Drawing over a button

[Awareness]

I have a custom button class derived from QPushButton.I want to draw a "/" over this button and some parts of "/" will be outside of this button.When I click on the button,it will emit a right click signal(actually I did signal-slot code and it works correctly).

I tried creating another custom button class and using qpainter with paintevent.But seems like actually it draws another button over my button,so I can't right click on the button under it.

How can I make this work?

[ChrisW67]

How can we tell you how to make your code work... We only have the vaguest idea what you have actually done. Perhaps you could show us some code.

[Awareness]

Thanks for your answer.


months.h :

class months:public QPushButton
{
 
   Q_OBJECT
   int day;
 
 
public:
 
   /
 
   months(){}
   months(QWidget* frame ):QPushButton(frame){}
 
 
   void setmonths(months** box2,int month2);
 
   void setmonths(int month2);
 
signals:
  void rightClickedd();
 
protected:
 
  void  mouseReleaseEvent(QMouseEvent *e );
 
public slots:
  void whenrightclicked();
 
};
 
 
 
class keyday:public QPushButton
{
 
   Q_OBJECT
   int day;
 
 
public:
 
 
 
   keyday(){}
   keyday(QWidget* frame ):QPushButton(frame){}
 
 
  void paintEvent(QPaintEvent*);
 
 
};

class months:public QPushButton
{

   Q_OBJECT
   int day;


public:

   /

   months(){}
   months(QWidget* frame ):QPushButton(frame){}
   
   
   void setmonths(months** box2,int month2);
   
   void setmonths(int month2);
  
signals:
  void rightClickedd();

protected:

  void  mouseReleaseEvent(QMouseEvent *e );

public slots:
  void whenrightclicked();

};



class keyday:public QPushButton
{

   Q_OBJECT
   int day;


public:

   

   keyday(){}
   keyday(QWidget* frame ):QPushButton(frame){}
   

  void paintEvent(QPaintEvent*);
 

};

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months.cpp :

months* box[2];
 
void keyday::paintEvent(QPaintEvent *) 
{
    QPainter painter(this);
    painter.setPen(Qt::white);
    painter.setFont(QFont("Arial", 15));
    painter.drawText(rect(), Qt::AlignCenter, "/");
 
}
 
 
 
void months::setmonths(int month2)
{
 keyday* button1 =new keyday(frame2);
 box[1]= new months(frame2);
 
 box[1]->setGeometry(47,2,70,15)
 button1->setGeometry(47,2,70,25); 
 button1->show(); 
}

months* box[2];

void keyday::paintEvent(QPaintEvent *) 
{
    QPainter painter(this);
    painter.setPen(Qt::white);
    painter.setFont(QFont("Arial", 15));
    painter.drawText(rect(), Qt::AlignCenter, "/");

}



void months::setmonths(int month2)
{
 keyday* button1 =new keyday(frame2);
 box[1]= new months(frame2);
 
 box[1]->setGeometry(47,2,70,15)
 button1->setGeometry(47,2,70,25); 
 button1->show(); 
}

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I am trying to paint "/" over box[1] and I tried using QPainter,but seems like it needs to be painter over a widget.So I created a new class derived from QPushButton(also tried QLabel).Now it paints "/" over box[1] but I can't click on box[1] because when I click on box[1] it actually clicks on button1.I tried QPainter without using it inside a derived class' QPaintEvent,but it doesn't work in that way I think.

There is wxMemoryDc class in Wxwidgets for doing what I want ,I am looking for a similar thing in Qt.

[ChrisW67]

I cannot fathom the logic of your setmonths() function. Nevertheless, drawing a line on top of a button without breaking its function is straightforward enough:

#include <QApplication>
#include <QPushButton>
#include <QPainter>
 
class CrossedButton: public QPushButton {
    Q_OBJECT
public:
    explicit CrossedButton(QWidget *p = 0): QPushButton(p) {
        setText("Test");
    }
 
protected:
    void paintEvent(QPaintEvent *event) {
        QPushButton::paintEvent(event);
 
        QPainter painter(this);
        painter.setPen(Qt::red);
        painter.setFont(QFont("Arial", 15));
        painter.drawText(rect(), Qt::AlignCenter, "/");
// OR
//        painter.setRenderHint(QPainter::Antialiasing, true);
//        painter.setPen(QPen(Qt::red, 2));
//        painter.drawLine(rect().topLeft(), rect().bottomRight());
    }
};
 
int main(int argc, char **argv) {
    QApplication app(argc, argv);
    CrossedButton b;
    b.show();
    return app.exec();
}
#include "main.moc"

#include <QApplication>
#include <QPushButton>
#include <QPainter>

class CrossedButton: public QPushButton {
    Q_OBJECT
public:
    explicit CrossedButton(QWidget *p = 0): QPushButton(p) {
        setText("Test");
    }

protected:
    void paintEvent(QPaintEvent *event) {
        QPushButton::paintEvent(event);

        QPainter painter(this);
        painter.setPen(Qt::red);
        painter.setFont(QFont("Arial", 15));
        painter.drawText(rect(), Qt::AlignCenter, "/");
// OR
//        painter.setRenderHint(QPainter::Antialiasing, true);
//        painter.setPen(QPen(Qt::red, 2));
//        painter.drawLine(rect().topLeft(), rect().bottomRight());
    }
};

int main(int argc, char **argv) {
    QApplication app(argc, argv);
    CrossedButton b;
    b.show();
    return app.exec();
}
#include "main.moc"

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[Awareness]

Thanks for your answer.

Is it possible to use QPainter for drawing without using it inside a widget?If I use it inside a widget and put that widget on another widget,when I run the program,I can't click on the lower widget.

[ChrisW67]

If I use it inside a widget and put that widget on another widget,when I run the program,I can't click on the lower widget.

Qt does the sane thing: the top-most widget under the mouse pointer is the one that gets first look at the click event. The widget can chose to ignore the event or, as makes sense for a button, consume it and be "pushed".

I have given you a button with an overdrawn line that you can click regardless of the line.

It sounds like you have a poorly designed UI.
Exactly what effect are you trying to achieve with this line?

[Awareness]

Thanks for your answer.

Maybe this image can explain my question better:


paint2.jpg


How can I do this using QPainter?Please click on the image (to make it larger), in small version the red line's borders are not visible clearly.

[stampede]

One way i can think of is to have the button embedded in QGraphicsScene as QGraphicsProxyWidget (via QGraphicsScene::addWidget). Then you can draw whatever you want on it with QPainter.

[Awareness]

Actually,after I sent my previous message with picture,I thought it was not a good idea to do it like I do it in the picture(at least for my current little project) and I used ChrisW67 's code in his reply,it is working good.But I didn't take my last question back,because I thought I may need the answer in the future and also I wondered if it was possible to do it in Qt.Thank you both ChrisW67 and stampede for your answers.