I need to be able to drag a row form one TableNode and drop it in another, but I don't see the required events for the TableNode class. 

I have derived a new class from TableNode and hooked into the parent diagram view's mouse events in order to implement this behavior, but it's fiddly and doesn't work perfectly (e.g. sometime a selection rectangle gets drawn after the drop).

Is there a better way to do this, or failing that, how can I stop the selection rectangle from being drawn and still allow the user to select a node by clicking on it?

Thanks.

Thanks Stoyan,

I want to change the cursor when the mouse is over a draggable row, so I think I'll go with your second suggestion and change the behavior (and the cursor) when the mouse is over the row.

But when I change the behavior back to "Modify" after the mouse moves off the row, how do I get the view to set the cursor back to what it should be (which obviously depends on it's current location)?  Is there a way to force the view to update the cursor immediately?

Thanks.

Brian

Hi Stoyan,

I'm processing the mouse move events for the diagram view, and when the mouse moves over a row I change the view's behavior to DoNothing.  I then set the current cursor, the view's Cursor property and the view's CurrentCursor property all to the cursor I want, but it still doesn't change! :S  Am I missing something?

Brian

Hi Brian,

Actually CurrentCursor lets you override the mouse cursor only while an item is being modified. Otherwise, the view uses the cursor specified by the Behavior object's SetMouseCursor method. For the time being, you can implement that by using a custom Behavior object:

public class MyBehavior : LinkTablesBehavior
{
	public MyBehavior(DiagramView view) : base(view)
	{
	}

	public override InteractionState StartDraw(PointF point)
	{
		if (OverDraggableRow(point))
			return null;

		return base.StartDraw(point);
	}

	public override CursorHint SetMouseCursor(PointF point, out bool startInteraction)
	{
		if (OverDraggableRow(point))
		{
			DiagramView.CurrentCursor = Cursors.Help;
			startInteraction = false;
			return CursorHint.DontChange;
		}

		return base.SetMouseCursor(point, out startInteraction);
	}

	private bool OverDraggableRow(PointF point)
	{
		int row = -1, col = -1;
		TableNode table = Diagram.GetNodeAt(point) as TableNode;
		return table != null && table.CellFromPoint(point, ref row, ref col) && row == 2;
	}
}
 

We'll try to make that easier in the next release, perhaps by extending the CurrentCursor feature to allow setting it when there isn't any item being modified.

Stoyan

If you decide to use the custom Behavior implementation, you could start the drag-and-drop operation in the StartDraw override, just before returning null. To make the control use your class, set diagramView.CustomBehavior = new MyBehavior(diagramView).

I hope that helps,
Stoyan