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Using custom QWidgets in QListWidgets

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  • SGaistS Offline
    SGaistS Offline
    SGaist
    Lifetime Qt Champion
    wrote on last edited by
    #8

    Then this looks bad. You should decouple the data from their graphic representation aka MVC.

    Since you are already using Qt's related class. You should consider implementing a QAbstractListModel that will wrap your list of BioBloomUnit and use a QListView to show them.

    By the way, what is ribbonAddress for a widget ?

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    Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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    • H Offline
      H Offline
      Hubbard
      wrote on last edited by
      #9

      ribbonAddress is a pointer to a UnitRibbon class and is a member in BioBloomUnit, its a widget with its own UI file, BioBloomUnit is NOT a widget and is a normal QObject class, I was to display all of the UnitRibbons for each unit in a list.

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      • SGaistS Offline
        SGaistS Offline
        SGaist
        Lifetime Qt Champion
        wrote on last edited by
        #10

        That I understood, hence my suggestion for a separation of concerns. BioBloomUnit should not care about the GUI that should show the data it represents.

        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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        • H Offline
          H Offline
          Hubbard
          wrote on last edited by
          #11

          Would it be better if the UnitRibbons exist in the mainWindow and instead take BioBloomUnit as an argument (either by constructor or member method) to get their data?

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          • H Offline
            H Offline
            Hubbard
            wrote on last edited by
            #12

            so I updated my code to the following

            UnitRibbon* exampleRibbonAddress = new UnitRibbon;
            QListWidgetItem* exampleItemAddress = new QListWidgetItem(ui->UnitList);
            //exampleItemAddress->setSizeHint(exampleRibbonAddress->sizeHint());
            ui->UnitList->setItemWidget(exampleItemAddress, exampleRibbonAddress);
            ui->UnitList->addItem(exampleItemAddress);
            

            Now it only shows the top half of the widget, when the sizeHint is uncommented it becomes invisible entirely

            mrjjM 1 Reply Last reply
            0
            • H Hubbard

              so I updated my code to the following

              UnitRibbon* exampleRibbonAddress = new UnitRibbon;
              QListWidgetItem* exampleItemAddress = new QListWidgetItem(ui->UnitList);
              //exampleItemAddress->setSizeHint(exampleRibbonAddress->sizeHint());
              ui->UnitList->setItemWidget(exampleItemAddress, exampleRibbonAddress);
              ui->UnitList->addItem(exampleItemAddress);
              

              Now it only shows the top half of the widget, when the sizeHint is uncommented it becomes invisible entirely

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

              @Hubbard
              Hi
              Setting size hint is good idea.
              It will use that for widget size when placed on "row"

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              • SGaistS Offline
                SGaistS Offline
                SGaist
                Lifetime Qt Champion
                wrote on last edited by
                #14

                Might be a silly question but are you sure your properly set the layouts on your widgets ? Having to call sizeHint like that is surprising.

                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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                • H Offline
                  H Offline
                  Hubbard
                  wrote on last edited by
                  #15

                  I have removed the graphical widget from my class and made it a separate class and now it is displaying, I'm surprised it works like that, however I've run into a different yet related issue:-

                  exampleUnitAddress = new BioBloomUnit(this);        //instance example
                  
                  setupOtherWindows();
                  setupPushButtons();
                  
                  UnitRibbon* exampleRibbonAddress = new UnitRibbon;
                  QListWidgetItem* exampleItemAddress = new QListWidgetItem(ui->UnitList);
                  exampleItemAddress->setSizeHint(exampleRibbonAddress->size());
                  ui->UnitList->setItemWidget(exampleItemAddress, exampleRibbonAddress);
                  ui->UnitList->addItem(exampleItemAddress);
                  
                  //UnitRibbonPressSlot() calls BioBloomUnit::UnitWindow->show()
                  
                  connect(ui->ExampleButton, SIGNAL(released()), exampleUnitAddress, SLOT(unitRibbonPressSlot()));
                  
                  connect(ui->UnitList, SIGNAL(itemClicked(exampleItemAddress)), exampleUnitAddress, SLOT(unitRibbonPressSlot()) );
                  

                  ExampleButton (a QPushButton on the ui) successfully opens the unit's window, however pressing on the Ribbon for the example Unit does not.

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                  • mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #16

                    Hi
                    When using the old SLOT and SIGNAl macros, you should always
                    check the return value of connect.
                    Also you seem to mix signatures/odd syntax
                    connect(ui->UnitList, SIGNAL(itemClicked(exampleItemAddress)), exampleUnitAddress, SLOT(unitRibbonPressSlot()) );
                    What is exampleItemAddress ?
                    and unitRibbonPressSlot should also accept such paramter
                    Are you sure that UnitLists signal itemClicked have that signature ?

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                    • H Offline
                      H Offline
                      Hubbard
                      wrote on last edited by
                      #17

                      void itemClicked(QListWidgetItem *item)

                      can you explain your response more please?

                      It takes in the item instanced above (and shown in the list) and has no return

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                      • H Offline
                        H Offline
                        Hubbard
                        wrote on last edited by
                        #18

                        What do you mean by the 'old' signal and slot macros?

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                        0
                        • H Offline
                          H Offline
                          Hubbard
                          wrote on last edited by
                          #19

                          Ah I see, the signals are only allowed to be passed parameter types, not names, so how do I link the specific item clicked on to it's specific unit's window?

                          mrjjM 1 Reply Last reply
                          0
                          • H Hubbard

                            Ah I see, the signals are only allowed to be passed parameter types, not names, so how do I link the specific item clicked on to it's specific unit's window?

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

                            @Hubbard
                            Hi
                            Yes for connect, you only list the type and not the parameter name.

                            The actual parameter is added by the widget that emit the signal.
                            ( in this case when you click something)

                            Normally, the SLOT should accept the same paramter(s)

                            by old i mean
                            https://wiki.qt.io/New_Signal_Slot_Syntax
                            Its possible to use other syntax that fails at compile time.
                            The price is a ugly syntax if there are overloaded signals ( one send index, other send string as example)

                            H 1 Reply Last reply
                            1
                            • mrjjM mrjj

                              @Hubbard
                              Hi
                              Yes for connect, you only list the type and not the parameter name.

                              The actual parameter is added by the widget that emit the signal.
                              ( in this case when you click something)

                              Normally, the SLOT should accept the same paramter(s)

                              by old i mean
                              https://wiki.qt.io/New_Signal_Slot_Syntax
                              Its possible to use other syntax that fails at compile time.
                              The price is a ugly syntax if there are overloaded signals ( one send index, other send string as example)

                              H Offline
                              H Offline
                              Hubbard
                              wrote on last edited by
                              #21

                              @mrjj
                              Could you explain what you meant about the actual parameter is passed by the item that's emits the signal please

                              How could I use this to open a different window for a different item?

                              jsulmJ 1 Reply Last reply
                              0
                              • H Hubbard

                                @mrjj
                                Could you explain what you meant about the actual parameter is passed by the item that's emits the signal please

                                How could I use this to open a different window for a different item?

                                jsulmJ Offline
                                jsulmJ Offline
                                jsulm
                                Lifetime Qt Champion
                                wrote on last edited by jsulm
                                #22

                                @Hubbard Please read http://doc.qt.io/qt-5/signalsandslots.html
                                Parameters are not passed at the time you connect a slot to a signal (how would it be possible?), but at the time the signal is emitted. So, the object emitting the signal passes the parameter.
                                For example lets say you have a class with void someSignal(int someParameter) signal, then an instance of this class would emit the signal like this:

                                emit someSignal(10);
                                

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

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