Hi There,

At the moment I'm working on DragPreview thingy. See example below.



Basically i have a NodeListView on the left from where i want to drag the nodes on the diagramfield(Which works). While I'm doing this i want to get a preview of the node before i drop it on the field. Comparable with function ModificationEffect.MoveShades does when i move a node in the diagram only.

What I've tried so far is in the example code below.

   protected override void OnGiveFeedback(GiveFeedbackEventArgs e)
        {
            base.OnGiveFeedback(e);

            if (e.Effects.HasFlag(DragDropEffects.Copy))
            {
                Mouse.SetCursor(Cursors.Wait);
            }
            else if (e.Effects.HasFlag(DragDropEffects.Move))
            {
                Mouse.SetCursor(Cursors.Cross);
            }
            else
            {
                Mouse.SetCursor(Cursors.Hand);
            }
        } 

I tried overriding several GiveFeedbackEvents, dragevents and mouseevents in my NodeListView class. To see if it was working i kept the logic simple, just for testing purposes, hence the cursors.wait setting, i know this doesn't give me a preview. But it didnt give me a wait icon or cross icon either.

Could anyone give me any insight?

Thanks in advance.

Greets,

Sander

Hi,

Thanks, that worked somewhat.

Does Mindfusion have a standard property that gives me the possibility to have a preview of the node under my cursor?

Greets,

Sander

Hmmm.

Do you happen to have an code-example?

Greets,

Sander

Nothing like that, more like this:

DiagramNode dragIndicator = null;

private void OnDiagramDragEnter(object sender, DragEventArgs e)
{
	if (dragIndicator == null &&
		e.Data.GetDataPresent(typeof(DraggedNode)))
	{
		var data = (DraggedNode)e.Data.GetData(typeof(DraggedNode));
		var position = e.GetPosition(diagram.DocumentPlane);
		dragIndicator = (DiagramNode)data.Node.Clone(false);
		dragIndicator.Move(position.X, position.Y);
		dragIndicator.Opacity = 0.5;
		diagram.Nodes.Add(dragIndicator);
		e.Effects = DragDropEffects.Copy;
		e.Handled = true;
	}
}

void OnDiagramDragOver(object sender, DragEventArgs e)
{
	if (dragIndicator != null)
	{
		var position = e.GetPosition(diagram.DocumentPlane);
		dragIndicator.Move(position.X, position.Y);
		e.Effects = DragDropEffects.Copy;
		e.Handled = true;
	}
}

private void OnNodeCreated(object sender, NodeEventArgs e)
{
	// NodeListView creates an instance automatically, so remove the indicator
	if (dragIndicator != null)
	{
		diagram.Nodes.Remove(dragIndicator);
		dragIndicator = null;
	}
} 

I hope that helps,
Stoyan

You can always post it to address from http://mindfusion.eu/contacts.html