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Need some help in Signal and Slots Connections.

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  • V Offline
    V Offline
    VPellas
    wrote on last edited by
    #11

    I only want Integer. For example. When you run the program the label has the value 0. Doing the procedure that you (thank god) solved, it just replaces the "text"(number) at the label.I want to keep the value, and every time OK is pushed, i want it to add the new value to the old one. So, i thought to make an int a; at the pushButtonClicked() procedure but i cannot give it value at the start because every time i click the button it won't keep the last value, but it will keep changing to 0.

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    • ZlatomirZ Offline
      ZlatomirZ Offline
      Zlatomir
      wrote on last edited by
      #12

      To the int a you give the value you get from ui->label->text() converted to int (see the documentation link from my previous post) than you add the int you get from spinbox and finally set the result to the label.
      Try to do it and post again if you get into some troubles.

      https://forum.qt.io/category/41/romanian

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      • V Offline
        V Offline
        VPellas
        wrote on last edited by
        #13

        Well, i am trying now the Conversion of text() to int and i am not sure i really understood the way that it is done. I read the Documentation you gave me but i am not sure i understood how to use QString, and especcially what tool to use.

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        • V Offline
          V Offline
          VPellas
          wrote on last edited by
          #14

          Just for informational reasons i managed to do that. So if anyone wants to learn how to use the QString::ToInt class that's how it is done :)

          @void MainWindow::pushButton1Clicked()
          {
          int l;

             l = ui->spinBox1 ->value();
             QString mystring1(ui->Score1->text());
             int c = mystring1.toInt();
             c = l + c;
          
             ui->Score1 -> setNum( c );
             ui->spinBox1 ->setValue(0);
          
          }@
          

          Zlatomir, Really thanks for your help. Dunno if i could do it without your help. I really appreciate it :)

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          • V Offline
            V Offline
            VPellas
            wrote on last edited by
            #15

            Alright, now i need some help in something else, it is again connected to "Signal and Slots" theme. First of all have a look at the Ui. !http://s17.postimage.org/lmu8852xb/image.jpg()! So, my "new" problem is that i want somehow to connect the Max and Min Buttons with the Done button, and after that i need to check with a bool:
            1st case. Max Clicked ---> Done clicked ---> +200 points in the Label when the Pushbutton is clicked
            2nd case. Min Clicked ---> Done Clicked ---> +100 points in the Label when the Pushbutton is clicked
            3rd case. Max Clicked ---> Done NOT Clicked ---> -200 points in the Label when Pushbutton clicked
            4th case. Min Clicked ---> Done NOT clicked ---> -100 points in the Label when Pushbutton clicked
            5th case. All buttons Unclicked, No difference to Label when Pushbutton clicked

            Let's have a look at the code

            mypage.h
            @#ifndef MYPAGE_H
            #define MYPAGE_H

            #include <QWidget>
            #include <QPushButton>
            #include <QLabel>
            #include <QSpinBox>
            #include <QString>
            #include <QAbstractButton>

            namespace Ui {
            class Mypage;
            }

            class Mypage : public QWidget
            {
            Q_OBJECT
            public:
            explicit Mypage(QWidget *parent = 0);

            // I will explain the "int" at the mypage.cpp code
            private slots:
            int on_Done_clicked();
            int on_MinPoints_clicked();
            int on_MaxPoints_clicked();
            void pushButtonClicked();

            private:
            Ui::Mypage *ui;

            };

            #endif // MYPAGE_H@

            mypage.cpp

            @#include "mypage.h"
            #include "ui_mypage.h"
            #include <QtGui>
            #include <QPushButton>
            #include <QLabel>
            #include <QSpinBox>
            #include <QString>
            #include <QAbstractButton>

            Mypage::Mypage(QWidget *parent) :
            QWidget(parent),
            ui(new Ui::Mypage)
            {
            ui->setupUi(this);
            QObject::connect(ui -> MaxPoints, SIGNAL(clicked()), this, SLOT(on_MaxPoints_clicked()));
            QObject::connect(ui -> MinPoints, SIGNAL(clicked()), this, SLOT(on_MaxPoints_clicked()));
            QObject::connect(ui -> Done, SIGNAL(clicked()), this, SLOT(on_Done_clicked()));
            QObject::connect(ui -> pushButton, SIGNAL(clicked()), this, SLOT(on_Done_clicked()));
            QObject::connect(ui -> pushButton, SIGNAL(clicked()), this, SLOT(pushButtonClicked()));
            }

            void MainWindow::pushButton1Clicked()
            {
            int l,s;

               l = ui->spinBox1 ->value();
               QString mystring1(ui->label->text());
               int c = mystring1.toInt();
               c = l + c;
            

