User-Drawn Controls in DataWindow Objects

The Paint (expr) expression functions allow you to draw objects in the DataWindow such as polygons, arrow tips, pie slices, and so on. The Paint expression function takes one string expression argument and returns the same string. This allows you to paint inside a DataWindow in a way that respects the position and z-order of other DataWindow objects. It should contain a function call to a drawing global function with rendering logic. If expr is a string expression and the value is not null, the Computed Field will render the evaluated string expression.

This feature also provides the following supporting functions:

  • GetPaintDC()

  • GetPaintRectX()

  • GetPaintRectY()

  • GetPaintRectWidth()

  • GetPaintRectHeight()