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Insert fill circle into cell of QTableWidget

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  • J juaniyoalm

    There are too many classes to just paint a circle in a cell. There is no other way?

    mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by mrjj
    #6

    @juaniyoalm
    Well you can also add the circle as an icon to the cell.
    If you add blank text, the effect is similar.

    alt text

    However, how big do u need the circle to be ?
    It cannot be bigger than the cell height in any case.

    Update: this was just to answer if there was alternatives.
    However, a delegate is far better for it.

    1 Reply Last reply
    0
    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #7

      You need one class: the delegate.

      In this example they have two if you take the custom editor that you likely don't need.

      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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      2
      • mrjjM Offline
        mrjjM Offline
        mrjj
        Lifetime Qt Champion
        wrote on last edited by mrjj
        #8

        Hi
        Adding to SGaist . Its not as bad as it looks.
        For a paint circle only delegate, you need very little code.

        #include <QStyledItemDelegate>
        #include <QPainter>
        
        class CircleDelegate: public QStyledItemDelegate {
         protected:
          void paint(QPainter* painter, const QStyleOptionViewItem& opt, const QModelIndex& index) const {
        
            // set brush to green if selected else blue ( not needed just for fun)
            if (opt.state & QStyle::State_Selected) {
              painter->setBrush(Qt::green);
            } else {
              painter->setBrush(Qt::blue);
            }
        
            // paint a circle
            int CircleSize=10;
            painter->drawEllipse(opt.rect.center(), CircleSize, CircleSize);
          }
        };
        

        and you set it to the table by
        ui->tableWidget->setItemDelegateForColumn(1, new CircleDelegate());
        the 1 is the col where u want it

        alt text

        You will need to read over
        http://doc.qt.io/qt-5/model-view-programming.html
        mostly section Item roles
        as to make circle dynamic in size, you can use
        a Qt::UserRole and setData.
        so the size comes from the model.

        1 Reply Last reply
        5
        • VRoninV Offline
          VRoninV Offline
          VRonin
          wrote on last edited by
          #9

          Just a couple of small addition to @mrjj 's code:

          • you'll probably also need to reimplement sizeHint() to return a size appropriate to contain the circle.
          • blindly modifying the painter argument is risky. You should call painter->save(); before setting the brush and painter->restore(); after you finished the painting

          "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
          ~Napoleon Bonaparte

          On a crusade to banish setIndexWidget() from the holy land of Qt

          1 Reply Last reply
          2
          • J Offline
            J Offline
            juaniyoalm
            wrote on last edited by
            #10

            Thank you, the solution is good for me!!! but I would like that the background of cells is fill too. This colour have to change too.
            I thought about inserting a rectangle but I would need the circle to be located on top...

            mrjjM 1 Reply Last reply
            0
            • J juaniyoalm

              Thank you, the solution is good for me!!! but I would like that the background of cells is fill too. This colour have to change too.
              I thought about inserting a rectangle but I would need the circle to be located on top...

              mrjjM Offline
              mrjjM Offline
              mrjj
              Lifetime Qt Champion
              wrote on last edited by
              #11

              @juaniyoalm
              Hi
              Just use other paint methods like
              painter->drawRect(opt.rect);

              J 1 Reply Last reply
              1
              • mrjjM mrjj

                @juaniyoalm
                Hi
                Just use other paint methods like
                painter->drawRect(opt.rect);

                J Offline
                J Offline
                juaniyoalm
                wrote on last edited by
                #12

                @mrjj Thank you so much!!

                Okay, I have that solved.

                Another question is that the size of each circle depends on a value that my mushroom class has. In my class I created a paint method but I do not know how to link that method with the delegate or what is the way to write the method.

                mrjjM 1 Reply Last reply
                0
                • J juaniyoalm

                  @mrjj Thank you so much!!

                  Okay, I have that solved.

                  Another question is that the size of each circle depends on a value that my mushroom class has. In my class I created a paint method but I do not know how to link that method with the delegate or what is the way to write the method.

                  mrjjM Offline
                  mrjjM Offline
                  mrjj
                  Lifetime Qt Champion
                  wrote on last edited by
                  #13

                  @juaniyoalm
                  Hi, is the value in the model ?
                  The delegate can use values from model.
                  so the color and size of circle could come from model.

                  J 1 Reply Last reply
                  1
                  • mrjjM mrjj

                    @juaniyoalm
                    Hi, is the value in the model ?
                    The delegate can use values from model.
                    so the color and size of circle could come from model.

