resizing a QTreeWidget

[drhex]

I'm trying to get a QTreeWidget to show a text column and some equally sized checkbox columns. This eventually works, but the QTreeWidget seems hell-bent on showing up at 256x192 pixels, although the stuff put in it requires less space.

QWidget::adjustSize() claims to resize a widget to fit the contents, but does not.
Calling resize() on the QTreeWidget helps if it is a top level widget, but does nothing if it is in a layout together with other widgets.

It is possible to let the user manually adjust the size after it is rendered, but how does one resize a QTreeWidget to fit its contents from code? (Tested in Qt-4.2.0-rc1)

/Joakim Rosqvist

#include <QApplication>
#include <QTreeWidget>
#include <QHeaderView>
#include <QHBoxLayout>
 
int main( int argc, char **argv )
{
    QApplication app( argc, argv );
 
    QWidget *hbox = new QWidget;
    QHBoxLayout *lay;
    hbox->setLayout(lay = new QHBoxLayout);
 
    QTreeWidget *tw = new QTreeWidget;
    tw->setColumnCount(3);
    QTreeWidgetItem *twi = new QTreeWidgetItem;
    twi->setText(0,"Text");
    twi->setCheckState(1,Qt::Checked);
    twi->setCheckState(2,Qt::Checked);
    tw->addTopLevelItem(twi);
    tw->resizeColumnToContents(0);
    tw->resizeColumnToContents(1);
    tw->resizeColumnToContents(2);
    tw->header()->setResizeMode(0, QHeaderView::Interactive);
    tw->header()->setResizeMode(1, QHeaderView::ResizeToContents);
    tw->header()->setResizeMode(2, QHeaderView::ResizeToContents);
    tw->header()->setStretchLastSection(false);
 
    tw->adjustSize();     // no effect!
    tw->resize(110,100);  // no effect!
 
    lay->addWidget(tw);
    hbox->show();
    app.exec();
    return 0;
}

#include <QApplication>
#include <QTreeWidget>
#include <QHeaderView>
#include <QHBoxLayout>

int main( int argc, char **argv )
{
    QApplication app( argc, argv );

    QWidget *hbox = new QWidget;
    QHBoxLayout *lay;
    hbox->setLayout(lay = new QHBoxLayout);

    QTreeWidget *tw = new QTreeWidget;
    tw->setColumnCount(3);
    QTreeWidgetItem *twi = new QTreeWidgetItem;
    twi->setText(0,"Text");
    twi->setCheckState(1,Qt::Checked);
    twi->setCheckState(2,Qt::Checked);
    tw->addTopLevelItem(twi);
    tw->resizeColumnToContents(0);
    tw->resizeColumnToContents(1);
    tw->resizeColumnToContents(2);
    tw->header()->setResizeMode(0, QHeaderView::Interactive);
    tw->header()->setResizeMode(1, QHeaderView::ResizeToContents);
    tw->header()->setResizeMode(2, QHeaderView::ResizeToContents);
    tw->header()->setStretchLastSection(false);

    tw->adjustSize();     // no effect!
    tw->resize(110,100);  // no effect!

    lay->addWidget(tw);
    hbox->show();
    app.exec();
    return 0;
}

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