            //Here is a first explanation of my code.
            //I need this int s; to take a value from the on_Done_Clicked()
            //that's why i have turned these functions from void to int
            s = on_Done_clicked();

               ui->label -> setNum( c + s );
               ui->spinBox1 ->setValue(0);
            
            }
            

            //Check that they are now int, not void as they should be
            int Mypage::on_MaxPoints_clicked()
            {
            //So in these functions i need to take a Signal (true or false) from Buttons MaxPoints
            //and MinPoints. If they are clicked i need to take true, if not i need to take false
            //and after that I use it in the "if (Status1 == true) e.t.c."
            int max;
            bool Status1;
            Status1 = ui->MaxPoints->clicked();
            if (Status1 == true)
            max = 200;
            else max =0;
            return max;
            }

            int Mypage::on_MinPoints_clicked()
            {
            int min;
            bool Status2;
            Status2 = ui->MinPoints->clicked();
            if (Status2 == true)
            min = 200;
            else min =0;
            return min;
            }

            int Mypage::on_Done_clicked()
            {
            //So here in this Function i want to take the Values from on_MaxPoints_clicked()
            //and on_MinPoints_clicked() check what is pressed and what not and return the right
            // "done" in the pushButton1Clicked()
            int done,Maxvalue,Minvalue;
            Maxvalue = on_MaxPoints_clicked();
            Minvalue = on_MinPoints_clicked();
            if (Maxvalue!=0 && Minvalue==0)
            done= Maxvalue;
            else if (Maxvalue==0 && Minvalue!=0)
            done= Minvalue;
            else
            done=0;
            return done;
            }
            //In Compiling i have really many errors. I want you to explain me
            //first of all if this that i'm trying can be done
            //and Secondly if i am following the right way to do it and what i am doing wrong
            @

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            • ZlatomirZ Offline
              ZlatomirZ Offline
              Zlatomir
              wrote on last edited by
              #16

              First tell us more about the errors, we can't help you if we don't know.

              Anyway at a first look i spotted a few things:

              1. You added slots so you most likely need to Run qmake and than Build/Run your project

              2. You call the on_Done_clicked slot manually in pushButton1Clicked are you sure you want that?

              3.1) In many places you call the signal clicked from the slot that is actually connected with the same signal.
              3.2 You try to get a bool return from the signal "call"
              Possible fix: maybe you actually need "check-able QPushButton":http://qt-project.org/doc/qt-4.8/qabstractbutton.html#checked-prop
              You do this in many places, example:
              @int Mypage::on_MaxPoints_clicked()
              {
              //... this code is excuted when MaxPoints button has been clicked so there is no point in calling clicked and also clicked is not returning anything
              Status1 = ui->MaxPoints->clicked();
              //...
              }@
              4) You use the naming convention for auto-connect and you also connect manually, this will result in two calls of the slot per each click on the button, auto-connect name convention is naming the slot like this: on_WIDGETNAME_SIGNALNAME you can read about it "here":http://qt-project.org/doc/qt-4.8/designer-using-a-ui-file.html#a-dialog-without-auto-connect (i prefer to avoid it and make the connections myself)

              https://forum.qt.io/category/41/romanian

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              • V Offline
                V Offline
                VPellas
                wrote on last edited by
                #17

                Alright, i solved the problem. My thoughts were correct :) The void -->int change is working. The only thing that i changed is the " Status1 = ui->MaxPoints->clicked(); " . I focused on the Check/uncheck buttons and with the ui-> MaxPointsCheck -> isChecked(); the job that i wanted is now done :) Again thanks for the answers :) You helped me a lot :)

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                • V Offline
                  V Offline
                  VPellas
                  wrote on last edited by
                  #18

                  Alright, here i am again with my Final Problem. I had to make some changes in my Final Program and now it's the Final Step to complete it. My problem now is Taking an int Value from a Second Window and add the Value to a Label at the First Window. Let's take a look at the U.I. of the program:
                  1st Screen : !http://s10.postimg.org/3mwa4ipc9/Main_Window1.jpg()!
                  2nd Screen: http://postimg.org/image/kp27co4d9/

                  Now. How I want it To Work. First Of all User Presses the Record Button at MainWindow1. MainWindow2 Pops up, User Writes an Int Value on the slot, and when the Done Button is Clicked i want this Value to be copied and added to the previous Value that MainWindow1's label had.

