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QItemDelegate with QComboBox and QSpinBox with QTableView control (how to pass signal)

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  • VRoninV Offline
    VRoninV Offline
    VRonin
    wrote on last edited by
    #4

    Just to clarify, you want a mechanism that allows people to just hover over an option in the combobox and that, in turn, will populate the rest of the data in the module to reflect the option under the mouse?

    "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
    0
    • shylockS Offline
      shylockS Offline
      shylock
      wrote on last edited by
      #5

      Yes. using mouse and keyboard's up n down an action. and refresh the retrieval values to their corresponding variable, without any further interruption for only for that row in the TableView main display.
      If you prefer I can attach a cut down version of a project.

      VRoninV 1 Reply Last reply
      0
      • shylockS shylock

        Yes. using mouse and keyboard's up n down an action. and refresh the retrieval values to their corresponding variable, without any further interruption for only for that row in the TableView main display.
        If you prefer I can attach a cut down version of a project.

        VRoninV Offline
        VRoninV Offline
        VRonin
        wrote on last edited by
        #6

        @shylock said in QItemDelegate with QComboBox and QSpinBox with QTableView control (how to pass signal):

        If you prefer I can attach a cut down version of a project.

        That would be really useful

        "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

        shylockS 2 Replies Last reply
        1
        • shylockS Offline
          shylockS Offline
          shylock
          wrote on last edited by
          #7

          [0_1508355091519_dialog.cpp](Uploading 100%)
          0_1508354940322_Invoicelayout.png
          [0_1508355042629_prodiddelegate.h](Uploading 100%) [0_1508355067261_prodiddelegate.cpp](Uploading 100%)

          1 Reply Last reply
          0
          • VRoninV VRonin

            @shylock said in QItemDelegate with QComboBox and QSpinBox with QTableView control (how to pass signal):

            If you prefer I can attach a cut down version of a project.

            That would be really useful

            shylockS Offline
            shylockS Offline
            shylock
            wrote on last edited by
            #8

            @VRonin
            I think the source files not got loaded!

            #ifndef PRODIDDELEGATE_H
            #define PRODIDDELEGATE_H
            
            #include "ak_connection.h"
            #include <QItemDelegate>
            #include <QStyledItemDelegate>
            #include <QComboBox>
            #include <vector>
            #include <string>
            
            class ProdIdDelegate : public QStyledItemDelegate
            {
                Q_OBJECT
            
            public:
                explicit ProdIdDelegate(QObject *parent = nullptr);
            
                QString getProdId () const { return m_proid;}
                QString getDescription () const { return m_description; }
                double getPrice () const { return m_price; }
                void setDescription (const QString &description) {m_description = description; }
                void setProdId(const QString &prodid) { m_proid = prodid; }
                void setPrice (const double &price) { m_price = price; }
            protected:
            
                QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option,
                                      const QModelIndex &index) const;
                void setEditorData(QWidget *editor, const QModelIndex &index) const;
                void setModelData(QWidget *editor, QAbstractItemModel *model,
                                  const QModelIndex &index) const;
                void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option,
                                          const QModelIndex &index) const;
                void paint (QPainter *painter,
                            const QStyleOptionViewItem &option,
                            const QModelIndex &index) const;
                QSize sizeHint (const QStyleOptionViewItem &option,
                                const QModelIndex &index) const;
            private:
                void setValuesToVariable(QString str);
                std::vector<std::string> Items;
                QString m_proid;
                QString m_description;
                double m_price;
                AK_connection *akdb;
            
            private slots:
                void onComboItemChanged(const QString &text);
                void commitAndCloseEditor();
            };
            
            #endif // PRODIDDELEGATE_H
            

            Implementation file

            #include "prodiddelegate.h"
            #include <QComboBox>
            #include <QDebug>
            #include <QStyledItemDelegate>
            #include <QSqlQuery>
            #include <QSqlError>
            
            // #define _TEST_
            
            ProdIdDelegate::ProdIdDelegate(QObject *parent)
                : QStyledItemDelegate (parent)
            {   
                (void) parent;
            #ifdef _TEST_
                m_description = "A Quick Borwn Fox Jump Over Little Lazy Dog.";
                m_price = 87634.90;
            
                Items.push_back("Test0");
                Items.push_back("Test1");
                Items.push_back("Test2");
                Items.push_back("Test3");
                Items.push_back("Test4");
                Items.push_back("Test5");
                Items.push_back("Test6");
                Items.push_back("Test7");
                Items.push_back("Test8");
                Items.push_back("Test9");
            #else
                 akdb = new AK_connection(this);
                 akdb->AK_open(true);
            #endif
            }
            
            QWidget *ProdIdDelegate::createEditor(QWidget *parent,
                                                  const QStyleOptionViewItem &option,
                                                  const QModelIndex &index) const
            {
                QComboBox *prodId = new QComboBox(parent);
            #ifndef _TEST_
                QSqlQuery q;
                q.prepare(QString("SELECT COALESCE(itemid,'') || " \
                                  "COALESCE(description,'') AS ProdId " \
                                  "FROM itemstbl WHERE status='1'"));
            
                if (!q.exec())
                    qDebug () << q.lastError().text();
                while (q.next()) {
                    prodId->addItem(q.value(0).toString());
                }
                q.clear();
            #else
                for (unsigned int i=0; i < Items.size(); i++)
                    prodId->addItem(Items[i].c_str());
            #endif
                (void) option;
                (void) index;
            
                connect(prodId, SIGNAL(currentIndexChanged(QString)), this, SLOT(onComboItemChanged(QString)));
                return prodId;
            }
            void ProdIdDelegate::setEditorData(QWidget *editor,
                                               const QModelIndex &index) const
            {
                QStyledItemDelegate m_siDelegate;
            
                if (QComboBox *cb = qobject_cast <QComboBox *> (editor)) {
                    QString curItem = index.data(Qt::EditRole).toString();
                    int cbIndex = cb->findText(curItem);
                    // Is it valid? then adjust.
                    if (cbIndex >= 0)
                        cb->setCurrentIndex(cbIndex);
                } else {
                    m_siDelegate.setEditorData(editor, index);
                }    
            
