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QPointerEvent throws error

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  • C curiosity

    @jsulm @JonB

    i switched to qt creator.

    i have an error here with signals and slots

    c4385b22-d686-4bc7-aa90-9d05909b0579-image.png

    looks like i have right signals and slots. but not getting about this errorgetting about

    JonBJ Offline
    JonBJ Offline
    JonB
    wrote on last edited by
    #20

    @curiosity
    Start by showing definition of the two slot functions you use.
    Is this an error only in the code completion inside Qt Creator, or do you get these errors when you actually compile?

    C 1 Reply Last reply
    0
    • C curiosity

      @jsulm @JonB

      i switched to qt creator.

      i have an error here with signals and slots

      c4385b22-d686-4bc7-aa90-9d05909b0579-image.png

      looks like i have right signals and slots. but not getting about this errorgetting about

      jsulmJ Offline
      jsulmJ Offline
      jsulm
      Lifetime Qt Champion
      wrote on last edited by
      #21

      @curiosity You probably need to tell the compiler which overload you want to connect, see https://wiki.qt.io/New_Signal_Slot_Syntax#Overload

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

      1 Reply Last reply
      2
      • JonBJ JonB

        @curiosity
        Start by showing definition of the two slot functions you use.
        Is this an error only in the code completion inside Qt Creator, or do you get these errors when you actually compile?

        C Offline
        C Offline
        curiosity
        wrote on last edited by
        #22

        @JonB
        these are errors in QtCreator. i am yet to compile.

        jsulmJ 1 Reply Last reply
        0
        • C curiosity

          @JonB
          these are errors in QtCreator. i am yet to compile.

          jsulmJ Offline
          jsulmJ Offline
          jsulm
          Lifetime Qt Champion
          wrote on last edited by
          #23

          @curiosity Well, then compile.
          Code model can produce false errors in QtCreator.

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

          C 1 Reply Last reply
          0
          • jsulmJ jsulm

            @curiosity Well, then compile.
            Code model can produce false errors in QtCreator.

            C Offline
            C Offline
            curiosity
            wrote on last edited by
            #24

            @jsulm

            i am trying to print the edited text(values entered by the user) onto the console. but still getting this error

            9ac99a19-8d19-4de9-b7ac-2b2e9c495079-image.png

            Christian EhrlicherC 1 Reply Last reply
            0
            • C curiosity

              @jsulm

              i am trying to print the edited text(values entered by the user) onto the console. but still getting this error

              9ac99a19-8d19-4de9-b7ac-2b2e9c495079-image.png

              Christian EhrlicherC Online
              Christian EhrlicherC Online
              Christian Ehrlicher
              Lifetime Qt Champion
              wrote on last edited by
              #25
              SIGNAL(&QLineEdit::textEdited)
              

              really?

              You should read the Qt signals and slot documentation and also re-read the wiki page which @jsulm already pointed you to.

              Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
              Visit the Qt Academy at https://academy.qt.io/catalog

              C 1 Reply Last reply
              3
              • Christian EhrlicherC Christian Ehrlicher
                SIGNAL(&QLineEdit::textEdited)
                

                really?

                You should read the Qt signals and slot documentation and also re-read the wiki page which @jsulm already pointed you to.

                C Offline
                C Offline
                curiosity
                wrote on last edited by
                #26

                @Christian-Ehrlicher

                connect(echoComboBox, &QComboBox::editTextChanged(echoLineEdit),
                        this, [=](const QString &edited){qDebug() << edited;});
                

                i made the above change. but signal is giving error
                "call to non static function without an object argument". editTextChanged has qstring . i tried with qsting and qlineEdit as arg. its giving same error with both

                jsulmJ 1 Reply Last reply
                0
                • C curiosity

                  @Christian-Ehrlicher

                  connect(echoComboBox, &QComboBox::editTextChanged(echoLineEdit),
                          this, [=](const QString &edited){qDebug() << edited;});
                  

                  i made the above change. but signal is giving error
                  "call to non static function without an object argument". editTextChanged has qstring . i tried with qsting and qlineEdit as arg. its giving same error with both

                  jsulmJ Offline
                  jsulmJ Offline
                  jsulm
                  Lifetime Qt Champion
                  wrote on last edited by
                  #27

                  @curiosity Please read the documentation! What you're doing is simply wrong and not even valid C++!
                  You do not pass parameters when calling connect! Parameters are passed to the signal when it is emitted and then from the signal to slot.

