On Sat, Sep 22, 2012 at 11:22 AM, Igor Stasenko <siguctua@gmail.com> wrote:

First, we need to make one thing:

Change the VM to not call ioProcessEvents function directly, but
rather use a variable which will hold a function pointer.
Initially, when VM starts, that function pointer is NULL, and so,
"process events" is NOP.

Please don't reinvent the wheel. �The Cog source has a variable inIOProcessEvents that controls this. �If negative it disables inIOProcessEvents. �If non-negative it prevents reentrancy, essential if one is receiving events from the OS. �There's a primitive,�primitiveEventProcessingControl, to flip it between the enabled and disabled states.

This code has been used for years in the Newspeak system which has a full native GUI on Windows.

Going your own way creates an unnecessary fork.

Then we need to implement �a module which will manage host windows,
and once image tells it to create a window,
it can change the function pointer to ioProcessEvents to own function.

This change, would allow us to temporary disable any external event
processing (like in case of callbacks).

Second, we should move all event-related stuff to new plugin (for
instance, all definitions in sq.h
like sqInputEvent , ioSetInputSemaphore() ioGetNextEvent() etc).

For all UI-related stuff the image should communicate with a new
plugin, while VM should get rid of all knowledge of any existence of
UI events,
like input semaphores, primitives for fetching them etc.

Third, of course, all screen update/refresh primitives should be
deprecated, and image should use new primitives to update the contents
of host window(s).

--
Best regards,
Igor Stasenko.