Belatedly, i added ScrollViewer to allow panning and autoscrolling etc but....

..suddenly, the NodeDeleting events do not fire.

All the other Mindfusion events are there like clicking, doubleclicking, etc, only deleting is silent.

If i remove the xaml <ScrollViewer> Tags, the events are back there again.

One COULD easily write own event handler that checks for delete key and deletes selection nodes, but it "seems" unappropriate & one worries what else got broke in the back..

Any ideas?

Thank you, that worked

Do we know how to detect the actual size of client visible area of the diagram within the ScrollViewer?

Bounds returns the rect of the background area, all of it...

Uh i was so happy with:

                       Rect size = new Rect(0, 0, v.ViewportWidth+v.HorizontalOffset, v.ViewportHeight+v.VerticalOffset);

                        if (!size.Contains(MousePosition)) //within itself
                        {  

as it detected even the pan-shifted inside of a viewport, UNTIL i understood that one can have also a floating window above, and then one needs discern the "topmost" property to be able to say if the hit is correct.

Diagram.Viewport does not have the Topmost property?

Is there a simple way to find out which diagram is topmost? (we use Avalon Dock)

cheers

well i can have multiple document avalon dock setup, and lets say 5 mindfusion diagrams. Some of them are floating (as not docked) and i need to detect which is the topmost when i e.g. drag onto it.

So was hoping for a cheap solution like (diagram.topmost == true) or via viewport property, in order to determine the topmost hit one.

cheers

Argh

It just crossed my mind that "topmost" does not help: one can have several floating diagrams around...

Best would be if there was a way to detect the uppermost hit diagram when the handler:

protected override void OnDrop(DragEventArgs e)

hits. Then one could ignore other bubbling drop events after the uppermost hit one has been done.

===

I also tried to discern what is hit per drop by using the

HitTestResult hit = VisualTreeHelper.HitTest((Visual)e.Source, MousePosition)

[not sure here if e.Source is a good origin]

but the HitTestResult is of mindfusion type A.UM ? Though it corresponds to the diagram background size 1500x1500 that we gave in xaml, i have no way of casting it to some actual diagram type in order to determine whats hit?

cheers

Ah thank you, Stoyan

"You shouldn't have to care which diagram is the 'uppermost hit' if you attach a Drop event handler to each diagram."

I do that already, but use OnDrop from windows and not from Mindfusion, so maybe it behaves differently: will have to consider rewriting it a bit.

The original reason to use windows OnDrop was to try simulate nice graphical draging of nodes from diagram to next diagram (the way nodes are dragged within the same diagram), but it didn't succeed in full.

Is there a Mindfusion way to attach a node to cursor while you drag over the diagram boundaries to next diagram or you always show only .NET drag cursors?

cheers

Good ideas, thank you 

Hi,

You can find an example below. It opens a new window that covers the whole screen to enable drawing the node everywhere. The drag operation is started by holding down shift while pressing the mouse button. It doesn't actually use the Windows drag/drop events, since MouseMove is enough when we cover the whole screen. VisualTreeHelper.HitTest might not work with the dock control you are using if it creates system windows via the Win32 API. In such case you will have to use the dock control's API for hit testing.

Another option might be to create a small window - just as big as the node - and move the window around while the mouse moves. This might be necessary if you have to support drag between two instances of the application, since VisualTreeHelper won't work then, and you will  have to use OLE drag/drop instead of MouseMove anyway.

The code below is from a modification of the MultiViews sample project, where you must also add these changes:

In MainWindow.xaml, add the following attribute to windowHost:
PreviewMouseDown="OnPreviewMouseDown"

In MainWindow.xaml.cs, replace the window.Content = view assignment with:
window.Content = new Diagram();

I hope that helps,
Stoyan

private void OnPreviewMouseDown(object sender, MouseButtonEventArgs e)
{
	if ((Keyboard.Modifiers & ModifierKeys.Shift) != 0)
	{
		VisualTreeHelper.HitTest((Visual)sender, null, StartDrag,
			new PointHitTestParameters(e.GetPosition((IInputElement)sender)));
		e.Handled = true;
	}
}

private HitTestResultBehavior StartDrag(HitTestResult result)
{
	var node = result.VisualHit as DiagramNode;
	if (node != null)
	{
		overlay = new Window();
		overlay.AllowsTransparency = true;
		overlay.WindowStyle = WindowStyle.None;
		overlay.Background = Brushes.Transparent;
		overlay.ShowInTaskbar = false;
		overlay.Left = 0;
		overlay.Top = 0;
		overlay.Width = 2000;
		overlay.Height = 2000;
		overlay.Show();
		overlay.Topmost = true;

		var diagram = new Diagram();
		diagram.BackBrush = new SolidColorBrush(Color.FromArgb(1, 0, 0, 0));
		diagram.Bounds = new Rect(0, 0, 2000, 2000);
		diagram.CaptureMouse();
		diagram.Focus();
		diagram.PreviewMouseMove += OnOverlayMouseMove;
		diagram.PreviewMouseUp += OnOverlayMouseUp;
		overlay.Content = diagram;

		var clone = (DiagramNode)node.Clone(false);
		diagram.Nodes.Add(clone);

		overlay.UpdateLayout();
		var pos = Mouse.GetPosition(diagram.DocumentPlane);
		clone.Move(
			pos.X - clone.Bounds.Width / 2,
			pos.Y - clone.Bounds.Height / 2);

		return HitTestResultBehavior.Stop;
	}

	return HitTestResultBehavior.Continue;
}

private void OnOverlayMouseMove(object sender, MouseEventArgs e)
{
	var diagram = (Diagram)sender;
	var pos = e.GetPosition(diagram.DocumentPlane);

	var clone = diagram.Nodes[0];
	clone.Move(
			pos.X - clone.Bounds.Width / 2,
			pos.Y - clone.Bounds.Height / 2);
}

private void OnOverlayMouseUp(object sender, MouseButtonEventArgs e)
{
	overlay.Close();

	windowHost.CaptureMouse();
	var mousePos = Mouse.GetPosition(windowHost);
	windowHost.ReleaseMouseCapture();
	VisualTreeHelper.HitTest(
		windowHost, null, EndDrag,
		new PointHitTestParameters(mousePos));
}

private HitTestResultBehavior EndDrag(HitTestResult result)
{
	// result.VisualHit is diagram.DocumentPlane
	var diagram = VisualTreeHelper.GetParent(result.VisualHit) as Diagram;
	if (diagram != null)
	{
		var overlayDiagram = (Diagram)overlay.Content;
		var clone = (DiagramNode)overlayDiagram.Nodes[0].Clone(false);
		diagram.Nodes.Add(clone);

		var pos = Mouse.GetPosition(diagram.DocumentPlane);
		clone.Move(
			pos.X - clone.Bounds.Width / 2,
			pos.Y - clone.Bounds.Height / 2);

		return HitTestResultBehavior.Stop;
	}

	return HitTestResultBehavior.Continue;
}

Window overlay;