OS X Quartz Events and the usage of some event flags - c

Question

I'm implementing virtual keyboard that is using modifier flags to enable input key events with this modification keys like: cmd, alt/opt, shift.
I would like to know two things:
what is the aim of kCGEventFlagMaskNonCoalesced and kCGEventFlagMaskNumericPad, can I map them to any key defined in kVK_* key codes?
What is the difference between kCGEventFlagMaskAlphaShift, kCGEventFlagMaskShift and how they corresponds to kVK_Shift, kVK_RightShift?
Is kCGEventFlagMaskSecondaryFn corresponding to kVK_Function?
I have done my modifier keys to modifier flags mapping function like this:
static uint64_t mod_key_code_to_mod_flag(uint16_t mod_key_code) {
switch(mod_key_code) {
case kVK_Shift:
return kCGEventFlagMaskAlphaShift;
case kVK_RightShift:
return kCGEventFlagMaskShift;
case kVK_Control:
return kCGEventFlagMaskControl;
case kVK_Option:
case kVK_RightOption:
return kCGEventFlagMaskAlternate;
case kVK_Command:
return kCGEventFlagMaskCommand;
case kVK_Help:
return kCGEventFlagMaskHelp;
case kVK_Function:
return kCGEventFlagMaskSecondaryFn;
default:
return 0;
}
}
Is it complete?

Answer 1

The purpose of kCGEventFlagMaskNonCoalesced isn't easily searchable at this point in time. Since one point of this site is to archive information necessary for answers, here is the definition of mouse coalescing in Cocoa (well, Carbon) from earlier documentation for IsMouseCoalescingEnabled:
If mouse coalescing is enabled, intemediate [sic] mouse movement events are merged into the most recent event, so that only one mouse moved or mouse dragged event is in the event queue at any time. For example, when the user moves the mouse across the screen, more mouse moved events are generated than most applications care about. Rather than place all these events in the queue (which would probably slow down the application), the Carbon Event Manager first checks to see if a mouse moved event already exists. If if does, that event is updated with the position and delta information from the more recently-generated event.
For some reason, current documentation leaves out this definition (the mouseCoalescingEnabled property might no longer be supported, even though it's in the documents). It's intended for consumers of mouse events. If your virtual keyboard isn't generating mouse events, this modifier can be largely ignored.