Reimplemented QHeaderView paints wrong on scrolling

[coyoteazul]

Hi. I've reimplemented QHeaderView to rotate text on the vertical header of my table (a QStandardItem through a QSortProxyModel)
Whenever i scroll to the sides, the painting goes wrong. Like it couldn't paint the new column headers. Also if i do something to fire the paint event, it only paints right if i'm on the initial position. How can i get it to paint properly?
Thanks in advance for your help.


Initial position
http://image.prntscr.com/image/2893c3e7470f4a2485c3fc8c692c66ad.png

Scroll to the furthest right
http://image.prntscr.com/image/94f4138006b94d709359ed8001fa3ffe.png

Scroll back to initial position
http://image.prntscr.com/image/0c7727efa0df447a8a75b53f50ab270e.png


This is my reimplementation

#include <QObject>
#include <QHeaderView>
#include <QPainter>

class QHeaderViewR : public QHeaderView
{
QStringList heads;

public:
QHeaderViewR(QStringList _heads):QHeaderView(Qt::Horizontal)
{
heads = _heads;
this->setSectionResizeMode(QHeaderView::Fixed);
this->setSectionsClickable(true);
}

void paintSection(QPainter * painter, const QRect & rect, int logicalIndex) const
{
QPen pen(Qt::black);
painter->setPen(pen);

painter->rotate(90);
painter->translate(0,-rect.width()+1);

QRect copy = rect;

copy.setWidth(rect.height());
copy.setHeight(rect.width());
copy.moveTo(0,-this->sectionPosition(logicalIndex));

if (logicalIndex == 0) //Show a line on the left
{
copy.setHeight(rect.width()-1);
painter->drawText(copy,Qt::AlignCenter, heads.at(logicalIndex));
}
else
{
painter->drawText(copy,Qt::AlignCenter ,heads.at(logicalIndex));
}

painter->drawRect(copy);
}
signals:
void sectionPressed(int logicalIndex());
};

[wysota]

What happens if in paintSection you comment out all of your code and call the superclass implementation of the method? Do the problems with repainting go away?

[coyoteazul]

I didn't know you could do that. Yes, if i do that the repainting is done correctly, but the text is not rotated anymore


void paintSection(QPainter * painter, const QRect & rect, int logicalIndex) const
{
QHeaderView::paintSection(painter,rect,logicalInde x);
//old code commented out
}

[wysota]

This works for me just fine:


#include <QtWidgets>

class MyHeader : public QHeaderView {
public:
MyHeader(QWidget*parent = 0) : QHeaderView(Qt::Horizontal, parent) {

}
protected:
QSize sectionSizeFromContents(int logicalIndex) const {
QSize s = QHeaderView::sectionSizeFromContents(logicalIndex) ;
return QSize(s.height(), std::max(100, s.width()));
}

void paintSection(QPainter *painter, const QRect & rect, int logicalIndex) const {
if (logicalIndex % 2) {
painter->save();
painter->translate(rect.left(), rect.bottom());
painter->rotate(-90);
QRect r(0, 0, rect.height(), rect.width());
painter->setBrush(Qt::red);
painter->drawRect(r);
painter->drawText(r, Qt::AlignCenter, QString::number(logicalIndex+1));
painter->restore();
} else QHeaderView::paintSection(painter, rect, logicalIndex);
}
};

int main(int argc, char**argv) {
QApplication app(argc, argv);
QTableView view;
QStandardItemModel model(800,400);
view.setModel(&model);
view.setHorizontalHeader(new MyHeader);
view.show();
return app.exec();
}

[anda_skoa]

Right, I would have also recommended saving and restoring the painter

Cheers,
_

[coyoteazul]

It worked!. I tried using save and restoring when i first reimplemented this class, but it wouldn't work as expected for some reason (dumb me probably)
Thanks a lot!