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Syntax for Vector of QPushbuttons added to FlowLayout

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  • Swati777999S Swati777999

    @JKSH said in Syntax for Vector of QPushbuttons added to FlowLayout:

    1. Where does QScrollArea fit in your widget hierarchy? (Remember that QScrollArea is a widget)
    flowLayout ->addWidget(scrollArea); flowLayout is the child Layout.

    2. Why do you call childWidget->setLayout(flowLayout); multiple times?
    It's by mistake I wrote it. childWidget is the widget for flowLayout. Refer the following code.

        {   int n=20;
        QWidget *parentWidget =new QWidget(this);
        QGridLayout *parentLayout =new QGridLayout(parentWidget);
        parentWidget->setLayout(parentLayout);
    
        FlowLayout *flowLayout = new FlowLayout();
        parentLayout->addLayout(flowLayout,1,0);  //Adding child layout to parentlayout
    
    
        QWidget *childWidget = new QWidget(); //Child Widget for flowLayout
        parentLayout->addWidget(childWidget); //Adding childWidget to parent layout
    
    
        QVector <QPushButton *> buttons(n);
        QScrollArea *scrollArea = new QScrollArea(parentWidget);
        flowLayout ->addWidget(scrollArea);
    
    
        for (int ii=0;ii<n;ii++)
        {
            QPushButton * pb = new QPushButton(); // creating buttons
               pb->setMinimumSize(200,200);
               buttons.push_back(pb); // adding buttons to qvector
               flowLayout->addWidget(pb);
         }
    
        childWidget->setLayout(flowLayout);  //setting Layout for the childWidget
    
        scrollArea->setWidget(childWidget);
        scrollArea->widget()->setEnabled(true);
      
      this->show();
    }
    

    I get the following result after making the change. I don't know what the first box is.

    flowLayout_scroll_pushbuttons_15.12.PNG

    JKSHJ Offline
    JKSHJ Offline
    JKSH
    Moderators
    wrote on last edited by
    #16

    @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

    1. Where does QScrollArea fit in your widget hierarchy? (Remember that QScrollArea is a widget)
    flowLayout ->addWidget(scrollArea); flowLayout is the child Layout.

    Your code puts things in this order:

    1. scrollArea inside flowLayout
    2. flowLayout inside childWidget
    3. childWidget inside scrollArea

    So which of these objects is meant to be the one "outside"?

    I suggest you update your diagram and include QScrollArea in the diagram.

    Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

    Swati777999S 1 Reply Last reply
    1
    • JKSHJ JKSH

      @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

      1. Where does QScrollArea fit in your widget hierarchy? (Remember that QScrollArea is a widget)
      flowLayout ->addWidget(scrollArea); flowLayout is the child Layout.

      Your code puts things in this order:

      1. scrollArea inside flowLayout
      2. flowLayout inside childWidget
      3. childWidget inside scrollArea

      So which of these objects is meant to be the one "outside"?

      I suggest you update your diagram and include QScrollArea in the diagram.

      Swati777999S Offline
      Swati777999S Offline
      Swati777999
      wrote on last edited by
      #17

      @JKSH said in Syntax for Vector of QPushbuttons added to FlowLayout:

      So which of these objects is meant to be the one "outside"?
      I suggest you update your diagram and include QScrollArea in the diagram.

      Here's the updated diagram for scrollArea, notice that the scrollArea Widget is in pink color.
      FlowLayoutDiag_scroll.PNG

      “ In order to be irreplaceable, one must always be different” – Coco Chanel

      JKSHJ 1 Reply Last reply
      0
      • Swati777999S Swati777999

        @JKSH said in Syntax for Vector of QPushbuttons added to FlowLayout:

        So which of these objects is meant to be the one "outside"?
        I suggest you update your diagram and include QScrollArea in the diagram.

        Here's the updated diagram for scrollArea, notice that the scrollArea Widget is in pink color.
        FlowLayoutDiag_scroll.PNG

        JKSHJ Offline
        JKSHJ Offline
        JKSH
        Moderators
        wrote on last edited by
        #18

        @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

        Here's the updated diagram for scrollArea, notice that the scrollArea Widget is in pink color.

        • According to your diagram, scrollArea is inside childWidget
        • According to your code, childWidget is inside scrollArea.

        Which one is correct?

        Notes:

        • I said this before: QScrollArea is a QWidget. You can't put a QScrollArea between your FlowLayout and your buttons.
        • In case it's not obvious: QPushButton is also a QWidget.
        • Your design is extremely complicated. I suggest you reduce the number of widgets and layouts.

        Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

        Swati777999S 1 Reply Last reply
        2
        • JKSHJ JKSH

          @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

          Here's the updated diagram for scrollArea, notice that the scrollArea Widget is in pink color.

          • According to your diagram, scrollArea is inside childWidget
          • According to your code, childWidget is inside scrollArea.

          Which one is correct?

          Notes:

          • I said this before: QScrollArea is a QWidget. You can't put a QScrollArea between your FlowLayout and your buttons.
          • In case it's not obvious: QPushButton is also a QWidget.
          • Your design is extremely complicated. I suggest you reduce the number of widgets and layouts.
          Swati777999S Offline
          Swati777999S Offline
          Swati777999
          wrote on last edited by
          #19

          @JKSH

          I want to set the scrolling functionality for the array of pushbuttons. That's the reason why I put scrollArea inside the flowLayout.

          “ In order to be irreplaceable, one must always be different” – Coco Chanel

          Pl45m4P JKSHJ 2 Replies Last reply
          0
          • Swati777999S Swati777999

            @JKSH

            I want to set the scrolling functionality for the array of pushbuttons. That's the reason why I put scrollArea inside the flowLayout.

            Pl45m4P Offline
            Pl45m4P Offline
            Pl45m4
            wrote on last edited by
            #20

            @Swati777999

            And where do you want to have your flowLayout?
            Your design is really confusing.

            How about putting a widget with a flowLayout containing your buttons in your ScrollArea?!
            Still don't know if that is what you are trying to achieve.
            From you figure, it looks like you have a least 1 or 2 (parent) widgets and layouts more than necessarily needed.


            If debugging is the process of removing software bugs, then programming must be the process of putting them in.

            ~E. W. Dijkstra

            Swati777999S 1 Reply Last reply
            1
            • Swati777999S Swati777999

              @JKSH

              I want to set the scrolling functionality for the array of pushbuttons. That's the reason why I put scrollArea inside the flowLayout.

              JKSHJ Offline
              JKSHJ Offline
              JKSH
              Moderators
              wrote on last edited by JKSH
              #21

              @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

              I want to set the scrolling functionality for the array of pushbuttons. That's the reason why I put scrollArea inside the flowLayout.

              Then you should:

              1. Put the flowLayout in a container/child widget
              2. Put that container/child widget in the scrollArea

              But before that, simplify your design and remove the widgets and layouts that you don't need. Both myself and @Pl45m4 have asked you to do this. Please don't ignore our words.

              Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

              Swati777999S 1 Reply Last reply
              4
              • Pl45m4P Pl45m4

                @Swati777999

                And where do you want to have your flowLayout?
                Your design is really confusing.

                How about putting a widget with a flowLayout containing your buttons in your ScrollArea?!
                Still don't know if that is what you are trying to achieve.
                From you figure, it looks like you have a least 1 or 2 (parent) widgets and layouts more than necessarily needed.

                Swati777999S Offline
                Swati777999S Offline
                Swati777999
                wrote on last edited by Swati777999
                #22

                @Pl45m4 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                How about putting a widget with a flowLayout containing your buttons in your ScrollArea?!

                I don't know if my layout design is the correct one. I should be able to navigate to the buttons at the bottom from the top buttons by scrolling. This is my objective. How can it be achieved?

                “ In order to be irreplaceable, one must always be different” – Coco Chanel

                1 Reply Last reply
                0
                • JKSHJ JKSH

                  @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                  I want to set the scrolling functionality for the array of pushbuttons. That's the reason why I put scrollArea inside the flowLayout.

                  Then you should:

                  1. Put the flowLayout in a container/child widget
                  2. Put that container/child widget in the scrollArea

                  But before that, simplify your design and remove the widgets and layouts that you don't need. Both myself and @Pl45m4 have asked you to do this. Please don't ignore our words.

                  Swati777999S Offline
                  Swati777999S Offline
                  Swati777999
                  wrote on last edited by Swati777999
                  #23

                  @JKSH and @Pl45m4

                  Yes, check the revised code as below:

                  {
                  QWidget *flowWidget = new QWidget(this);
                  FlowLayout *flowLayout = new FlowLayout();
                  flowWidget->setLayout(flowLayout);
                  int n=20;
                  QVector <QPushButton *> buttons(n);
                  
                  for (int ii=0;ii<n;ii++)
                  {
                        QPushButton * pb = new QPushButton(); // creating buttons
                         pb->setMinimumSize(200,200);
                         buttons.push_back(pb); // adding buttons to qvector
                         flowLayout->addWidget(pb);
                  }
                  
                  QScrollArea *scroll =new QScrollArea(this);
                  scroll->setWidget(flowWidget);
                   this->show();
                  }
                  

                  It gives me following output :
                  Program-1-17.12.PNG
                  scrollArea inside another window .