            }
            void ProdIdDelegate::setModelData(QWidget *editor,
                                              QAbstractItemModel *model,
                                              const QModelIndex &index) const
            {
                QStyledItemDelegate m_siDelegate;
            
                if (QComboBox *cb = qobject_cast <QComboBox *> (editor)) {
                    // Save current text of combo box to an item.
                    model->setData(index, cb->currentText(), Qt::EditRole);
                } else {
                    m_siDelegate.setModelData(editor, model, index);
                }
            }
            void ProdIdDelegate::updateEditorGeometry(QWidget *editor,
                                                      const QStyleOptionViewItem &option,
                                                      const QModelIndex &index) const
            {
                editor->setGeometry(option.rect);
                (void) index;
            }
            void ProdIdDelegate::paint(QPainter *painter,
                                       const QStyleOptionViewItem &option,
                                       const QModelIndex &index) const
            {
                (void) painter;
                (void) option;
                (void) index;
            }
            QSize ProdIdDelegate::sizeHint(const QStyleOptionViewItem &option,
                                           const QModelIndex &index) const
            {
               return QStyledItemDelegate::sizeHint(option, index);
            }
            
            void ProdIdDelegate::onComboItemChanged(const QString &text)
            {    
                emit commitData(qobject_cast <QWidget *> (sender()));
                setProdId(text.left(5));
                //qDebug () << "SIGNAL OnComboChanged gives string:" << text
                          //<< " File: " << __FILE__;
                setValuesToVariable(text.left(5));
            }
            
            void ProdIdDelegate::setValuesToVariable(QString str)
            {
            #ifdef _TEST_
                (void) str;
                setDescription(m_description);
                setPrice(m_price);
            #else
                QSqlQuery q; q.prepare(QString("SELECT description,price FROM itemstbl "
                                               "WHERE itemid ='%1'AND status='1'").arg(str));
                if (!q.exec())
                    qDebug () << q.lastError().text();
            
                while (q.next()) {
                    setDescription(q.value(0).toString());
                    setPrice(q.value(1).toDouble());
                }
            #endif
                qDebug () << "Description:" << getDescription() << "Price:" << getPrice();
            }
            
            void ProdIdDelegate::commitAndCloseEditor()  // This signal yet to fired up.
            {
                QWidget *editor = qobject_cast <QWidget *> (sender());
                emit commitData(editor);
                emit closeEditor(editor);
            }
            

            Main dialog.cpp

            #include "dialog.h"
            #include "ui_dialog.h"
            #include "prodiddelegate.h"
            #include "vatdelegate.h"
            #include "qtyspin.h"
            #include <QStandardItemModel>
            #include <QTableWidget>
            #include <QDebug>
            #include <QLabel>
            #include <cassert>
            
            Dialog::Dialog(QWidget *parent) :
                QDialog(parent),
                ui(new Ui::Dialog)
            {
                ui->setupUi(this);
                QDialog::setWindowTitle(">> Invoice Delegate <<");
                m_price = 20.87;
                m_vatrate = 0.0;
                m_qty     = 0;
                /*QPixmap Invpix(":/home/imrank/gdrive/work/qtProgs/png/earth_PNG22.png");
                QLabel hello;
                hello.resize(128,128);
                hello.setPixmap(Invpix);
                QDialog::setWindowIcon(QIcon(Invpix));
                hello.show();  */
            
                m_modelo         = new QStandardItemModel(this);
                m_prodIdDelegate = new ProdIdDelegate(this);
                m_qtyspinDelegate= new QtySpin(this);
                m_vatDelegate    = new VATDelegate(this);
            
                m_modelo->setRowCount(10);
                m_modelo->setColumnCount(7);
            
                m_modelo->setHorizontalHeaderItem(0, new QStandardItem("Prod ID"));
                m_modelo->setHorizontalHeaderItem(1, new QStandardItem("Description"));
                m_modelo->setHorizontalHeaderItem(2, new QStandardItem("Qty"));
                m_modelo->setHorizontalHeaderItem(3, new QStandardItem("Price"));
                m_modelo->setHorizontalHeaderItem(4, new QStandardItem("Amount"));
                m_modelo->setHorizontalHeaderItem(5, new QStandardItem("VATAmt"));
                m_modelo->setHorizontalHeaderItem(6, new QStandardItem("VAT"));
            
                ui->mytableView->setModel(m_modelo);
                assert (ui->mytableView->model());
            
                // set the column width
                ui->mytableView->setColumnWidth(0, 70);
                ui->mytableView->setItemDelegateForColumn(0, m_prodIdDelegate);
                ui->mytableView->showColumn(0);
                ui->mytableView->setColumnWidth(1, 400);
                ui->mytableView->setColumnWidth(2, 60);
                ui->mytableView->setItemDelegateForColumn(2, m_qtyspinDelegate);
                ui->mytableView->setColumnWidth(3, 80);
                ui->mytableView->setColumnWidth(4, 100);
                ui->mytableView->setColumnWidth(5, 80);
                ui->mytableView->setColumnWidth(6, 50);
                ui->mytableView->setItemDelegateForColumn(6, m_vatDelegate);
            
                QMetaObject::invokeMethod(ui->mytableView, "updateGeometries");
            
                for (int i=0; i<m_modelo->rowCount(); i++) {
                    ui->mytableView->openPersistentEditor(m_modelo->index(i, 0));
                    ui->mytableView->openPersistentEditor(m_modelo->index(i, 2));
                    ui->mytableView->openPersistentEditor(m_modelo->index(i, 6));
                }
            
                ui->mytableView->show();
            }
            
            Dialog::~Dialog()
            {
                delete ui;
            }
            
            void Dialog::on_QuitpushButton_clicked()
            {
                close();
            }
            
            void Dialog::on_mytableView_clicked(const QModelIndex &index)
            {    (void) index;
                //qDebug() << "SIGNAL: QTableView_clicked at Row " <<  index.row() << " Column " << index.column();
                //qDebug () << "SIGNAL FROM Dialog_clicked " << ui->mytableView->model()->data(index).toString();
                //int curCol = index.column();
            /*
                switch (curCol) {
                    case 0:
                        qDebug () << "ProdID " << ui->mytableView->model()->data(index).toString();
                        GetCurrentItem(index.row());
                      break;
                    case 2:
                        m_qty = ui->mytableView->model()->data(index).toInt();
                        qDebug () << "Qty" << m_qty;
                        putAmount(index.row());
                      break;
                    case 6:
                        QString code = ui->mytableView->model()->data(index).toString();
                        qDebug () << "VAT code " << code;
                        switch (code.data()->toLatin1())
                        {
                            case 'S': m_vatrate = 20.0; break;
                            case 'H': m_vatrate = 10.0; break;
                            case 'Q': m_vatrate =  5.0; break;
                            case 'E':
                            case 'Z': m_vatrate = 0.0; break;
                            default:  m_vatrate = 0.0;
                        }
                        putVatAmt (index.row());
                      break;
                    //default:
                   }  */
                qDebug () << "Description" << m_prodIdDelegate->getProdId();
                qDebug () << "Price" << m_prodIdDelegate->getPrice();
                qDebug () << "QTY came:" << m_qtyspinDelegate->getQty();
                qDebug () << "VAT Rate came" << m_vatDelegate->getVATRate();
            }
            
            void Dialog::on_mytableView_doubleClicked(const QModelIndex &index)
            {
                qDebug() << "SIGNAL: QTableView_doubleClicked at Row " << index.row() << " Column " << index.column();
            }
            
            void Dialog::GetCurrentItem(int rowCount)
            {   QString myprc = QString("%1").arg(m_price);
                QStandardItem *m_descrpt = new QStandardItem("This is a test procedure");
                QStandardItem *m_pric   = new QStandardItem(myprc);
                m_modelo->setItem(rowCount, 1, m_descrpt);
                m_modelo->setItem(rowCount, 3, m_pric);
            }
            
            void Dialog::putAmount(int rowCount)
            {
                double amt = m_price * m_qty;
                QString stramt = QString("%1").arg(amt);
                QStandardItem *m_amt     = new QStandardItem(stramt);
                m_modelo->setItem(rowCount, 4, m_amt);
            }
            void Dialog::putVatAmt(int rowCount)
            {
                qDebug () << "VATrate" << m_vatrate;
                double vatam = (((m_price * m_qty) * m_vatrate) /100);
                QString strvat = QString("%1").arg(vatam);
                QStandardItem  *m_vatamt = new QStandardItem(strvat);
                m_modelo->setItem(rowCount, 5, m_vatamt);
            }
            
