Signal and slot problem

[mrjj]

@azravian said:
ok super so they accept the connect.

your error is here

void gpio::ISR()
{
gpio GPIO; <<<<<<<<<<<<<< that is not the one u connect !?

That is not the
gpio* GPIO=new gpio();
one :)

Update:
So when you do
GPIO.emit_FallingSignal();
with your local copy, no signal is sent to mainwin as
its an other instance than the one you new in main.

[A Former User]

@mrjj that's seems to be a problem but if i change my ISR()

void gpio::ISR()
{
    gpio* GPIO=new gpio;
    if(gpio::isHIGH())
    {
        qDebug()<<"RISING Interrupt called";
        GPIO->emit_RisingSignal();
    }

    else if(gpio::isLOW())
    {

        qDebug() <<"FALLING edge";
        GPIO->emit_FallingSignal();
    }
}
i have the same problem, it didn't solve the problem/

[mrjj]

but why are u creating a new Object???
Use the one in/from main.

That is the one you have connect to mains slots so making a new one
in that function will not send any signals to main as you do not connect it
like the other one.

So just newing the local copy instead, will not make any difference :)

[mrjj]

@mrjj

wait, i just saw
you create a gpio INSIDE gpio ????

why?

[mrjj]

I would expect

void gpio::ISR()
{

if(gpio::isHIGH())
{
    qDebug()<<"RISING Interrupt called";
    emit_RisingSignal();
}

No local object of same type! ?

[A Former User]

@mrjj Sir, ISR() is a static function. So to access other functions of the class i need to create an object :) thats why i have defined two other function emit_RisingEdge() and emit_FallingEdge() so i can emit my signals independent of any object.

[mrjj]

Ok, if u create a instance for use with signals, then its fine.
You just need to connect this new object to the slots again.

[A Former User]

@mrjj thanks but i'm pretty much beginner with signals and slots,where do i need to change my code

[mrjj]

@azravian
Hi,
void gpio::ISR()
{
gpio* GPIO=new gpio;
// here u need to connect again
// since its not pr type, but pr instance
// so the connect u made in main, are not on GPIO here

[A Former User]

@mrjj thank you it worked thank you so much Sir :)

[mrjj]

@azravian
Super, np :)
sorry I missed ur static function. The scroll area is so tiny .)

[A Former User]

@mrjj
Oh it's Ok sir, thanks Again for your input and help :) I've surely learned a lot

[SGaist]

Hi,

Just one thing, you have now a memory leak.

But in any case, I must say I don't see any reason for making all these methods static.

[mrjj]

@SGaist
Thank champ. In the static heat, i completely missed that.

@azravian
You should have a
delete GPIO in the end of the function or even better
just go back to using the stack again. (so it cleans it self)
void gpio::ISR()
{
gpio GPIO;

[A Former User]

@mrjj @SGaist
Yes i noticed it later and have deleted it. thanks again sir

[A Former User]

@SGaist thank you for it :) and the point od making these methods statics is that i am using wiringPi library which need a function as a parameter so i need make it static.

[jsulm]

@azravian In this case you could add a public static method to get the pointer to the gpio instance (basically you create a singleton):

class gpio : public QObject
{
    Q_OBJECT
public:
    gpio(): instancePtr(nullptr) {}
    static gpio* instance()
    {
        if (!instancePtr) instancePtr = new gpio();
        return instancePtr;
    }
private:
    gpio* instancePtr;

You can use this method in main to setup the connection and in static methods in gpio to get the pointer to the instance. Don't forget to delete the instance later.

[SGaist]

@jsulm you forgot to also make instancePtr static. However, I don't think the singleton pattern should be applied here.

[jsulm]

@SGaist Yes, I forgot, thanks for pointing :-)

[A Former User]

@mrjj @SGaist
Now it's all working now but i cannot use ui memeber like label, lineEdit etc. For example

void MainWindow::inserted()
{
    qDebug()<<"Inserted...";
    ui->label->setText("Inserted");
}

i do get "Inserted..." but the label does not change Text :(