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Basic question: Including headers with INCLUDEPATH doesn't work

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  • B Offline
    B Offline
    Binary91
    wrote on last edited by
    #33

    I know what moc files are, but they were not permanently created by QtCreator (not in my build folder).
    But can you tell me why I should have to generate them and manually include them when it works to simply add the headers to the project?
    I mean, I wanted to reduce work by using INCLUDEPATH and NOT adding all the included headers.
    Generating moc files and manually adding them is not reducing but increasing work.

    Also I do not understand why I should include them when I don't need it if I add the headers directly...

    jsulmJ 1 Reply Last reply
    0
    • B Binary91

      but from where do I get this moc file?
      If I try to include, compiler gives me an error that it can not find such file or directory

      btw:
      https://www.dropbox.com/s/whqdkcat767224t/test.zip?dl=0

      jsulmJ Offline
      jsulmJ Offline
      jsulm
      Lifetime Qt Champion
      wrote on last edited by
      #34

      @Binary91 Where is myudp.cpp ?

      https://forum.qt.io/topic/113070/qt-code-of-conduct

      jsulmJ 1 Reply Last reply
      0
      • jsulmJ jsulm

        @Binary91 Where is myudp.cpp ?

        jsulmJ Offline
        jsulmJ Offline
        jsulm
        Lifetime Qt Champion
        wrote on last edited by
        #35

        @jsulm With some fixes I can build your project.
        pro file:

        QT       += core network
        
        QT       -= gui
        
        TARGET = test
        CONFIG   += console
        CONFIG   -= app_bundle
        
        TEMPLATE = app
        
        INCLUDES += lib/headers/myQLineEdit.h
        
        SOURCES += main.cpp \
            #myudp.cpp
        
        #HEADERS += \
        #    myudp.h
        

        main.cpp

        #include <QCoreApplication>
        
        int main(int argc, char *argv[])
        {
          QCoreApplication applicationApp(argc, argv);
          //clsWindowMain windowMain;
        
          //QTimer::singleShot(0, &windowMain, SLOT(slotStart()));
          int ret = applicationApp.exec();
          return ret;
        }
        

        https://forum.qt.io/topic/113070/qt-code-of-conduct

        1 Reply Last reply
        1
        • B Binary91

          I know what moc files are, but they were not permanently created by QtCreator (not in my build folder).
          But can you tell me why I should have to generate them and manually include them when it works to simply add the headers to the project?
          I mean, I wanted to reduce work by using INCLUDEPATH and NOT adding all the included headers.
          Generating moc files and manually adding them is not reducing but increasing work.

          Also I do not understand why I should include them when I don't need it if I add the headers directly...

          jsulmJ Offline
          jsulmJ Offline
          jsulm
          Lifetime Qt Champion
          wrote on last edited by
          #36

          @Binary91 Where I did say you have to create moc_ files manually?
          They are generated for you. And they are completely unrelated to your problem!

          https://forum.qt.io/topic/113070/qt-code-of-conduct

          1 Reply Last reply
          1
          • B Offline
            B Offline
            Binary91
            wrote on last edited by
            #37

            It's getting strange now :-D

            What is a myudp.cpp ?? I didn't ever used this...

            @jsulm
            But you are including the header directly now. That is exaclty what I tried to avoid...

            Why is main.h unusual? I think using headers as a bundle of #include directives for my purposes is the correct way, so in the source file, there only exists one #include directive to its corresponding header file. Not good?

            jsulmJ 2 Replies Last reply
            0
            • B Binary91

              It's getting strange now :-D

              What is a myudp.cpp ?? I didn't ever used this...

              @jsulm
              But you are including the header directly now. That is exaclty what I tried to avoid...

              Why is main.h unusual? I think using headers as a bundle of #include directives for my purposes is the correct way, so in the source file, there only exists one #include directive to its corresponding header file. Not good?

              jsulmJ Offline
              jsulmJ Offline
              jsulm
              Lifetime Qt Champion
              wrote on last edited by
              #38

              @Binary91 That is what you uploaded:

              SOURCES += main.cpp \
                  myudp.cpp
              

              main.h is unusual because there is no need for it. You only need a header file if you need to include some functionality provided in one source code file in another one. Where do you want to include main.h and why (and please do not say in main.cpp, because there is no need to do it this way)?
              I will try to change your project to use INCLUDEPATH.

              https://forum.qt.io/topic/113070/qt-code-of-conduct

              1 Reply Last reply
              0
              • B Binary91

                It's getting strange now :-D

                What is a myudp.cpp ?? I didn't ever used this...

                @jsulm
                But you are including the header directly now. That is exaclty what I tried to avoid...

