QStandardItemModel and QStandardItem

[DmitryNik]

Hello!

I have a question which concerns models and items in models and probably a bit QVariant. The question is: why will not appear a picture after executing the code presented bellow?

QStandardItem *item2 = new QStandardItem;
    QVariant v1;
    QIcon ico(":/block.png");
    v1.setValue(ico);
    item2->setData(v1, Qt::DisplayRole);
    model->setItem(0, 0, item2);
    QTreeView *tv = new QTreeView;
    tv->setModel(model);
    tv->show();

QStandardItem *item2 = new QStandardItem;
    QVariant v1;
    QIcon ico(":/block.png");
    v1.setValue(ico);
    item2->setData(v1, Qt::DisplayRole);
    model->setItem(0, 0, item2);
    QTreeView *tv = new QTreeView;
    tv->setModel(model);
    tv->show();

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And another question, which was born by my curiosity, is: Does QStandardItem class's method setData work only with primitive data, such strings, integers etc.? Does it depend on QVariant-class?

[llev]

Try to use setIcon instead of item2->setData(v1, Qt:isplayRole);
Does it work as expected?

[DmitryNik]

Thank you for answer.

Yes, it works perfectly. But still, it's a bit strange that setData() - method works only for text-data(in this case: strings, numbers etc.).

[llev]

Just take a look at implementation of setIcon:

inline void QStandardItem::setIcon(const QIcon &aicon)
{ 
  setData(aicon, Qt::DecorationRole); 
}

inline void QStandardItem::setIcon(const QIcon &aicon)
{ 
  setData(aicon, Qt::DecorationRole); 
}

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It seems the role rules

[DmitryNik]

Now I got it. Thank you for answering!

[wysota]

Does QStandardItem class's method setData work only with primitive data, such strings, integers etc.? Does it depend on QVariant-class?

It works with anything that can fit into QVariant. Since you can fit practically anything there, it works practically with anything.