QStiledItemDelegate setModelData doesn't display image

[SGaist]

Like I already wrote somewhere else: QSqlTableModel doesn't handle Qt::Decoration in its setData implementation (or rather it calls the base class implementation and following up that chain, it ends with nothing done) so if you want to use it you have to handle it yourself.

Otherwise, you can use the EditRole as usual to store the data and paint the image when the decoration role is requested..

[gabor53]

@SGaist
I changed setModelData:

void FixViewDelegate::setModelData(QWidget* editor, QAbstractItemModel* fixModel, const QModelIndex& index) const {
  qDebug() << "Entered setModelData. ";

  ImagePickButton* imgPick = qobject_cast<ImagePickButton*>(editor);
  Q_ASSERT(imgPick);

  QString value;
  value = imgPick->selectedFile ();

  QPixmap newImage(value);
  newImage = newImage.scaled (100, 100, Qt::KeepAspectRatio);
  qDebug() << "newImage size: " << newImage.size ();

  qDebug()  << "Index: " << index;

  if(fixModel->setData(index, newImage, Qt::EditRole) == true) {
    qDebug() << "Data IS set. ";
  } else {
    qDebug() << "Data is NOT set. ";
  }
}

Everything looks ok (newImage exists and Data is set), but it still doesn't paint the image and it is not saved in the db either. Do I need to implement saving and painting, or something is still incorrect?

[VRonin]

Apologies, I did not read the model was QSqlTableModel. You can put a proxy like this one (You'll have to add if(role==Qt::EditRole) return QIdentityProxyModel::setData(index,value,role); in line 29) in between to make the multiple roles work. On the other hand, you latest implementations of setModelData look like you do not completely understand how models work and you are panicking and try to mix a bunch of stuff together hoping that it works

#include "fixviewdelegate.h"

FixViewDelegate::FixViewDelegate(QObject* parent) : QStyledItemDelegate(parent) {
  qDebug() << "Entered fixViewDelegate (1).";
}

QWidget* FixViewDelegate::createEditor(QWidget* parent, const QStyleOptionViewItem& option, const QModelIndex& index) const {

  qDebug() << "Entered createEditor";
  Q_UNUSED(option);
  Q_UNUSED(index);


  return new ImagePickButton(parent);


}

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

 QPixmap loadedImage=index.data(Qt::DecorationRole).value<QPixmap>();


 

  const QWidget* widget = option.widget;


  QStyle* style = widget ? widget->style() : QApplication::style();
  style->drawItemPixmap (painter, option.rect, Qt::AlignCenter, loadedImage);

}

void FixViewDelegate::updateEditorGeometry(QWidget* editor, const QStyleOptionViewItem& option, const QModelIndex& index) const {
  Q_UNUSED(index);
  editor->setGeometry(option.rect);
}

void FixViewDelegate::setEditorData(QWidget* editor, const QModelIndex& index) const {

  qDebug() << "Entered setEditorData.";
  ImagePickButton* imgPick = qobject_cast<ImagePickButton*>(editor);
  Q_ASSERT(imgPick);
  imgPick->setSelectedFile(index.data(Qt::UserRole).toString());

}

void FixViewDelegate::setModelData(QWidget* editor, QAbstractItemModel* fixModel, const QModelIndex& index) const {
  qDebug() << "Entered setModelData. ";

  ImagePickButton* imgPick = qobject_cast<ImagePickButton*>(editor);
  Q_ASSERT(imgPick);

  QString value;
  value = imgPick->selectedFile ();

  QPixmap newImage(value);
if(newImage.isNull()){
fixModel->setData(index, QVariant(), Qt::DecorationRole);
fixModel->setData(index, QVariant(), Qt::UserRole);
return;
}
  newImage = newImage.scaled (100, 100, Qt::KeepAspectRatio);
  qDebug() << "newImage size: " << newImage.size ();

  qDebug()  << "Index: " << index;

  fixModel->setData(index, newImage, Qt::DecorationRole);
fixModel->setData(index, value, Qt::UserRole);
}

You will still need to use the proxy I linked above inbetween

[gabor53]

@VRonin
Thank you.
I created a class named ExtraRolesProxyModel.
I added

#include "extrarolesproxymodel.h"

to fixviewdelegate.h.
My fixviewdelegate.cpp looks like this now:

