Drag and Drop: New Data Transfer Capabilities in the JavaTM 2 Platform, Standard Edition (J2SETM), version 1.4

Drag and Drop: New Data Transfer Capabilities in the JavaTM 2 Platform, Standard Edition (J2SETM), version 1.4(8) While the process of transferring a String is done through the StringSelection class, there is no sUCh class available for transferring images. You must create your own Transferable object that implements ClipboardOwner, too. If StringSelection is for transferring String objects, the logical name for transferring images is ImageSelection.

If you plan on creating transferable objects that will interact with Swing components, you don't have to implement the two interfaces yourself. Instead, there is a helper TransferHandler class that does most of the work for you. The handler does the interaction with the clipboard, and you just have to override four of its methods:

• public int getSourceActions(JComponent c) -- Returns the supported operations. There are four constants in the TransferHandler class for the operations: COPY, COPY_OR_MOVE, MOVE, and NONE.
• public boolean canImport(JComponent comp, DataFlavor flavor[]) -- Returns true if the component can support one of the data flavors, false otherwise.
• public Transferable createTransferable(JComponent comp) -- Here, you need to save a reference to the data to be transferred, and return the TransferHandler (this). The component represents where the data is coming from. This is your copy operation. The handler does the actual copy to the clipboard at the appropriate time.
• public boolean importData(JComponent comp, Transferable t) -- Returns true if the component supports getting one of the data flavors from the Transferable object, and sUCcessfully gets it, false otherwise. This is your paste operation. Again, the handler gets the data from the clipboard, you just have to get it from the Transferable.