Communication between widgets

[asttekin]

Hi all,

I have to pass data from mainwidget to second widget.
The serial port is processed data contionusly in the main widget.
Data needs to be sent to a secondary screen.

Can you help to do that?

[mvuori]

When you send data from one widget (the processing one) to another widget (the one that puts things to the other screen), the default way in Qt is to send a signal from the first to the slot in the second widget...

[asttekin]

Can you show an example?

[SGaist]

Hi,

Qt's documentation is filed with these kind of examples and demos. You should be able to get them all together and work with the Qt. .

[Pradeep Kumar]

Hi,

So you want to send data from mainwidget class to second widget. class
Here is the sample code.

class MainwidgetClass : public QObject{
Q_OBJECT;
...
public signals:
void yourSignal();
};

...

class SecondWidgetClass: public QObject{
Q_OBJECT;
...
public slots:
void slotFunc();
}

MainwidgetClass *youObject = new MainwidgetClass ;
connect(MainwidgetClass , SIGNAL(yourSignal()), SecondWidgetClass, SLOT(someSlot()));

so if you want to send the data from the first MainwidgetClass class then you have use emit call emit yourSignal();

And establish the connect between the two classes. U will recieve data in slotFunc() of
SecondWidgetClass Class.

[jsulm]

@Pradeep-Kumar
That's not valid code.
It should be:

MainwidgetClass *youObject = new MainwidgetClass ;
SecondWidgetClass *secondWidget = new SecondWidgetClass();
connect(youObject , SIGNAL(yourSignal()), secondWidget, SLOT(slotFunc()));

You need pointer to class instances, you cannot pass a class to connect.

[Pradeep Kumar]

@jsulm
Sorry for that how could i miss that.

Mistake corrected.

class MainwidgetClass : public QObject{
Q_OBJECT;
...
public signals:
void yourSignal();
};

...

class SecondWidgetClass: public QObject{
Q_OBJECT;
...
public slots:
void slotFunc();
}

MainwidgetClass *youObject = new MainwidgetClass ;
SecondWidgetClass *secondWidget = new SecondWidgetClass;

connect(youObject , SIGNAL(yourSignal()), secondWidget, SLOT(slotFunc()));

Thanks for correcting me @jsulm