            Header file dialog.h
            ===============
            #ifndef DIALOG_H
            #define DIALOG_H
            
            #include <QDialog>
            
            namespace Ui {
            class Dialog;
            }
            
            class QStandardItemModel;
            class ProdIdDelegate;
            class VATDelegate;
            class QtySpin;
            class QTableWidget;
            
            class Dialog : public QDialog
            {
                Q_OBJECT
            
            public:
                explicit Dialog(QWidget *parent = nullptr);
                ~Dialog();
            
            private slots:
                void on_QuitpushButton_clicked();
                void on_mytableView_clicked(const QModelIndex &index);
                void on_mytableView_doubleClicked(const QModelIndex &index);
                void GetCurrentItem(int rowCount);
                void putAmount(int rowCount);
                void putVatAmt(int rowCount);
            private:
                Ui::Dialog *ui;
            
                QStandardItemModel *m_modelo;
                ProdIdDelegate     *m_prodIdDelegate;
                QtySpin            *m_qtyspinDelegate;
                VATDelegate        *m_vatDelegate;
                QTableWidget       *m_curRow;
                QString            m_pid;
                double             m_vatrate;
                double             m_price;
                int                m_qty;
            };
            
            #endif // DIALOG_H
            
            1 Reply Last reply
            0
            • VRoninV VRonin

              @shylock said in QItemDelegate with QComboBox and QSpinBox with QTableView control (how to pass signal):

              If you prefer I can attach a cut down version of a project.

              That would be really useful

              shylockS Offline
              shylockS Offline
              shylock
              wrote on last edited by
              #9

              @VRonin
              I wonder did anyone managed to figure out, above stated problem logic?
              Although I have a crude solution for the same problem which works. But I am interested to have more efficient and less CPU intensive solution, I am sure there were many Qt experts exists on the Forum with huge points in their credit, surely may have to jog their Qt knowledge to an extra mile or on a treadmill?

              VRoninV 1 Reply Last reply
              0
              • shylockS shylock

                @VRonin
                I wonder did anyone managed to figure out, above stated problem logic?
                Although I have a crude solution for the same problem which works. But I am interested to have more efficient and less CPU intensive solution, I am sure there were many Qt experts exists on the Forum with huge points in their credit, surely may have to jog their Qt knowledge to an extra mile or on a treadmill?

                VRoninV Offline
                VRoninV Offline
                VRonin
                wrote on last edited by
                #10

                @shylock Sorry, I was away for a few days, I'll have a look at it today

                "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
                1
                • VRoninV Offline
                  VRoninV Offline
                  VRonin
                  wrote on last edited by
                  #11

                  Unfortunately the posted code is not enough to test it.

                  A few notes/questions:

                  • What should QStyledItemDelegate m_siDelegate; do?
                  • ProdIdDelegate::paint doesn't do anything. is that what you want?
                  • ProdIdDelegate::sizeHint why do you reimplement it? just delete it
                  • ui->mytableView->openPersistentEditor why do you use this if you are using a custom delegate?
                  • Why do you call a query evey time to refresh the combo instead of just using a member QSqlTableModel?
                  • What should ProdIdDelegate::m_proid, ProdIdDelegate::m_description, ProdIdDelegate::m_price represent?

                  "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

                  shylockS 2 Replies Last reply
                  0
                  • VRoninV VRonin

                    Unfortunately the posted code is not enough to test it.

                    A few notes/questions:

                    • What should QStyledItemDelegate m_siDelegate; do?
                    • ProdIdDelegate::paint doesn't do anything. is that what you want?
                    • ProdIdDelegate::sizeHint why do you reimplement it? just delete it
                    • ui->mytableView->openPersistentEditor why do you use this if you are using a custom delegate?
                    • Why do you call a query evey time to refresh the combo instead of just using a member QSqlTableModel?
                    • What should ProdIdDelegate::m_proid, ProdIdDelegate::m_description, ProdIdDelegate::m_price represent?
                    shylockS Offline
                    shylockS Offline
                    shylock
                    wrote on last edited by
                    #12

                    @VRonin
                    1/ The vars editor,model,index simply to reuse them instead of having a warning messages.
                    2/ ProdIdDelegate::paint does not do anything due it does not have a handle of myTableView control which
                    resides in dialog class, hence it cant precisely paint the column 2 and 3
                    3/ Ignore::sizeHint function it is there and according to QStyledItemDelegate help note this function can be
                    overwritten.
                    4/ First time SQL Query called to fill or populate the QComboBox for user's selection, after selection prodId
                    The second time SQL Query called find description and price. Although This can be amalgamated in a single
                    call. But I thought since I have a Signal to process I can use this facility to re-scan the table again with
                    prodId pick the Description, and Price; this info extracted from a SQLITE3 table and displayed in
                    Dialog::myTableView table column 1 and 3 respectively. m_prodId, m_description, are string variable and
                    m_price is double.
                    5/ If you see the attached png file will explain a bit more in details.

                    1 Reply Last reply
                    0
                    • VRoninV VRonin

                      Unfortunately the posted code is not enough to test it.

                      A few notes/questions:

                      • What should QStyledItemDelegate m_siDelegate; do?
                      • ProdIdDelegate::paint doesn't do anything. is that what you want?
                      • ProdIdDelegate::sizeHint why do you reimplement it? just delete it
                      • ui->mytableView->openPersistentEditor why do you use this if you are using a custom delegate?
                      • Why do you call a query evey time to refresh the combo instead of just using a member QSqlTableModel?
                      • What should ProdIdDelegate::m_proid, ProdIdDelegate::m_description, ProdIdDelegate::m_price represent?
                      shylockS Offline
                      shylockS Offline
                      shylock
                      wrote on last edited by
                      #13

                      @VRonin
                      The posted code file Dialog.cpp; from constructor, if you remove two variables, whose code is not posted
                      m_qtyspinDelegate= new QtySpin(this);
                      m_vatDelegate = new VATDelegate(this);

                      This program a compile successfully and run with single QComboBox Delegate.

                      1 Reply Last reply
                      0
                      • VRoninV Offline
                        VRoninV Offline
                        VRonin
                        wrote on last edited by
                        #14

                        I'm missing the ui file.

                        Btw it looks like you are trying to use the delegate to do something that should not do. a delegate should paint and handle the edit of 1 and only 1 QModelIndex.

                        Remove ui->mytableView->openPersistentEditor as it just destroys performance.

