Create new class with many argument

CharlieG

Hello,

It is surely simple, but since yesterday I am trying to create a class with several arguments (shame ....).

Currently I use this example to run my code :

//myobject1.h
class MyPainter1 : public QObject
{
public:
    explicit MyPainter1(QObject *parent = 0);

private slots:

public slots:
    void test();
    void setPainter(QPainter *painter);

public:
    QPainter *m_painter;
};


//myobject1.cpp
#include "myobject1.h"

MyPainter1::MyPainter1(QObject *parent) : QObject(parent)
{

}

void MyPainter1::test()
{
    QRectF m_headerRect(0, 350, 300, 250);

    m_painter->setPen(Qt::yellow);
    m_painter->drawRect(m_headerRect);
    qDebug() << "this is a test";
}

void MyPainter1::setPainter(QPainter *painter)
{
    m_painter = painter;
}

//and the use where painter is a QPainter which is defined rather :
MyPainter1 myObj;
myObj.setPainter(painter);
myObj.test();

This works, but finally, I would prefer use MyPainter this way :

MyPainter1 myObj(painter)
myObj.test();

But I can't find a way to build my class correctly.

Can you help me ?

Thank you in advance.

Charlie.

VRonin

Several problems here:

missing Q_OBJECT macro
uninitialised m_painter (calling test before calling setPainter crashes)
no checks on m_painter (calling setPainter with a null pointer argument and then calling test crashes)
m_painter is in the public section despite having an encapsulated setter (setPainter)

class MyPainter1 : public QObject
{
Q_OBJECT
public:
    explicit MyPainter1(QPainter *painter=Q_NULLPTR, QObject *parent = Q_NULLPTR)
:QObject (parent), m_painter(painter){}

public slots:
    void test(){
if(!m_painter) return;
    QRectF m_headerRect(0, 350, 300, 250);

    m_painter->setPen(Qt::yellow);
    m_painter->drawRect(m_headerRect);
    qDebug() << "this is a test";
}
    void setPainter(QPainter *painter){
    m_painter = painter;
}
private:
    QPainter *m_painter;
};

CharlieG

This is super... Thank you very much.

I really have to do more C++ and a (little) less QML :-).