How to draw rectangle with all corners rounded ?

JoeCFD

void myRect::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    QRectF rect = QRectF(widget->rect());
    QPainterPath path;
    path->addRoundedRect(rect, 10, 10); /* add not draw sorry */
    auto copied_option = *option;
    copied_option.state &= ~QStyle::State_Selected;
    auto selected = option->state & QStyle::State_Selected;
    //QGraphicsRectItem::paint(painter, &copied_option, widget);  /* drawing is finished here and no need to call parent->paint()  */
    painter->save();
    if (selected) {
        painter->setBrush(Qt::NoBrush);
        painter->setPen(QPen(option->palette.windowText(), 0, Qt::SolidLine));
   }
   else {
       set pen color;
   }       
   painter->drawPath(path); 
   painter->restore();
}

JoeCFD

@tushu You also need to try the example first

void myRect::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
painter->setRenderHint(QPainter::Antialiasing);
QPainterPath path;
path.addRoundedRect(QRectF(10, 10, 100, 50), 10, 10);
QPen pen(Qt::black, 10);
painter->setPen(pen);
painter->fillPath(path, Qt::red);
painter->drawPath(path);
}

tushu

@JoeCFD
For this , getting the same above output.
(i.e. No border of any rectangle)

JoeCFD

@tushu did you try the example?

tushu

@JoeCFD

Example's output

I have just removed

//painter->fillPath(path, Qt::red);

tushu

@JoeCFD
Is the below line correct ?

QRectF rect = QRectF(widget->rect());

because of the above line , it is creating bigger rectangle ?
But bigger rectangle ( outermost ) has curved corner.

JoeCFD

@tushu you know the size of your rects, right? I do not know.

tushu

@JoeCFD
Your rectangle size suggestion worked.
Current output.

Now I want to round corner of middle 5 rectangle only ( i.e. sw1,sw2,PD_blue, PD_green,PD_yellow)
But left side rectangle ( small ) also got changed and looking like circle.

I think, I will need to set some flag and will have to decide, which rectangle's corner should be rounded.

But now main concern is PD_blue, PD_green,PD_yellow rectangles color is not visible.

I set their color, after creating rectangle using setBrush(). I do not set their color in paint(). After creating rectangle, if they are full filling some criteria, then I set color on them.

Why that color is not visible ?

Here is my paint()

void guiSchematicRect::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    Q_UNUSED(option);
    Q_UNUSED(widget);
    QRectF rect = QRectF(_polyRect);
    QPainterPath path;
    path.addRoundedRect(rect, 4, 4);
   auto copied_option = *option;
    copied_option.state &= ~QStyle::State_Selected;
    auto selected = option->state & 
   QStyle::State_Selected;
    painter->save();
    if (selected) {
        painter->setBrush(Qt::NoBrush);
        painter->setPen(QPen(option->palette.windowText(), 1, Qt::SolidLine));
   }
   else {
       painter->setPen(Qt::blue);
   }
   painter->drawPath(path);
   painter->restore();
}

mpergand

@tushu said in How to draw rectangle with all corners rounded ?:

if they are full filling some criteria, then I set color on them.
Why that color is not visible ?

fill your form first:
painter->fillPath(path, yourColor);

tushu

@JoeCFD
If I add below line in paint() , then I get my 3 rectangle ( PD_blue, PD_green, PD_yellow) with thier respective color.

QGraphicsRectItem::paint(painter, &copied_option, widget);

BUt output I get like this :

Can you see the corners ? There is a round shape but it is getting overlapped.

What is the issue with this line ?

QGraphicsRectItem::paint(painter, &copied_option, widget);

With this I get color of remaining rectangle but could not see round shape at edge.

JoeCFD

@tushu QGraphicsRectItem::paint(painter, &copied_option, widget); is to call the parent to paint the rect without round corners. Look at the example and this call is not needed.

tushu

@JoeCFD
You are correct.
But now problem is, after creating rectangle, for some of the rectangle, I am setting some colour with

SetBrush()

And the color applied with above method, is not visible to the rectangle. They are appearing colorless.

Can we use paint() parameter in this case ?

paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)

Or is there any other way to solve this issue ?

JoeCFD

@tushu can you show your full code of this func?

tushu

@JoeCFD

myRect.h

class myRect : public QGraphicsRectItem 
{
      explicit myRect(QRectF &rectPoints, QGraphicsScene *_scene, QGraphicsItem *parent = nullptr) : QGraphicsRectItem(rectPoints, parent),  _scene(_scene)
    {}
}

myRect.cpp

void myRect::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    Q_UNUSED(widget);
    QRectF rect = QRectF(_polyRect);
    QPainterPath path;
    path.addRoundedRect(rect, 4, 4);

    auto copied_option = *option;
    copied_option.state &= ~QStyle::State_Selected;
    auto selected = option->state & QStyle::State_Selected;
    painter->save();
    if (selected) {
        painter->setBrush(Qt::NoBrush);
        painter->setPen(QPen(option->palette.windowText(), 0, Qt::SolidLine));
    }
    else
         painter->setPen(Qt::blue);
    painter->drawPath(path);
    painter->restore();
}

void myRect::CreateRect(QRectF rect)
{
    this->_polyRect = rect;
    QPen mPen;
    mPen.setWidth(1);
    mPen.setBrush(Qt::blue);
    this->setPen(mPen);
    this->setFlag(QGraphicsItem::ItemIsSelectable);
}

mySymbol.cpp

DrawSymbol()
{
   QRectF Rect( co-ordinates );
    myRect* rect = new myRect(Rect, _scene);
     rect->CreateRect(Rect);
    if( if it is power domain ) 
      CreatePD(rect);
}

CreatePD(myRect* rect)
{
    QColor pdColor{some color };
    rect->setBrush(pdColor);
}

Note : If I add following line in paint()

QGraphicsRectItem::paint(painter, &copied_option, widget);

then I can see my rectangle with color. But gets problem with rounded corner.

JoeCFD

@tushu Check the example and @mpergand's reply. You do not have
painter->fillPath(path, yourColor);
Try to set yourColor = Qt::green to see what you get.

tushu

@JoeCFD
Your suggestion worked.
Thanks for help !

tushu

@mpergand
Your solution worked.
Thanks for help !

tushu

@JoeCFD @mpergand
I am facing another small issue in paint()

When I left click on any rectangular object, it's paint() runs. And it highlights that object perfectly.

But when I right click on object ( I have few Right mouse button options ) , paint() method runs, but it does not highlight that object.

Her is my paint()

void myRect::paint(QPainter *painter, QPainterPath path,
                                            const QStyleOptionGraphicsItem *option)
{
    auto copied_option = *option;
    copied_option.state &= ~QStyle::State_Selected;
    auto selected = option->state & QStyle::State_Selected;
    if(selected)
        qDebug()<<"TRUE ";
    else
        qDebug()<<"FALSE ";
    painter->save();
    if (selected) {
        qDebug()<<"In selected ";
        painter->setBrush(Qt::NoBrush);
        painter->setPen(QPen(option->palette.windowText(), 1, Qt::SolidLine));
        qDebug()<<"Selected completing  ";
    } else
    {
        painter->setPen(Qt::blue);
        qDebug()<<"NOT Selected";
    }
    painter->drawPath(path);
    painter->restore();
}

I checked through qDebug statements, and I found that,

auto selected

variable has value false on Right click.( i.e. selected = false)

On left click, It works perfectly ( i.e. selected = true )

JoeCFD

@tushu That means you do not use right click to select your widget. I do not know if it is a good idea to add right click to this feature. If you want to add it, you have to override mouse event to catch mouse right click and then set selected to be true.