                        this is a possible implementation of a combo box delegate I had around:

                        header

                        #ifndef COMBOBOXDELEGATE_H
                        #define COMBOBOXDELEGATE_H
                        
                        #include <QStyledItemDelegate>
                        #include <QString>
                        class QComboBox;
                        class QStandardItemModel;
                        class QSortFilterProxyModel;
                        class ComboBoxDelegate : public QStyledItemDelegate
                        {
                            Q_OBJECT
                            Q_DISABLE_COPY(ComboBoxDelegate)
                        public:
                            ComboBoxDelegate(QObject *parent = Q_NULLPTR);
                            virtual ~ComboBoxDelegate() = default;
                            virtual void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                            virtual QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                            virtual void setEditorData(QWidget *editor, const QModelIndex &index) const Q_DECL_OVERRIDE;
                            virtual void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const Q_DECL_OVERRIDE;
                            virtual void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                            virtual QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index)  const Q_DECL_OVERRIDE;
                            virtual void clear();
                            virtual void addItem(const QString& txt, const QVariant& val);
                            virtual void addItem(const QString& txt);
                            virtual QString textForData(const QVariant& val);
                            virtual void setItemData(int index, const QVariant& data, int role = Qt::UserRole);
                            virtual QVariant itemData(int index, int role = Qt::UserRole);
                            virtual void removeItem(int index);
                            virtual int findText(const QString & text) const;
                            virtual int findData(const QVariant & data, int role = Qt::UserRole) const;
                            virtual QAbstractItemModel* model() const;
                            bool alwaysPaintCombo() const;
                            void setAlwaysPaintCombo(bool val);
                        protected:
                            QStandardItemModel* m_comboModel;
                            QSortFilterProxyModel* m_comboProxy;
                            bool m_alwaysPaintCombo;
                        };
                        
                        #endif // COMBOBOXDELEGATE_H
                        

                        Source

                        #include "ComboBoxDelegate.h"
                        #include <QComboBox>
                        #include <QStandardItemModel>
                        #include <QApplication>
                        #include <QSortFilterProxyModel>
                        #include <QStyleOptionComboBox>
                        ComboBoxDelegate::ComboBoxDelegate(QObject *parent)
                            : QStyledItemDelegate(parent)
                            , m_alwaysPaintCombo(false)
                        {
                            m_comboModel = new QStandardItemModel(this);
                            m_comboModel->insertColumn(0);
                            m_comboProxy = new QSortFilterProxyModel(this);
                            m_comboProxy->setSourceModel(m_comboModel);
                        }
                        
                        void ComboBoxDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const 
                        {
                            if (!m_alwaysPaintCombo)
                                return ComboBoxDelegate::paint(painter, option, index);
                            const QWidget* const widget = option.widget;
                            QStyle* const style = widget ? widget->style() : QApplication::style();
                            QStyleOptionComboBox cbOption;
                            cbOption.rect = option.rect;
                            cbOption.direction = option.direction;
                            cbOption.currentIcon = index.data(Qt::DecorationRole).value<QIcon>();
                            cbOption.currentText = index.data(Qt::DisplayRole).toString();
                            cbOption.fontMetrics = option.fontMetrics;
                            const int iconWidth = style->pixelMetric(QStyle::PM_SmallIconSize, Q_NULLPTR, widget);
                            cbOption.iconSize = QSize(iconWidth, iconWidth);
                            cbOption.palette = option.palette;
                            cbOption.state = option.state;
                            cbOption.styleObject = option.styleObject;
                            style->drawComplexControl(QStyle::CC_ComboBox, &cbOption, painter, widget);
                            style->drawControl(QStyle::CE_ComboBoxLabel, &cbOption, painter, widget);
                        }
                        
                        QWidget* ComboBoxDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &, const QModelIndex &) const
                        {
                            QComboBox* result = new QComboBox(parent);
                            m_comboProxy->sort(0);
                            result->setModel(m_comboProxy);
                            return result;
                        }
                        
                        void ComboBoxDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
                        {
                            if (index.model()->data(index, Qt::EditRole).isNull())
                                qobject_cast<QComboBox*>(editor)->setCurrentIndex(-1);
                            else
                                qobject_cast<QComboBox*>(editor)->setCurrentText(index.model()->data(index, Qt::EditRole).toString());
                        }
                        
                        void ComboBoxDelegate::clear()
                        {
                            m_comboModel->removeRows(0,m_comboModel->rowCount());
                        }
                        
                        void ComboBoxDelegate::addItem(const QString& txt, const QVariant& val)
                        {
                            const int newRow = m_comboModel->rowCount();
                            m_comboModel->insertRow(newRow);
                            m_comboModel->setData(m_comboModel->index(newRow, 0), txt);
                            m_comboModel->setData(m_comboModel->index(newRow, 0), val, Qt::UserRole);
                        }
                        
                        void ComboBoxDelegate::addItem(const QString& txt)
                        {
                            addItem(txt, QVariant());
                        }
                        
                        QString ComboBoxDelegate::textForData(const QVariant& val)
                        {
                            for (int i = 0; i < m_comboModel->rowCount();++i){
                                if (m_comboModel->index(i, 0).data(Qt::UserRole) == val)
                                    return m_comboModel->index(i, 0).data().toString();
                            }
                            return QString();
                        }
                        
                        void ComboBoxDelegate::setItemData(int index, const QVariant& data, int role)
                        {
                            if (index < 0 || index >= m_comboProxy->rowCount())
                                return;
                            m_comboModel->setData(m_comboProxy->mapToSource(m_comboProxy->index(index, 0)), data, role);
                        }
                        
                        QVariant ComboBoxDelegate::itemData(int index, int role)
                        {
                            if (index < 0 || index >= m_comboProxy->rowCount())
                                return QVariant();
                            return m_comboProxy->index(index, 0).data(role);
                        }
                        
                        void ComboBoxDelegate::removeItem(int index)
                        {
                            if (index < 0 || index >= m_comboProxy->rowCount())
                                return;
                            m_comboModel->removeRow(m_comboProxy->mapToSource(m_comboProxy->index(index,0)).row());
                        }
                        
                        int ComboBoxDelegate::findText(const QString & text) const
                        {
                            for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                if (m_comboProxy->index(i, 0).data().toString().compare(text, Qt::CaseInsensitive) == 0)
                                    return i;
                            }
                            return -1;
                        }
                        
                        int ComboBoxDelegate::findData(const QVariant & data, int role) const
                        {
                            for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                if (m_comboProxy->index(i, 0).data(role) == data)
                                    return i;
                            }
                            return -1;
                        }
                        
                        QAbstractItemModel* ComboBoxDelegate::model() const
                        {
                            return m_comboModel;
                        }
                        
                        bool ComboBoxDelegate::alwaysPaintCombo() const
                        {
                            return m_alwaysPaintCombo;
                        }
                        
                        void ComboBoxDelegate::setAlwaysPaintCombo(bool val)
                        {
                            m_alwaysPaintCombo = val;
                        }
                        
                        void ComboBoxDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
                        {
                            auto combo = qobject_cast<QComboBox*>(editor);
                            if (combo->currentIndex() < 0) {
                                model->setData(index, QVariant(), Qt::EditRole);
                                model->setData(index, QVariant(), Qt::UserRole);
                            }
                            else {
                                model->setData(index, combo->currentText(), Qt::EditRole);
                                model->setData(index, combo->currentData(), Qt::UserRole);
                            }
                        }
                        void ComboBoxDelegate::updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &) const
                        {
                            editor->setGeometry(option.rect);
                        }
                        
                        QSize ComboBoxDelegate::sizeHint(const QStyleOptionViewItem &option, const QModelIndex &) const
                        {
                            int MaxWid = 0;
                            for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                if (option.fontMetrics.width(m_comboProxy->index(i, 0).data().toString())>MaxWid)
                                    MaxWid = option.fontMetrics.width(m_comboProxy->index(i, 0).data().toString());
                            }
                            return qApp->style()->sizeFromContents(
                                QStyle::CT_ComboBox,
                                &option,
                                QSize(MaxWid, option.fontMetrics.height())
                                );
                        }
                        

                        "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

                        shylockS C 3 Replies Last reply
                        1
                        • VRoninV VRonin

                          I'm missing the ui file.

