use with drag and drop transfers. Calling it when isDrop() is false results in an IllegalStateException.

  Returns:

  the action chosen for the drop

  Throws:

  IllegalStateException - if this is not a drop

  See Also:

  setDropAction(int), getUserDropAction(), isDrop()

• getUserDropAction

  public int getUserDropAction()

  Returns the user drop action for the drop, when this TransferSupport represents a drop.

  The user drop action is chosen for a drop as described in the documentation for DropTargetDragEvent and DropTargetDropEvent. A different action may be chosen as the drop action by way of the setDropAction method.

  You may wish to query this in TransferHandler's canImport method when determining the suitability of a drop or when deciding on a drop action to explicitly choose.

  This method is only for use with drag and drop transfers. Calling it when isDrop() is false results in an IllegalStateException.

  Returns:

  the user drop action

  Throws:

  IllegalStateException - if this is not a drop

  See Also:

  setDropAction(int), getDropAction(), isDrop()

• getSourceDropActions

  public int getSourceDropActions()

  Returns the drag source's supported drop actions, when this TransferSupport represents a drop.

  The source actions represent the set of actions supported by the source of this transfer, and are represented as some bitwise-OR combination of COPY, MOVE and LINK. You may wish to query this in TransferHandler's canImport method when determining the suitability of a drop or when deciding on a drop action to explicitly choose. To determine if a particular action is supported by the source, bitwise-AND the action with the source drop actions, and then compare the result against the original action. For example:

   boolean copySupported = (COPY & getSourceDropActions()) == COPY;
   

  This method is only for use with drag and drop transfers. Calling it when isDrop() is false results in an IllegalStateException.

  Returns:

  the drag source's supported drop actions

  Throws:

  IllegalStateException - if this is not a drop

  See Also:

  isDrop()

• getDataFlavors

  public DataFlavor[] getDataFlavors()

  Returns the data flavors for this transfer.

  Returns:

  the data flavors for this transfer

• isDataFlavorSupported

  public boolean isDataFlavorSupported(DataFlavor df)

  Returns whether or not the given data flavor is supported.

  Parameters:

  df - the DataFlavor to test

  Returns:

  whether or not the given flavor is supported.

• getTransferable

  public Transferable getTransferable()

  Returns the Transferable associated with this transfer.

  Note: Unless it is necessary to fetch the Transferable directly, use one of the other methods on this class to inquire about the transfer. This may perform better than fetching the Transferable and asking it directly.

  Returns:

  the Transferable associated with this transfer