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Reading image from QSqlTableModel

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  • raven-worxR raven-worx

    @gabor53
    2 reasons your csetModelData() isn't called:

    1. the correct signatur for setModelData() would be: void setModelData(QWidget * editor, QAbstractItemModel * model, const QModelIndex & index) const
    2. setModelData() is used as the name implies to set data in the model. Means when the editor has finished editing and wants to save

    the correct method to reimplement is the delegates paint() and sizeHint() methods. In there you check if the column is your image column and do the work appropriately, else just call the base class implementation.

    G Offline
    G Offline
    gabor53
    wrote on last edited by
    #22

    @raven-worx
    Thank you. I'm working on it.

    1 Reply Last reply
    0
    • raven-worxR raven-worx

      @gabor53
      2 reasons your csetModelData() isn't called:

      1. the correct signatur for setModelData() would be: void setModelData(QWidget * editor, QAbstractItemModel * model, const QModelIndex & index) const
      2. setModelData() is used as the name implies to set data in the model. Means when the editor has finished editing and wants to save

      the correct method to reimplement is the delegates paint() and sizeHint() methods. In there you check if the column is your image column and do the work appropriately, else just call the base class implementation.

      G Offline
      G Offline
      gabor53
      wrote on last edited by
      #23

      @raven-worx
      I believe in the paint() method I need to use

      void QPainter::drawPixmap(const QRectF &target, const QPixmap &pixmap, const QRectF &source)
      

      How can I get the pixmap out of the model?

      artwawA 1 Reply Last reply
      0
      • G gabor53

        @raven-worx
        I believe in the paint() method I need to use

        void QPainter::drawPixmap(const QRectF &target, const QPixmap &pixmap, const QRectF &source)
        

        How can I get the pixmap out of the model?

        artwawA Offline
        artwawA Offline
        artwaw
        wrote on last edited by
        #24

        @gabor53 of course. Model's data() method returns QVariant, you can get QByteArray this way.

        For more information please re-read.

        Kind Regards,
        Artur

        G 3 Replies Last reply
        0
        • artwawA artwaw

          @gabor53 of course. Model's data() method returns QVariant, you can get QByteArray this way.

          G Offline
          G Offline
          gabor53
          wrote on last edited by gabor53
          #25
          This post is deleted!
          1 Reply Last reply
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          • artwawA artwaw

            @gabor53 of course. Model's data() method returns QVariant, you can get QByteArray this way.

            G Offline
            G Offline
            gabor53
            wrote on last edited by
            #26

            @artwaw
            The delegate's paint looks like this:

            void FixViewDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const {
            

            I can get the index of the item from QModelIndex& index, but as there is no model, how can I get the QByteArray from the db (or model)?
            Thank you.

            1 Reply Last reply
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            • artwawA artwaw

              @gabor53 of course. Model's data() method returns QVariant, you can get QByteArray this way.

              G Offline
              G Offline
              gabor53
              wrote on last edited by
              #27

              @artwaw
              As I have no access to the model, is it OK to use a query to get the bytearray from the model?

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              • SGaistS Offline
                SGaistS Offline
                SGaist
                Lifetime Qt Champion
                wrote on last edited by
                #28

                Index is your point of access to the model. See QModelIndex::data.

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

                G 1 Reply Last reply
                2
                • SGaistS SGaist

                  Index is your point of access to the model. See QModelIndex::data.

                  G Offline
                  G Offline
                  gabor53
                  wrote on last edited by
                  #29

                  @SGaist
                  I tried the following:

                  QVariant fixImg;
                  
                    fixImg = index.data (Qt::DisplayRole);
                  
                    QPixmap pixMap2;
                    pixMap2 = fixImg.value<QPixmap>();
                  
                    qDebug() << "pixMap2 size: " << pixMap2.size ();
                    qDebug() << "pixMap2 width: " << pixMap2.width ();
                  
                  

                  No error message, but the size is 0. Did I miss a step?
                  Thank you.

                  1 Reply Last reply
                  0
                  • SGaistS Offline
                    SGaistS Offline
                    SGaist
                    Lifetime Qt Champion
                    wrote on last edited by SGaist
                    #30

                    Do you store a QPixmap in your model for that role ?

