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Access and inheritance

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  • tomyT tomy

    @kshegunov

    So we will never have to call the base class's constructor from the subclass, because if there is an explicit constructor for the base class, the compiler calls (implicitly) for us (with the absence of an explicit call from us), and if there is no constructor for the base class, the compiler creates a default one and implicitly calls that in the subclass. Hence, we had better never involve ourselves with calling a base class's constructor directly (from the subclass)! :) :)

    mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by mrjj
    #29

    @tomy
    Hi
    The automatic version is only for a default constructor.
    As soon as base class constructor takes parameters, it must be called from subclass as compiler cannot
    know how to obtain the parameters to give to base class.
    However the compiler will tell you that.

    1 Reply Last reply
    3
    • tomyT tomy

      @kshegunov

      So we will never have to call the base class's constructor from the subclass, because if there is an explicit constructor for the base class, the compiler calls (implicitly) for us (with the absence of an explicit call from us), and if there is no constructor for the base class, the compiler creates a default one and implicitly calls that in the subclass. Hence, we had better never involve ourselves with calling a base class's constructor directly (from the subclass)! :) :)

      kshegunovK Offline
      kshegunovK Offline
      kshegunov
      Moderators
      wrote on last edited by
      #30

      What @mrjj said, plus the moment you define a constructor, the compiler stops generating for you. Thus if you define a constructor with parameters, the compiler will not generate a default constructor for you. Beautiful system, right? :)

      Read and abide by the Qt Code of Conduct

      tomyT 1 Reply Last reply
      3
      • mrjjM mrjj

        @tomy
        Hi
        Nope its just how the QWidgets look.
        If you change the icons to flat style,
        it will look more "modern"

        You could use something like
        https://github.com/laserpants/qt-material-widgets
        if you want to go all in for "modern" look.

        tomyT Offline
        tomyT Offline
        tomy
        wrote on last edited by
        #31

        @mrjj

        If you change the icons to flat style, it will look more "modern"

        Hi,
        The example you posted look very modern and stylish, but too advanced for me now. Thank you.
        I like to go step by step. So for the icons, I must download some "flat .png related files" from the Internet and substitute the old ones with these. Right?

        mrjjM 1 Reply Last reply
        0
        • tomyT tomy

          @mrjj

          If you change the icons to flat style, it will look more "modern"

          Hi,
          The example you posted look very modern and stylish, but too advanced for me now. Thank you.
          I like to go step by step. So for the icons, I must download some "flat .png related files" from the Internet and substitute the old ones with these. Right?

          mrjjM Offline
          mrjjM Offline
          mrjj
          Lifetime Qt Champion
          wrote on last edited by
          #32

          @tomy
          Hi
          Yes, that could be the first step.
          Maybe a bit of stylesheet to make QToolbar more flat to fit the new icons.
          I dont have an image of spreadsheet app around so im not sure what else you can
          do currently. will write of get any other ideas.

          1 Reply Last reply
          1
          • kshegunovK kshegunov

            What @mrjj said, plus the moment you define a constructor, the compiler stops generating for you. Thus if you define a constructor with parameters, the compiler will not generate a default constructor for you. Beautiful system, right? :)

            tomyT Offline
            tomyT Offline
            tomy
            wrote on last edited by
            #33

            @kshegunov

            Beautiful system, right? :)

            Right. :)

            @mrjj

            Yes, that could be the first step.
            Maybe a bit of stylesheet to make QToolbar more flat to fit the new icons.
            I dont have an image of spreadsheet app around so im not sure what else you can
            do currently. will write of get any other ideas.

            Hi, Thanks. So I need to lookup "stylesheet".

            mrjjM 1 Reply Last reply
            0
            • tomyT tomy

              @kshegunov

              Beautiful system, right? :)

              Right. :)

              @mrjj

              Yes, that could be the first step.
              Maybe a bit of stylesheet to make QToolbar more flat to fit the new icons.
              I dont have an image of spreadsheet app around so im not sure what else you can
              do currently. will write of get any other ideas.

