QTreeView in QTreeWidgetItem

[Craetor]

Hi, guys!

I have QTreeWidget with QTreeWidgetItems.
QTreeWidgetItem should contain QTreeView.

It work, but i need to resize QTreeView automaticaly by content.
tree->setSizeAdjustPolicy(QAbstractScrollArea::AdjustToContents); // do not work

void MainWindow::addTreeView()
{
    QFileSystemModel *model = new QFileSystemModel();
    model->setRootPath(QDir::currentPath());

    QTreeView *tree = new QTreeView();
    tree->setModel(model);
    tree->setRootIndex(model->index(QDir::currentPath()));

    // ??
    tree->setSizeAdjustPolicy(QAbstractScrollArea::AdjustToContents);   // not work
    tree->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);

    QTreeWidgetItem *item = new QTreeWidgetItem(ui->treeWidget);
    ui->treeWidget->setItemWidget(item, 0, tree);

    // ??
    ui->treeWidget->setSizeAdjustPolicy(QAbstractScrollArea::AdjustToContents);
    ui->treeWidget->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    addTreeView();
    addTreeView();
}

How it can be implemented?

[jsulm]

@Craetor said in QTreeView in QTreeWidgetItem:

QTreeWidgetItem should contain QTreeView.

I don't understand this: do you mean an item in your tree should contain another tree?!

[Craetor]

@jsulm, yes, on screenshot you can see tree QTreeWidget with QTreeWidgetItem which the contain QTreeView.
But QTreeView can't execute setSizeAdjustPolicy - AdjustToContents.

[qwasder85]

This can't be solved with a single QTreeWidget and a clever model instead? I'm surprised you got this to work.

[Craetor]

@qwasder85,
how it can be solved?

[Craetor]

I fixed this issue.

1. QTreeView return correct sizeHint for AdjustToContents.
2. I implemented QStyledItemDelegate for sending sizeHint to QTreeWidgetItem from the QTreeView and force call QTreeWidget updateGeometries.
3. Child class of QTreeView call SetData(0, Qt::SizeHintRole, sizeHint()) for QTreeWidgetItem on expanded and collapsed

it work fine, may be it very strange way, but i don't known another)

QSize CSResizeDelegate::sizeHint(const QStyleOptionViewItem&, const QModelIndex& index) const
{
    CSResizableTreeWidgetItem *item = static_cast<CSResizableTreeWidgetItem*>(index.internalPointer());
    if(item->treeWidget())
        ((CSResizableTreeWidget*)item->treeWidget())->updateGeometriesPublic(); // force call QTreeWidget::updateGeometries
    return item->getTree()->sizeHint(); // return QTreeView::sizeHint
}

[JonB]

@Craetor
Just to say: I don't really know what you're trying to achieve here. You say you're nesting QTreeViews within QTreeWidget, why do you not just use 2 separate QTreeWidget/Views? But I may not be understanding...

[Craetor]

@JonB
This code is a small example to find solution.
In my real project i need to show tree with different items and nested trees.