Drag and drop support for a visual part is enabled in VA Smalltalk through the settings for the part. You can use these settings to enable a user to move, copy, or link an instance of an object using a simple drag and drop interface.

You can enable a part to be a drag source, a drag target, or both. Both the source and target of a drag operation must agree on the operation to be performed. For example, both the source and and target must be enabled for a move operation for a move to occur. When the source and target cannot agree on the operation the end user sees a forbidden symbol as a mouse pointer when dragging over the target window.

Because you are dragging instances of objects, the target of the drag must understand the class of object(s) being dropped on it. You specify the acceptable object classes in the target's settings.