                Why is main.h unusual? I think using headers as a bundle of #include directives for my purposes is the correct way, so in the source file, there only exists one #include directive to its corresponding header file. Not good?

                jsulmJ Offline
                jsulmJ Offline
                jsulm
                Lifetime Qt Champion
                wrote on last edited by
                #39

                @Binary91 It builds here if I do:

                QT       += core network
                
                QT       -= gui
                
                TARGET = test
                CONFIG   += console
                CONFIG   -= app_bundle
                
                TEMPLATE = app
                
                #INCLUDES += lib/headers/myQLineEdit.h
                INCLUDEPATH += lib/headers
                
                SOURCES += main.cpp
                

                https://forum.qt.io/topic/113070/qt-code-of-conduct

                1 Reply Last reply
                0
                • B Offline
                  B Offline
                  Binary91
                  wrote on last edited by
                  #40

                  I really don't know from where this "myudp.cpp" comes. Maybe a de-zipping error. That should mean "lib/sources/myQLineEdit.cpp"

                  Yeah this way its getting built on my computer as well, but there you manually added the header file to the project:
                  INCLUDES += ...
                  or
                  HEADERS +=...

                  That is what I try to avoid by using INCLUDEPATH. That was what the discussion is all about...

                  jsulmJ 1 Reply Last reply
                  0
                  • B Binary91

                    I really don't know from where this "myudp.cpp" comes. Maybe a de-zipping error. That should mean "lib/sources/myQLineEdit.cpp"

                    Yeah this way its getting built on my computer as well, but there you manually added the header file to the project:
                    INCLUDES += ...
                    or
                    HEADERS +=...

                    That is what I try to avoid by using INCLUDEPATH. That was what the discussion is all about...

                    jsulmJ Offline
                    jsulmJ Offline
                    jsulm
                    Lifetime Qt Champion
                    wrote on last edited by
                    #41

                    @Binary91 Where did I add the header file manually?
                    I commented out the old line, please take a look again:

                    QT       += core network
                    
                    QT       -= gui
                    
                    TARGET = test
                    CONFIG   += console
                    CONFIG   -= app_bundle
                    
                    TEMPLATE = app
                    
                    #INCLUDES += lib/headers/myQLineEdit.h <-- this line is commented out
                    INCLUDEPATH += lib/headers
                    
                    SOURCES += main.cpp
                    

                    https://forum.qt.io/topic/113070/qt-code-of-conduct

                    1 Reply Last reply
                    0
                    • B Offline
                      B Offline
                      Binary91
                      wrote on last edited by
                      #42

                      but where is the myQLineEdit.cpp ?
                      You just added the main.cpp. The error occures in myQLineEdit.cpp, because it holds methods of myQLineEdit class in myQLineEdit.h that has a Q_OBJECT within...

                      jsulmJ 1 Reply Last reply
                      0
                      • B Binary91

                        but where is the myQLineEdit.cpp ?
                        You just added the main.cpp. The error occures in myQLineEdit.cpp, because it holds methods of myQLineEdit class in myQLineEdit.h that has a Q_OBJECT within...

                        jsulmJ Offline
                        jsulmJ Offline
                        jsulm
                        Lifetime Qt Champion
                        wrote on last edited by
                        #43

                        @Binary91 Your project is really broken:

                        QT       += core network
                        
                        QT       += gui widgets
                        
                        TARGET = test
                        CONFIG   += console
                        CONFIG   -= app_bundle
                        
                        TEMPLATE = app
                        
                        HEADERS += lib/headers/myQLineEdit.h
                        INCLUDEPATH += lib/headers
                        
                        SOURCES += main.cpp \
                            lib/sources/myQLineEdit.cpp
                        

                        myQLineEdit.cpp

                        #include <myQLineEdit.h> // absolute path or absolute path with whitespaces also doesn't work
                        
                        
                        // ----- constructors -----
                        
                        myQLineEdit::myQLineEdit(QWidget* widgetParent) : QLineEdit(widgetParent)
                        {
                           // stuff
                        }
                        
                        myQLineEdit::~myQLineEdit()
                        {
                        
                        }
                        
                        #include "../build-test-Desktop-Debug/moc_myQLineEdit.cpp"
                        

                        Without HEADERS moc_ file is not generated and the header file is not shown in QtCreator, so you should use HEADERS.

                        https://forum.qt.io/topic/113070/qt-code-of-conduct

                        jsulmJ 1 Reply Last reply
                        0
                        • jsulmJ jsulm

                          @Binary91 Your project is really broken:

                          QT       += core network
                          
                          QT       += gui widgets
                          
                          TARGET = test
                          CONFIG   += console
                          CONFIG   -= app_bundle
                          
                          TEMPLATE = app
                          
                          HEADERS += lib/headers/myQLineEdit.h
                          INCLUDEPATH += lib/headers
                          
                          SOURCES += main.cpp \
                              lib/sources/myQLineEdit.cpp
                          

                          myQLineEdit.cpp

                          #include <myQLineEdit.h> // absolute path or absolute path with whitespaces also doesn't work
                          
                          
                          // ----- constructors -----
                          
                          myQLineEdit::myQLineEdit(QWidget* widgetParent) : QLineEdit(widgetParent)
                          {
                             // stuff
                          }
                          
                          myQLineEdit::~myQLineEdit()
                          {
                          
                          }
                          
                          #include "../build-test-Desktop-Debug/moc_myQLineEdit.cpp"
                          

                          Without HEADERS moc_ file is not generated and the header file is not shown in QtCreator, so you should use HEADERS.