                  Here is my Code:
                  mainwindow1.h
                  @#ifndef MAINWINDOW1_H
                  #define MAINWINDOW1_H
                  #include <QWidget>
                  #include <QPushButton>
                  #include<mainwindow2.h>
                  namespace Ui {
                  class MainWindow1;
                  }

                  class MainWindow1 : public QWidget
                  {
                  Q_OBJECT

                  public:
                  explicit MainWindow1(QWidget *parent = 0);
                  ~MainWindow1();

                  public slots:
                  void openNewWindow();

                  private:
                  Ui::MainWindow1 *ui;
                  class MainWindow2 *mMyNewWindow;

                  private slots:
                  void on_Record_clicked();
                  };

                  #endif // MAINWINDOW1_H@

                  mainwindow2.h
                  @#ifndef MAINWINDOW2_H
                  #define MAINWINDOW2_H
                  #include <QWidget>
                  #include<mainwindow1.h>
                  #include <QPushButton>
                  namespace Ui {
                  class MainWindow2;
                  }

                  class MainWindow2 : public QWidget
                  {
                  Q_OBJECT

                  public:
                  explicit MainWindow2(QWidget *parent = 0);
                  ~MainWindow2();

                  public slots:
                  void openOldWindow();

                  private:
                  Ui::MainWindow2 *ui;
                  class MainWindow1 *mMyOldWindow;

                  private slots:
                  void on_Done_clicked();

                  };

                  #endif // MAINWINDOW2_H@

                  mainwindow1.cpp
                  @#include "mainwindow1.h"
                  #include "ui_mainwindow1.h"
                  #include <QWidget>
                  #include <QPushButton>
                  MainWindow1::MainWindow1(QWidget *parent) :
                  QWidget(parent),
                  ui(new Ui::MainWindow1)
                  {
                  ui->setupUi(this);
                  QObject::connect(ui->Record, SIGNAL( clicked() ), this, SLOT(on_Record_clicked()));
                  }

                  MainWindow1::~MainWindow1()
                  {
                  delete ui;
                  }

                  void MainWindow1::openNewWindow()
                  {
                  mMyNewWindow = new MainWindow2();

                  mMyNewWindow->show();
                  

                  }

                  void MainWindow1::on_Record_clicked()
                  {
                  openNewWindow();
                  }
                  @

                  mainwindow2.cpp

                  @#include "mainwindow2.h"
                  #include "ui_mainwindow2.h"
                  #include <QWidget>
                  #include <QPushButton>
                  MainWindow2::MainWindow2(QWidget *parent) :
                  QWidget(parent),
                  ui(new Ui::MainWindow2)
                  {
                  ui->setupUi(this);

                  QObject::connect(ui->Done, SIGNAL( clicked() ), this, SLOT(on_Done_clicked()));
                  

                  }

                  MainWindow2::~MainWindow2()
                  {
                  delete ui;
                  }

                  void MainWindow2::openOldWindow()
                  {
                  mMyOldWindow = new MainWindow1();

                  mMyOldWindow->show();
                  

                  }

                  void MainWindow2::on_Done_clicked()
                  {
                  //Here I am taking the Value that user Entered in the "Score1" as Int
                  //Now the problem is that i Want this Value to be added to the previous Window
                  //At the Label Slot
                  //QString mystring1(ui->Score1->text());
                  //int c = mystring1.toInt();

                  openOldWindow();
                  

                  }
                  @

                  Thanks for your help :)

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                  • V Offline
                    V Offline
                    VPellas
                    wrote on last edited by
                    #19

                    I've made some progress, although I am still waiting for your help :-/ ... Let's take a look again at the Ui of MainWindow1 and MainWindow2:
                    MainWindow1 : !http://s18.postimg.org/53h2p1w0p/Main_Window1.jpg()!
                    MainWindow2 : !http://s22.postimg.org/oy6xeu7mp/Main_Window2.jpg()!

