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Newbie Question, Working with multiple CPP files and Headers

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  • S Offline
    S Offline
    Stevendragoes
    wrote on 10 Feb 2020, 08:20 last edited by Stevendragoes 2 Oct 2020, 08:26
    #9

    Okay I think I get it. I need to initialise

    conlinecam* cam = new conlinecam();
    

    in my Main Code when I initialise the UI.

    And I have to make my timer public already because I am initialising the timer when I press a Button to get the WebCam Feed

    EDIT: I get then error about __inline because I initialise in the header file

    J 1 Reply Last reply 10 Feb 2020, 08:27
    0
    • S Offline
      S Offline
      Stevendragoes
      wrote on 10 Feb 2020, 08:21 last edited by
      #10

      Then I have a question. why would they say _inline?
      Because I tried to initialise the Timer QObject in the Header FIle. But It simply doesn't allow me @jsulm

      1 Reply Last reply
      0
      • S Stevendragoes
        10 Feb 2020, 08:20

        Okay I think I get it. I need to initialise

        conlinecam* cam = new conlinecam();
        

        in my Main Code when I initialise the UI.

        And I have to make my timer public already because I am initialising the timer when I press a Button to get the WebCam Feed

        EDIT: I get then error about __inline because I initialise in the header file

        J Offline
        J Offline
        jsulm
        Lifetime Qt Champion
        wrote on 10 Feb 2020, 08:27 last edited by
        #11

        @Stevendragoes said in Newbie Question, Working with multiple CPP files and Headers:

        And I have to make my timer public

        NO!
        Why do you think so?
        The timer is private implementation detail in conlinecam, the outside world does not have to know it even exists.
        Initialise the timer inside conlinecam.

        "why would they say _inline?" who?
        "Because I tried to initialise the Timer QObject in the Header FIle. But It simply doesn't allow me" - please show your code.
        It is actually as simple as

        class conlinecam
        {
        private:
            QTimer timer;
        }
        

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

        1 Reply Last reply
        1
        • S Offline
          S Offline
          Stevendragoes
          wrote on 10 Feb 2020, 08:32 last edited by
          #12

          To simplify the situation, @jsulm I have the following files
          483bb332-8bca-404a-b603-7d0aa9737752-image.png

          conlinecam.h has the following code

          #ifndef CONLINECAM_H
          #define CONLINECAM_H
          
          #include <mainwindow.h>
          #include <QMainWindow>
          
          class conlinecam : public QObject
          {
              Q_OBJECT
          public:
              conlinecam();
              ~conlinecam();
          private:
              QTimer* camtimer;
              
          signals:
              void update();
          };
          
          #endif // CONLINECAM_H
          
          

          conlinecam.cpp has the following code

          #include "conlinecam.h"
          #include "ui_mainwindow.h"
          #include "mainwindow.h"
          
          conlinecam::conlinecam() : QObject()
          {
               camtimer = new QTimer(this);
               connect(camtimer,SIGNAL(timeout()),this,SIGNAL(update()));
               camtimer->start(100);
          }
          
          conlinecam::~conlinecam()
          {
              camtimer->stop();
          }
          
          

          in my mainwindow.cpp , I have the following code to connect to the conlinecam

          void MainWindow::on_online_clicked()
          {
              conlinecam* cam = new conlinecam();
              connect(cam, SIGNAL(update()), this, SLOT(update_screen()));
              onlinecam.open(0);                                 //------------------------CAMERA INPUT---------------------------------//
              int framewidth = onlinecam.get(cv::CAP_PROP_FRAME_WIDTH);
              int frameheight = onlinecam.get(cv::CAP_PROP_FRAME_HEIGHT);
              QString fwidth= QString::number(framewidth);
              QString fheight = QString::number(frameheight);
              ui->textEdit->append(fwidth);
              ui->textEdit->append(fheight);
          }
          

          Now I just want to include Pause and STOP button to pause and stop the timer. But can't because of the following.