                  connect(echoComboBox, &QComboBox::editTextChanged,
                          this, [=](const QString &edited){qDebug() << edited;});
                  

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

                  C 1 Reply Last reply
                  3
                  • jsulmJ jsulm

                    @curiosity Please read the documentation! What you're doing is simply wrong and not even valid C++!
                    You do not pass parameters when calling connect! Parameters are passed to the signal when it is emitted and then from the signal to slot.

                    connect(echoComboBox, &QComboBox::editTextChanged,
                            this, [=](const QString &edited){qDebug() << edited;});
                    
                    C Offline
                    C Offline
                    curiosity
                    wrote on last edited by
                    #28

                    @jsulm

                    thanks for correcting.

                    i am trying to echo the text entered by the user into QCombobox in the next line.

                    connect(echoComboBox, &QComboBox::currentTextChanged,this, &Window::onCurrentTextChanged);

                        auto text = echoComboBox->currentText();
                     passwordLineEdit = new QLineEdit;
                    
                        passwordLineEdit->setPlaceholderText("Password entered is : ");     //But this line is displayed in a new window. and password is not echoed.
                    

                    passwordLineEdit->show();

                        echoComboBox->show();
                    
                    JonBJ jsulmJ 2 Replies Last reply
                    0
                    • C curiosity

                      @jsulm

                      thanks for correcting.

                      i am trying to echo the text entered by the user into QCombobox in the next line.

                      connect(echoComboBox, &QComboBox::currentTextChanged,this, &Window::onCurrentTextChanged);

                          auto text = echoComboBox->currentText();
                       passwordLineEdit = new QLineEdit;
                      
                          passwordLineEdit->setPlaceholderText("Password entered is : ");     //But this line is displayed in a new window. and password is not echoed.
                      

                      passwordLineEdit->show();

                          echoComboBox->show();
                      
                      JonBJ Offline
                      JonBJ Offline
                      JonB
                      wrote on last edited by JonB
                      #29

                      @curiosity said in QPointerEvent throws error:

                      //But this line is displayed in a new window

                      You have created a new QLineEdit but not put it anywhere (e.g. on an existing window), so where do you expect it to go? I do not know why you are choosing to create a new QLineEdit dynamically, but give it a parent and/or place it on some widget's layout.

                      I really don't know what you are doing with a combobox."i am trying to echo the text entered by the user into QCombobox" --- what text is being entered how by user into combobox. Why in the world would you have a combobox, to choose an existing item from, if you want a user to enter a line of text for a password?

                      passwordLineEdit->setPlaceholderText("Password entered is : "); //But this line is displayed in a new window. and password is not echoed.

                      "Password is not echoed", what do you mean or expect? All you have done here is set the placeholder text of a QLineEdit to a fixed string. I see nothing in your code which perhaps copes/displays the auto text = echoComboBox->currentText(); anywhere.

                      @jsulm gave you sample code for picking up changed edited text. All you have to do is change his lambda slot to (preferably using his signal) to call a method of you own, like you show with &Window::onCurrentTextChanged, and write the code in that to access the current text or the text parameter sent from void QComboBox::editTextChanged(const QString &text) signal.

                      1 Reply Last reply
                      2
                      • C curiosity

                        @jsulm

                        thanks for correcting.

                        i am trying to echo the text entered by the user into QCombobox in the next line.

                        connect(echoComboBox, &QComboBox::currentTextChanged,this, &Window::onCurrentTextChanged);

                            auto text = echoComboBox->currentText();
                         passwordLineEdit = new QLineEdit;
                        
                            passwordLineEdit->setPlaceholderText("Password entered is : ");     //But this line is displayed in a new window. and password is not echoed.
                        

                        passwordLineEdit->show();

                            echoComboBox->show();
                        
                        jsulmJ Offline
                        jsulmJ Offline
                        jsulm
                        Lifetime Qt Champion
                        wrote on last edited by
                        #30

                        @curiosity said in QPointerEvent throws error:

                        auto text = echoComboBox->currentText();
                        passwordLineEdit = new QLineEdit;

                        passwordLineEdit->setPlaceholderText("Password entered is : ");
                        

                        Please think about this code and why it can't do what you want it to do and why you get a new window.
                        @JonB gave you all needed hints.

