“A better solution for now might be to implement this entirely in the
app, using SDL_SYSWMEVENT, at least as a test case for making it part of
SDL (and failing that, good example code for others). I think
Objective-C lets you do some voodoo to catch messages targetted at other
objects (so you can let SDL handle the drag-n-drops until the app’s
mainline is called, and then handle the rest yourself).”
Application level voodoo to catch this is too scary to be practical.
Especially since SDLMain is already a delegate of the NSApplication. (ie
we’re already doing this to setup SDL_main()). It would be wiser to
implement register a callback, or induce an event. In any case, since
SDLMain is handling the event right now the correct place is to stick the
Now it is pretty trivial to add a SDL_SysWMEvent there. However, we still
need to squirrel away, the data associated with this event. Of course,
currently the mac platform has no SDL_SysWMmsg* support requireing we touch
include/sdl_events.h, include/sdl_syswm.h/ and src/video/maccommon/mac_wm*
which are pretty sparse, so we could add a NSString* to a mac specific
SDL_SysWMmsg, just for the openFile: case. But this also feels like a hack,
and doesn’t translate well for adding DND on other platforms.
As for handling other Mac event types, well there really aren’t many others.
There are some Tablet events that I can’t find SDL support for, and there
are all the NSResponder activity for selecting and manipulating buffers. So
in the odd event that we need to add new SDL_SysWMmsg for mac, the choice
here would prejudice the implementation of those. The handling of openFile:
isn’t like the handling of xatoms under X11.
I don’t necessarily object to adding this as an SDL event, but we only
have room for nine more event types, total, since the events become a
32-bit mask, and bits 25 through 32 are reserved for user-defined
things, off limits to SDL.
Well since over half are available I don’t see the problem then
Seriously, I wouldn’t suggest adding a new SDL_Event, unless it would be a
cross platform event. And in this case, I thing it would have to be a
SDL_DND event, which most platforms do have this concept of dropping a file
on an application, or double clicking on a document to load the associated
I’ll do some research into how Windows handles these events before I post a
patch. I simply love the idea of double clicking on a save game to return to
that save point But I think adding a full drag and drop event, would be
worth the effort. (And I’ve wanted it for ages
Comments and patches are welcome…be prepared for a hearty fight for
Oh I know damn well that online fights over implementation are nice and
hearty, I have plenty of war stories on that front.
And for sake of argument:
There is another option other than adding an SDL_Event type, we could simply
have a callback that is registered by the user’s application to handle
openFile: requests. This would be similar to using atexit() or the like. The
default behaior here would actually be to fork() and call main() again, with
file as the first argument. There by spawning a new instance of the
application and creating an entirely new NSApplication instance.
By providing the end user with a callback here, you could override this
behavior within your own application, and process the openFile: requests
within the current SDL & NSApplication context. This isn’t a crossplatform
modification, and would only effect how SDL applications work under Mac OS
X. It would help solve the “you can only run one instance” bug, and provide
a means for Mac programmers to respond to openFile: requests.
“The universal aptitude for ineptitude makes any human accomplishment an
-Stapp’s Ironical ParadoxOn 10/13/05, Ryan C. Gordon wrote: