[lazarus] Enable/CheckMenuItem

[Mattias Gaertner]

On Sat, 22 Nov 2003 18:56:35 +0100  Micha Nelissen
<M.Nelissen at student.tue.nl> wrote:

> Marc Weustink wrote:
> 
> > At 17:34 22-11-2003, Mattias Gaertner wrote:
> > 
> >> On Sat, 22 Nov 2003 17:18:31 +0100  Marc Weustink
> ><marc at dommelstein.net>> wrote:
> >>
> >> > At 17:08 22-11-2003, Mattias Gaertner wrote:
> >> > >On Sat, 22 Nov 2003 12:41:30 +0100  Marc Weustink 
> >> <marc at dommelstein.net>
> >> > >wrote:
> >> > >
> >> > > > At 09:04 22-11-2003, Micha Nelissen wrote:
> >> > > > >Marc Weustink wrote:
> >> > > > >
> >> > > > >>At 22:23 21-11-2003, Micha wrote:
> >> > > > >>
> >> > > > >>>Specification of Enable/CheckMenuItem needs to be more
> >specific.> > > > >Due>>to  win32api obscurities it needs to be changed:
> >note that > only
> >> > > > >hndMenu
> >> > > > >
> >> > > > >>>changed:
> >> > > > >>>
> >> > > > >>>hndMenu: specifies _parent_ of menuitem to change
> >> > > > >>
> >> > > > >>??? Doesn't the win32 interface keep track of that (or can't 
> >> it be
> >> > > > >quiried) ?
> >> > > > >
> >> > > > >(1) No. (2) It can't be, there is no GetParentMenu(handle) call
> >or> > > > >something like that.
> >> > > >
> >> > > > I should have read before asking :)
> >> > > >
> >> > > > Your original message:
> >> > > > >Specification of Enable/CheckMenuItem needs to be more 
> >> specific. Due
> >> > > > >to  win32api obscurities it needs to be changed: note that only
> >> > > > >hndMenu changed:
> >> > > > >
> >> > > > >hndMenu: specifies _parent_ of menuitem to change
> >> > > > >uIDEnableItem: Integer - menu item to check/uncheck
> >> > > > >bChecked: Boolean      - new state of the menu item
> >> > > >
> >> > > >
> >> > > > Ehm, now I understand your question. The GTK winapi 
> >> implementation of
> >> > > > CheckMenuItem is wrong. It uses hndMenu as the item to check and
> >> > > > ignores uIDEnableItem. But it should use hndMenu as menu and
> >> > > > uIDEnableItem as"command or index" to the Item.
> >> > >
> >> > >Why that complicated?
> >> >
> >> > It is not complicated.
> >> >
> >> > >We want to enable/check a menu item, and not to emulate the win32
> >api.> > >If the win32api function does not do, what we need, then we
> >should > simply
> >> > >rename the interface function (e.g. function
> >> > >EnableOrCheckMenuItem(AMenuItem: TComponent; EnableCheck: boolean):
> >> > >boolean).
> >> > >The win32 intf can then simply get the parent handle.
> >> >
> >> > If functions are close, I prefer winApi compatible functions. It
> >makes> > porting easier. I don't feel like introducing a load of
> >> > similar_but_not_the_same functions.
> >> > We started with a load of api functions, I see no reason why we would
> >> > replace them. If we want the api function, we have to implement it 
> >> anyhow.
> >>
> >> We want the most commonly used winapi functions. If you think, that
> >this> function is commonly used, then ok, let's emulate it. I doubt it.
> >>
> >> IMO the win32api function is too win32 specific. I think, nearly all 
> >> other
> >> interfaces will have the ability to enable a menu item directly and
> >don't> have an "Index". So, adding this function to the interface means
> >overhead> for all interfaces, except the win32. While a direct function
> >means > overhead
> >> only for the win32 intf.
> > 
> > 
> > I don't see overhead as an issue here. There willbe always overhead.
> > For these menufuntions we could introduce a MH_HANDLE flag (there is 
> > already a MF_INDEX and a MF_COMMAND) to tell the interface to use the 
> > handle.
> 
> Nooo...please, that's an ugly hack imho. TMenuItem's have a MenuIndex 
> right? So why don't we pass that around? Remove the ugly Command, and 
> use an index for positioning. Then it's easy in gtk and win32.

"Easy" in the sense of "not very smart"  ;) 

in gtk:

- Get LCL component of Parent Menu Handle
- Get i-th child menu item and its handle
- enable menu item

The LCL converts the request into a win32api function call and the gtk
interface converts it back. ;)


Mattias