QScrollBar vertical scrollbar set width

SPlatten

@hskoglund , one thing that comes to mind....the slider value is normally at the center point of the handle? Can this be offset? If the handle is adjusted to show a proportional representation then the value would have to be at the very top of the handle.

SPlatten

@hskoglund , I'm not sure this is going to work, for starters using the StyleSheet to set the handle width and height doesn't seem to work and there is the other issue where the origin / value seems to be central to the orientation of the handle.

hskoglund

Hi, dug up some old code that assumes you have a vertical QSlider with a height of say 400 pixels, minimum = 0, maximum = 400, singleStep = 1 and pageStep = 25:

mpSlider->setStyleSheet(
    "QSlider::groove { background: transparent; width: 4px; } "
    "QSlider::handle { background: blue; border-radius: 5px; border: 1px solid gray; height:200px;}");

then moving the slider will give you values between 0 and 400 :-)

Edit:
here's the simplified test program, create a vanilla QWidget app, in mainwindow.cpp and #include "qslider.h" and insert this code in MainWindow::MainWindow() after ui->setupUi(this):

auto mpSlider = new QSlider(Qt::Vertical,this);
mpSlider->setGeometry(QRect(100,100,100,400));
mpSlider->setRange(0,400);
mpSlider->setStyleSheet(
"QSlider::groove { background: transparent; width: 4px; } "
"QSlider::handle { background: blue; border-radius: 5px; border: 1px solid gray; height:200px;}");
connect(mpSlider,&QSlider::valueChanged,[this](int value) { setWindowTitle("Slider value: " + QString::number(value));});

should give you this:
Screenshot 2021-06-21 at 11.41.07.png

SPlatten

@hskoglund, thank you, where on the slider is the value indicated?

mrjj

@SPlatten

QSlider don't show the current value as far as i know.

there is a handy subclass here to get text the handle.
https://stackoverflow.com/questions/18383885/qslider-show-min-max-and-current-value

Also do note that a 4 pixel slider will drive people nuts on a hi res screen.

SPlatten

@mrjj , the application itself is being written for a specific target in mind, its for training software.

mrjj

@SPlatten

Hi
Ok. Well so its purpose with such a tiny scrollbar.
I guess that makes better sense then.

SPlatten

@mrjj , its not really my decision, I'm working to a specification which includes mock images.

SPlatten

@hskoglund , sorry for the delay, been busy with other stuff.

    QRect rctGeom(rect());
    int intHeight(rctGeom.height()),
    //Using the maximum and minimum actual values calculate percentage visible
        intSpan(truth::msintMaximum - truth::msintMinimum);
    double dblPercent = (double)intHeight / (double)intSpan,
    //Now work out how much of the scale the percentage into the visible area
           dblVisible = dblPercent * intHeight;
    QString strStyle(QString("QSlider::handle {"
                             "background:blue;"
                             "border-radius: 0px;"
                             "border: 1px solid gray;"
                             "height: %1px;}").arg((int)dblVisible));
    truth::mspSlider->setStyleSheet(strStyle);

intHeight contains 486
intSpan contains 2000
dblPercent contains 0.243
dblVisible contains 118.098
strStyle contains:

QSlider::handle {background:blue;border-radius: 0px;border: 1px solid gray;height: 118px;}

However what I'm seeing on the screen is:

So clearly the handle is not 118 px, what haven't I done?

hskoglund

Hi, I also stumbled on this (QSlider refusing to cooperate). What's odd here is to make that height of 118px work, you also have to mess with QSlider's groove in your setStyleShee() call. And the easiest way was to make it invisible, like this:

QString strStyle(QString(
"QSlider::groove { background: transparent; } "
"QSlider::handle {"
"background:blue;"
"border-radius: 0px;"
"border: 1px solid gray;"
"height: %1px;}").arg((int)dblVisible));

Ok problem solved, but now you got another problem: no groove.
If you need one, you can draw your own, I used a QFrame say like this:

auto pFrame = new QFrame(mpSlider->parentWidget());
pFrame->setGeometry(mpSlider->geometry());
pFrame->setFrameStyle(QFrame::VLine | QFrame::Sunken);
pFrame->stackUnder(mpSlider);   // z-order (important!)

note: maybe some more settings are needed on that QFrame for grey color etc. to make it look more like a QSlider's groove :-)

SPlatten

@hskoglund , thank you, that works.