                          Btw it looks like you are trying to use the delegate to do something that should not do. a delegate should paint and handle the edit of 1 and only 1 QModelIndex.

                          Remove ui->mytableView->openPersistentEditor as it just destroys performance.

                          this is a possible implementation of a combo box delegate I had around:

                          header

                          #ifndef COMBOBOXDELEGATE_H
                          #define COMBOBOXDELEGATE_H
                          
                          #include <QStyledItemDelegate>
                          #include <QString>
                          class QComboBox;
                          class QStandardItemModel;
                          class QSortFilterProxyModel;
                          class ComboBoxDelegate : public QStyledItemDelegate
                          {
                              Q_OBJECT
                              Q_DISABLE_COPY(ComboBoxDelegate)
                          public:
                              ComboBoxDelegate(QObject *parent = Q_NULLPTR);
                              virtual ~ComboBoxDelegate() = default;
                              virtual void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                              virtual QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                              virtual void setEditorData(QWidget *editor, const QModelIndex &index) const Q_DECL_OVERRIDE;
                              virtual void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const Q_DECL_OVERRIDE;
                              virtual void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                              virtual QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index)  const Q_DECL_OVERRIDE;
                              virtual void clear();
                              virtual void addItem(const QString& txt, const QVariant& val);
                              virtual void addItem(const QString& txt);
                              virtual QString textForData(const QVariant& val);
                              virtual void setItemData(int index, const QVariant& data, int role = Qt::UserRole);
                              virtual QVariant itemData(int index, int role = Qt::UserRole);
                              virtual void removeItem(int index);
                              virtual int findText(const QString & text) const;
                              virtual int findData(const QVariant & data, int role = Qt::UserRole) const;
                              virtual QAbstractItemModel* model() const;
                              bool alwaysPaintCombo() const;
                              void setAlwaysPaintCombo(bool val);
                          protected:
                              QStandardItemModel* m_comboModel;
                              QSortFilterProxyModel* m_comboProxy;
                              bool m_alwaysPaintCombo;
                          };
                          
                          #endif // COMBOBOXDELEGATE_H
                          

                          Source

                          #include "ComboBoxDelegate.h"
                          #include <QComboBox>
                          #include <QStandardItemModel>
                          #include <QApplication>
                          #include <QSortFilterProxyModel>
                          #include <QStyleOptionComboBox>
                          ComboBoxDelegate::ComboBoxDelegate(QObject *parent)
                              : QStyledItemDelegate(parent)
                              , m_alwaysPaintCombo(false)
                          {
                              m_comboModel = new QStandardItemModel(this);
                              m_comboModel->insertColumn(0);
                              m_comboProxy = new QSortFilterProxyModel(this);
                              m_comboProxy->setSourceModel(m_comboModel);
                          }
                          
                          void ComboBoxDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const 
                          {
                              if (!m_alwaysPaintCombo)
                                  return ComboBoxDelegate::paint(painter, option, index);
                              const QWidget* const widget = option.widget;
                              QStyle* const style = widget ? widget->style() : QApplication::style();
                              QStyleOptionComboBox cbOption;
                              cbOption.rect = option.rect;
                              cbOption.direction = option.direction;
                              cbOption.currentIcon = index.data(Qt::DecorationRole).value<QIcon>();
                              cbOption.currentText = index.data(Qt::DisplayRole).toString();
                              cbOption.fontMetrics = option.fontMetrics;
                              const int iconWidth = style->pixelMetric(QStyle::PM_SmallIconSize, Q_NULLPTR, widget);
                              cbOption.iconSize = QSize(iconWidth, iconWidth);
                              cbOption.palette = option.palette;
                              cbOption.state = option.state;
                              cbOption.styleObject = option.styleObject;
                              style->drawComplexControl(QStyle::CC_ComboBox, &cbOption, painter, widget);
                              style->drawControl(QStyle::CE_ComboBoxLabel, &cbOption, painter, widget);
                          }
                          
                          QWidget* ComboBoxDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &, const QModelIndex &) const
                          {
                              QComboBox* result = new QComboBox(parent);
                              m_comboProxy->sort(0);
                              result->setModel(m_comboProxy);
                              return result;
                          }
                          
                          void ComboBoxDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
                          {
                              if (index.model()->data(index, Qt::EditRole).isNull())
                                  qobject_cast<QComboBox*>(editor)->setCurrentIndex(-1);
                              else
                                  qobject_cast<QComboBox*>(editor)->setCurrentText(index.model()->data(index, Qt::EditRole).toString());
                          }
                          
                          void ComboBoxDelegate::clear()
                          {
                              m_comboModel->removeRows(0,m_comboModel->rowCount());
                          }
                          
                          void ComboBoxDelegate::addItem(const QString& txt, const QVariant& val)
                          {
                              const int newRow = m_comboModel->rowCount();
                              m_comboModel->insertRow(newRow);
                              m_comboModel->setData(m_comboModel->index(newRow, 0), txt);
                              m_comboModel->setData(m_comboModel->index(newRow, 0), val, Qt::UserRole);
                          }
                          
                          void ComboBoxDelegate::addItem(const QString& txt)
                          {
                              addItem(txt, QVariant());
                          }
                          
                          QString ComboBoxDelegate::textForData(const QVariant& val)
                          {
                              for (int i = 0; i < m_comboModel->rowCount();++i){
                                  if (m_comboModel->index(i, 0).data(Qt::UserRole) == val)
                                      return m_comboModel->index(i, 0).data().toString();
                              }
                              return QString();
                          }
                          
                          void ComboBoxDelegate::setItemData(int index, const QVariant& data, int role)
                          {
                              if (index < 0 || index >= m_comboProxy->rowCount())
                                  return;
                              m_comboModel->setData(m_comboProxy->mapToSource(m_comboProxy->index(index, 0)), data, role);
                          }
                          
                          QVariant ComboBoxDelegate::itemData(int index, int role)
                          {
                              if (index < 0 || index >= m_comboProxy->rowCount())
                                  return QVariant();
                              return m_comboProxy->index(index, 0).data(role);
                          }
                          
                          void ComboBoxDelegate::removeItem(int index)
                          {
                              if (index < 0 || index >= m_comboProxy->rowCount())
                                  return;
                              m_comboModel->removeRow(m_comboProxy->mapToSource(m_comboProxy->index(index,0)).row());
                          }
                          