                  If I declare scroll widget as below:
                  QScrollArea *scroll =new QScrollArea();
                  I get a blank window.

                  If I declare scroll widget as follows:
                  QScrollArea *scroll =new QScrollArea(flowWidget);
                  my program crashes.

                  “ In order to be irreplaceable, one must always be different” – Coco Chanel

                  JKSHJ 1 Reply Last reply
                  0
                  • Swati777999S Swati777999

                    @JKSH and @Pl45m4

                    Yes, check the revised code as below:

                    {
                    QWidget *flowWidget = new QWidget(this);
                    FlowLayout *flowLayout = new FlowLayout();
                    flowWidget->setLayout(flowLayout);
                    int n=20;
                    QVector <QPushButton *> buttons(n);
                    
                    for (int ii=0;ii<n;ii++)
                    {
                          QPushButton * pb = new QPushButton(); // creating buttons
                           pb->setMinimumSize(200,200);
                           buttons.push_back(pb); // adding buttons to qvector
                           flowLayout->addWidget(pb);
                    }
                    
                    QScrollArea *scroll =new QScrollArea(this);
                    scroll->setWidget(flowWidget);
                     this->show();
                    }
                    

                    It gives me following output :
                    Program-1-17.12.PNG
                    scrollArea inside another window .

                    If I declare scroll widget as below:
                    QScrollArea *scroll =new QScrollArea();
                    I get a blank window.

                    If I declare scroll widget as follows:
                    QScrollArea *scroll =new QScrollArea(flowWidget);
                    my program crashes.

                    JKSHJ Offline
                    JKSHJ Offline
                    JKSH
                    Moderators
                    wrote on last edited by
                    #24

                    @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                    Yes, check the revised code as below:

                    Good! It is much cleaner now.

                    scrollArea inside another window .

                    That's because your scrollArea is a child widget but you did not put it inside a layout.

                    Questions:

                    1. In your latest code, who is scrollArea's parent?
                    2. Do you need scrollArea to be a child widget? In other words, does scrollArea need a parent?
                    3. How would you make scrollArea a top-level widget?

                    Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

                    Swati777999S 1 Reply Last reply
                    0
                    • JKSHJ JKSH

                      @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                      Yes, check the revised code as below:

                      Good! It is much cleaner now.

                      scrollArea inside another window .

                      That's because your scrollArea is a child widget but you did not put it inside a layout.

                      Questions:

                      1. In your latest code, who is scrollArea's parent?
                      2. Do you need scrollArea to be a child widget? In other words, does scrollArea need a parent?
                      3. How would you make scrollArea a top-level widget?
                      Swati777999S Offline
                      Swati777999S Offline
                      Swati777999
                      wrote on last edited by Swati777999
                      #25

                      @JKSH said in Syntax for Vector of QPushbuttons added to FlowLayout:

                      That's because your scrollArea is a **child widget** but you did not put it inside a **layout.
                      If I write flowLayout ->addWidget(scroll); , my program ends forcefully.

                      Questions:
                      1. In your latest code, who is scrollArea's parent?
                      Ans: the mainwindow (I've set its parent to be this . As mentioned above, if I set it's parent to be flowWidget,my program crashes.

                      2. Do you need scrollArea to be a child widget? In other words, does scrollArea need a parent?
                      Ans : It's like the main window is the parent ; its child is flowWidget whose children are buttons , scroll is to be applied to flowWidget such that scroll functionality works for all the buttons simultaneously.

                      Note : I should be able to navigate to the buttons at the bottom from the top buttons by scrolling. This is my objective.

                      3. How would you make scrollArea a top-level widget?
                      Ans: It was just a part of my experimentation, as it is not working neither for scroll->setWidget(flowWidget) nor for QScrollArea *scroll = new QScrollArea (flowWidget);

                      I hope it makes much sense now/

                      “ In order to be irreplaceable, one must always be different” – Coco Chanel

                      Pl45m4P 1 Reply Last reply
                      0
                      • Swati777999S Swati777999

                        @JKSH said in Syntax for Vector of QPushbuttons added to FlowLayout:

                        That's because your scrollArea is a **child widget** but you did not put it inside a **layout.
                        If I write flowLayout ->addWidget(scroll); , my program ends forcefully.