          1. Timer is private in conlinecam.cpp
          2. conlinecam is only initialised when I pressed the Online PushButton.
            Hence, I cannot access it's data members
          J 2 Replies Last reply 10 Feb 2020, 08:36
          0
          • S Stevendragoes
            10 Feb 2020, 08:32

            To simplify the situation, @jsulm I have the following files
            483bb332-8bca-404a-b603-7d0aa9737752-image.png

            conlinecam.h has the following code

            #ifndef CONLINECAM_H
            #define CONLINECAM_H
            
            #include <mainwindow.h>
            #include <QMainWindow>
            
            class conlinecam : public QObject
            {
                Q_OBJECT
            public:
                conlinecam();
                ~conlinecam();
            private:
                QTimer* camtimer;
                
            signals:
                void update();
            };
            
            #endif // CONLINECAM_H
            
            

            conlinecam.cpp has the following code

            #include "conlinecam.h"
            #include "ui_mainwindow.h"
            #include "mainwindow.h"
            
            conlinecam::conlinecam() : QObject()
            {
                 camtimer = new QTimer(this);
                 connect(camtimer,SIGNAL(timeout()),this,SIGNAL(update()));
                 camtimer->start(100);
            }
            
            conlinecam::~conlinecam()
            {
                camtimer->stop();
            }
            
            

            in my mainwindow.cpp , I have the following code to connect to the conlinecam

            void MainWindow::on_online_clicked()
            {
                conlinecam* cam = new conlinecam();
                connect(cam, SIGNAL(update()), this, SLOT(update_screen()));
                onlinecam.open(0);                                 //------------------------CAMERA INPUT---------------------------------//
                int framewidth = onlinecam.get(cv::CAP_PROP_FRAME_WIDTH);
                int frameheight = onlinecam.get(cv::CAP_PROP_FRAME_HEIGHT);
                QString fwidth= QString::number(framewidth);
                QString fheight = QString::number(frameheight);
                ui->textEdit->append(fwidth);
                ui->textEdit->append(fheight);
            }
            

            Now I just want to include Pause and STOP button to pause and stop the timer. But can't because of the following.

            1. Timer is private in conlinecam.cpp
            2. conlinecam is only initialised when I pressed the Online PushButton.
              Hence, I cannot access it's data members
            J Offline
            J Offline
            jsulm
            Lifetime Qt Champion
            wrote on 10 Feb 2020, 08:36 last edited by
            #13

            @Stevendragoes

            1. As I said add slots to conlinecam where you have full access to the timer
            2. You don't have to access its members - this is whole point of encapsulation.
            class conlinecam
            {
            public slots:
                void start();
                void stop();
                void pause();
            private:
                QTimer timer;
            }
            

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

            1 Reply Last reply
            0
            • S Stevendragoes
              10 Feb 2020, 08:32

              To simplify the situation, @jsulm I have the following files
              483bb332-8bca-404a-b603-7d0aa9737752-image.png

              conlinecam.h has the following code

              #ifndef CONLINECAM_H
              #define CONLINECAM_H
              
              #include <mainwindow.h>
              #include <QMainWindow>
              
              class conlinecam : public QObject
              {
                  Q_OBJECT
              public:
                  conlinecam();
                  ~conlinecam();
              private:
                  QTimer* camtimer;
                  
              signals:
                  void update();
              };
              
              #endif // CONLINECAM_H
              
              

              conlinecam.cpp has the following code

              #include "conlinecam.h"
              #include "ui_mainwindow.h"
              #include "mainwindow.h"
              
              conlinecam::conlinecam() : QObject()
              {
                   camtimer = new QTimer(this);
                   connect(camtimer,SIGNAL(timeout()),this,SIGNAL(update()));
                   camtimer->start(100);
              }
              
              conlinecam::~conlinecam()
              {
                  camtimer->stop();
              }
              
              

              in my mainwindow.cpp , I have the following code to connect to the conlinecam

              void MainWindow::on_online_clicked()
              {
                  conlinecam* cam = new conlinecam();
                  connect(cam, SIGNAL(update()), this, SLOT(update_screen()));
                  onlinecam.open(0);                                 //------------------------CAMERA INPUT---------------------------------//
                  int framewidth = onlinecam.get(cv::CAP_PROP_FRAME_WIDTH);
                  int frameheight = onlinecam.get(cv::CAP_PROP_FRAME_HEIGHT);
                  QString fwidth= QString::number(framewidth);
                  QString fheight = QString::number(frameheight);
                  ui->textEdit->append(fwidth);
                  ui->textEdit->append(fheight);
              }
              

              Now I just want to include Pause and STOP button to pause and stop the timer. But can't because of the following.

