formatting a QTableView header

mzimmers

OK, I have a little spare time now. I've copied this code (from the page):

class MyProxyStyle : public QProxyStyle
{
  public:
    int styleHint(StyleHint hint, const QStyleOption *option = 0,
                  const QWidget *widget = 0, QStyleHintReturn *returnData = 0) const override
    {
        if (hint == QStyle::SH_UnderlineShortcut)
            return 0;
        return QProxyStyle::styleHint(hint, option, widget, returnData);
    }
};

What would you suggest I use instead of SH_UnderlineShortcut to test whether my styling is taking effect? (Given the trouble we were having earlier.)

Thanks.

SGaist

Hi,

How did you set your custom style ?

mzimmers

Hi SGaist - like this:

    MyProxyStyle *mps = new MyProxyStyle;
    ui->tableView->setStyle(mps);

SGaist

What if you set it application wide ?

mzimmers

I can try that. What I was asking for, though, was a style hint that would be readily apparent in my app. The one in the example might work perfectly, but I'd never see it without implementing any shortcuts (at least I think not).

mzimmers

For what it's worth, this line of code produces expected results:

ui->tableView->setStyleSheet("background-color: red");

But this one does not:

    ui->tableView->horizontalHeader()->setStyleSheet("background-color: red");

So the problem seems to be in the header object, doesn't it?

kshegunov

You don't need a style hint if you're trying to override the painting. You'd have to reimplement QStyle::drawControl and handle the QStyle::CE_Header control. Something like this:

class MyProxyStyle : public QProxyStyle
{
public:
    void drawControl(ControlElement element, const QStyleOption *option, QPainter *painter, const QWidget *widget = nullptr) const override
    {
        if (element != QStyle::CE_Header)  {
             baseStyle()->drawControl(element, option, painter, widget);
             return;
        }

        // Paint here ...
    }
};

It's been a long time since I last played with the styles, but I hope this is of help.

VRonin

You might want to try just adding QApplication::setStyle(QStyleFactory::create("Fusion")); to your main(). The fusion style supports the styling of QHeaderViews even on windows

mzimmers

@VRonin using that style, along with the style sheet, did in fact paint my header background red. Thank you!

Now, for creating a separation line under the header...is it recommended that I try to use a style sheet, or QStyles?

VRonin

Try the fast way, use stylesheet

mzimmers

Interesting results...I tried this:

    ui->tableView->horizontalHeader()->setStyleSheet("border-bottom: 5px solid red");

And got this:

I must be malforming the stylesheet (I pulled the contents directly from a CSS example I found online), but the curious (to me) part is I'm now getting an underline (actually a bottom border, I guess) across the entire header, but only the middle column is painted red (which I don't understand either).

Thoughts?

VRonin

http://doc.qt.io/qt-5/stylesheet-examples.html#customizing-qheaderview

mzimmers

Disregard my image above: the setting of the red background was due to a separate experiment I'd been performing on the model. It was disguised when I set the entire header view to red, then reappeared when I removed that CSS in favor of the bottom border.

I'd actually read that page you referenced, but I don't fully understand the syntax. I can see that everything in the braces is Qt style information, but what is the context in which they're used? For example, in this:

QHeaderView::section

What is "section?"

VRonin

it's the sub element inside the headerview. That style applies to every single row/column header cell

mzimmers

Ah, I see (I think). Well, the upshot is that I can remove all of my stylesheet settings. The use of the Fusion style gave me the desired look:

Which is fortunate, because this attempt at stylesheet setting didn't work:

    ui->tableView->horizontalHeader()->setStyleSheet("border-bottom: 5px solid red");

Not sure why (the red background worked).