                        Questions:
                        1. In your latest code, who is scrollArea's parent?
                        Ans: the mainwindow (I've set its parent to be this . As mentioned above, if I set it's parent to be flowWidget,my program crashes.

                        2. Do you need scrollArea to be a child widget? In other words, does scrollArea need a parent?
                        Ans : It's like the main window is the parent ; its child is flowWidget whose children are buttons , scroll is to be applied to flowWidget such that scroll functionality works for all the buttons simultaneously.

                        Note : I should be able to navigate to the buttons at the bottom from the top buttons by scrolling. This is my objective.

                        3. How would you make scrollArea a top-level widget?
                        Ans: It was just a part of my experimentation, as it is not working neither for scroll->setWidget(flowWidget) nor for QScrollArea *scroll = new QScrollArea (flowWidget);

                        I hope it makes much sense now/

                        Pl45m4P Offline
                        Pl45m4P Offline
                        Pl45m4
                        wrote on last edited by Pl45m4
                        #26

                        @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                        I hope it makes much sense now

                        Not really, at least not to me.

                        For what purpose is the FlowWidget now?
                        Can't you just assign the flowLayout to your mainWindow?

                        Note: scrollArea can handle one entire widget (with all of its sub-widgets and layouts). As far as I understood, your buttons are on multiple widgets, am I right?!
                        Don't know how your "scroll from top buttons down to bottom buttons" should work. At least when the entire widget is as big as the parent window.

                        Edit:
                        Quick fix: set your main widget (whatever it might be, maybe scrollArea?!) as centralWidget with setCentralWidget(.....), so the content covers your whole mainWindow.


                        If debugging is the process of removing software bugs, then programming must be the process of putting them in.

                        ~E. W. Dijkstra

                        Swati777999S 1 Reply Last reply
                        1
                        • Pl45m4P Pl45m4

                          @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                          I hope it makes much sense now

                          Not really, at least not to me.

                          For what purpose is the FlowWidget now?
                          Can't you just assign the flowLayout to your mainWindow?

                          Note: scrollArea can handle one entire widget (with all of its sub-widgets and layouts). As far as I understood, your buttons are on multiple widgets, am I right?!
                          Don't know how your "scroll from top buttons down to bottom buttons" should work. At least when the entire widget is as big as the parent window.

                          Edit:
                          Quick fix: set your main widget (whatever it might be, maybe scrollArea?!) as centralWidget with setCentralWidget(.....), so the content covers your whole mainWindow.

                          Swati777999S Offline
                          Swati777999S Offline
                          Swati777999
                          wrote on last edited by Swati777999
                          #27

                          @Pl45m4 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                          For what purpose is the FlowWidget now?

                          Can't you just assign the flowLayout to your mainWindow?
                          Yes, this is what I did at the first place but I followed the suggestion of @JKSH for implementing the scrollArea for all button widgets.

                          Then you should:
                          Put the flowLayout in a container/child widget
                          Put that container/child widget in the scrollArea
                          

                          So, I put the entire flowlayout inside a flowWidget.

                          Note: scrollArea can handle one entire widget (with all of its sub-widgets and layouts). As far as I understood, your buttons are on multiple widgets, am I right?!
                          Yes, my buttons are arrays of widgets. I want to enable scrolling property just the way I use this link of this forum ; to be able to navigate from top to bottom of this page where the contents of my windows are buttons.

                          Don't know how your "scroll from top buttons down to bottom buttons" should work. At least when the entire widgets is as big as the parent window.

                          I want to navigate to the bottom of the mainwindow through the scrollbar where the contents of the mainWindow are buttons , just like the following picture; scrollbar in the bottom and right side. In the figure, there are 20 push buttons but I can only view 12 out of them in my window.

                          flow_Layout_QPushButtons.PNG

                          “ In order to be irreplaceable, one must always be different” – Coco Chanel

                          Pl45m4P 1 Reply Last reply
                          0
                          • Swati777999S Swati777999

                            @Pl45m4 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                            For what purpose is the FlowWidget now?

                            Can't you just assign the flowLayout to your mainWindow?
                            Yes, this is what I did at the first place but I followed the suggestion of @JKSH for implementing the scrollArea for all button widgets.

                            Then you should:
                            Put the flowLayout in a container/child widget
                            Put that container/child widget in the scrollArea
                            

                            So, I put the entire flowlayout inside a flowWidget.

