connect multiple signal to a slot - qt

Question

I've the follwoing issue.
There are two signals :
void buttonChanged(int);
void pulseWidthValue(int);
buttonChanged is emitted from a slot nextBtn:
void Program::nextBtn()
{
m_currentBtn++;
if(m_currentBtn > btnGrp->buttons().size())
{
m_currentBtn = 0;
phaseOver = true;
saveToXMLFile();
}
emit buttonChanged(m_currentBtn);
}
it's connected as follows:
connect(ui->btn_nextPhase, &QPushButton::clicked, this, &Program::nextBtn);
connect(this, &Program::buttonChanged, this, &Program::paintBtn);
the signal, buttonChanged is used in another slot to paint button:
void Program::paintBtn(int id) // how do I change the def of this function to receive to signal?
{
if(id==1)
{
ui->btn1->setStyleSheet(StyleSheetOn);
ui->btn2->setStyleSheet(StyleSheetOff);
ui->btn3->setStyleSheet(StyleSheetOff);
}
else if(id==2)
{
ui->btn1->setStyleSheet(StyleSheetOff);
ui->btn2->setStyleSheet(StyleSheetOn);
ui->btn3->setStyleSheet(StyleSheetOff);
}
else if(id==3)
{
ui->btn1->setStyleSheet(StyleSheetOff);
ui->btn2->setStyleSheet(StyleSheetOff);
ui->btn3->setStyleSheet(StyleSheetOn);
}
else
{
ui->btn1->setStyleSheet(StyleSheetOff);
ui->btn2->setStyleSheet(StyleSheetOff);
ui->btn3->setStyleSheet(StyleSheetOff);
}
ui->label_7->setText(QString::number(pw_value)); // this pw_value is from the other signal pulseWidthValue
}
the basic idea is , there are 3 phase buttons , clicking Next will switch between these buttons and change its color. Now I need to use the other signal pulseWidthValue inside paintBtn
Now I come to the question:
How do I connect two signals, buttonChanged and pulseWidthValue, (both signals are coming from different functions) to the paintBtn slot?

Answer 1

Qt allows you to connect multiple times even to the same slots. It even allows you to connect between signals.
Check this example, is not meant to be functional but descriptive enought to see many options and accesability.
class A:public QObject
{
Q_OBJECT
...
signals:
void signalA1();
void signalA2(const QString &);
}
class B:public QObject
{
Q_OBJECT...
signals:
void signalB();
public slots:
void slotB();
}
class C:public QObject
{
...
public:
C(QObject *parent):QObject(parent)
{
a=new A(this);
b=new B(this);
}
void connectionTest()
{
connect (a,&A::signalA1,b,&B::slotB) ; // one connection to slot B::slotB
connect (this,&C::signalC,b,&B::slotB); // another connection to B::slotB
connect (a,&A::signalA1,this,&C::slotC) ; // another connection from A::signalA, slotC is private so only I can connect
connect (b,&B::signalB,this,&C::signalC); // connection from signal to signal
connect (a,&A::signalA2,this,&C::slotC); //connection from A::signalA2 to C::slotC
//with different argument count, but compatible as slotC doesn't need an argument
connect (a,&A::signalA1,b,&B::slotB) ; // duplicate connection to slot B::slotB (signalA1 will trigger slotB two times)
}
signals:
void signalC();
private slots:
void slotC();
private:
class A *a;
class B *b;
}