Hi Stoyan,

To perform zooming from the center of the diagram, we have used following code.

public void SetZoom(double percentage)

  {


try


{


    diagram.ZoomToFit();


    if (percentage > 200)


    {



  percentage = 200;


    }


    else if (percentage < 10)


    {



  percentage = 10;


    }



    ScrollViewer scrollViewer = diagram.Parent as ScrollViewer;


    Point oldCenter = diagram.ClientToDoc(new Point(scrollViewer.ViewportWidth / 2, scrollViewer.ViewportHeight / 2));



    double newScrollX = diagram.ScrollX;


    double newScrollY = diagram.ScrollY;


    diagram.ZoomFactor = percentage;



    Rect newBounds = diagram.ClientToDoc(new Rect(0, 0, scrollViewer.ViewportWidth, scrollViewer.ViewportHeight));


    Point newCenter = diagram.ClientToDoc(new Point(scrollViewer.ViewportWidth / 2, scrollViewer.ViewportHeight / 2));



    double diffx = (oldCenter.X - newCenter.X);


    double diffy = (oldCenter.Y - newCenter.Y);


    newScrollX += diffx;


    newScrollY += diffy;


    newBounds.X = newScrollX;


    newBounds.Y = newScrollY;



    newBounds.Union(diagram.GetContentBounds(false, false));


    newBounds.Inflate(200, 200);


    diagram.Bounds = newBounds;


    diagram.ScrollTo(new Point(newScrollX, newScrollY));


    }


catch (Exception ex)


{


    Debug.WriteLine("Exception in SetZoom : " + ex.Message);


}

  } 

Problem:

After zoom when we try to drag the node at extreme right of the diagram, horizontal bar position get change. Now if we zoom again it performs zooming from the diagram center, so in this case we get a different view during zooming from the view on which we were doing some work.

Requirement:

We want zooming should perform from the center of the visible client area. Client area which is viewable should have zooming center.


Please suggest how can we achieve this? ???

Regards,
Anshul

Hi,

My requirment is:
I get the content bounds using GetContentBounds().
Need to fill the entire diagram with the content rectangle and  need to make the view port center coincide with the center of the rect obtained from GetContentBounds().

How could this be done.!?

Regards,

Hi Stoyan,

We have tried given code in our application. Now nodes are coming at the center but when we go for zooming they are shifting in up direction. Sometimes diagram gets fluctuate for a while when we performzoom using mouse wheel.

We want zoom should always perform from the content's area center.

Please suggest what we need to do this?

Regards,
Anshul

Hi,

Try this:

private void OnSelectionChanged(object sender, EventArgs e)
{
	diagram.ZoomToRect(diagram.Selection.Bounds);
	diagram.BringIntoView(diagram.Selection, true);
}
 

I hope that helps,
Stoyan