                            Note: scrollArea can handle one entire widget (with all of its sub-widgets and layouts). As far as I understood, your buttons are on multiple widgets, am I right?!
                            Yes, my buttons are arrays of widgets. I want to enable scrolling property just the way I use this link of this forum ; to be able to navigate from top to bottom of this page where the contents of my windows are buttons.

                            Don't know how your "scroll from top buttons down to bottom buttons" should work. At least when the entire widgets is as big as the parent window.

                            I want to navigate to the bottom of the mainwindow through the scrollbar where the contents of the mainWindow are buttons , just like the following picture; scrollbar in the bottom and right side. In the figure, there are 20 push buttons but I can only view 12 out of them in my window.

                            flow_Layout_QPushButtons.PNG

                            Pl45m4P Offline
                            Pl45m4P Offline
                            Pl45m4
                            wrote on last edited by
                            #28

                            @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                            where the contents of the mainWindow are buttons

                            The content (= centralwidget) of your mainWindow should be your scrollArea then. And inside this scrollArea you place the widget with your buttons.


                            If debugging is the process of removing software bugs, then programming must be the process of putting them in.

                            ~E. W. Dijkstra

                            Swati777999S 1 Reply Last reply
                            1
                            • Pl45m4P Pl45m4

                              @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                              where the contents of the mainWindow are buttons

                              The content (= centralwidget) of your mainWindow should be your scrollArea then. And inside this scrollArea you place the widget with your buttons.

                              Swati777999S Offline
                              Swati777999S Offline
                              Swati777999
                              wrote on last edited by Swati777999
                              #29

                              @Pl45m4
                              The content (= centralwidget) of your mainWindow should be your scrollArea then. And inside this scrollArea you place the widget with your buttons.
                              Okay, Let me write the whole function according to your suggestion.

                              Window::Window()
                              {
                              QMainWindow *a= new QMainWindow(this);
                              
                              QWidget *flowWidget = new QWidget();
                              FlowLayout *flowLayout = new FlowLayout();
                              flowWidget->setLayout(flowLayout);
                              int n=20;
                              QVector <QPushButton *> buttons(n);
                              
                              for (int ii=0;ii<n;ii++)
                              {
                                  QPushButton * pb = new QPushButton(); // creating buttons
                              
                                     pb->setMinimumSize(200,200);
                                     buttons.push_back(pb); // adding buttons to qvector
                              
                                     flowLayout->addWidget(pb);
                              
                              }
                              
                              QScrollArea *scroll =new QScrollArea();
                              scroll->setWidget(flowWidget);
                              
                              a->setCentralWidget(scroll);
                              
                              
                              a->show();
                              
                              setWindowTitle(tr("Flow Layout"));
                              }
                              

                              I obviously,get 2 windows from the above code, Window1 corresponding to this by default window which is blank.
                              Window2 is as shown below
                              Program-2-17.12_window2.PNG

                              scroll Area is applied to the window but the flowLayout seems not to be working and the widgets take vertical Layout. Can you help me to fix this?

                              “ In order to be irreplaceable, one must always be different” – Coco Chanel

                              Pl45m4P JKSHJ 2 Replies Last reply
                              0
                              • Swati777999S Swati777999

                                @Pl45m4
                                The content (= centralwidget) of your mainWindow should be your scrollArea then. And inside this scrollArea you place the widget with your buttons.
                                Okay, Let me write the whole function according to your suggestion.

                                Window::Window()
                                {
                                QMainWindow *a= new QMainWindow(this);
                                
                                QWidget *flowWidget = new QWidget();
                                FlowLayout *flowLayout = new FlowLayout();
                                flowWidget->setLayout(flowLayout);
                                int n=20;
                                QVector <QPushButton *> buttons(n);
                                
                                for (int ii=0;ii<n;ii++)
                                {
                                    QPushButton * pb = new QPushButton(); // creating buttons
                                
                                       pb->setMinimumSize(200,200);
                                       buttons.push_back(pb); // adding buttons to qvector
                                
                                       flowLayout->addWidget(pb);
                                
                                }
                                
                                QScrollArea *scroll =new QScrollArea();
                                scroll->setWidget(flowWidget);
                                
                                a->setCentralWidget(scroll);
                                
                                
                                a->show();
                                
                                setWindowTitle(tr("Flow Layout"));
                                }
                                

                                I obviously,get 2 windows from the above code, Window1 corresponding to this by default window which is blank.
                                Window2 is as shown below
                                Program-2-17.12_window2.PNG

                                scroll Area is applied to the window but the flowLayout seems not to be working and the widgets take vertical Layout. Can you help me to fix this?

