recent change to nsterm.m: four pixels where the Dock is hidden

[David Reitter]

Anders,

I appreciate your work on the NS/OSX port.
Reviewing a recent change, I can’t help but wonder:  Do we really need 50 lines 
of a hack to counteract design decisions made at the system level?  

If [NSScreen visibleFrame] tells us not to occupy certain space on the screen - 
four pixels where the Dock is hidden - then that’s a standard that all 
applications should adhere to.  It’s probably done for a reason (such as being 
able to un-hide the Dock and to grab the lower horizontal edge of the window 
for resizing).  

ns_screen_margins_ignoring_hidden_dock is, excuse my bluntness, ugly as it 
hardcodes some numbers that can change any time with a new OS version. It’s a 
burden for future maintenance.

If this is what #22988 really was about, then it’s not a bug and we shouldn’t 
mess with it.  Also not in 25.1.

If I’m wrong, please excuse me.  Could you explain if there is some deeper 
reasoning that I’m missing?

Thanks,
David


> Author: Anders Lindgren <address@hidden>
> Date:   Tue Mar 22 20:18:33 2016 +0100
> 
>     Make `toggle-frame-maximized' respect the dock on OS X (bug#22988).
> 
>     * src/nsterm.m (ns_screen_margins): New function.
>     (ns_screen_margins_ignoring_hidden_dock): New function.
>     (ns_menu_bar_height): Reimplement in terms of `ns_screen_margins'.
>     ([EmacsWindow zoom:]): Take all screen margins (except those
>     originating from a hidden dock) into account.
>