[PyQt] Using own module in SIP interface as parameter

[Phil Thompson]

On Mon, 16 Aug 2010 12:25:43 +0200, "Stefan Dentro"
<S.C.Dentro-1 at student.tudelft.nl> wrote:
> I'm currently working on replacing a custom PyQt module with a custom
> Qt module. Before I'm diving in I thought I'd create a HelloWorld
> testcase. But for some reason I can't get it to work properly. My
> question is, how should I create a single Python-SIP module containing
> two classes in which one takes the other as parameter when
> instantiating?
> 
> An overview of what I've got untill now:
> Class A takes an object of class B as parameter (see a.cpp below).
> I've included b.h in a.h in order for a to be able to see b. Both c++
> modules compile and issuing ldd shows b is properly linked into a.
> Since the SIP interface must also contain a description of this
> constructor it also needs to know about both classes a and b.
> Therefore I've included a.h and b.h in their respective SIP files.
> 
> But when I issue make on the SIP files I keep running into circular
> import errors:
> In file included from b.sip:7:
> ./b.h:3: error: redefinition of ‘class HW::B’
> ./b.h:3: error: previous definition of ‘class HW::B’
> make: *** [sipAHWA.o] Error 1
> 
> Obviously that is because both a.h and b.h are included and a.h
> includes b.h. But removing either an include or adding a %Import b.sip
> makes me run around in circles. It's either a redefinition, or SIP
> can't find the specification of B. What am I overlooking?
> 
> My files:
> b.h
> -----------------------------
> namespace HW {
> class B {
> public:
>        B();
> };
> }
> 
> b.cpp
> -----------------------------
> #include "b.h"
> namespace HW {
> int B() {
> }
> }
> 
> a.h
> -----------------------------
> #include "b.h"
> 
> namespace HW {
> class A {
> public:
>        A(B b);
> };
> }
> 
> a.cpp
> -----------------------------
> #include "a.h"
> namespace HW {
> int A(B b) {
> 
> }
> }
> 
> a.sip
> -----------------------------
> %Module A 0
> 
> namespace HW {
> class A {
> 
> %TypeHeaderCode
> #include <a.h>
> %End
> 
> public:
>        A(HW::B b);
> };
> };

So a.sip needs to %Import b.sip so that it knows about HW::B

> b.sip
> -----------------------------
> %Module B 0
> 
> namespace HW{
> class B {
> 
> %TypeHeaderCode
> #include <b.h>
> %End
> 
> public:
>        B();
> };
> };
> 
> helloworld.sip
> -----------------------------
> %Module HelloWorld
> 
> %Include b.sip
> %Include a.sip

If A and B are separate modules then the HelloWorld module should %Import
them and not %Include them.

Phil