                          jsulmJ Offline
                          jsulmJ Offline
                          jsulm
                          Lifetime Qt Champion
                          wrote on last edited by
                          #44

                          @jsulm said in Basic question: Including headers with INCLUDEPATH doesn't work:

                          #include "../build-test-Desktop-Debug/moc_myQLineEdit.cpp"

                          you can change it to:

                          #include "moc_myQLineEdit.cpp"
                          

                          It builds now on my machine.

                          https://forum.qt.io/topic/113070/qt-code-of-conduct

                          1 Reply Last reply
                          0
                          • BuckwheatB Buckwheat

                            @jsulm , why would you include the MOC files? I "never" include the MOC files in my source because they get generated, compiled, and linked after the normal build. The only generated file I would include is the ui_NameOfForm.h file created when using the form designer. And, only in the CPP for the UI class.

                            @Binary91 , I am sure it was explained that INCLUDEPATH tells qmake where to find common include files. I use it for 3rd party libraries or pre-built packages I developed for Qt (I treat them like 3rd party libraries). And, as I know you know... always run qmake after changing a PRO file.

                            There is one curious item I have found about QtCreator though... if you are using static libraries (even if your dependencies are setup) and make a change to a CPP file in the library... Press build-all and it will build the library and NOT re-link the application or shared library that depends on that static library. Kind of annoying but I just get around it!

                            jsulmJ Offline
                            jsulmJ Offline
                            jsulm
                            Lifetime Qt Champion
                            wrote on last edited by
                            #45

                            @Buckwheat You need to include moc_ files for your own classes which are derived from QObject (directly or indirectly).

                            https://forum.qt.io/topic/113070/qt-code-of-conduct

                            BuckwheatB 1 Reply Last reply
                            0
                            • B Offline
                              B Offline
                              Binary91
                              wrote on last edited by
                              #46

                              Hi jsulm,

                              so you say, I need to include the headers with HEADERS in the project file. Well, then I'm asking myself what the INCLUDEPATH command is for?

                              mrjjM 1 Reply Last reply
                              0
                              • B Binary91

                                Hi jsulm,

                                so you say, I need to include the headers with HEADERS in the project file. Well, then I'm asking myself what the INCLUDEPATH command is for?

                                mrjjM Offline
                                mrjjM Offline
                                mrjj
                                Lifetime Qt Champion
                                wrote on last edited by mrjj
                                #47

                                @Binary91 said in Basic question: Including headers with INCLUDEPATH doesn't work:

                                INCLUDEPATH
                                http://doc.qt.io/qt-5/qmake-variable-reference.html#includepath

                                Its used to specify where to look for headers.
                                So when it sees #include "YYYY" it will search for them there.

                                as shown with

                                INCLUDEPATH += ../../Common/CONET
                                ../../Common/XML/pugixml-1.5/src/ \

                                the pugixml.h is in the src and i can just use
                                it like
                                #include "pugixml.h"

                                Without it I would have to do use full path to it.

                                That is its role and it works fine here.

                                You seem to expect that point to a folder with INCLUDEPATH,
                                implies that all should be used ?

                                Like all where already added to HEADERS ?

                                There is one issue if it did that.
                                For all HEADERS , it need to run moc on them so
                                if you use INCLUDEPATH to point to a place with many .H files
                                you be wasting tons of time running moc on those completely unrelated files.
                                Hence HEADERS tells us what files to run moc on.
                                Of course this could be fixed checking against which are actually seen via #include
                                but it's not the way it works currently. :)

                                1 Reply Last reply
                                2
                                • B Offline
                                  B Offline
                                  Binary91
                                  wrote on last edited by
                                  #48

                                  thank you mrjj, that was the explanation I was looking for!

                                  I didn't know that with HEADERS I tell the compiler which moc files should be generated!

                                  So all in all, I have to include those headers to my project and everything is going well.

                                  Thank you for your help.

                                  Kind regards,
                                  Binary

                                  1 Reply Last reply
                                  1
                                  • jsulmJ jsulm

                                    @Buckwheat You need to include moc_ files for your own classes which are derived from QObject (directly or indirectly).

                                    BuckwheatB Offline
                                    BuckwheatB Offline
                                    Buckwheat
                                    wrote on last edited by
                                    #49

                                    @jsulm Actually you don't. When the build system sees the Q_OBJECT, it will build and compile a MOC file for you. It will link into the application and be part of it. No inclusion is necessary. None at all. The only think you would ever include is a form generated header file (ie. ui_MainWindow.h) that will hold the form variables for you.

                                    If doubting, watch your build on any system. You will see the CPP files compile and then the moc_*.cpp files compile and then the linker will have both on it. The MOC files tie your class to the signal/slots and meta object data all under the scenes. It is quite beautifully designed.

                                    Dave Fileccia

                                    1 Reply Last reply
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                                    • SGaistS Offline
                                      SGaistS Offline
                                      SGaist
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #50

                                      If your QObject based class is in a .cpp file then you need to include the moc file at the bottom. See the unit tests form Qt for example.

                                      Interested in AI ? www.idiap.ch
                                      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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