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Set background color to a cell of a tableView

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  • I Offline
    I Offline
    ihtzudismqa
    wrote on last edited by
    #43

    Well,
    I have a SqlRelationalTableModel and one column which holds either 1 or 2, shown is the corresponding name. (From Sqlite Database)

    Like it's descripted in this thread, I have to inherit from QSortFilterProxyModel and override data().

    How do I implement it, that the "real" value behind the cell is going to be evaluated and not the name? Which way could be the best?

    It may sound confused, sorry for that. Can you understand my matter?

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    • A Offline
      A Offline
      andre
      wrote on last edited by
      #44

      I think what you are after, is that you need to convert the model index that you have for the proxy model to the model index that you need for the source model. QSortFilterProxyModel has mapping methods for both ways. You need mapToSource. This allows you to get the model index for the source data model that corresponds to the item that data() is currently called for in your proxy model.

      @
      // in your data reimplementation
      if (role == Qt::BackgroundRole ) {
      sourceIndex = mapToSource(proxyIndex);
      if (sourceIndex.data(Qt::EditRole).toInt() == 1) {
      return QVariant(Qt::blue);
      }
      }
      @

      Or something like that.

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      • I Offline
        I Offline
        ihtzudismqa
        wrote on last edited by
        #45

        I guess proxyIndex is equal to QModelIndex &index?

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        • A Offline
          A Offline
          andre
          wrote on last edited by
          #46

          [quote author="ihtzudismqa" date="1302861095"]I guess proxyIndex is equal to QModelIndex &index?[/quote]

          Yes, sorry.

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          • P Offline
            P Offline
            poporacer
            wrote on last edited by
            #47

            I have been reading to see if I can figure out how to get the table to be highlighted correctly after it is sorted but I have not been able to figure it out. I drew a blank with having four models as suggested but I did find something else that might work....but it isn't. I think I should be able to capture the signal from when the user clicks on the header and emit a signal to reload the table. Here is what I tried but when I debug, the signal does not get called.
            @QHeaderView *horizHeader;
            QSqlRelationalTableModel printModel;
            MyProxyModel
            proxy;

            printModel= new QSqlRelationalTableModel (this);
            printModel-> setTable (mTableName);
            printModel-> setRelation (2, QSqlRelation("name", "id", "LName"));

            printModel->select();
            proxy = new MyProxyModel(this);
            proxy->setSourceModel(printModel);
            ui->printView->setModel(proxy);
            horizHeader= ui->printView->horizontalHeader(); connect(horizHeader, SIGNAL(sortIndicatorChanged (int) ),
            proxy,SIGNAL(dataChanged ( ) ));
            @
            I am pretty sure it is because of the wrong syntax for the dataChanged signal, but I am not sure how to make it work. Will this work? Or am I going down the wrong path? Is the model method better? If so, how do I make it work? I have no clue on how to start.

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            • I Offline
              I Offline
              ihtzudismqa
              wrote on last edited by
              #48

              Hello,
              I implemented the data function, but my tableview stays empty. The Grid is shown, but without any data inside. Here is the code:

              data implementation
              @QVariant proxymodel::data(const QModelIndex &index, int role) const
              {
              QModelIndex sourceIndex;
              if (!index.isValid())
              return QVariant();

              if (role == Qt::BackgroundRole ) {
              sourceIndex = mapToSource(index);
              if (sourceIndex.data(Qt::EditRole).toInt() == 1) {
              return QVariant(Qt::blue);
              }
              }
              return QVariant();
              }@

              the filltable function
              @
              void Window::fillTable()
              {
              model = new QSqlRelationalTableModel( tableView );
              model->setTable("Protokoll");
              proxy = new proxymodel(tableView);

                  model->setRelation(12,QSqlRelation("Status", "ID", "Status"));
                  model->setEditStrategy(QSqlTableModel::OnFieldChange);
                
                  tableView->setItemDelegate(new QSqlRelationalDelegate(tableView));
                  proxy->setSourceModel(model);
              

              tableView->setModel(proxy);
              model->select();
              }
              @
              What is wrong?

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              • Z Offline
                Z Offline
                ZapB
                wrote on last edited by
                #49

                It looks to me as if you have not finished implementing the data() function in your proxy. You check for the role to see if it is the background role and correctly return blue if the data matches your criteria.

                However, you have not handled the case where the data does not match your criteria. You have also not handled any of the cases where the role is not the background role.

                I think it needs to look more like this:

                @
                QVariant proxymodel::data(const QModelIndex &index, int role) const
                {
                QModelIndex sourceIndex;
                if (!index.isValid())
                return QVariant();

                // We only wish to override the background role
                if (role == Qt::BackgroundRole ) {
                    sourceIndex = mapToSource(index);
                    if (sourceIndex.data(Qt::EditRole).toInt() == 1) {
                        return QVariant(Qt::blue);
                    } else {
                        return QSortFilterProxyModel::data( index, role );
                    }
                }
                
                // Let the base class handle all other cases
                return QSortFilterProxyModel::data( index, role );
                

                }
                @

                Nokia Certified Qt Specialist
                Interested in hearing about Qt related work

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                • A Offline
                  A Offline
                  andre
                  wrote on last edited by
                  #50

                  Indeed, which can be further simplified to:

                  @
                  QVariant proxymodel::data(const QModelIndex &index, int role) const
                  {
                  QModelIndex sourceIndex;
                  if (!index.isValid())
                  return QVariant();

                  // We only wish to override the background role
                  if (role == Qt::BackgroundRole ) {
                      sourceIndex = mapToSource(index);
                      if (sourceIndex.data(Qt::EditRole).toInt() == 1) {
                          return QVariant(Qt::blue);
                      } 
                  }
                   
                  // Let the base class handle all other cases
                  return QSortFilterProxyModel::data( index, role );
                  

                  }
                  @

                  :-)

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                  • Z Offline
                    Z Offline
                    ZapB
                    wrote on last edited by
                    #51

                    Yeah - I've not had my second cup of tea yet this morning ;-)

                    Nokia Certified Qt Specialist
                    Interested in hearing about Qt related work

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                    • I Offline
                      I Offline
                      ihtzudismqa
                      wrote on last edited by
                      #52

                      It works now! Thank you!!

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                      • I Offline
                        I Offline
                        ihtzudismqa
                        wrote on last edited by
                        #53

                        Sorry for double post, but I have a few questions remaining. One point is that the ItemDelegate does not work anymore.
                        @tableView->setItemDelegate(new QSqlRelationalDelegate(this));@

                        And last but not least I cant access every cell in my table - It's just not editable?!

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                        • P Offline
                          P Offline
                          poporacer
                          wrote on last edited by
                          #54

                          So any ideas on how to get the proper row highlighted AFTER the table is sorted? I have not had any luck with my attempts.

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