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

                    G 1 Reply Last reply
                    0
                    • G Offline
                      G Offline
                      gabor53
                      wrote on last edited by
                      #31

                      It's a QByteArray.

                      jsulmJ 1 Reply Last reply
                      0
                      • SGaistS SGaist

                        Do you store a QPixmap in your model for that role ?

                        G Offline
                        G Offline
                        gabor53
                        wrote on last edited by
                        #32

                        @SGaist
                        I ran

                         QVariant fixImg(index.data (Qt::EditRole));
                        
                          qDebug() << "QVariant type: " << fixImg.type ();
                        

                        and the result was
                        QVariant type: QVariant::QString

                        1 Reply Last reply
                        0
                        • G gabor53

                          It's a QByteArray.

                          jsulmJ Offline
                          jsulmJ Offline
                          jsulm
                          Lifetime Qt Champion
                          wrote on last edited by
                          #33

                          @gabor53 said in Reading image from QSqlTableModel:

                          It's a QByteArray.

                          QByteArray of what? What and how are you storing in the DB? What is the data type of the corresponding column?

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

                          G 1 Reply Last reply
                          0
                          • jsulmJ jsulm

                            @gabor53 said in Reading image from QSqlTableModel:

                            It's a QByteArray.

                            QByteArray of what? What and how are you storing in the DB? What is the data type of the corresponding column?

                            G Offline
                            G Offline
                            gabor53
                            wrote on last edited by
                            #34

                            @jsulm
                            QByteArray of the original image. The data type of that column is BLOB.

                            raven-worxR 1 Reply Last reply
                            0
                            • G gabor53

                              @jsulm
                              QByteArray of the original image. The data type of that column is BLOB.

                              raven-worxR Offline
                              raven-worxR Offline
                              raven-worx
                              Moderators
                              wrote on last edited by raven-worx
                              #35

                              @gabor53
                              i asked in a post before:

                              QByteArray ba = fixModel->record (1).value ("Pic").toByteArray ();
                              qDebug() << ba.size() << ba;
                              

                              in your delegates paint() method (if really a QByteArray is returned) do the following:

                              if( index.column() == NUMBER_OF_PIXMAP_COLUMN )
                              {
                                    QByteArray ba = index.data( ROLE_USED_IN_MODEL ).toByteArray();
                                   QPixmap pix;
                                      pix.loadFromData ( ba );
                                   painter->save();
                                       painter->translate( option.rect.topLeft() );
                                       painter->drawPixmap( pix );
                                   painter->restore();
                              }
                              

                              I you should probably post your model code to avoid further guessing.

                              --- SUPPORT REQUESTS VIA CHAT WILL BE IGNORED ---
                              If you have a question please use the forum so others can benefit from the solution in the future

                              VRoninV 1 Reply Last reply
                              0
                              • raven-worxR raven-worx

                                @gabor53
                                i asked in a post before:

                                QByteArray ba = fixModel->record (1).value ("Pic").toByteArray ();
                                qDebug() << ba.size() << ba;
                                

                                in your delegates paint() method (if really a QByteArray is returned) do the following:

                                if( index.column() == NUMBER_OF_PIXMAP_COLUMN )
                                {
                                      QByteArray ba = index.data( ROLE_USED_IN_MODEL ).toByteArray();
                                     QPixmap pix;
                                        pix.loadFromData ( ba );
                                     painter->save();
                                         painter->translate( option.rect.topLeft() );
                                         painter->drawPixmap( pix );
                                     painter->restore();
                                }
                                

                                I you should probably post your model code to avoid further guessing.

                                VRoninV Offline
                                VRoninV Offline
                                VRonin
                                wrote on last edited by
                                #36
                                • I don't like index.column() == NUMBER_OF_PIXMAP_COLUMN as it ties the delegate to a single model so I consider it bad design, view->setItemDelegateForColumn() should be used instead.
                                • index.data( ROLE_USED_IN_MODEL ) it's a QSqlTableModel so just delete ROLE_USED_IN_MODEL and use the default
                                • It's a QStyledItemDelegate so let's use style
                                void FixViewDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const {
                                QPixmap loadedImage;
                                loadedImage.loadFromData(index.data().toByteArray());
                                const QWidget *widget = option.widget;
                                QStyle *style = widget ? widget->style() : QApplication::style();
                                style->drawItemPixmap(painter,option.rect,Qt::AlignCenter,loadedImage);
                                }
                                

