Scrolling and Zooming
In order to enable scrolling, you must place the Diagram control inside a ScrollViewer or a Ruler.
The diagram size is set through the Bounds property. Its value is a Rect instance that specifies the origin of the diagram coordinate system and the diagram size. The diagram can be resized automatically when the user moves or resizes nodes, as specified by the AutoResize property value. Call ResizeToFitItems after building a diagram programmatically to make it fit its items.
Use the ScrollX and ScrollY properties to get the current scroll position or to scroll the document contents programmatically. These properties correspond to the HorizontalOffset and VerticalOffset values of the parent ScrollViewer, but are converted to the current MeasureUnit.
Zooming is controlled by the ZoomFactor property. The zoom factor is expressed as a percentage, 100% meaning no zoom. Higher than 100% makes the diagram items look closer and bigger on the screen - zooming in. Less than 100% makes items look further and smaller on screen - zooming out. To zoom and scroll the view so it fits a specified rectangular document area to the control's client area, call ZoomToRect.
The diagram view can be panned by holding SHIFT while dragging the mouse with the left button down. To enable panning without using the SHIFT key, set Behavior to Pan.
The ZoomControl class lets users change interactively the current zoom level and scroll position of a Diagram. To set it up, add a ZoomControl to the page, place it anywhere over the target diagram, and set the control's Target property to that diagram. Set the ZoomStep and ScrollStep properties to specify the amount added to view's zoom level or scroll position by ZoomControl's buttons. You can customize the control's appearance by setting properties such as Fill, Stroke, CornerRadius and TickPosition.
