Refreshes the given window. This function must be used instead
of BeginRefresh(), if gadtools-gadgets are used. When you are
finished with refreshing the window, you must call GT_EndRefresh().
INPUTS
gad
Gadget, for which the specified attributes should be set for.
win
Window, in which the gadget is.
req
Not used. Specify NULL for now.
tagList
List of attributes to set.
RESULT
The gadget may be set to the specified attributes.
NOTES
Note that there is no possibility to check, if the setting of an
attribute was successful, except by getting the attribute and
checking it. The setting of some attributes cannot fail. Refer to
the description of the tags to check this.