                    J Offline
                    J Offline
                    juaniyoalm
                    wrote on last edited by
                    #14

                    @mrjj

                    No, that value is in a c++class. I have to create a custom model... It's ok?? Or I can use a default model??

                    mrjjM 1 Reply Last reply
                    0
                    • J juaniyoalm

                      @mrjj

                      No, that value is in a c++class. I have to create a custom model... It's ok?? Or I can use a default model??

                      mrjjM Offline
                      mrjjM Offline
                      mrjj
                      Lifetime Qt Champion
                      wrote on last edited by
                      #15

                      @juaniyoalm
                      You can use http://doc.qt.io/qt-5/qstandarditemmodel.html
                      if it is. dont have to be custom.
                      I though you already had a model ?
                      Also is this with a QTableWidget ?
                      (it uses a model already )

                      J 1 Reply Last reply
                      1
                      • mrjjM mrjj

                        @juaniyoalm
                        You can use http://doc.qt.io/qt-5/qstandarditemmodel.html
                        if it is. dont have to be custom.
                        I though you already had a model ?
                        Also is this with a QTableWidget ?
                        (it uses a model already )

                        J Offline
                        J Offline
                        juaniyoalm
                        wrote on last edited by
                        #16

                        @mrjj

                        No, I use QTableView.

                        I used a model to try but I don't know how to implement it

                        mrjjM 1 Reply Last reply
                        0
                        • J juaniyoalm

                          @mrjj

                          No, I use QTableView.

                          I used a model to try but I don't know how to implement it

                          mrjjM Offline
                          mrjjM Offline
                          mrjj
                          Lifetime Qt Champion
                          wrote on last edited by
                          #17

                          @juaniyoalm
                          Super. With view its much easier.
                          so you have to construct a model with the data
                          that comes from the class.
                          Did you make a qstandarditemmodel before ?

                          J 1 Reply Last reply
                          1
                          • mrjjM mrjj

                            @juaniyoalm
                            Super. With view its much easier.
                            so you have to construct a model with the data
                            that comes from the class.
                            Did you make a qstandarditemmodel before ?

                            J Offline
                            J Offline
                            juaniyoalm
                            wrote on last edited by
                            #18

                            @mrjj
                            Yes, I did but without data class

                            1 Reply Last reply
                            0
                            • J Offline
                              J Offline
                              juaniyoalm
                              wrote on last edited by
                              #19

                              @mrjj
                              Do you show me how to make??

                              mrjjM 1 Reply Last reply
                              0
                              • J juaniyoalm

                                @mrjj
                                Do you show me how to make??

                                mrjjM Offline
                                mrjjM Offline
                                mrjj
                                Lifetime Qt Champion
                                wrote on last edited by
                                #20

                                @juaniyoalm
                                Hi
                                Please read about userRoles and setData

                                http://doc.qt.io/qt-5/model-view-programming.html
                                section Item roles

                                you can simply put the color / size in user role, or you can have
                                it directly as an item in your model.
                                Both ways are fine.
                                Then delegate read the user role and use the data.

                                1 Reply Last reply
                                4
                                • J Offline
                                  J Offline
                                  juaniyoalm
                                  wrote on last edited by juaniyoalm
                                  #21

                                  I read it and I have tried it but my problem is that size circle depends that value of class and colour of background another value of class. I don't know how do it...

                                  mrjjM 1 Reply Last reply
                                  0
                                  • J juaniyoalm

                                    I read it and I have tried it but my problem is that size circle depends that value of class and colour of background another value of class. I don't know how do it...

                                    mrjjM Offline
                                    mrjjM Offline
                                    mrjj
                                    Lifetime Qt Champion
                                    wrote on last edited by
                                    #22

                                    @juaniyoalm
                                    Hi
                                    Well the delegate cannot go read into other external classes.
                                    So you have to at some point take the values from the classes and
                                    put into the model.
                                    How often does those values change in the classes ?

                                    J 1 Reply Last reply
                                    1
                                    • mrjjM mrjj

                                      @juaniyoalm
                                      Hi
                                      Well the delegate cannot go read into other external classes.
                                      So you have to at some point take the values from the classes and
                                      put into the model.
                                      How often does those values change in the classes ?

                                      J Offline
                                      J Offline
                                      juaniyoalm
                                      wrote on last edited by
                                      #23

                                      @mrjj

                                      The parameters will change very often. There will be hundreds of instances of the class and the values ​​will change.

                                      1 Reply Last reply
                                      0
                                      • SGaistS Offline
                                        SGaistS Offline
                                        SGaist
                                        Lifetime Qt Champion
                                        wrote on last edited by
                                        #24

                                        The problem is not in the number of instances but rather how you access them.

                                        How are you currently handling these differed classes ?

                                        Interested in AI ? www.idiap.ch
                                        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                        1 Reply Last reply
                                        1
                                        • J Offline
                                          J Offline
                                          juaniyoalm
                                          wrote on last edited by
                                          #25

                                          @mrjj @SGaist Hi!!

                                          The program will be a simulation of the habitat of fungus and fungivores. I have a world class, which contains a matrix (world), and an array of fungivores. The matrix is composed of cell. The cell class contains an array of fungivores (fungivores that are in that cell) and an int that represents the amount of fungus there is. In the course of the execution the value of fungus and the number of fungivores that there will be in each cell will change. That's what I have to represent in the UI. The amount of fungus will represent it by painting the green cells, with an intensity between 0 and 255, depending on the value, and the amount of fungivors will represent it with a circle, the size of the circle will depend on the value. Once I have this sequential version, I will have to make a parallel version.

                                          JonBJ 1 Reply Last reply
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