the simplest custom slot

[tommy]

hi Jacek

Thanks for confirming my code. No, I do not use qmake. I'm going to need
another piece of help here if you don't mind because I do not know how to use qmake.
My compiler is Dev-C++ (mingw). I guess I have to put "qmake" somewhere in the
project options sections? Or is qmake a standalone program you run before or when you compile? (instead of your compiler?).
Thanks to you and the other helpful people my problem is now narrowed down to
compiler/linker problem and most likely qmake.

Tommy

[jacek]

My compiler is Dev-C++ (mingw). I guess I have to put "qmake" somewhere in the
project options sections? Or is qmake a standalone program you run before or when you compile? (instead of your compiler?).

qmake is a tool that generates makefiles from .pro files, which are much simplier. To generate an initial .pro file you have to run "qmake -project" in the directory where your project is. Then you run "qmake" or "qmake filename.pro" to generate makefile. I don't use Dev-C++, but AFAIR you can make it use a custom makefile, so you just have to point it to the makefile generated by qmake.

[tommy]

Thanks Jacek,

You made a lot of things much more clear for me, I'm beginning to understand the basics now.
I was able to use qmake just as you suggested but did not get it to work with Dev-C++. I'm thinking of abandoning Dev-C++ and trying command line (just get plain mingw). How do you include the makefile when you compile from command line? What's the syntax?

Thankfully,
Tommy

[jacek]

I'm thinking of abandoning Dev-C++ and trying command line (just get plain mingw).

I'm sure you can find some tutorials about using Dev-C++ for Qt applications on google.

[mchara]

Hi,
I'm using qt on dev-cpp, so i had similar problem
I'm not using qmake(it says it can't find FORCE target), but i didn't searched the reason of this error, because i'm using multiple makefiles to have effect of several projects in one solution (dev-cpp works on projects only).
You need to set use custom makefile in projects options, add a tatget *.moc, with 2 commands:
1 moc your *.h to *.moc(or moc_*.cpp)
2 compile generated file

or the simpler way makefile that calls only qmake & make on file generated by, unfortunately i can't test this because of mentioned qmake error.

[jacek]

I'm not using qmake(it says it can't find FORCE target), but i didn't searched the reason of this error

What is the value of the TARGET variable in your .pro file? If it isn't set, what is the name of the .pro file?

You need to set use custom makefile in projects options, add a tatget *.moc, with 2 commands:
1 moc your *.h to *.moc(or moc_*.cpp)
2 compile generated file

What about all of those magic macros Qt needs?

[mchara]

What is the value of the TARGET variable in your .pro file? If it isn't set, what is the name of the .pro file?

Doesn't matter, i have the same error for every makefile generated by qmake, i found that
FORCE: is an empty target used to force something to be build even if there's no dependencies so it shall be empty definition.
It is in deed in generated makefiles' but i suppose that problem might be in missing tab & newline after FORCE: - some make's are sensitive for tabs instead of spaces etc., i think make is one of them.

What about all of those magic macros Qt needs?

What macros?
DO you mean those defines at the beginning

-DUNICODE -DQT_LARGEFILE_SUPPORT -DQT_DLL -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_GUI_LIB -DQT_THREAD_SUPPORT -DQT_NEEDS_QMAIN

-DUNICODE -DQT_LARGEFILE_SUPPORT -DQT_DLL -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_GUI_LIB -DQT_THREAD_SUPPORT -DQT_NEEDS_QMAIN

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, i've copied them from first makefile found in qt's exapmles & worked fine.

Those are always the same view defines(& view more depending on used modules -DQT_*_LIB) so it's not much work.

I thought that maybe custom makefie that would have defined only qmake -project; qmake &make on newly generated makefile would solve the problem if we would find what's wrong with FORCE error... can anyone check is this common problem on mingw or just mine?

Oh, one more thing : make sure to not use --short-double or --expensive-optimizations because using one of them causes QPainter::drawPixmap()/drawImage() stops working... it's really strange but i've checked it several times & it really happens.

[wysota]

What macros?
DO you mean those defines at the beginning

-DUNICODE -DQT_LARGEFILE_SUPPORT -DQT_DLL -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_GUI_LIB -DQT_THREAD_SUPPORT -DQT_NEEDS_QMAIN

-DUNICODE -DQT_LARGEFILE_SUPPORT -DQT_DLL -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_GUI_LIB -DQT_THREAD_SUPPORT -DQT_NEEDS_QMAIN

To copy to clipboard, switch view to plain text mode 

, i've copied them from first makefile found in qt's exapmles & worked fine.

This is not a good thing to do. The macros change depending on how you configure your project - in this situation you only enable core and gui libraries. What if you want to use other Qt modules like network, xml or any of the others? Your static compilation rule will fail. If you install newer Qt release that has more switches, your compilation will fail. If you want to switch between debug and release, it won't be possible, etc.

[mchara]

I know it's not good solution, but the only one working i have for now...
I promise to let you know, when i'll find what's wrong with that "FORCE" qmake's error & figure out how to use dev-cpp's makefile to generate & build second one from qmake.
P.S.
If i'm adding some module i have to add include, lib & define by hand, i have to add each file i'm adding to project to makefile also, so it's lots of unnecessary work...
Only positive side of this solution is the fact that application compiles itself from dev-cpp environtment.

[wysota]

Isn't it possible to do the compilation just by making qmake && make your build sequence in the IDE?

[mchara]

It should be possible, i've used only use custom makefile option. As i said i got an error on makefiles generated by qmake & i don't know the reason jet so i was using own makefiles.
it would be nice to have qmake & make integrated with IDE but first qmake must work. When i'll force qmake to work properly, i'll start searching how to integrate it with dev-cpp in best way.

[wysota]

What kind of make do you have? What does make -v return?