              Hi, Thanks. So I need to lookup "stylesheet".

              mrjjM Offline
              mrjjM Offline
              mrjj
              Lifetime Qt Champion
              wrote on last edited by
              #34

              @tomy

              Hi
              https://doc.qt.io/qt-5/stylesheet.html

              tomyT 2 Replies Last reply
              1
              • mrjjM mrjj

                @tomy

                Hi
                https://doc.qt.io/qt-5/stylesheet.html

                tomyT Offline
                tomyT Offline
                tomy
                wrote on last edited by
                #35

                @mrjj
                Thanks to you. :)

                1 Reply Last reply
                0
                • mrjjM mrjj

                  @tomy

                  Hi
                  https://doc.qt.io/qt-5/stylesheet.html

                  tomyT Offline
                  tomyT Offline
                  tomy
                  wrote on last edited by
                  #36

                  @mrjj Hi,

                  I created a new project called MySpreadsheet and added a few more options to the context menu and renewed the icons to flat ones.
                  Now when I run the project, it runs normally, but when we close it, the follwoing message is written in the Application Output window:

                  Starting D:\Projects\Qt\MySpreadsheet\MySpreadsheet\build-MySpreadsheet-Desktop_Qt_5_12_0_MinGW_64_bit-Debug\debug\MySpreadsheet.exe...
                  FTH: (243752): *** Fault tolerant heap shim applied to current process. This is usually due to previous crashes. ***
                  The program has unexpectedly finished.
                  The process was ended forcefully.
                  D:/Projects/Qt/MySpreadsheet/MySpreadsheet/build-MySpreadsheet-Desktop_Qt_5_12_0_MinGW_64_bit-Debug/debug/MySpreadsheet.exe crashed.

                  What is the problem please?
                  Is it not related to the .pro file, please?

                  jsulmJ 1 Reply Last reply
                  0
                  • tomyT tomy

                    @mrjj Hi,

                    I created a new project called MySpreadsheet and added a few more options to the context menu and renewed the icons to flat ones.
                    Now when I run the project, it runs normally, but when we close it, the follwoing message is written in the Application Output window:

                    Starting D:\Projects\Qt\MySpreadsheet\MySpreadsheet\build-MySpreadsheet-Desktop_Qt_5_12_0_MinGW_64_bit-Debug\debug\MySpreadsheet.exe...
                    FTH: (243752): *** Fault tolerant heap shim applied to current process. This is usually due to previous crashes. ***
                    The program has unexpectedly finished.
                    The process was ended forcefully.
                    D:/Projects/Qt/MySpreadsheet/MySpreadsheet/build-MySpreadsheet-Desktop_Qt_5_12_0_MinGW_64_bit-Debug/debug/MySpreadsheet.exe crashed.

                    What is the problem please?
                    Is it not related to the .pro file, please?

                    jsulmJ Offline
                    jsulmJ Offline
                    jsulm
                    Lifetime Qt Champion
                    wrote on last edited by
                    #37

                    @tomy Please run through debugger and post stack trace after it crashed...

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

                    tomyT 1 Reply Last reply
                    0
                    • jsulmJ jsulm

                      @tomy Please run through debugger and post stack trace after it crashed...

                      tomyT Offline
                      tomyT Offline
                      tomy
                      wrote on last edited by
                      #38

                      @jsulm
                      Do you mean by pressing F5, please?
                      If so, I did it, but how to post stack trace?

                      0_1550499661735_Capture_1.PNG

                      1 Reply Last reply
                      0
                      • mrjjM Offline
                        mrjjM Offline
                        mrjj
                        Lifetime Qt Champion
                        wrote on last edited by
                        #39

                        Hi
                        It is the list to the right we are after

                        The code
                        for entries Level 2,3 would help a lot.

                        tomyT 1 Reply Last reply
                        2
                        • mrjjM mrjj

                          Hi
                          It is the list to the right we are after

                          The code
                          for entries Level 2,3 would help a lot.

                          tomyT Offline
                          tomyT Offline
                          tomy
                          wrote on last edited by
                          #40

                          @mrjj,
                          Hi,

                          0_1550500483783_1.PNG

                          Do you mean I copy and paste code for level 7 and 11 here?
                          7 is the project's code but 11 includes thousands of lines of code.

                          mrjjM 1 Reply Last reply
                          0
                          • tomyT tomy

                            @mrjj,
                            Hi,

                            0_1550500483783_1.PNG

                            Do you mean I copy and paste code for level 7 and 11 here?
                            7 is the project's code but 11 includes thousands of lines of code.