                          int ComboBoxDelegate::findText(const QString & text) const
                          {
                              for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                  if (m_comboProxy->index(i, 0).data().toString().compare(text, Qt::CaseInsensitive) == 0)
                                      return i;
                              }
                              return -1;
                          }
                          
                          int ComboBoxDelegate::findData(const QVariant & data, int role) const
                          {
                              for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                  if (m_comboProxy->index(i, 0).data(role) == data)
                                      return i;
                              }
                              return -1;
                          }
                          
                          QAbstractItemModel* ComboBoxDelegate::model() const
                          {
                              return m_comboModel;
                          }
                          
                          bool ComboBoxDelegate::alwaysPaintCombo() const
                          {
                              return m_alwaysPaintCombo;
                          }
                          
                          void ComboBoxDelegate::setAlwaysPaintCombo(bool val)
                          {
                              m_alwaysPaintCombo = val;
                          }
                          
                          void ComboBoxDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
                          {
                              auto combo = qobject_cast<QComboBox*>(editor);
                              if (combo->currentIndex() < 0) {
                                  model->setData(index, QVariant(), Qt::EditRole);
                                  model->setData(index, QVariant(), Qt::UserRole);
                              }
                              else {
                                  model->setData(index, combo->currentText(), Qt::EditRole);
                                  model->setData(index, combo->currentData(), Qt::UserRole);
                              }
                          }
                          void ComboBoxDelegate::updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &) const
                          {
                              editor->setGeometry(option.rect);
                          }
                          
                          QSize ComboBoxDelegate::sizeHint(const QStyleOptionViewItem &option, const QModelIndex &) const
                          {
                              int MaxWid = 0;
                              for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                  if (option.fontMetrics.width(m_comboProxy->index(i, 0).data().toString())>MaxWid)
                                      MaxWid = option.fontMetrics.width(m_comboProxy->index(i, 0).data().toString());
                              }
                              return qApp->style()->sizeFromContents(
                                  QStyle::CT_ComboBox,
                                  &option,
                                  QSize(MaxWid, option.fontMetrics.height())
                                  );
                          }
                          
                          shylockS Offline
                          shylockS Offline
                          shylock
                          wrote on last edited by
                          #15

                          @VRonin
                          Thank you, Ronin,
                          Although I am going through the codes, I have attached my bog standard cut down version of the program, it is not an efficient way to complete and I am still looking a more tangible solution to complete the project.
                          Your provided class seems to more help a QComboBox and its various virtual functions.
                          AS you mentioned in the last post I am trying to do away different nature of job from QStyledItemDelegate class; perhaps you are right and in my judgment, if QStyledItemDelegate class provide a facility such as combo box, spin box, progress bar sliders, and other controls can be embedded into QTableView, QListView, QTreeView then their functionality can be must be more transparent to an extend functionality suited to a developer. As in this case nothing new as you can depict from the png image.
                          I am still grappling with real-time synchronization with two combo box and qty spin box selection, with their changes while displaying info on the QTableView Grid in a formatted manner.

                          0_1508864321649_Invoicelayout_01.png

                          1 Reply Last reply
                          0
                          • VRoninV VRonin

                            I'm missing the ui file.

                            Btw it looks like you are trying to use the delegate to do something that should not do. a delegate should paint and handle the edit of 1 and only 1 QModelIndex.

                            Remove ui->mytableView->openPersistentEditor as it just destroys performance.

                            this is a possible implementation of a combo box delegate I had around:

                            header

                            #ifndef COMBOBOXDELEGATE_H
                            #define COMBOBOXDELEGATE_H
                            
                            #include <QStyledItemDelegate>
                            #include <QString>
                            class QComboBox;
                            class QStandardItemModel;
                            class QSortFilterProxyModel;
                            class ComboBoxDelegate : public QStyledItemDelegate
                            {
                                Q_OBJECT
                                Q_DISABLE_COPY(ComboBoxDelegate)
                            public:
                                ComboBoxDelegate(QObject *parent = Q_NULLPTR);
                                virtual ~ComboBoxDelegate() = default;
                                virtual void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                                virtual QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                                virtual void setEditorData(QWidget *editor, const QModelIndex &index) const Q_DECL_OVERRIDE;
                                virtual void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const Q_DECL_OVERRIDE;
                                virtual void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                                virtual QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index)  const Q_DECL_OVERRIDE;
                                virtual void clear();
                                virtual void addItem(const QString& txt, const QVariant& val);
                                virtual void addItem(const QString& txt);
                                virtual QString textForData(const QVariant& val);
                                virtual void setItemData(int index, const QVariant& data, int role = Qt::UserRole);
                                virtual QVariant itemData(int index, int role = Qt::UserRole);
                                virtual void removeItem(int index);
                                virtual int findText(const QString & text) const;
                                virtual int findData(const QVariant & data, int role = Qt::UserRole) const;
                                virtual QAbstractItemModel* model() const;
                                bool alwaysPaintCombo() const;
                                void setAlwaysPaintCombo(bool val);
                            protected:
                                QStandardItemModel* m_comboModel;
                                QSortFilterProxyModel* m_comboProxy;
                                bool m_alwaysPaintCombo;
                            };
                            
                            #endif // COMBOBOXDELEGATE_H
                            

                            Source

                            #include "ComboBoxDelegate.h"
                            #include <QComboBox>
                            #include <QStandardItemModel>
                            #include <QApplication>
                            #include <QSortFilterProxyModel>
                            #include <QStyleOptionComboBox>
                            ComboBoxDelegate::ComboBoxDelegate(QObject *parent)
                                : QStyledItemDelegate(parent)
                                , m_alwaysPaintCombo(false)
                            {
                                m_comboModel = new QStandardItemModel(this);
                                m_comboModel->insertColumn(0);
                                m_comboProxy = new QSortFilterProxyModel(this);
                                m_comboProxy->setSourceModel(m_comboModel);
                            }
                            
                            void ComboBoxDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const 
                            {
                                if (!m_alwaysPaintCombo)
                                    return ComboBoxDelegate::paint(painter, option, index);
                                const QWidget* const widget = option.widget;
                                QStyle* const style = widget ? widget->style() : QApplication::style();
                                QStyleOptionComboBox cbOption;
                                cbOption.rect = option.rect;
                                cbOption.direction = option.direction;
                                cbOption.currentIcon = index.data(Qt::DecorationRole).value<QIcon>();
                                cbOption.currentText = index.data(Qt::DisplayRole).toString();
                                cbOption.fontMetrics = option.fontMetrics;
                                const int iconWidth = style->pixelMetric(QStyle::PM_SmallIconSize, Q_NULLPTR, widget);
                                cbOption.iconSize = QSize(iconWidth, iconWidth);
                                cbOption.palette = option.palette;
                                cbOption.state = option.state;
                                cbOption.styleObject = option.styleObject;
                                style->drawComplexControl(QStyle::CC_ComboBox, &cbOption, painter, widget);
                                style->drawControl(QStyle::CE_ComboBoxLabel, &cbOption, painter, widget);
                            }
                            
                            QWidget* ComboBoxDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &, const QModelIndex &) const
                            {
                                QComboBox* result = new QComboBox(parent);
                                m_comboProxy->sort(0);
                                result->setModel(m_comboProxy);
                                return result;
                            }
                            