                                Pl45m4P Offline
                                Pl45m4P Offline
                                Pl45m4
                                wrote on last edited by
                                #30

                                @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                                Window::Window()
                                {
                                QMainWindow *a= new QMainWindow(this);

                                QWidget *flowWidget = new QWidget();
                                FlowLayout *flowLayout = new FlowLayout();
                                flowWidget->setLayout(flowLayout);
                                int n=20;
                                QVector <QPushButton *> buttons(n);

                                for (int ii=0;ii<n;ii++)
                                {
                                QPushButton * pb = new QPushButton(); // creating buttons

                                   pb->setMinimumSize(200,200);
                                   buttons.push_back(pb); // adding buttons to qvector
                                
                                   flowLayout->addWidget(pb);
                                

                                }

                                QScrollArea *scroll =new QScrollArea();
                                scroll->setWidget(flowWidget);

                                a->setCentralWidget(scroll);

                                a->show();

                                That's not what I suggested....

                                The window with the title flowLayout IS your MainWindow, right?! Why you created another one ?

                                I obviously,get 2 windows from the above code, Window1 corresponding to this by default window which is blank.

                                Yes, not very surprising from above code...

                                Window::Window()

                                What is this class? Your first mainWindow? Then you dont need to create another QMainWindow *a= new QMainWindow(this);
                                inside this class. Remove it and call this->setCentralWidget(....) instead (assuming Window is a QMainWindow class).


                                If debugging is the process of removing software bugs, then programming must be the process of putting them in.

                                ~E. W. Dijkstra

                                Swati777999S 2 Replies Last reply
                                2
                                • Swati777999S Swati777999

                                  @Pl45m4
                                  The content (= centralwidget) of your mainWindow should be your scrollArea then. And inside this scrollArea you place the widget with your buttons.
                                  Okay, Let me write the whole function according to your suggestion.

                                  Window::Window()
                                  {
                                  QMainWindow *a= new QMainWindow(this);
                                  
                                  QWidget *flowWidget = new QWidget();
                                  FlowLayout *flowLayout = new FlowLayout();
                                  flowWidget->setLayout(flowLayout);
                                  int n=20;
                                  QVector <QPushButton *> buttons(n);
                                  
                                  for (int ii=0;ii<n;ii++)
                                  {
                                      QPushButton * pb = new QPushButton(); // creating buttons
                                  
                                         pb->setMinimumSize(200,200);
                                         buttons.push_back(pb); // adding buttons to qvector
                                  
                                         flowLayout->addWidget(pb);
                                  
                                  }
                                  
                                  QScrollArea *scroll =new QScrollArea();
                                  scroll->setWidget(flowWidget);
                                  
                                  a->setCentralWidget(scroll);
                                  
                                  
                                  a->show();
                                  
                                  setWindowTitle(tr("Flow Layout"));
                                  }
                                  

                                  I obviously,get 2 windows from the above code, Window1 corresponding to this by default window which is blank.
                                  Window2 is as shown below
                                  Program-2-17.12_window2.PNG

                                  scroll Area is applied to the window but the flowLayout seems not to be working and the widgets take vertical Layout. Can you help me to fix this?

                                  JKSHJ Offline
                                  JKSHJ Offline
                                  JKSH
                                  Moderators
                                  wrote on last edited by JKSH
                                  #31

                                  @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                                  scroll Area is applied to the window but the flowLayout seems not to be working and the widgets take vertical Layout. Can you help me to fix this?

                                  Your flowWidget is too narrow -- that's why the flow layout can't put buttons side-by-side. Give it a larger minimum width.

                                  Remember: The width of the QScrollArea is not the same as the width of the widget it holds

                                  Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

                                  Swati777999S 1 Reply Last reply
                                  1
                                  • Pl45m4P Pl45m4

                                    @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                                    Window::Window()
                                    {
                                    QMainWindow *a= new QMainWindow(this);

                                    QWidget *flowWidget = new QWidget();
                                    FlowLayout *flowLayout = new FlowLayout();
                                    flowWidget->setLayout(flowLayout);
                                    int n=20;
                                    QVector <QPushButton *> buttons(n);

                                    for (int ii=0;ii<n;ii++)
                                    {
                                    QPushButton * pb = new QPushButton(); // creating buttons

                                       pb->setMinimumSize(200,200);
                                       buttons.push_back(pb); // adding buttons to qvector
                                    
                                       flowLayout->addWidget(pb);
                                    

                                    }

                                    QScrollArea *scroll =new QScrollArea();
                                    scroll->setWidget(flowWidget);

                                    a->setCentralWidget(scroll);

                                    a->show();

                                    That's not what I suggested....

