I have a working model derived from QAbstractTableModel. It's currently happily populating lists and tables with the appropriate values.

I want to display a selected item in a widget view with some labels, text fields, etc.

Currently, I'm just trying to statically display the first item in the list to see it work. Code references are below.

First, I did not use mapper->setCurrentModelIndex(), but the mapper->toFirst() method always returned a QModelIndex of (-1,-1).

I'm having a lot of issues debugging because this seems to do virtually nothing.

It appears like it cycles through the items and calls the data() method with the Qt::EditRole, but that's it.

Currently, editing of values is not implemented. I just need to display them in the widget fields. Am I not using QDataWidgetMapper correctly? Is it only for editable widgets? Why is it only calling the EditRole and never the DisplayRole?

Any tips are greatly appreciated.

My Model:

Qt Code: 
  1. #ifndef COMPONENTMODEL_H
  2. #define COMPONENTMODEL_H
  3. #include <QAbstractTableModel>
  4. #include <QResource>
  5. #include <QStringList>
  6. #include <QIcon>
  7.  
  8. #include "Common/Global.h"
  9. #include "Components/ComponentList.h"
  10. #include "Components/ComponentInterface.h"
  11.  
  12. namespace kex
  13. {
  14.   class ComponentModel : public QAbstractTableModel
  15.   {
  16.     Q_OBJECT
  17.  
  18.   public:
  19.     ComponentModel(int types = ComponentInterface::AllComponents, 
  20.                    QObject *parent = 0);
  21.  
  22.     /** \brief  Default destructor.
  23.      *
  24.      * Copyright 2010 KSpace MRI. All Rights Reserved.
  25.      *
  26.      * \author James Kyle
  27.      * \author $LastChangedBy$
  28.      * \date 2010-4-12
  29.      * \date $LastChangedDate$
  30.      * \version $Rev$
  31.      **/
  32.     ~ComponentModel() {}
  33.  
  34.     int rowCount(const QModelIndex &parent = QModelIndex()) const;
  35.     int columnCount(const QModelIndex &parent = QModelIndex()) const;
  36.  
  37.     QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const;
  38.     QVariant headerData(int section, Qt::Orientation orientation,
  39.                         int role) const;
  40.  
  41.   private:
  42.     const ComponentList::ComponentQList *_componentList;
  43.   public slots:
  44.     void updateComponentList();
  45.   };
  46.  
  47.  
  48. }
  49. #endif // COMPONENTMODEL_H
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My Model's data() method:

Qt Code: 
  1. QVariant ComponentModel::data(const QModelIndex &index, int role) const
  2.   {
  3.     QVariant result;
  4.     if (role == Qt::DecorationRole)
  5.     {
  6.       QIcon icon(":/images/other/Science-64.png");
  7.       result = icon;
  8.     } else if (role == Qt::DisplayRole)
  9.     {
  10.       qDebug() << "called model data() display role";
  11.  
  12.       if (index.row()     < _componentList->count() &&
  13.           index.row()     >= 0 &&
  14.           index.column()  >= 0 &&
  15.           index.column()  < columnCount())
  16.       {
  17.         qDebug() << "valid index";
  18.  
  19.         AbstractComponent::Pointer comp = (*_componentList)[index.row()];
  20.  
  21.         if (index.column() == 0)
  22.         {
  23.           qDebug() << "column 0";
  24.  
  25.           result.setValue(comp->name());
  26.         }
  27.         else {
  28.           result.setValue(QString("a column value"));
  29.         }
  30.       }
  31.     }
  32.     return result;
  33.   }
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The method that configures the QDataWidgetMapper

Qt Code: 
  1. void MainWindow::setUpWidgetMapper()
  2.   {
  3.     // set up the data mapper for displaying
  4.     ComponentModel *model = new ComponentModel(ComponentInterface::AllComponents, 
  5.                                                this);
  6.     mapper->setModel(model);
  7.     mapper->addMapping(componentNameLabel, 0);
  8.     mapper->addMapping(typeNameLabel, 1);
  9.     mapper->addMapping(componentDurationLabel, 4);
  10.     mapper->addMapping(componentDescriptionTextEdit, 3);
  11.     mapper->setSubmitPolicy(QDataWidgetMapper::ManualSubmit);
  12.     mapper->setCurrentModelIndex(model->index(0,0));
  13.     mapper->toFirst();
  14.   }
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