                            void ComboBoxDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
                            {
                                if (index.model()->data(index, Qt::EditRole).isNull())
                                    qobject_cast<QComboBox*>(editor)->setCurrentIndex(-1);
                                else
                                    qobject_cast<QComboBox*>(editor)->setCurrentText(index.model()->data(index, Qt::EditRole).toString());
                            }
                            
                            void ComboBoxDelegate::clear()
                            {
                                m_comboModel->removeRows(0,m_comboModel->rowCount());
                            }
                            
                            void ComboBoxDelegate::addItem(const QString& txt, const QVariant& val)
                            {
                                const int newRow = m_comboModel->rowCount();
                                m_comboModel->insertRow(newRow);
                                m_comboModel->setData(m_comboModel->index(newRow, 0), txt);
                                m_comboModel->setData(m_comboModel->index(newRow, 0), val, Qt::UserRole);
                            }
                            
                            void ComboBoxDelegate::addItem(const QString& txt)
                            {
                                addItem(txt, QVariant());
                            }
                            
                            QString ComboBoxDelegate::textForData(const QVariant& val)
                            {
                                for (int i = 0; i < m_comboModel->rowCount();++i){
                                    if (m_comboModel->index(i, 0).data(Qt::UserRole) == val)
                                        return m_comboModel->index(i, 0).data().toString();
                                }
                                return QString();
                            }
                            
                            void ComboBoxDelegate::setItemData(int index, const QVariant& data, int role)
                            {
                                if (index < 0 || index >= m_comboProxy->rowCount())
                                    return;
                                m_comboModel->setData(m_comboProxy->mapToSource(m_comboProxy->index(index, 0)), data, role);
                            }
                            
                            QVariant ComboBoxDelegate::itemData(int index, int role)
                            {
                                if (index < 0 || index >= m_comboProxy->rowCount())
                                    return QVariant();
                                return m_comboProxy->index(index, 0).data(role);
                            }
                            
                            void ComboBoxDelegate::removeItem(int index)
                            {
                                if (index < 0 || index >= m_comboProxy->rowCount())
                                    return;
                                m_comboModel->removeRow(m_comboProxy->mapToSource(m_comboProxy->index(index,0)).row());
                            }
                            
                            int ComboBoxDelegate::findText(const QString & text) const
                            {
                                for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                    if (m_comboProxy->index(i, 0).data().toString().compare(text, Qt::CaseInsensitive) == 0)
                                        return i;
                                }
                                return -1;
                            }
                            
                            int ComboBoxDelegate::findData(const QVariant & data, int role) const
                            {
                                for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                    if (m_comboProxy->index(i, 0).data(role) == data)
                                        return i;
                                }
                                return -1;
                            }
                            
                            QAbstractItemModel* ComboBoxDelegate::model() const
                            {
                                return m_comboModel;
                            }
                            
                            bool ComboBoxDelegate::alwaysPaintCombo() const
                            {
                                return m_alwaysPaintCombo;
                            }
                            
                            void ComboBoxDelegate::setAlwaysPaintCombo(bool val)
                            {
                                m_alwaysPaintCombo = val;
                            }
                            
                            void ComboBoxDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
                            {
                                auto combo = qobject_cast<QComboBox*>(editor);
                                if (combo->currentIndex() < 0) {
                                    model->setData(index, QVariant(), Qt::EditRole);
                                    model->setData(index, QVariant(), Qt::UserRole);
                                }
                                else {
                                    model->setData(index, combo->currentText(), Qt::EditRole);
                                    model->setData(index, combo->currentData(), Qt::UserRole);
                                }
                            }
                            void ComboBoxDelegate::updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &) const
                            {
                                editor->setGeometry(option.rect);
                            }
                            
                            QSize ComboBoxDelegate::sizeHint(const QStyleOptionViewItem &option, const QModelIndex &) const
                            {
                                int MaxWid = 0;
                                for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                    if (option.fontMetrics.width(m_comboProxy->index(i, 0).data().toString())>MaxWid)
                                        MaxWid = option.fontMetrics.width(m_comboProxy->index(i, 0).data().toString());
                                }
                                return qApp->style()->sizeFromContents(
                                    QStyle::CT_ComboBox,
                                    &option,
                                    QSize(MaxWid, option.fontMetrics.height())
                                    );
                            }
                            
                            shylockS Offline
                            shylockS Offline
                            shylock
                            wrote on last edited by
                            #16

                            @VRonin
                            I am afraid your provided class logic simply does not work as it cannot be instantiated, the function
                            paint is persistent in the paint state for QVariants; even the list become exhausted, it gave me far more aggro to embed within QTableView.
                            A basically I am still at Square One! The requirements (ie problem) remained stirring at me more vehemently than ever, I bet I have to go deep undercover in Qt's systems source code to do a bit of hacking.

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                            • MucipM Offline
                              MucipM Offline
                              Mucip
                              wrote on last edited by
                              #17

                              Dear shlock,
                              I need this kind of invoice detail imput tableview. May I ask please? Which kind of Database did you use and how did you add new lines and write them in DB?
                              Regards,
                              Mucip:)

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                              • VRoninV VRonin

                                I'm missing the ui file.

                                Btw it looks like you are trying to use the delegate to do something that should not do. a delegate should paint and handle the edit of 1 and only 1 QModelIndex.

                                Remove ui->mytableView->openPersistentEditor as it just destroys performance.

                                this is a possible implementation of a combo box delegate I had around:

                                header

                                #ifndef COMBOBOXDELEGATE_H
                                #define COMBOBOXDELEGATE_H
                                
                                #include <QStyledItemDelegate>
                                #include <QString>
                                class QComboBox;
                                class QStandardItemModel;
                                class QSortFilterProxyModel;
                                class ComboBoxDelegate : public QStyledItemDelegate
                                {
                                    Q_OBJECT
                                    Q_DISABLE_COPY(ComboBoxDelegate)
                                public:
                                    ComboBoxDelegate(QObject *parent = Q_NULLPTR);
                                    virtual ~ComboBoxDelegate() = default;
                                    virtual void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                                    virtual QWidget *createEditor(QWidget *parent, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                                    virtual void setEditorData(QWidget *editor, const QModelIndex &index) const Q_DECL_OVERRIDE;
                                    virtual void setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const Q_DECL_OVERRIDE;
                                    virtual void updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &index) const Q_DECL_OVERRIDE;
                                    virtual QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index)  const Q_DECL_OVERRIDE;
                                    virtual void clear();
                                    virtual void addItem(const QString& txt, const QVariant& val);
                                    virtual void addItem(const QString& txt);
                                    virtual QString textForData(const QVariant& val);
                                    virtual void setItemData(int index, const QVariant& data, int role = Qt::UserRole);
                                    virtual QVariant itemData(int index, int role = Qt::UserRole);
                                    virtual void removeItem(int index);
                                    virtual int findText(const QString & text) const;
                                    virtual int findData(const QVariant & data, int role = Qt::UserRole) const;
                                    virtual QAbstractItemModel* model() const;
                                    bool alwaysPaintCombo() const;
                                    void setAlwaysPaintCombo(bool val);
                                protected:
                                    QStandardItemModel* m_comboModel;
                                    QSortFilterProxyModel* m_comboProxy;
                                    bool m_alwaysPaintCombo;
                                };
                                
