Setup QMake for a Qt library

Aslund

Hello guys

I am enjoying developing programs in Qt.
After almost 2 years improving my design and sending programs out to customers I feel the need to start developing a library for commonly used functions.
Making and using a library is easy enough using the wizard in Qt Creator, but I wish something more advance.

I am using Qwt for several projects and I wish something like that. Multiple libraries that is compiled into a single .dll file, but the whole setup of QMake files seems complicated and I hoped for a simpler solution.

Anyone who has any tips/guide or code examples that I can work from?

Regards
Sebastian Aslund

SGaist

Hi,

Do you mean you would like to have a Qt module for your common stuff to use like e.g. QtGui ?

Aslund

Heĺlo SGaist

Yes, that would be the ideal goal. :)

Aslund

Hello everyone

I followed the qmake files in Qwt and I managed, I think, to make what I want. The only issue I have right now is that it seems to be a pain to add new project folder to the setup.
Is my setup okay or could it be done better?

What I want to avoid compared to Qwt is to have all my source and header files in one folder. I prefer every class to has it own sub-folder.

My eeqt.pro file:

################################################################
# EEQT Widget Library
################################################################

include( eeqtconfig.pri )

TEMPLATE = subdirs
CONFIG += ordered

SUBDIRS = \
	src \
	
eeqtspec.files = eeqtconfig.pri eeqtfunctions.pri eeqt.prf
eeqtspec.path = $${EEQT_INSTALL_FEATURES}

INSTALLS += eeqtspec

eeqtconfig.pri:

################################################################
# EEQT Widget Library
################################################################

EEQT_VER_MAJ			= 0
EEQT_VER_MIN			= 0
EEQT_VER_PAT			= 1
EEQT_VERSION			= $${EEQT_VER_MAJ}.$${EEQT_VER_MIN}.$${EEQT_VER_PAT}

######################################################################
# Install paths
######################################################################

EEQT_INSTALL_PREFIX		= $$[QT_INSTALL_PREFIX]

win32 {
        EEQT_INSTALL_PREFIX	= C:/EEQT-$${EEQT_VERSION}
}

EEQT_INSTALL_DOCS		= $${EEQT_INSTALL_PREFIX}/doc
EEQT_INSTALL_HEADERS            = $${EEQT_INSTALL_PREFIX}/include
EEQT_INSTALL_LIBS		= $${EEQT_INSTALL_PREFIX}/lib

######################################################################
# Add features
######################################################################

EEQT_INSTALL_FEATURES	= $${EEQT_INSTALL_PREFIX}/features

######################################################################
# Add dynamic linking
######################################################################

EEQT_CONFIG				+= EEQtDLL

######################################################################
# Add EEQwtWidget
######################################################################

EEQT_CONFIG				+= EEQwtWidget

eeqtfunctions.pri:

################################################################
# EEQT Widget Library
################################################################

# Copied and modified from qwtfunctions.pri

defineReplace(eeqtLibraryTarget) {

    unset(LIBRARY_NAME)
    LIBRARY_NAME = $$1

    contains(TEMPLATE, .*lib):CONFIG(debug, debug|release) {

        !debug_and_release|build_pass {

            mac:RET = $$member(LIBRARY_NAME, 0)_debug
            win32:RET = $$member(LIBRARY_NAME, 0)d
        }
    }

    isEmpty(RET):RET = $$LIBRARY_NAME
    return($$RET)
}

defineTest(eeqtAddLibrary) {

    LIB_PATH = $$1
    LIB_NAME = $$2

    mac:contains(QWT_CONFIG, QwtFramework) {

        LIBS      *= -F$${LIB_PATH}
    }
    else {

        unix:lessThan(QT_MAJOR_VERSION, 5) {

            # Many Linux distributions install Qwt in the same directory
            # as the Qt libs and thus we need to prepend the path for the local build
            # to avoid conflicting with the installed version.
            # Qt5 qmake appends ( instead of prepending ) the path to the Qt libs
            # to LIBS, but for Qt4 we need to use the QMAKE_LIBDIR_FLAGS.

            QMAKE_LIBDIR_FLAGS *= -L$${LIB_PATH}
        }
        else {
            LIBS *= -L$${LIB_PATH}
        }
    }

    unset(LINKAGE)

    isEmpty(LINKAGE) {

        if(!debug_and_release|build_pass):CONFIG(debug, debug|release) {

            mac:LINKAGE = -l$${LIB_NAME}_debug
            win32:LINKAGE = -l$${LIB_NAME}d
        }
    }

    isEmpty(LINKAGE) {

        LINKAGE = -l$${LIB_NAME}
    }

    !isEmpty(QMAKE_LSB) {

        QMAKE_LFLAGS *= --lsb-shared-libs=$${LIB_NAME}
    }

    LIBS += $$LINKAGE
    export(LIBS)
    export(QMAKE_LFLAGS)
    export(QMAKE_LIBDIR_FLAGS)

    return(true)
}

eeqt.prf:

################################################################
# EEQT Widget Library
################################################################

include ( ./eeqtconfig.pri )
include ( ./eeqtfunctions.pri )

contains(EEQT_CONFIG, EEQtDll) {

    DEFINES *= EEQT_DLL
}

INCLUDEPATH *= $${EEQT_INSTALL_HEADERS}

qwtAddLibrary($${EEQT_INSTALL_LIBS}, eeqt)

src.pro

################################################################
# EEQT Widget Library
################################################################

EEQT_ROOT		= $${PWD}/..
include($${EEQT_ROOT}/eeqtconfig.pri)
include($${EEQT_ROOT}/eeqtbuild.pri)
include($${EEQT_ROOT}/eeqtfunctions.pri)

EEQT_OUT_ROOT = $${OUT_PWD}/..

TEMPLATE		= lib
TARGET			= $$eeqtLibraryTarget(eeqt)

contains(EEQT_CONFIG, EEQtDLL) {

	CONFIG += dll
	win32: DEFINES += QT_DLL EEQT_DLL EEQT_MAKEDLL
}

contains(EEQT_CONFIG, EEQwtWidget) {

    include($${PWD}/EEQwtWidget/eeqwtwidget.pri)
}

target.path    = $${EEQT_INSTALL_LIBS}
INSTALLS       = target 

headers.files  = $${HEADERS}
headers.path   = $${EEQT_INSTALL_HEADERS}
INSTALLS += headers

eeqwtwidget.pri:

HEADERS += \
		EEQwtWidget/eeqwtwidget.h \
        eeqt_global.h \
		EEQwtWidget/customscaledraw.h
		
SOURCES += \
		EEQwtWidget/eeqwtwidget.cpp \
		EEQwtWidget/customscaledraw.cpp

SGaist

One subfolder by class ? Isn't that a bit too much ?

Usually it's rather one subfolder per "logical block"

Aslund

Hello SGaist

Yea, I came to the same conclusion. To much work making all these separate folders.
But how would you add these "logical blocks"?

headers.files  = $${HEADERS}
headers.path   = $${EEQT_INSTALL_HEADERS}
INSTALLS += headers

Here all headers will be installed at the same level. If the idea of logical blocks should work then different headers should go into different sub-folders. Whats the best approach here?

jsulm

@Aslund

HEADERS += \
		module_1/class_1.h \
                module_2/class_1.h \
                ...
		
SOURCES += \
		module_1/class_1.cpp \
                module_2/class_1.cpp \

SGaist

Or add a .pri file per module that extends these variables and include them in your main .pro file.

Important: Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

Setup QMake for a Qt library