[Chapter 16] 16.5 StringSelection

16.5 StringSelection

StringSelection is a convenience class that can be used for copy and paste operations on Unicode text strings (String). It implements both the ClipboardOwner and Transferable interfaces, so it can be used both as the contents of the clipboard and as its owner. For example, if s is a StringSelection, you can call Clipboard.setContents(s,s). StringSelection supports both stringFlavor and plainTextFlavor and doesn't do anything when it loses clipboard ownership.

StringSelection Methods

Constructors

public StringSelection(String data): The constructor creates an instance of StringSelection containing data. You can use this object to place the data on a clipboard.

Miscellaneous methods

public DataFlavor[] getTransferDataFlavors()

The getTransferDataFlavors() method returns a two-element DataFlavor array consisting of DataFlavor.stringFlavor and DataFlavor.plainTextFlavor. This means that you can paste a StringSelection as either a Java String or as plain text (i.e., the MIME type plain/text).

public boolean isDataFlavorSupported(DataFlavor flavor)

The isDataFlavorSupported() method is returns true if flavor is either DataFlavor.stringFlavor or DataFlavor.plainTextFlavor; it returns false for any other flavor.

public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException

The getTransferData() method returns an object from which you can get the data on the clipboard; the object's type is determined by the flavor parameter. This method returns a String containing the data on the clipboard if flavor is DataFlavor.stringFlavor; it returns a StringBufferInputStream from which you can read the data on the clipboard if you ask for DataFlavor.plainTextFlavor. Otherwise, getTransferData() throws an UnsupportedFlavorException.

public void lostOwnership(Clipboard clipboard, Transferable contents)

The lostOwnership() method of StringSelection is an empty stub; it does nothing when you lose ownership. If you want to know when you've lost ownership of string data placed on the clipboard, write a subclass of StringSelection and override this method.