Import Methods

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 canImport method for that component's TransferHandler should 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.

Version note:

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.