Compiling OO graphics

QNX DEVELOPERS GUI Programming
1

I have an existing app which has been built with PhAB on top of C++ code. Now I am trying to add a dialog module and stay consistent with the C++ coding style, and I have problems getting it to compile.

I’m adding a dialog called GetDataDlg that is instantiated in response to a menu selection. The dialog has three widgets, and the only callbacks I’m concerned about at present are a setup function called before realizing the dialog, an item selection callback, and an action function to be called upon a button click. The functions are all declared and defined in a class GetDataDlg, in the files GetDataDlg.h & GetDataDlg.cpp.

I have had this all compiled and working in the straight C code for which PhAB generates stubs.

Now when I try to compile I get the following messages:
abevents.h:149: assuming & on GetDataDlg::gd_getSelection' abevents.h:149: converting from int (GetDataDlg::*)(PtWidget_t *, ApInfo_t *, P
tCallbackInfo_t )’ to int (*)(PtWidget_t *, ApInfo_t *, PtCallbackInfo_t *)' abevents.h:149: assuming & on GetDataDlg::gd_action’
abevents.h:149: converting from int (GetDataDlg::*)(PtWidget_t *, ApInfo_t *, P tCallbackInfo_t *)' to int ()(PtWidget_t *, ApInfo_t *, PtCallbackInfo_t *)’

I have looked at abevents.h (which is a generated file), and the line in question looks like:
static const ApEventLink_t AbLinks_GetDataDlg[] = {
{ 8, 0, 0L, 0L, 0L, NULL, NULL, “PtGetDataList”, 23010, GetDataDlg::gd_getSelection, 0, 0, 0, 0 }
{ 10, 0, 0L, 0L, 0L, NULL, NULL, “PtCancel”, 2009, NULL, 0, 0, 0, 0, },
{ 8, 0, 0L, 0L, 0L, NULL, NULL, “PtPerfActionBtn”, 2009, GetDataDlg::gd_action, 0, 0, 0, 0 }
{ 0 }
};

I can’t see that these entries differ in form or substance from other entries that compile just fine.

Can anyone shed any light on this conundrum?

Thanks,
Randy C.

2

so the other functions are in classes as well?

I am not an OO expert so I do not really understand how this is supposed to work. I mean, having a function in the class you would need an instance of your class to call the callback-function, i.e. something like GetDataDlg my_dlg; my_dlg.gd_getSelection(widget, foo, bar);Right?
I don’t know whether PhAB is able to handle functions that way.

The alternative would be to declare your functions to be static, but I think this would violate with the structure of your ApEventLink_t because this demands for a ApCallbackF_t function and this is defined as int (Ap.h):/* Callback function type */ typedef int ApCallbackF_t( PtWidget_t *widget, ApInfo_t *data, PtCallbackInfo_t *cbinfo );
So could you please post some of the working code with class functions?

3

OK, here’s an extraction of code that compiles.

This first sample is the setup callback, defined in the file HomeDlg.cpp:

==========================
int HomeDlg::setup( PtWidget_p wdgt, ApInfo_t* apinfo, PtCallbackInfo_t* cbinfo )
{
if ( apinfo->reason == ABR_PRE_REALIZE )
return _instance->preRealizeSetup
(wdgt, apinfo, cbinfo );
else
return _instance->postRealizeSetup( wdgt, apinfo, cbinfo );
}

This is the extract of the header, HomeDlg.h, where the HomeDlg class is declared.

=============================
class HomeDlg
{
private:

// some stuff

public:
HomeDlg();
~HomeDlg();
//
// setup function - called before module is displayed
//
static int setup( PtWidget_p instance, ApInfo_t* apinfo,
PtCallbackInfo_t* cbinfo );
//
// all menu items callback to this - dispatches to member methods
//
static int action( PtWidget_p wdgt, ApInfo_p api, PtCBI_p cb );
//
// invoked before menu is displayed
//
int preRealizeSetup( PtWidget_p w, ApInfo_t* info,
PtCallbackInfo_t* cbinfo );
//
// invoked right after menu is displayed
//
int postRealizeSetup( PtWidget_p w, ApInfo_t* info,
PtCallbackInfo_t* cbinfo );
};

I’m probably asking an unanswerable question, because there are so many possible ways to go off in the weeds. But this is working code, and I followed this model in creating my new dialog, but it won’t compile – see the errors in the first post.

Has there been anything written about using PhAB with C++?

At this point, in order to make progress, I’ve given up and done my dialog as a standalone written in straight C. I’ll just invoke it from a menu entry with minimal linkage, but it seems like a cheap solution.

Thanks,
Randy C.

4

As I suggested you need to declare your function as static within your header.

I got an example working now, but I needed to remove the entries with a :: from proto.h and to use the class-header as global header instead.

However your compiler errors should result from not having your methods declared to be static.

5

I know that cdm coded in C++ with PhAB … but I don’t think he was using C++ the same way that you are … There is however, a C++ SDK for QNX that you may want to look into … who knows that could be helpful ;-)

hexazen.com/Products/SDK/Zinzala/

6

Thanks to JLV and Smeeagain for the info and the suggestion on the SDK. I’ll look into that.

Randy C.

7

[quote=“SmeeAgain”]

I got an example working now, but I needed to remove the entries with a :: from proto.h and to use the class-header as global header instead.

[quote]

can you post some example code here. I also encounter this problem .
in proto.h , void A::b(); are all errors . A.h ,A.cpp. Thanks

8

I’m not at my qnx-box for another 3 weeks, but then I’ll have a look.

9

SmeeAgain : ok ,Thanks a lot. and I have learned about indHfiles and indSfiles: it can contain non-phAB header files and source files. but in my src,I didn’t find these two files . just have abLfiles,abWfiles,indLfiles. my qnx is 6.3.0. you can look into it in your spare time.