                                #endif // COMBOBOXDELEGATE_H
                                

                                Source

                                #include "ComboBoxDelegate.h"
                                #include <QComboBox>
                                #include <QStandardItemModel>
                                #include <QApplication>
                                #include <QSortFilterProxyModel>
                                #include <QStyleOptionComboBox>
                                ComboBoxDelegate::ComboBoxDelegate(QObject *parent)
                                    : QStyledItemDelegate(parent)
                                    , m_alwaysPaintCombo(false)
                                {
                                    m_comboModel = new QStandardItemModel(this);
                                    m_comboModel->insertColumn(0);
                                    m_comboProxy = new QSortFilterProxyModel(this);
                                    m_comboProxy->setSourceModel(m_comboModel);
                                }
                                
                                void ComboBoxDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const 
                                {
                                    if (!m_alwaysPaintCombo)
                                        return ComboBoxDelegate::paint(painter, option, index);
                                    const QWidget* const widget = option.widget;
                                    QStyle* const style = widget ? widget->style() : QApplication::style();
                                    QStyleOptionComboBox cbOption;
                                    cbOption.rect = option.rect;
                                    cbOption.direction = option.direction;
                                    cbOption.currentIcon = index.data(Qt::DecorationRole).value<QIcon>();
                                    cbOption.currentText = index.data(Qt::DisplayRole).toString();
                                    cbOption.fontMetrics = option.fontMetrics;
                                    const int iconWidth = style->pixelMetric(QStyle::PM_SmallIconSize, Q_NULLPTR, widget);
                                    cbOption.iconSize = QSize(iconWidth, iconWidth);
                                    cbOption.palette = option.palette;
                                    cbOption.state = option.state;
                                    cbOption.styleObject = option.styleObject;
                                    style->drawComplexControl(QStyle::CC_ComboBox, &cbOption, painter, widget);
                                    style->drawControl(QStyle::CE_ComboBoxLabel, &cbOption, painter, widget);
                                }
                                
                                QWidget* ComboBoxDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &, const QModelIndex &) const
                                {
                                    QComboBox* result = new QComboBox(parent);
                                    m_comboProxy->sort(0);
                                    result->setModel(m_comboProxy);
                                    return result;
                                }
                                
                                void ComboBoxDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
                                {
                                    if (index.model()->data(index, Qt::EditRole).isNull())
                                        qobject_cast<QComboBox*>(editor)->setCurrentIndex(-1);
                                    else
                                        qobject_cast<QComboBox*>(editor)->setCurrentText(index.model()->data(index, Qt::EditRole).toString());
                                }
                                
                                void ComboBoxDelegate::clear()
                                {
                                    m_comboModel->removeRows(0,m_comboModel->rowCount());
                                }
                                
                                void ComboBoxDelegate::addItem(const QString& txt, const QVariant& val)
                                {
                                    const int newRow = m_comboModel->rowCount();
                                    m_comboModel->insertRow(newRow);
                                    m_comboModel->setData(m_comboModel->index(newRow, 0), txt);
                                    m_comboModel->setData(m_comboModel->index(newRow, 0), val, Qt::UserRole);
                                }
                                
                                void ComboBoxDelegate::addItem(const QString& txt)
                                {
                                    addItem(txt, QVariant());
                                }
                                
                                QString ComboBoxDelegate::textForData(const QVariant& val)
                                {
                                    for (int i = 0; i < m_comboModel->rowCount();++i){
                                        if (m_comboModel->index(i, 0).data(Qt::UserRole) == val)
                                            return m_comboModel->index(i, 0).data().toString();
                                    }
                                    return QString();
                                }
                                
                                void ComboBoxDelegate::setItemData(int index, const QVariant& data, int role)
                                {
                                    if (index < 0 || index >= m_comboProxy->rowCount())
                                        return;
                                    m_comboModel->setData(m_comboProxy->mapToSource(m_comboProxy->index(index, 0)), data, role);
                                }
                                
                                QVariant ComboBoxDelegate::itemData(int index, int role)
                                {
                                    if (index < 0 || index >= m_comboProxy->rowCount())
                                        return QVariant();
                                    return m_comboProxy->index(index, 0).data(role);
                                }
                                
                                void ComboBoxDelegate::removeItem(int index)
                                {
                                    if (index < 0 || index >= m_comboProxy->rowCount())
                                        return;
                                    m_comboModel->removeRow(m_comboProxy->mapToSource(m_comboProxy->index(index,0)).row());
                                }
                                
                                int ComboBoxDelegate::findText(const QString & text) const
                                {
                                    for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                        if (m_comboProxy->index(i, 0).data().toString().compare(text, Qt::CaseInsensitive) == 0)
                                            return i;
                                    }
                                    return -1;
                                }
                                
                                int ComboBoxDelegate::findData(const QVariant & data, int role) const
                                {
                                    for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                        if (m_comboProxy->index(i, 0).data(role) == data)
                                            return i;
                                    }
                                    return -1;
                                }
                                
                                QAbstractItemModel* ComboBoxDelegate::model() const
                                {
                                    return m_comboModel;
                                }
                                
                                bool ComboBoxDelegate::alwaysPaintCombo() const
                                {
                                    return m_alwaysPaintCombo;
                                }
                                
                                void ComboBoxDelegate::setAlwaysPaintCombo(bool val)
                                {
                                    m_alwaysPaintCombo = val;
                                }
                                
                                void ComboBoxDelegate::setModelData(QWidget *editor, QAbstractItemModel *model, const QModelIndex &index) const
                                {
                                    auto combo = qobject_cast<QComboBox*>(editor);
                                    if (combo->currentIndex() < 0) {
                                        model->setData(index, QVariant(), Qt::EditRole);
                                        model->setData(index, QVariant(), Qt::UserRole);
                                    }
                                    else {
                                        model->setData(index, combo->currentText(), Qt::EditRole);
                                        model->setData(index, combo->currentData(), Qt::UserRole);
                                    }
                                }
                                void ComboBoxDelegate::updateEditorGeometry(QWidget *editor, const QStyleOptionViewItem &option, const QModelIndex &) const
                                {
                                    editor->setGeometry(option.rect);
                                }
                                
                                QSize ComboBoxDelegate::sizeHint(const QStyleOptionViewItem &option, const QModelIndex &) const
                                {
                                    int MaxWid = 0;
                                    for (int i = 0; i < m_comboProxy->rowCount(); ++i) {
                                        if (option.fontMetrics.width(m_comboProxy->index(i, 0).data().toString())>MaxWid)
                                            MaxWid = option.fontMetrics.width(m_comboProxy->index(i, 0).data().toString());
                                    }
                                    return qApp->style()->sizeFromContents(
                                        QStyle::CT_ComboBox,
                                        &option,
                                        QSize(MaxWid, option.fontMetrics.height())
                                        );
                                }
                                
                                C Offline
                                C Offline
                                charry
                                wrote on last edited by
                                #18

                                @VRonin hi, I run the code sucess, how to keep baseEditor always display not that I should click the mouse.

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