CODEWITHSUNDEEP
c++qtscrollqheaderview
sashoalm
sashoalm

Reputation: 79625

Get absolute/global position of table header section while accounting for horizontal scroll

I'm creating a column tracking layout that inherits from QHBoxLayout, which will align a couple of line edits to the table columns:

enter image description here

To do that, I calculate the absolute screen position of each section size in ColumnAlignedLayout::setGeometry() using this code:

void ColumnAlignedLayout::setGeometry(const QRect &r)
{
    QHBoxLayout::setGeometry(r);
    int widgetX = parentWidget()->mapToGlobal(QPoint(0, 0)).x();
    int headerX = headerView->mapToGlobal(QPoint(0, 0)).x();
    int delta = headerX - widgetX;
    for (int ii = 0; ii < headerView->count(); ++ii) {
        int pos = headerView->sectionPosition(ii);
        int size = headerView->sectionSize(ii);

        auto item = itemAt(ii);
        auto r = item->geometry();
        r.setLeft(pos + delta);
        r.setWidth(size);
        item->setGeometry(r);
    }
}

The layout already works, except when the table has a horizontal scroll.

enter image description here

The full project is at https://github.com/sashoalm/ColumnAlignedLayout, and running it will reproduce the problem easily - just enlarge the columns until the horizontal scrollbar appears, and then scroll until the first column is hidden.

headerView->mapToGlobal(QPoint(0, 0)).x(); gives the same value whether the table has been resized or not.

I found a similar question but it's for objective C, and it doesn't account for scrolling which is my problem.

how to get the absolute position of a section header in tableview？

Upvotes: 0

Views: 890

Answers (1)

sashoalm
sashoalm

Reputation: 79625

Eventually I went into Qt's source for their paint event, assuming they would need the actual position for it, and they use sectionViewportPosition(), which gives the actual section position relative to the QTableWidget/QTableView's upper-left corner.

You can use that along with mapToGlobal() to get the global horizontal position of the section.

Upvotes: 3

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