[news.eclipse.platform.rcp] Re: LocalSelectionTransfer and clipboard

[Thomas Fahrmeyer <lauritziu_ii@xxxxxxxx>]

Hi,

Francis Upton schrieb:
> Try this instead:
>
> clipboard.setContents(new Object[] {new 
> StructuredSelection(selectedObject)},
>                new Transfer[] {LocalSelectionTransfer.getTransfer()});
>
> The LocalSelectionTransfer expects to deal with an ISelection.
>
> Then to get the contents, I use:
>
> ISelection selection = LocalSelectionTransfer.getTransfer()
>                         .getSelection();

I assume, that will not work this way. The point is that is, as I can 
see, irrelevant what will be stored as Object in 
clipboard.setContents(Object[], Transfer[]), because the implementation 
of LocalSelectionTransfer.nativeToJava() Method, just returns the stored 
selection. In my understanding the Transfer type is an identifier for 
the implemation which transforms a byte[] from java to native and back. 
Each Transfer implementation have a

- javaToNative(Object, TransferData data)
- nativeToJava(TransferData data)

method. The implementation of LocalSelectionTransfer.nativeToJava just 
checks whether the transferData was created by an 
LocalSelectionTransfer, but doesn't use any native bytes from the 
clipboard. It returns the prior stored selection.
A little bit confusing, isn't it? :) I have the following code working:

in the copy Action:

copy() {
	LocalSelectionTransfer transfer = LocalSelectionTransfer.getTransfer();
	// very important, store your selection
	transfer.setSelection(new StructureSelection(getYourSelection())

	// the object[] doesn't really matters
	getClipboard().setContents(new Object[] {getYourSelection()}, 				new 
Transfer[] {transfer});

}

in the paste Action():

paste() {
	LocalSelectionTransfer transfer = LocalSelectionTransfer.getTransfer();

	// that returns the selection stored in copy()
	IStructuredSelection selection = 
(IStructuredSelection)getClipboard().getContents(transfer)
}

Hope this helps. Just have a look at the implementation of 
LocalSelectionTransfer.

bye
Thomas


> Kerri wrote:
> > Is it ok to use LocalSelectionTransfer with the 
> > org.eclipse.swt.dnd.Clipboard?  I'm having a problem getting contents 
> > back from the clipboard so I wrote these 2 lines of code.  In the 
> > debugger I can see that the data is stored in the clipboard from the 
> > first line but I can't get it back out.
> >
> > I have these 2 lines of code and the second one returns null.
> >
> > clipboard.setContents(new Object[] {selectedObject},               new 
> > Transfer[] {LocalSelectionTransfer.getTransfer()});
> >        
> > Object lsObject = clipboard.getContents( 
> > LocalSelectionTransfer.getTransfer());
> >
> >
> > Thanks for any advice!
> > Kerri