                    So, My New Goal is to make the proccess that i will explain now work.

                    1. User Open the Program
                    2. He/she presses the Recount Button and MainWindow2 is coming Up
                    3. He/she Enteres a Value at the "QlineEdit" Widget
                    4. When he/she presses the Done Button I need the program to Save the Value that user entered, and send it to the MainWindow1
                    5. After Pushing the Done Button MainWindow1 is coming up again
                    6. When User presses the Count Button i want the Value that he/she entered to appear at one of the Qlabels (you can check them on photos).

                    I managed to have a progress, but still it doesn't work, It seems like values are reset after Windows Changes. Have a look at the Code now:

                    MainWindow1.h
                    @#ifndef MAINWINDOW1_H
                    #define MAINWINDOW1_H
                    #include <QWidget>
                    #include <QPushButton>
                    #include<mainwindow2.h>
                    namespace Ui {
                    class MainWindow1;
                    }

                    class MainWindow1 : public QWidget
                    {
                    Q_OBJECT

                    public:
                    explicit MainWindow1(QWidget *parent = 0);
                    ~MainWindow1();

                    public slots:
                    void openNewWindow();
                    void on_Count_clicked();
                    void on_Record_clicked();
                    void Proccess(int a);

                    private:
                    Ui::MainWindow1 *ui;
                    class MainWindow2 *mMyNewWindow;

                    private slots:

                    };

                    #endif // MAINWINDOW1_H@

                    MainWindow2.h
                    @#ifndef MAINWINDOW2_H
                    #define MAINWINDOW2_H
                    #include <QWidget>
                    #include<mainwindow1.h>
                    #include <QPushButton>
                    namespace Ui {
                    class MainWindow2;
                    }

                    class MainWindow2 : public QWidget
                    {
                    Q_OBJECT

                    public:
                    explicit MainWindow2(QWidget *parent = 0);
                    ~MainWindow2();

                    public slots:
                    void openOldWindow();
                    void on_Done_clicked();
                    int GetNumber();

                    private:
                    Ui::MainWindow2 *ui;
                    class MainWindow1 *mMyOldWindow;

                    private slots:

                    };

                    #endif // MAINWINDOW2_H@

                    MainWindow1.cpp
                    @#include "mainwindow1.h"
                    #include "ui_mainwindow1.h"
                    #include "mainwindow2.h"
                    #include <QWidget>
                    #include <QPushButton>

                    MainWindow1::MainWindow1(QWidget *parent) :
                    QWidget(parent),
                    ui(new Ui::MainWindow1)
                    {
                    ui->setupUi(this);
                    QObject::connect(ui->Record, SIGNAL( clicked() ), this, SLOT(on_Record_clicked()));
                    QObject::connect(ui->Count, SIGNAL( clicked() ), this, SLOT(on_Count_clicked()));
                    }

                    MainWindow1::~MainWindow1()
                    {
                    delete ui;
                    }

                    void MainWindow1::openNewWindow()
                    {
                    mMyNewWindow = new MainWindow2();
                    mMyNewWindow->show();

                    }

                    void MainWindow1::on_Record_clicked()
                    {
                    openNewWindow();
                    }

                    void MainWindow1::Proccess(int a)
                    {
                    ui->Test->setNum(a);
                    }

                    void MainWindow1::on_Count_clicked()
                    {
                    int number;
                    MainWindow2 key2;
                    key2.on_Done_clicked();
                    }@

                    MainWindow2.cpp
                    @#include "mainwindow2.h"
                    #include "ui_mainwindow2.h"
                    #include <QWidget>
                    #include <QPushButton>
                    #include <QString>
                    MainWindow2::MainWindow2(QWidget *parent) :

                    QWidget(parent),
                    ui(new Ui::MainWindow2)
                    

                    {
                    int p;
                    ui->setupUi(this);
                    p = GetNumber();
                    MainWindow1 key;
                    key.Proccess(p);

                    QObject::connect(ui->Done, SIGNAL( clicked() ), this, SLOT(on_Done_clicked()));
                    