                                "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

                                G 2 Replies Last reply
                                3
                                • VRoninV VRonin
                                  • I don't like index.column() == NUMBER_OF_PIXMAP_COLUMN as it ties the delegate to a single model so I consider it bad design, view->setItemDelegateForColumn() should be used instead.
                                  • index.data( ROLE_USED_IN_MODEL ) it's a QSqlTableModel so just delete ROLE_USED_IN_MODEL and use the default
                                  • It's a QStyledItemDelegate so let's use style
                                  void FixViewDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const {
                                  QPixmap loadedImage;
                                  loadedImage.loadFromData(index.data().toByteArray());
                                  const QWidget *widget = option.widget;
                                  QStyle *style = widget ? widget->style() : QApplication::style();
                                  style->drawItemPixmap(painter,option.rect,Qt::AlignCenter,loadedImage);
                                  }
                                  
                                  G Offline
                                  G Offline
                                  gabor53
                                  wrote on last edited by
                                  #37
                                  This post is deleted!
                                  1 Reply Last reply
                                  0
                                  • VRoninV VRonin
                                    • I don't like index.column() == NUMBER_OF_PIXMAP_COLUMN as it ties the delegate to a single model so I consider it bad design, view->setItemDelegateForColumn() should be used instead.
                                    • index.data( ROLE_USED_IN_MODEL ) it's a QSqlTableModel so just delete ROLE_USED_IN_MODEL and use the default
                                    • It's a QStyledItemDelegate so let's use style
                                    void FixViewDelegate::paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const {
                                    QPixmap loadedImage;
                                    loadedImage.loadFromData(index.data().toByteArray());
                                    const QWidget *widget = option.widget;
                                    QStyle *style = widget ? widget->style() : QApplication::style();
                                    style->drawItemPixmap(painter,option.rect,Qt::AlignCenter,loadedImage);
                                    }
                                    
                                    G Offline
                                    G Offline
                                    gabor53
                                    wrote on last edited by
                                    #38

                                    @VRonin
                                    Thank you. It runs without error, but paint nothing in the view.

                                    1 Reply Last reply
                                    0
                                    • VRoninV Offline
                                      VRoninV Offline
                                      VRonin
                                      wrote on last edited by
                                      #39

                                      How do you save your image in the database? do you save it via Qt? can you show us the save part of the code?

                                      "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

                                      G 1 Reply Last reply
                                      0
                                      • VRoninV VRonin

                                        How do you save your image in the database? do you save it via Qt? can you show us the save part of the code?

                                        G Offline
                                        G Offline
                                        gabor53
                                        wrote on last edited by gabor53
                                        #40

                                        @VRonin
                                        Sure. I also added

                                         qDebug() << "loadedImage size: " << loadedImage.size ();
                                        

                                        and the result is
                                        loadedImage size: QSize(0, 0)

                                        I save the image via Qt like this:

                                        #include "review.h"
                                        #include "ui_review.h"
                                        
                                        Review::Review(QWidget* parent) :
                                          QDialog(parent),
                                          ui(new Ui::Review) {
                                          ui->setupUi(this);
                                        
                                          connect(this, &Review::RecAdded, this, &Review::updateTable);
                                        
                                        }
                                        
                                        Review::~Review() {
                                          delete ui;
                                        }
                                        
                                        void Review::dispRev(QString sID, QString& name, QString& whatChosen, QString& fileNameChosen, QString& materialChosen, QString& colorChosen, QString& description, QDate& adoptDate, QString& SignedbyChosen, QString& history, QString& age, QString& notesTemp) {
                                          name = name.simplified ();
                                          description = description.simplified ();
                                        
                                          ui->ID_display_Label->setText (sID);
                                          ui->Name_Disp_Label->setText (name);
                                          ui->What_Display_Label->setText (whatChosen);
                                          ui->MadeOf_Disp_Label->setText (materialChosen);
                                          ui->Color_Disp_Label->setText (colorChosen);
                                          ui->textBrowser_Descr->setText (description);
                                          adoptDateStr = adoptDate.toString ("MM/dd/yyyy");
                                          ui->AdoptionDate_Disp_Label->setText (adoptDateStr);
                                          ui->SignedBy_Disp_label->setText (SignedbyChosen);
                                          ui->textBrowser_History->setText (history);
                                          ui->Age_Display_Label_2->setText (age);
                                          ui->textBrowser_Notes->setText (notesTemp);
                                        