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

                        C 1 Reply Last reply
                        0
                        • jsulmJ jsulm

                          @curiosity said in QPointerEvent throws error:

                          auto text = echoComboBox->currentText();
                          passwordLineEdit = new QLineEdit;

                          passwordLineEdit->setPlaceholderText("Password entered is : ");
                          

                          Please think about this code and why it can't do what you want it to do and why you get a new window.
                          @JonB gave you all needed hints.

                          C Offline
                          C Offline
                          curiosity
                          wrote on last edited by
                          #31

                          @jsulm @JonB

                          echoLayout->addWidget(passwordLabel, 2, 0);
                          echoLayout->addWidget(passwordLineEdit, 2, 1, 2, 3 );
                          this is added to the grid layout

                          QObject::connect(echoComboBox, &QComboBox::editTextChanged, this, [=](const QString &text) {
                          Window::onCurrentTextChanged(text);
                          });

                          void onCurrentTextChanged(const QString &text)
                          {
                              passwordLineEdit->setPlaceholderText("Password entered is : ");
                              passwordLineEdit->setText(text);  //Is this the right way to set the text   received from above signal. }
                          

                          value entered is still not reflecting

                          jsulmJ C JonBJ 3 Replies Last reply
                          0
                          • C curiosity

                            @jsulm @JonB

                            echoLayout->addWidget(passwordLabel, 2, 0);
                            echoLayout->addWidget(passwordLineEdit, 2, 1, 2, 3 );
                            this is added to the grid layout

                            QObject::connect(echoComboBox, &QComboBox::editTextChanged, this, [=](const QString &text) {
                            Window::onCurrentTextChanged(text);
                            });

                            void onCurrentTextChanged(const QString &text)
                            {
                                passwordLineEdit->setPlaceholderText("Password entered is : ");
                                passwordLineEdit->setText(text);  //Is this the right way to set the text   received from above signal. }
                            

                            value entered is still not reflecting

                            jsulmJ Offline
                            jsulmJ Offline
                            jsulm
                            Lifetime Qt Champion
                            wrote on last edited by
                            #32

                            @curiosity said in QPointerEvent throws error:

                            QObject::connect(echoComboBox, &QComboBox::editTextChanged, this, [=](const QString &text) {
                            Window::onCurrentTextChanged(text);
                            });

                            There is no need for a lambda, just connect onCurrentTextChanged directly to the signal.

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

                            1 Reply Last reply
                            0
                            • C curiosity

                              @jsulm @JonB

                              echoLayout->addWidget(passwordLabel, 2, 0);
                              echoLayout->addWidget(passwordLineEdit, 2, 1, 2, 3 );
                              this is added to the grid layout

                              QObject::connect(echoComboBox, &QComboBox::editTextChanged, this, [=](const QString &text) {
                              Window::onCurrentTextChanged(text);
                              });

                              void onCurrentTextChanged(const QString &text)
                              {
                                  passwordLineEdit->setPlaceholderText("Password entered is : ");
                                  passwordLineEdit->setText(text);  //Is this the right way to set the text   received from above signal. }
                              

                              value entered is still not reflecting

                              C Offline
                              C Offline
                              curiosity
                              wrote on last edited by
                              #33

                              @curiosity
                              c1211f47-d3fc-4cf7-be62-2ce6511bf141-image.png

                              1 Reply Last reply
                              0
                              • C curiosity

                                @jsulm @JonB

                                echoLayout->addWidget(passwordLabel, 2, 0);
                                echoLayout->addWidget(passwordLineEdit, 2, 1, 2, 3 );
                                this is added to the grid layout

                                QObject::connect(echoComboBox, &QComboBox::editTextChanged, this, [=](const QString &text) {
                                Window::onCurrentTextChanged(text);
                                });

                                void onCurrentTextChanged(const QString &text)
                                {
                                    passwordLineEdit->setPlaceholderText("Password entered is : ");
                                    passwordLineEdit->setText(text);  //Is this the right way to set the text   received from above signal. }
                                

                                value entered is still not reflecting

                                JonBJ Offline
                                JonBJ Offline
                                JonB
                                wrote on last edited by
                                #34

                                @curiosity said in QPointerEvent throws error:

                                value entered is still not reflecting

                                Not sure where you are at now. Yes, calling passwordLineEdit->setText(text); should set the text from the string. Check what is in the string. Check you are getting the signal by putting a qDebug() or something in the slot so that you know it is being called.

