ImageDim of an Image Property ?

[cippyboy]

Can I set a widget's dimensions based on an image property ? Like a I have an image customizing button, and based on whatever images I set up to it (so I won't have to write duplicate definitions with only 3 lines changed) I want it to have the size of an image property.

EDIT : While making a spinner I encountered another problem. I can't make it readonly despite setting the ReadOnly property. Is this normal ?

EDIT2 : Why can't I set defined properties to be used for the vertical or horizontal text formatting ? Plain values work, properties, don't, why ?