                    }

                    MainWindow2::~MainWindow2()
                    {
                    delete ui;
                    }

                    int MainWindow2::GetNumber()
                    {
                    QString mystring1(ui->Score1->text());
                    int c = mystring1.toInt();

                    ui->label->setNum(c);
                    
                    return c;
                    

                    }

                    void MainWindow2::on_Done_clicked()
                    {
                    int k;
                    k = GetNumber();
                    MainWindow1 key1;
                    key1.Proccess(k);
                    openOldWindow();
                    }

                    void MainWindow2::openOldWindow()
                    {
                    mMyOldWindow = new MainWindow1();
                    mMyOldWindow->show();
                    }@

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                    • SGaistS Offline
                      SGaistS Offline
                      SGaist
                      Lifetime Qt Champion
                      wrote on last edited by
                      #20

                      Hi,

                      It seems that you are creating new widgets every time you click on a button. May I suggest to simplify things a bit ? It seems that what you want to do with MainWindow2 already exists as "QInputDialog":http://qt-project.org/doc/qt-4.8/qinputdialog.html

                      I would also suggest to have a look at the examples from the Qt documentation to better understand how widget interaction may be achieved.

                      Hope it helps

                      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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                      • V Offline
                        V Offline
                        VPellas
                        wrote on last edited by
                        #21

                        I saw the QInputDialog , I read the whole forum, but I can't understand how I can connect this with my program.

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                        • SGaistS Offline
                          SGaistS Offline
                          SGaist
                          Lifetime Qt Champion
                          wrote on last edited by
                          #22

                          Read the "example":http://qt-project.org/doc/qt-4.8/dialogs-standarddialogs.html

                          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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                          • V Offline
                            V Offline
                            VPellas
                            wrote on last edited by
                            #23

                            Hmmm. It's interesting. But, is it possible to do it with Widgets? As you can understand this is just the "problem" i have in my main Program. In there when i Press the Recount Button a New Window(main Class QWidget) pops up in which the user enter the values from a Calculator-type keyboard I created...

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                            • SGaistS Offline
                              SGaistS Offline
                              SGaist
                              Lifetime Qt Champion
                              wrote on last edited by
                              #24

                              Sure it is, apply the same techniques used by QInputDialog.

                              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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                              • V Offline
                                V Offline
                                VPellas
                                wrote on last edited by
                                #25

                                After reading tons of posts, questions, answers, i realized that what i need to do is to make my own "QInputDialog::getInteger()" . I read the example you gave me , I Isolated the part that i am interested in, which is to take Int from the pop up dialog that shows up, but i also realized that this is a Standar procedure in Qt Libraries and i cannot change the Widgets used in it. So is there a way to make MainWindow2 on my code to be my own "QInputDialog::getInteger()" - style Dialog?

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                                • SGaistS Offline
                                  SGaistS Offline
                                  SGaist
                                  Lifetime Qt Champion
                                  wrote on last edited by
                                  #26

                                  Read the source from QInputDialog, you'll see the pattern used and you can then replicate it for your purpose.

                                  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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                                  • V Offline
                                    V Offline
                                    VPellas
                                    wrote on last edited by
                                    #27

                                    Ok problem solved

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                                    • K Offline
                                      K Offline
                                      koleygr
                                      wrote on last edited by
                                      #28

                                      For them who want to know how the problem solved:

                                      The easier way to take something of your dialog back to your mainwindow is to
                                      define an external variable at the "top" of your mainwindow.cpp (for example @extern int c@)
                                      and then just to pass it to your dialog (just @int c@ at the top of your dialog cpp).
                                      For more details search for external variables.

                                      I know that we should avoid external declarations, but this way the life of a
                                      non-profesional programmer... is realy much easier....

                                      This method, interrupts and the problem of arguments in SLOTS...
                                      you don't realy need them.

                                      Using:Qt Creator 2.4.1 under UBUNTU

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                                      • K Offline
                                        K Offline
                                        koleygr
                                        wrote on last edited by
                                        #29

                                        Another way, is to use a public (non void) function in your dialog
                                        and to call this function (after executing the dialog) fron your main window.

                                        P.S.: If someone need the code,
                                        just ask me to post it.

                                        Using:Qt Creator 2.4.1 under UBUNTU

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