                                C 1 Reply Last reply
                                1
                                • JonBJ JonB

                                  @curiosity said in QPointerEvent throws error:

                                  value entered is still not reflecting

                                  Not sure where you are at now. Yes, calling passwordLineEdit->setText(text); should set the text from the string. Check what is in the string. Check you are getting the signal by putting a qDebug() or something in the slot so that you know it is being called.

                                  C Offline
                                  C Offline
                                  curiosity
                                  wrote on last edited by
                                  #35

                                  @JonB
                                  Ialready checked by planting a breakpoint in onCurrentTextChanged . on running and entering the text in the place holder i was expecting to hit the breakpoint, but it didnt hit.
                                  this is my connect statement

                                  connect(echoComboBox,&QComboBox::editTextChanged, this, &Window::onCurrentTextChanged);

                                  void onCurrentTextChanged(const QString &text)
                                  {
                                      qDebug() << QString(" entered text is ")<<  text;
                                  

                                  //nothing is printed here in the application tab in qtcreator. it is not even hitting this breakpoint
                                  passwordLineEdit->setPlaceholderText("Password entered is : ");
                                  passwordLineEdit->setText(text);
                                  passwordLineEdit->show();
                                  passwordLineEdit->setEchoMode(QLineEdit::PasswordEchoOnEdit);

                                  }
                                  
                                  Christian EhrlicherC 1 Reply Last reply
                                  0
                                  • C curiosity

                                    @JonB
                                    Ialready checked by planting a breakpoint in onCurrentTextChanged . on running and entering the text in the place holder i was expecting to hit the breakpoint, but it didnt hit.
                                    this is my connect statement

                                    connect(echoComboBox,&QComboBox::editTextChanged, this, &Window::onCurrentTextChanged);

                                    void onCurrentTextChanged(const QString &text)
                                    {
                                        qDebug() << QString(" entered text is ")<<  text;
                                    

                                    //nothing is printed here in the application tab in qtcreator. it is not even hitting this breakpoint
                                    passwordLineEdit->setPlaceholderText("Password entered is : ");
                                    passwordLineEdit->setText(text);
                                    passwordLineEdit->show();
                                    passwordLineEdit->setEchoMode(QLineEdit::PasswordEchoOnEdit);

                                    }
                                    
                                    Christian EhrlicherC Online
                                    Christian EhrlicherC Online
                                    Christian Ehrlicher
                                    Lifetime Qt Champion
                                    wrote on last edited by Christian Ehrlicher
                                    #36

                                    @curiosity said in QPointerEvent throws error:

                                    void onCurrentTextChanged(const QString &text)...

                                    This is a free function... How does this even compile?

                                    Please provide your full relevant code which actually compiles.

                                    Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
                                    Visit the Qt Academy at https://academy.qt.io/catalog

                                    C 1 Reply Last reply
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                                    • Christian EhrlicherC Christian Ehrlicher

                                      @curiosity said in QPointerEvent throws error:

                                      void onCurrentTextChanged(const QString &text)...

                                      This is a free function... How does this even compile?

                                      Please provide your full relevant code which actually compiles.

                                      C Offline
                                      C Offline
                                      curiosity
                                      wrote on last edited by
                                      #37

                                      @Christian-Ehrlicher
                                      but i am using this as a slot. Please check the connect statement

                                      Christian EhrlicherC 1 Reply Last reply
                                      0
                                      • C curiosity

                                        @Christian-Ehrlicher
                                        but i am using this as a slot. Please check the connect statement

                                        Christian EhrlicherC Online
                                        Christian EhrlicherC Online
                                        Christian Ehrlicher
                                        Lifetime Qt Champion
                                        wrote on last edited by
                                        #38

                                        void MainWindow::onCurrentTextChanged() and void onCurrentTextChanged() are two different functions. Provide your full code including the header.

                                        Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
                                        Visit the Qt Academy at https://academy.qt.io/catalog

                                        C 1 Reply Last reply
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                                        • Christian EhrlicherC Christian Ehrlicher

                                          void MainWindow::onCurrentTextChanged() and void onCurrentTextChanged() are two different functions. Provide your full code including the header.

                                          C Offline
                                          C Offline
                                          curiosity
                                          wrote on last edited by
                                          #39
                                          This post is deleted!
                                          Christian EhrlicherC 1 Reply Last reply
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