QTableView and Image

[VRonin]

• Where does m_image come from?
• Are you subclassing QItemDelegate or QStyledItemDelegate?
• Are you implementing myDelegate::sizeHint?

---

LEAKFEST!

The view does not own either the model or the delegate. You need to pass a parent to them or they are leaked

[MokJ]

thank you @VRonin , It was a mistake of mine ,that I didn't provide the complete information.
I'm subclassing QItemDelegate....on this note how its different from subclassing QStyledItemDelegate?? I mean Qt document says that

QStyledItemDelegate uses the current style to paint its items

whats the current style here !!

QSize myDelegate::sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const{
          return  QSize newSize(70,30);
}

QImage m_image(":/new/prefix1/d.jpg");

m_image is in private of myDelegate.

[VRonin]

So m_image does not depend at all on what's in the model?

@MokJ said in QTableView and Image:

whats the current style here !!

http://doc.qt.io/qt-5/style-reference.html

Let's go step by step. The below should be an improvement already, correct?

void myDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const{
(option.widget ? option.widget.style() : QApplication::style())->drawItemPixmap(painter,option.rect(),QPixmap::fromImage(m_image.scaled(option.rect().size())));
}

[MokJ]

@VRonin Thanks
yes, m_image doesn't depend on model at all.
I'm clear about current style now.

Let's go step by step. The below should be an improvement already, correct?

yes , after a small change It has improved.
So whats the next step !
What method should be used to get desired output !

@MokJ said in QTableView and Image:

Another thing is , is it possible to create something like, whenever a block from QTableView is selected ,the image on that particular block should get changed?

[VRonin]

@MokJ said in QTableView and Image:

So whats the next step !

We make the image depend on the model.
In the constructor add:

connect(view->selectionModel(),&QItemSelectionModel::selectionChanged,[view](const QItemSelection &selected, const QItemSelection &deselected)->void{
QModelIndexList indexList = selected.indexes();
for(auto& index : qAsConst(indexList))
view->model()->setData(index,true,Qt::UserRole);
indexList = deselected.indexes();
for(auto& index : qAsConst(indexList))
view->model()->setData(index,QVariant(),Qt::UserRole);
});

now in myDelegate::paint you can add if(index.data(Qt::UserRole).toBool()) to check if an item is selected or not

[MokJ]

@VRonin Thank you
I have added that snippet too, now question is , How is it making m_image depend on model ?

[VRonin]

@MokJ I made a mistake, if(index.data().toBool()) should have been if(index.data(Qt::UserRole).toBool()) fixed above now

P.S.
if(index.data(Qt::UserRole).isValid()) does the same and it's probably more efficient

[MokJ]

@VRonin
I'm a bit confused about how its supposed to work. I mean once I select an Index it goes inside

if(index.data(Qt::UserRole).isValid()) {}

What should get implemented in If?

I appreciate your help greatly.

[hjohn]

@VRonin
can we take the Image as string ?

[MokJ]

@VRonin
I got it,
in If , I'm drawing the new Image.
Thanks very much @VRonin.
Now If we want to keep that image in model should we implement

void setModelData(QWidget*editor,QAbstractItemModel *model,const QModelIndex &index)const

again thanks @VRonin .

[MokJ]

@hjohn
I came across this , maybe it could be helpful.