                                        
                                          QPixmap pix2(fileNameChosen);
                                          int w = 0;
                                          int h = 0;
                                          w = ui->Image_Display_Label->width ();
                                          h = ui->Image_Display_Label->height ();
                                          ui->Image_Display_Label->setPixmap (pix2.scaled(w, h, Qt::KeepAspectRatio));
                                        
                                          QFile fileReview(fileNameChosen);
                                        
                                          if(fileReview.open (QIODevice::ReadOnly)) {
                                            fileByteArray = fileReview.readAll ();
                                          }
                                        
                                          nameReview = name;
                                          whatReview = whatChosen;
                                          fileNameReview = fileNameChosen;
                                          materialReview = materialChosen;
                                          colorReview = colorChosen;
                                          descriptionReview = description;
                                          adoptDateReview = adoptDate;
                                          SignedbyReview = SignedbyChosen;
                                          historyReview = history;
                                          sIDReview = sID;
                                          ageReview = age;
                                          notesReview = notesTemp;
                                        
                                        }
                                        
                                        
                                        void Review::on_pushButton_Add_to_DB_clicked() {
                                        
                                        //    date = adoptDateReview.toString ("MM/dd/yyyy");
                                          qDebug() << "date in review.cpp: " << date;
                                          QSqlDatabase db = QSqlDatabase::addDatabase ("QSQLITE", "writedb");
                                          db.setDatabaseName (fileQstring);
                                        
                                          QSqlQuery querys(db);
                                        
                                          if(!db.open ())
                                        
                                          {
                                            qDebug() << "The database is not open (submit)!";
                                          } else {
                                            qDebug() << "The database is open (submit)!";
                                          }
                                          querys.prepare("INSERT INTO Items (ID, Name, Pic, Description, AdoptDate, History, Age, Notes, Color, Material, Signed, What) VALUES(:ID, :Name, :Pic, :Description, :AdoptDate, :History, :Age, :Notes, :Color, :Material, :Signed, :What)" );
                                          querys.bindValue (":ID", sIDReview);
                                          querys.bindValue (":Name", nameReview);
                                          querys.bindValue (":Pic", fileByteArray);
                                          querys.bindValue (":Description", descriptionReview);
                                          querys.bindValue (":AdoptDate", adoptDateStr);
                                          querys.bindValue (":History", historyReview);
                                          querys.bindValue (":Age", ageReview);
                                          querys.bindValue (":Notes", notesReview);
                                          querys.bindValue (":Color", colorReview);
                                          querys.bindValue (":Material", materialReview);
                                          querys.bindValue (":Signed", SignedbyReview);
                                          querys.bindValue (":What", whatReview);
                                        
                                          bool result = querys.exec ();
                                        
                                          if(!result) {
                                            qDebug() << "Error inserting into the main db!" << querys.lastError ();
                                        
                                            QMessageBox::warning (this, "Add to Database Warning", "<b><font size='16' color='red'>Error 1002: The Friend was not added to the database.");
                                        
                                          } else {
                                            qDebug() << "Entered FunctAdd OK loop.";
                                        
                                            QMessageBox::information (this, "Confirmation", "<b><font size = '16' color = 'green'>The Friend was added to the database.</font>");
                                        
                                        
                                        
                                            emit RecAdded ();
                                          }
                                        }
                                        
                                        
                                        void Review::on_pushButton_Fix_clicked() {
                                          Additem* mAdditem = new Additem(this);
                                          mAdditem->FixFriend (sIDReview, nameReview, whatReview, fileNameReview, materialReview, colorReview, descriptionReview, date, SignedbyReview, historyReview, ageReview, notesReview);
                                        
                                        
                                          mAdditem->show ();
                                        }
                                        
                                        
                                        void Review::updateTable() {
                                          qDebug() << "Entered updateTable!";
                                          MainWindow* mMainWindow = new MainWindow(this);
                                        
                                          mMainWindow->Addview ();
                                          mMainWindow->show ();
                                        }
                                        
                                        

                                        Data in the db is stored as BLOB.

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                                        • SGaistS Offline
                                          SGaistS Offline
                                          SGaist
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #41

                                          You don't do anything in case fileReview.open fails so you might be storing empty QByteArrays in your database.

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

                                          G 1 Reply Last reply
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