qtqlistviewqsplitter

How to force QAbstractItemView recalculate items sizeHints

I have QListView and QTabWidget inside QSplitter. QListView is using custom model and custom delegates. In delegate I reimplemented paint and sizeHint methods. But when I resize view - height of elements doesn't recalculated. How can I fix it? Sample images:

Before resizingAfter resizing

In google I found that it is possible to emit layoutChanged from the model, but I want only current view to be updated, because content of model doesn't change.

Delegate code:

void ChatItemDelegate::paint( QPainter *painter, const QStyleOptionViewItem& option, const QModelIndex& index ) const
{
    painter->save();

    ChatItem *item = static_cast< ChatItem * >( index.internalPointer() );
    QTextDocument doc;

    doc.setHtml( item->htmlText() );
    doc.setTextWidth( option.rect.width() );

    QRect clip( 0, 0, option.rect.width(), option.rect.height() );
    painter->translate( option.rect.topLeft() );

    QColor bgColor = index.row() % 2 ? QColor( 255, 0, 0, 40 ) : QColor( 0, 255, 0, 40 );
    painter->fillRect( clip, bgColor );
    doc.drawContents( painter, clip );

    qDebug() << "paint: " << option.rect.width() << " idx: " << index.row();

    painter->restore();
}

QSize ChatItemDelegate::sizeHint( const QStyleOptionViewItem& option, const QModelIndex& index ) const
{
    ChatItem *item = static_cast< ChatItem * >( index.internalPointer() );
    QTextDocument doc;

    doc.setHtml( item->htmlText() );
    doc.setTextWidth( option.rect.width() );

    qDebug() << "hint:  " << option.rect.width() << " idx: " << index.row();

    return doc.size().toSize();
}

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Solution

  • After digging in Qt source code, I found that scheduleDelayedItemsLayout() function is solving the issue on my side.