                                    The window with the title flowLayout IS your MainWindow, right?! Why you created another one ?

                                    I obviously,get 2 windows from the above code, Window1 corresponding to this by default window which is blank.

                                    Yes, not very surprising from above code...

                                    Window::Window()

                                    What is this class? Your first mainWindow? Then you dont need to create another QMainWindow *a= new QMainWindow(this);
                                    inside this class. Remove it and call this->setCentralWidget(....) instead (assuming Window is a QMainWindow class).

                                    Swati777999S Offline
                                    Swati777999S Offline
                                    Swati777999
                                    wrote on last edited by
                                    #32

                                    @Pl45m4 said in Syntax for Vector of QPushbuttons added to FlowLayout:
                                    Actually, I'm using the example file of flowLayout given in the section of Examples in Qt Creator where class Window used [subclass of QWidget].

                                    The window with the title flowLayout IS your MainWindow, right?! Why you created another one ?
                                    As you can see, there are two windows with names as flowLayout and FlowLayout . My mainwindow should be Flow Layout for which I wrote the following code:
                                    I needed to add scroll functionality to the following code.

                                        #include<QScrollArea>	
                                        Window::Window
                                    {
                                        FlowLayout *flowLayout = new FlowLayout(this);
                                        int n=20;
                                        QVector <QPushButton *> buttons(n);
                                    
                                        for (int ii=0;ii<n;ii++)
                                        {
                                            QPushButton * pb = new QPushButton(this); // creating buttons
                                            
                                               pb->setMinimumSize(200,200);
                                               buttons.push_back(pb); // adding buttons to qvector
                                    
                                               flowLayout->addWidget(pb);
                                          }
                                    this ->show();
                                    }
                                    
                                    

                                    What is this class? Your first mainWindow? Then you dont need to create another QMainWindow *a= new QMainWindow(this);
                                    inside this class. Remove it and call this->setCentralWidget(....) instead (assuming Window is a QMainWindow class).

                                    I used QMainWindow *a= new QMainWindow(this); because it seemed to be working partially.

                                    “ In order to be irreplaceable, one must always be different” – Coco Chanel

                                    1 Reply Last reply
                                    0
                                    • Pl45m4P Pl45m4

                                      @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                                      Window::Window()
                                      {
                                      QMainWindow *a= new QMainWindow(this);

                                      QWidget *flowWidget = new QWidget();
                                      FlowLayout *flowLayout = new FlowLayout();
                                      flowWidget->setLayout(flowLayout);
                                      int n=20;
                                      QVector <QPushButton *> buttons(n);

                                      for (int ii=0;ii<n;ii++)
                                      {
                                      QPushButton * pb = new QPushButton(); // creating buttons

                                         pb->setMinimumSize(200,200);
                                         buttons.push_back(pb); // adding buttons to qvector
                                      
                                         flowLayout->addWidget(pb);
                                      

                                      }

                                      QScrollArea *scroll =new QScrollArea();
                                      scroll->setWidget(flowWidget);

                                      a->setCentralWidget(scroll);

                                      a->show();

                                      That's not what I suggested....

                                      The window with the title flowLayout IS your MainWindow, right?! Why you created another one ?

                                      I obviously,get 2 windows from the above code, Window1 corresponding to this by default window which is blank.

                                      Yes, not very surprising from above code...

                                      Window::Window()

                                      What is this class? Your first mainWindow? Then you dont need to create another QMainWindow *a= new QMainWindow(this);
                                      inside this class. Remove it and call this->setCentralWidget(....) instead (assuming Window is a QMainWindow class).

                                      Swati777999S Offline
                                      Swati777999S Offline
                                      Swati777999
                                      wrote on last edited by
                                      #33

                                      @Pl45m4 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                                      inside this class. Remove it and call this->setCentralWidget(....) instead (assuming Window is a QMainWindow class).

                                      this->setCentralWidget(....) this gives me error as this is an object of Window class which is a subclass of QWidget.
                                      setCentralWidget(.....) can be applied to the object of QMainWindow.

                                      “ In order to be irreplaceable, one must always be different” – Coco Chanel

                                      1 Reply Last reply
                                      0
                                      • JKSHJ JKSH

                                        @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                                        scroll Area is applied to the window but the flowLayout seems not to be working and the widgets take vertical Layout. Can you help me to fix this?

                                        Your flowWidget is too narrow -- that's why the flow layout can't put buttons side-by-side. Give it a larger minimum width.