#include "fixviewdelegate.h"

FixViewDelegate::FixViewDelegate(QObject* parent) : QStyledItemDelegate(parent) {
  qDebug() << "Entered fixViewDelegate (1).";
}

QWidget* FixViewDelegate::createEditor(QWidget* parent, const QStyleOptionViewItem& option, const QModelIndex& index) const {

  qDebug() << "Entered createEditor";
  Q_UNUSED(option);
  Q_UNUSED(index);


  return new ImagePickButton(parent);


}

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

  if(role == Qt::EditRole) return;
  QIdentityProxyModel::setData(index, value, role);

  QPixmap loadedImage = index.data (Qt::DecorationRole).value<QPixmap>();

//  loadedImage.loadFromData (index.data ().toByteArray ()) ;
//  loadedImage = loadedImage.scaled (100, 100, Qt::KeepAspectRatio);

  const QWidget* widget = option.widget;

 QStyle* style = widget ? widget->style() : QApplication::style();
  style->drawItemPixmap (painter, option.rect, Qt::AlignCenter, loadedImage);
}

void FixViewDelegate::updateEditorGeometry(QWidget* editor, const QStyleOptionViewItem& option, const QModelIndex& index) const {
  Q_UNUSED(index);
  editor->setGeometry(option.rect);
}

void FixViewDelegate::setEditorData(QWidget* editor, const QModelIndex& index) const {

  qDebug() << "Entered setEditorData.";
  ImagePickButton* imgPick = qobject_cast<ImagePickButton*>(editor);
  Q_ASSERT(imgPick);
  imgPick->setSelectedFile(index.data(Qt::UserRole).toString());

}

void FixViewDelegate::setModelData(QWidget* editor, QAbstractItemModel* fixModel, const QModelIndex& index) const {
  qDebug() << "Entered setModelData. ";

  ImagePickButton* imgPick = qobject_cast<ImagePickButton*>(editor);
  Q_ASSERT(imgPick);

  QString value;
  value = imgPick->selectedFile ();

  QPixmap newImage(value);
  if(newImage.isNull ()) {
    fixModel->setData (index, QVariant(), Qt::DecorationRole);
    fixModel->setData (index, QVariant(), Qt::UserRole);
    return;
  }


  newImage = newImage.scaled (100, 100, Qt::KeepAspectRatio);
  qDebug() << "newImage size: " << newImage.size ();

  qDebug()  << "Index: " << index;

//  if(fixModel->setData(index, newImage, Qt::EditRole) == true) {
//    qDebug() << "Data IS set. ";
//  } else {
//    qDebug() << "Data is NOT set. ";
//  };

  fixModel->setData (index, newImage, Qt::DecorationRole);
  fixModel->setData (index, newImage, Qt::UserRole);
}

When I build it it gives the following errors:
'role' was not declared in this scope.
'value' was not declared in this scope.
Did I add the proxy incorrectly?

[VRonin]

That's a proxy model, it has nothing to do with the delegate. I have no idea why you merged the 2. I gave you the code of both the delegate and the proxy model. You just have to copy-paste them, add 1 single line I posted at the place I posted inside extrarolesproxymodel.h it and then use them

[gabor53]

@VRonin
Is

if(role == Qt::EditRole) return QIdentityProxyModel::setData(index, value, role);

goes into extrarolesproxymodel.h or cpp?
There are no line 29 in .h. If it goes to the cpp file it replaces line 29, goes before or after?
I tried to add it before and after

 if(!index.isValid()) return false;

in cpp. Tried to place it before and after line 29 and actually replaced line 29 but still images were not displayed.

[VRonin]

@gabor53 said in QStiledItemDelegate setModelData doesn't display image:

goes into extrarolesproxymodel.h or cpp?

