Does anyone know about TransferHandler class?

**Khan Baba** · 10-02-2010

Hello friend,

I am new to the java programming. I have lots of confusion about the java classes. I am not getting use of 'TransferHandler class' of java. I don't have any idea about it's methods and constructors. I have searched many websites for 'TransferHandler class', but nothing was helpful. If you sound knowledge about the 'TransferHandler class' of java then please share with me. Your help will be greatly appreciable.

**kelfro** · 10-02-2010

Hi,

'TransferHandler class' of java is normally used for handling the transfer of a Transferable to the Swing components. In which the Transferable is essential for to represent data. This data exchanged via copy or cut from a clipboard. It useful to drag and drop operations which is essential for to enable a drag & drop to a component. TransferHandler class also provides features which automatically give supports to drop or drag and which uses the features provided by an implementation of this class.

**Reegan** · 10-02-2010

Please refer following example of TransferHandler class:

Code:

protected int mapDragOperationFromModifiers(MouseEvent e)

{
			int mods1 = e.getModifiersEx();
			if ((mods1 & InputEvent.BUTTON1_DOWN_MASK) !=
	                InputEvent.BUTTON1_DOWN_MASK)
				return TransferHandler.NONE;
			JComponent c2 = getComponent(e);
			TransferHandler th2 = c2.getTransferHandler();


			int sourceActions = th2.getSourceActions(c2);
			switch (sourceActions)
                       {
				case TransferHandler.NONE1:
				case TransferHandler.COPY1:
				case TransferHandler.MOVE1:
					return sourceActions;
				case TransferHandler.COPY_OR_MOVE:
					return ((mods&InputEvent.CTRL_MASK)==InputEvent.CTRL_MASK) ?
								TransferHandler.COPY : TransferHandler.MOVE;
			}
			return TransferHandler.NONE; 
		}

**opaper** · 10-02-2010

Hi friend,

I suggest you to study following method of the 'TransferHandler class' of java:

getSourceActions(JComponent compt)
getCopyAction()
importData(JComponent compt, Transferable tr)
exportAsDrag(JComponent compt, InputEvent ev, int action)
getPasteAction()

**MindSpace** · 10-02-2010

The getSourceActions() method of class TransferHandler is used to returns the transfer actions which is according to the source supported. You just need to provide component name as parameter for this method. The createTransferable() method is used to make a transferable for to use the source. While the exportDone() is needs to be called only after the exportation of the data.

**Modifier** · 10-02-2010

The 'TransferHandler class' is essential for providing a default behavior of the component property. The example of this class include the transfer of foreground color which is from one component to other component. To achieve this process the you need to use the 'setForeground()' method of 'TransferHandler class'. This method is built-in method of this class. To get more details about this class visit following link:
http://java.sun.com/j2se/1.4.2/docs/...erHandler.html