                                        Remember: The width of the QScrollArea is not the same as the width of the widget it holds

                                        Swati777999S Offline
                                        Swati777999S Offline
                                        Swati777999
                                        wrote on last edited by Swati777999
                                        #34

                                        @JKSH said in Syntax for Vector of QPushbuttons added to FlowLayout:
                                        Your flowWidget is too narrow -- that's why the flow layout can't put buttons side-by-side. Give it a larger minimum width.
                                        Remember: The width of the QScrollArea is not the same as the width of the widget it holds

                                        This works like a charm! Thanks a ton! I was thinking it to be the fault of my design and made it too complicated.

                                        Just a doubt about the number of buttons appearing/row.

                                        Window::Window
                                        {
                                        QMainWindow *a= new QMainWindow(this);
                                        
                                        QWidget *flowWidget = new QWidget();
                                        FlowLayout *flowLayout = new FlowLayout();
                                        flowWidget->setLayout(flowLayout);
                                        flowWidget ->setMinimumSize(1200,1200);
                                        int n=20;
                                        QVector <QPushButton *> buttons(n);
                                        
                                        for (int ii=0;ii<n;ii++)
                                        {
                                            QPushButton * pb = new QPushButton(); // creating buttons
                                        
                                               pb->setMinimumSize(200,200);
                                               buttons.push_back(pb); // adding buttons to qvector
                                        
                                               flowLayout->addWidget(pb);
                                        }
                                        
                                        QScrollArea *scroll =new QScrollArea();
                                        scroll->setWidget(flowWidget);
                                        
                                        a->setCentralWidget(scroll);
                                        a->show();
                                        }
                                        
                                        

                                        This is the result I get in flowLayout window.
                                        Program-1-20.12.PNG

                                        From the figure, I get 5 buttons per row but as per the following lines , shouldn't I be getting 6 buttons/row ( 1200/200=6)

                                        flowWidget ->setMinimumSize(1200,1200); // size of widget
                                        pb->setMinimumSize(200,200); //size of buttons
                                        
                                        

                                        “ In order to be irreplaceable, one must always be different” – Coco Chanel

                                        Christian EhrlicherC 1 Reply Last reply
                                        0
                                        • Swati777999S Swati777999

                                          @JKSH said in Syntax for Vector of QPushbuttons added to FlowLayout:
                                          Your flowWidget is too narrow -- that's why the flow layout can't put buttons side-by-side. Give it a larger minimum width.
                                          Remember: The width of the QScrollArea is not the same as the width of the widget it holds

                                          This works like a charm! Thanks a ton! I was thinking it to be the fault of my design and made it too complicated.

                                          Just a doubt about the number of buttons appearing/row.

                                          Window::Window
                                          {
                                          QMainWindow *a= new QMainWindow(this);
                                          
                                          QWidget *flowWidget = new QWidget();
                                          FlowLayout *flowLayout = new FlowLayout();
                                          flowWidget->setLayout(flowLayout);
                                          flowWidget ->setMinimumSize(1200,1200);
                                          int n=20;
                                          QVector <QPushButton *> buttons(n);
                                          
                                          for (int ii=0;ii<n;ii++)
                                          {
                                              QPushButton * pb = new QPushButton(); // creating buttons
                                          
                                                 pb->setMinimumSize(200,200);
                                                 buttons.push_back(pb); // adding buttons to qvector
                                          
                                                 flowLayout->addWidget(pb);
                                          }
                                          
                                          QScrollArea *scroll =new QScrollArea();
                                          scroll->setWidget(flowWidget);
                                          
                                          a->setCentralWidget(scroll);
                                          a->show();
                                          }
                                          
                                          

                                          This is the result I get in flowLayout window.
                                          Program-1-20.12.PNG

                                          From the figure, I get 5 buttons per row but as per the following lines , shouldn't I be getting 6 buttons/row ( 1200/200=6)

                                          flowWidget ->setMinimumSize(1200,1200); // size of widget
                                          pb->setMinimumSize(200,200); //size of buttons
                                          
                                          
                                          Christian EhrlicherC Online
                                          Christian EhrlicherC Online
                                          Christian Ehrlicher
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #35

                                          @Swati777999 said in Syntax for Vector of QPushbuttons added to FlowLayout:

                                          From the figure, I get 5 buttons per row but as per the following lines , shouldn't I be getting 6 buttons/row ( 1200/200=6)

                                          And you see that the widgets have some margins between them? So why should 6 widgets with 200x each + margins fit into 1200px??

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

                                          Swati777999S 1 Reply Last reply
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