Interpreting WPF Dependency Properties as a Set

So I have control. It renders an image based on XML document and an optional parameter

• "Document" - XML ​​document
• "RenderingOption" - optional rendering of images (sharpness, softening)

So:

<XMLRenderingWidget Document="xxxxxx"/>

      

        
        
        
      

    

The above document will be displayed once

<XMLRenderingWidget Document="xxxxxx" RenderingOption="Sharpen"/>

      

        
        
        
      

    

The above will sometimes process the document once, more often:

• Render the document as if renderer had not been set
• then redefine the document with the Sharpen parameter

I am rendering to the PropertyChangedCallback assigned to this property. How do I tell the control "hey, before rendering, apply changes to other properties set too"

Isn't that impossible? Should I strip them as one property?