What makes RealGetWindowClass so much more real than GetClassName?

Raymond Chen

Raymond

There’s
Get­Class­Name
and then there’s
Real­Get­Window­Class.
What makes
Real­Get­Window­Class more real?

Recall from last time that

the Real... functions were added to support
Windows accessibility
.
The goal with Real­Get­Window­Class is to help
accessibility tools identify what kind of window it is working with,
even if the application did a little disguising in the form of

superclassing
.

If you ask
Real­Get­Window­Class for the class name of a window,
it digs through all the superclassing and returns the name of the
base class (if the base class is one of the standard window manager classes).
For example, if your application superclassed the button
class,
a call to Get­Class­Name would return
Awesome­Button,
but a call to
Real­Get­Window­Class would return button.
Returning the underlying window class allows accessibility tools
to know that the user is interacting with some type of button control
(albeit a customized one),
so that it can adjust the interaction to something appropriate
for buttons.
Without Real­Get­Window­Class,
the accessibility tool would just see Awesome­Button,
and it would probably shrug and say,
“I have no idea what a Awesome­Button is.”

(I guess you could have the accessibility tool do a
strstr for button,
but then it would be faked out by classes like
Button­Bar or applications which superclass
a button but call it something completely different like
Awesome­Radio.)

If you read the winuser.h header file,
you can see a comment next to the
Real­Get­Window­Class
function:

/*
 * This gets the name of the window TYPE, not class.  This allows us to
 * recognize ThunderButton32 et al.
 */

What is Thunder­Button32?

Thunder was

the code name for Visual Basic 1.0
.
Visual Basic superclassed all the standard Windows controls
and called its superclassed version Thunder­Whatever.

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