Now we will look at the methods used for importing data into a component. These methods are invoked for the drop gesture, or the paste action, when the component is the target of the operation. The
TransferHandler methods for importing data are:
canImport(TransferHandler.TransferSupport)— This method is called repeatedly during a drag gesture and returns true if the area below the cursor can accept the transfer, or false if the transfer will be rejected. For example, if a user drags a color over a component that accepts only text, the
canImportmethod for that component's
TransferHandlershould return false.
importData(TransferHandler.TransferSupport)— This method is called on a successful drop (or paste) and initiates the transfer of data to the target component. This method returns true if the import was successful and false otherwise.
These methods replace older versions that do not use the
TransferSupport class. Unlike its replacement method,
canImport(JComponent, DataFlavor) is not called continuously.
You will notice that these import methods take a
TransferHandler.TransferSupport argument. Next we look at the
TransferSupport class and then some sample import methods.