                            mrjjM Offline
                            mrjjM Offline
                            mrjj
                            Lifetime Qt Champion
                            wrote on last edited by
                            #41

                            @tomy
                            Hi
                            The line it shows when you click on 11 ? line 1339

                            tomyT 1 Reply Last reply
                            1
                            • mrjjM mrjj

                              @tomy
                              Hi
                              The line it shows when you click on 11 ? line 1339

                              tomyT Offline
                              tomyT Offline
                              tomy
                              wrote on last edited by
                              #42

                              @mrjj, Hi,

                              Here you are:

                              0_1550504186993_2.PNG

                              1 Reply Last reply
                              0
                              • mrjjM Offline
                                mrjjM Offline
                                mrjj
                                Lifetime Qt Champion
                                wrote on last edited by
                                #43

                                Hi
                                it was not what i as i had hoped, it being inside some of the user code.
                                I wonder if you have a double free.
                                Did you change anything in main.cpp?

                                tomyT 1 Reply Last reply
                                0
                                • mrjjM mrjj

                                  Hi
                                  it was not what i as i had hoped, it being inside some of the user code.
                                  I wonder if you have a double free.
                                  Did you change anything in main.cpp?

                                  tomyT Offline
                                  tomyT Offline
                                  tomy
                                  wrote on last edited by tomy
                                  #44

                                  @mrjj Hi,

                                  Here is main.cpp:

                                  #include "myspreadsheet.h"
                                  #include <QApplication>
                                  #include <QSplashScreen>
                                  
                                  int main(int argc, char *argv[])
                                  {
                                      QApplication app(argc, argv);
                                  
                                      QSplashScreen* splash = new QSplashScreen;
                                      splash->setPixmap(QPixmap(":/images/splash.jpg"));
                                      splash->show();
                                  
                                      Qt::Alignment topRight = Qt::AlignRight | Qt::AlignTop;
                                      splash->showMessage(QObject::tr("Setting up the main window..."), topRight, Qt::white);
                                  
                                  
                                      MySpreadsheet* mySP = new MySpreadsheet;
                                      if(argc > 1)
                                          mySP -> loadFile(argv[1]);
                                  
                                      mySP -> show();
                                      splash -> finish(mySP);
                                      delete splash;
                                  
                                      return app.exec();
                                  }
                                  

                                  I added those splash stuff and now apparently it's fine!

                                  1 Reply Last reply
                                  0
                                  • mrjjM Offline
                                    mrjjM Offline
                                    mrjj
                                    Lifetime Qt Champion
                                    wrote on last edited by
                                    #45

                                    Hi
                                    Does look fine.
                                    Try set breakpoint in main.cpp and press f10 to signle step over it and
                                    see if we can find the reason for the crash.
                                    Since its first on close, it might be inside MySpreadsheet indirectly.

                                    tomyT 1 Reply Last reply
                                    1
                                    • mrjjM mrjj

                                      Hi
                                      Does look fine.
                                      Try set breakpoint in main.cpp and press f10 to signle step over it and
                                      see if we can find the reason for the crash.
                                      Since its first on close, it might be inside MySpreadsheet indirectly.

                                      tomyT Offline
                                      tomyT Offline
                                      tomy
                                      wrote on last edited by
                                      #46

                                      @mrjj
                                      Hi, It's fine now. :) Thanks so much. :)

                                      mrjjM 1 Reply Last reply
                                      1
                                      • tomyT tomy

                                        @mrjj
                                        Hi, It's fine now. :) Thanks so much. :)

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

                                        @tomy
                                        Hi
                                        What was it ? Just to learn also.

                                        tomyT 1 Reply Last reply
                                        0
                                        • mrjjM mrjj

                                          @tomy
                                          Hi
                                          What was it ? Just to learn also.

                                          tomyT Offline
                                          tomyT Offline
                                          tomy
                                          wrote on last edited by
                                          #48

                                          @mrjj Hi,

                                          The faulty one didn't include splash stuff and was this way I think:

                                          #include "myspreadsheet.h"
                                          #include <QApplication>
                                          
                                          int main(int argc, char *argv[])
                                          {
                                              QApplication app(argc, argv);
                                              MySpreadsheet* mySP = new MySpreadsheet;
                                              mySP -> show();
                                          
                                              return app.exec();
                                          }
                                          

                                          Then I added the splash stuff. Now it "apparently" is fine, but I'm still not sure not do I know of the exact reason for that red message either. :(

                                          1 Reply Last reply
                                          1

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