On Friday, 11 May 2012 at 15:23:10 UTC, Steven Schveighoffer
wrote:
Yes I did mean that.
I'm thinking about it, one thing you did not mention, but
almost certainly is the case (it usually is with GUI toolkits)
is that the WndProc is called in a different thread or context
than the constructor.
It's in the same exact thread as the caller of CreateWindow in
Win32 (not sure what you mean by "context" here, but AFAIK
nothing is changed about the thread... nothing fiber-like or
anything like that going on).
I'm not familiar with other OSes though.
This means, there may be functions that you can call in WndProc
that you cannot call in the ctor.
So even though CreateWindow returning means WM_CREATE must have
been received, the context you need to handle WM_CREATE is
gone. Is that true?
Again, not sure what you mean by "context", but there is nothing
changed about the thread here.
You could nest the creation of 10 windows down this chain of
WM_CREATE's (in fact, that's one of its purposes) and it's all
gonna happen for the same thread, in the same "context" (assuming
that's referring to the thread context).
Furthermore, the system waits for your response, because if you
return -1, the window is not created, and an error is returned to
the caller. (Yet another reason why you need to be able to handle
the message when it's sent, not a year later.)
I'll wait for an answer before thinking more about this. It
feels imminently solvable...
Okay. :P Though I've thought about it for a while and I'm getting
more and more convinced there isn't a good solution for this
without the ability to do custom construction...
