[Development] Qt Platform Extras

[Sorvig Morten]

On Mar 1, 2013, at 12:28 AM, Thiago Macieira <thiago.macieira at intel.com> wrote:

> On quinta-feira, 28 de fevereiro de 2013 21.32.26, Sorvig Morten wrote:
>> On Feb 28, 2013, at 4:50 PM, Thiago Macieira <thiago.macieira at intel.com>
>> 
>> wrote:
>>> On quinta-feira, 28 de fevereiro de 2013 14.42.53, Tor Arne Vestbø wrote:
>>>> I'm probably missing something obvious here, but why are these not with
>>>> the class that they convert from?
>>>> 
>>>> - conversion operator (or toFoo function if expensive)
>>>> - constructor (explicit if expensive)
>>> 
>>> Because we cannot assure that the library that contains the class in
>>> question is actually linking to the necessary libraries.
>>> 
>>> This is the case on Mac OS X. QtGui does not link to ApplicationServices,
>>> so it does not have access to CGRect.
>> 
>> Well, we can make QtGui link to ApplicationServices if needed - It already
>> links to CoreFoundation. Why would it be a problem in practice?
> 
> Because we can't do the same for other architectures and windowing systems.
> 

Which ones?

It seems reasonable to divide the platform set in two then:

1) The platform can guarantee the presence of certain libraries at runtime. QtCore and QtGui can contain conversion functions to native types.

2) It's uncertain what libraries you'll find.  No conversion functions.

In other words, optimize for the capabilities of each platform instead of using the lowest common denominator.

Morten