Draw a QFrame-like rectangle

Harry123

I am trying to draw a rectangle that is QFrame-like with 3D border, but I only ever get a simple 1-pixel rectangle.

When testing the simplest case, that of a box with a 10-pixels border, my simplified test-code :

void Win::paintEvent(QPaintEvent * event)
{
  QWidget::paintEvent(event);
  QPainter painter(this);
  QStyleOptionFrame  option;
  option.initFrom(this);
  option.rect = QRect(100,100,100,100);
  option.lineWidth = 10;
  option.frameShape = QFrame::Box;
  style()->drawPrimitive(QStyle::PE_Frame,  &option,  &painter,  this);
}

The above draws a 1-pixel rectangle. If I replace the drawPrimitive call with :

painter.setPen(QPen(Qt::red, 10));
painter.drawRect(QRect(100,100,100,100));

then the rectangle is correct.

What am I doing wrong ?

mrjj

Hi
Might need
Option.state = QStyle::State_Sunken; // or what ever
Since values might be random (not all set by initFrom) ,
you must set all used for a PE_X style.

If still not working, check out QFrame source for what it really needs.

This works for me. ( for line)

       QStyleOptionFrame option;
        option.initFrom(this);
        option.state = QStyle::State_Sunken;
        option.frameShape = QFrame::HLine;
        style()->drawPrimitive(QStyle::PE_Frame, &option, &painter, this);

Harry123

@mrjj :

I have tried to assign every possible documented member variable, but no go.
The code now looks like :

void Win::paintEvent(QPaintEvent * event)
{
  QWidget::paintEvent(event);
  QPainter painter(this);
  QStyleOptionFrame  option;
  option.initFrom(this);
  option.rect = QRect(100,100,100,100);
  option.lineWidth = 10;
  option.frameShape = QFrame::Box;
  option.state = QStyle::State_Sunken;
  option.direction = Qt::LeftToRight;
  option.features = QStyleOptionFrame::Rounded;
  option.fontMetrics = QFontMetrics(QFont("Arial"));
  option.midLineWidth = 4;
  option.type = QStyleOption::SO_Frame;
  style()->drawPrimitive(QStyle::PE_Frame,  &option,  &painter,  this);
}

I have also tried to take out the call to option.initFrom(this);, but this changed nothing.
I have even changed option.frameShape = QFrame::HLine;, but I still get a 1-pixel rectangle/line.

Chris Kawa

You are using the wrong drawing function and element. It should be

style()->drawControl(QStyle::CE_ShapedFrame, &option, &painter, this);

Harry123

@Chris-Kawa :

YES! This was it.
Unfortunate that drawPrimitive was wrongly recommended so many times on StackOverflow and elsewhere.
Many thanks.