Java Foundation Classes in a Nutshell

Example 6−1: TransferableColor.java (continued)

/** Check whether a specified DataFlavor is available */

public boolean isDataFlavorSupported(DataFlavor flavor) {

if (flavor.equals(colorFlavor) ||

flavor.equals(DataFlavor.stringFlavor) ||

flavor.equals(DataFlavor.plainTextFlavor)) return true;

return false;

}

/**

* Transfer the data. Given a specified DataFlavor, return an Object

* appropriate for that flavor. Throw UnsupportedFlavorException if we

* don't support the requested flavor.

*/

public Object getTransferData(DataFlavor flavor)

throws UnsupportedFlavorException, IOException

{

if (flavor.equals(colorFlavor)) return color;

else if (flavor.equals(DataFlavor.stringFlavor)) return color.toString();

else if (flavor.equals(DataFlavor.plainTextFlavor))

return new ByteArrayInputStream(color.toString().getBytes("Unicode"));

else throw new UnsupportedFlavorException(flavor);

}

}

Cut-and-Paste

In addition to the data transfer framework classes, the java.awt.datatransfer

package also defines the Clipboard class and the ClipboardOwner inter face, which

implement data transfer with the cut-and-paste metaphor.

A typical cut-and-paste transfer works as follows:

•Inthe initiating application, the user types Ctrl-C or Ctrl-X or in some other

way tells the application that he wants to copy or cut some data.

• The application takes the selected data and encapsulates it in an appropriate

Transferable object. The next step ...