After reading some articles on DnD, I figured out how to implement
startDrag. I added a bunch of comments (and a referring URL) into the
function.
2006-07-06 Lillian Angel <[EMAIL PROTECTED]>
* java/awt/dnd/DragSource.java
(startDrag): Implemented. Added comments describing
what the function should do. Removed FIXME.
Index: java/awt/dnd/DragSource.java
===================================================================
RCS file: /cvsroot/classpath/classpath/java/awt/dnd/DragSource.java,v
retrieving revision 1.7
diff -u -r1.7 DragSource.java
--- java/awt/dnd/DragSource.java 5 Jul 2006 17:45:50 -0000 1.7
+++ java/awt/dnd/DragSource.java 6 Jul 2006 17:34:03 -0000
@@ -127,9 +127,39 @@
Image dragImage, Point imageOffset,
Transferable trans, DragSourceListener dsl,
FlavorMap map)
- throws NotImplementedException
{
- // FIXME: Implement this
+ // http://www.javaworld.com/javaworld/jw-03-1999/jw-03-dragndrop.html
+
+ // This function creates a DragSourceContext object. This object tracks the
+ // state of the operation by listening to a native peer. In this situation,
+ // the DragSource may be obtained from the event or by an instance variable.
+ // This function also creates a new DragSourceContextPeer.
+
+ // This function sends the same message to the context, which then forwards
+ // it to the peer, passing itself as a parameter. Now, the native system has
+ // access to the Transferable through the context.
+
+ try
+ {
+ flavorMap = map;
+ DragSourceContextPeer peer = Toolkit.getDefaultToolkit().
+ createDragSourceContextPeer(trigger);
+ DragSourceContext context = createDragSourceContext(peer, trigger,
+ dragCursor,
+ dragImage,
+ imageOffset, trans,
+ dsl);
+
+ if (peer == null)
+ throw new InvalidDnDOperationException();
+
+ peer.startDrag(context, dragCursor, dragImage, imageOffset);
+ }
+ catch (Exception e)
+ {
+ throw new InvalidDnDOperationException("Drag and Drop system is "
+ + "unable to initiate a drag operation.");
+ }
}
/**