The link I posted is header only so I don't know what you are referring to. Use the line numbering you see in pastebin to understand where to put it

[gabor53]

@VRonin
extraroleproxymodel.h looks like this:

#include <QIdentityProxyModel>
#include <QVariant>
#include <QHash>
class ExtraRolesProxyModel : public QIdentityProxyModel {
  Q_OBJECT
  Q_DISABLE_COPY(ExtraRolesProxyModel)
 public:
  ExtraRolesProxyModel(QObject* parent = Q_NULLPTR)
    : QIdentityProxyModel(parent) {

  }
  virtual QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const Q_DECL_OVERRIDE {
    if(!index.isValid()) return QIdentityProxyModel::data(index, role);
    const QHash<int, QHash<int, QHash<int, QVariant> > >::const_iterator rowIter = m_extraData.constFind(index.row());
    if(rowIter == m_extraData.cend())
      return QIdentityProxyModel::data(index, role);
    const QHash<int, QHash<int, QVariant> >::const_iterator colIter = rowIter->constFind(index.column());
    if(colIter == rowIter->cend())
      return QIdentityProxyModel::data(index, role);
    const QHash<int, QVariant>::const_iterator roleIter = colIter->constFind(role);
    if(roleIter == colIter->cend())
      return QIdentityProxyModel::data(index, role);
    return roleIter.value();
  }
  virtual bool setData(const QModelIndex& index, const QVariant& value, int role = Qt::EditRole)Q_DECL_OVERRIDE{
    if(!index.isValid()) return false;
    if(role == Qt::EditRole) return QIdentityProxyModel::setData(index, value, role);
    if(index.parent().isValid()) return QIdentityProxyModel::setData(index, value, role);
    QHash<int, QHash<int, QHash<int, QVariant> > >::iterator rowIter = m_extraData.find(index.row());
    if(rowIter == m_extraData.end()) {
      if(value.isNull()) return false;
      rowIter = m_extraData.insert(index.row(), QHash<int, QHash<int, QVariant> >());
    }
    QHash<int, QHash<int, QVariant> >::iterator colIter = rowIter->find(index.column());
    if(colIter == rowIter->end()) {
      if(value.isNull()) return false;
      colIter = rowIter->insert(index.column(), QHash<int, QVariant>());
    }
    QHash<int, QVariant>::iterator roleIter = colIter->find(role);
    if(roleIter == colIter->end()) {
      if(value.isNull()) return false;
      roleIter = colIter->insert(role, value);
      return true;
    }
    if(value.isNull()) {
      colIter->erase(roleIter);
      if(colIter->isEmpty()) {
        rowIter->erase(colIter);
        if(rowIter->isEmpty()) {
          m_extraData.erase(rowIter);
        }
      }
      return true;
    }
    roleIter.value() = value;
    return true;
  }
 private:
  QHash<int, QHash<int, QHash<int, QVariant> > > m_extraData;
};

It gives the following errors:
C:\Programming\Projects\Folkfriends_bzr\checkout\extrarolesproxymodel.cpp:5: error: redefinition of 'QVariant ExtraRolesProxyModel::data(const QModelIndex&, int) const'
QVariant ExtraRolesProxyModel::data(const QModelIndex& index, int role) const {
^
C:\Programming\Projects\Folkfriends_bzr\checkout\extrarolesproxymodel.cpp:21: error: redefinition of 'bool ExtraRolesProxyModel::setData(const QModelIndex&, const QVariant&, int)'
bool ExtraRolesProxyModel::setData(const QModelIndex& index, const QVariant& value, int role) {
^
Am I still doing something incorrectly?
Thank you.

[SGaist]

Like the error suggests: you have the functions implemented twice. Once in the header and once in the .cpp file.

[VRonin]

either properly split declarations and definitions between .h and .cpp or just leave everything in the .h file and delete extrarolesproxymodel.cpp altogether. The compilation process takes a bit longer but your compiler should be smart enough to avoid any difference in performance from one to the other in release mode

[gabor53]

@VRonin
Now I'm just using the code in the .h file and there is no error.

I have the

 if(role == Qt::EditRole) return QIdentityProxyModel::setData(index, value, role);

line after

if(!index.isValid()) return false;

(that is line 29) and I pushed the original line 29 one line down. Was that the correct way?
At this point no error message, but no image displayed either. Do I need to link the proxy to fixdb.cpp or fixviewdelegate .cpp?

[gabor53]

@VRonin
How can I connect the proxy to my oriinal model or fixdb?

[VRonin]

http://doc.qt.io/qt-5/qabstractproxymodel.html#setSourceModel

[gabor53]

@VRonin
Is this supposed to go in the ExtraRolesProxyModel?