get reasonably good behaviour on all platforms.
All of the bitmaps must be of the same size and the normal bitmap must be
- set first (to a valid bitmap), before setting any other ones.
+ set first (to a valid bitmap), before setting any other ones. Also, if the
+ size of the bitmaps is changed later, you need to change the size of the
+ normal bitmap before setting any other bitmaps with the new size (and you
+ do need to reset all of them as their original values can be lost when the
+ normal bitmap size changes).
The position of the image inside the button be configured using
SetBitmapPosition(). By default the image is on the left of the text.