              1. Timer is private in conlinecam.cpp
              2. conlinecam is only initialised when I pressed the Online PushButton.
                Hence, I cannot access it's data members
              J Offline
              J Offline
              jsulm
              Lifetime Qt Champion
              wrote on 10 Feb 2020, 08:42 last edited by
              #14

              @Stevendragoes One correction to one of my previous posts: "Yes, in your main window add play(), pause() and stop() signals. When you create the child class instance connect these signals to slots in that child class." - there is no need for to define these signals in main window, just connect the clicked() signals from the buttons to the slots in conlinecam.

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

              S 1 Reply Last reply 10 Feb 2020, 08:47
              0
              • J jsulm
                10 Feb 2020, 08:42

                @Stevendragoes One correction to one of my previous posts: "Yes, in your main window add play(), pause() and stop() signals. When you create the child class instance connect these signals to slots in that child class." - there is no need for to define these signals in main window, just connect the clicked() signals from the buttons to the slots in conlinecam.

                S Offline
                S Offline
                Stevendragoes
                wrote on 10 Feb 2020, 08:47 last edited by
                #15

                @jsulm said in Newbie Question, Working with multiple CPP files and Headers:

                just connect the clicked() signals from the buttons to the slots in conlinecam.

                May I know exactly how? Because I have created the slots. The Signals, Comes from the ToolButtons I have created in my UI form. Do you mean via the Signal/Slot Editor in the UI?

                J 1 Reply Last reply 10 Feb 2020, 08:49
                0
                • S Stevendragoes
                  10 Feb 2020, 08:47

                  @jsulm said in Newbie Question, Working with multiple CPP files and Headers:

                  just connect the clicked() signals from the buttons to the slots in conlinecam.

                  May I know exactly how? Because I have created the slots. The Signals, Comes from the ToolButtons I have created in my UI form. Do you mean via the Signal/Slot Editor in the UI?

                  J Offline
                  J Offline
                  jsulm
                  Lifetime Qt Champion
                  wrote on 10 Feb 2020, 08:49 last edited by
                  #16

                  @Stevendragoes

                  connect(ui->some_tool_button, SIGNAL(clicked()), conlinecamInstance, SLOT(start()));
                  

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

                  1 Reply Last reply
                  3
                  • S Offline
                    S Offline
                    Stevendragoes
                    wrote on 10 Feb 2020, 08:51 last edited by
                    #17

                    @jsulm
                    Wow. you are amazing. Or maybe I am too inexperienced 4 months into coding..

                    J 1 Reply Last reply 10 Feb 2020, 08:51
                    1
                    • S Stevendragoes
                      10 Feb 2020, 08:51

                      @jsulm
                      Wow. you are amazing. Or maybe I am too inexperienced 4 months into coding..

                      J Offline
                      J Offline
                      jsulm
                      Lifetime Qt Champion
                      wrote on 10 Feb 2020, 08:51 last edited by
                      #18

                      @Stevendragoes No problem. It takes some time to learn new concepts. Keep learning :-)

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

                      1 Reply Last reply
                      2
                      • S Offline
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                        Stevendragoes
                        wrote on 10 Feb 2020, 08:54 last edited by
                        #19

                        @jsulm Just a question Do you experienced guys have like Discord Chat Groups with the moderators and professionals?

                        J 1 Reply Last reply 11 Feb 2020, 07:24
                        0
                        • S Stevendragoes
                          10 Feb 2020, 08:54

                          @jsulm Just a question Do you experienced guys have like Discord Chat Groups with the moderators and professionals?

                          J Offline
                          J Offline
                          jsulm
                          Lifetime Qt Champion
                          wrote on 11 Feb 2020, 07:24 last edited by
                          #20

                          @Stevendragoes You can chat here.
                          For professional support from Qt Company you will need a commercial license.

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

                          1 Reply Last reply
                          0

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                          10 Feb 2020, 08:51

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