Ho to use signals and slots to execute a command?

[claudio-cit]

Here is my guess:

I create an object and I define a method. I link the action (signal) to the method (slot). The method, in this case, should contain a command launched on a system's shell.

Is that - at least in part - right?!

[caduel]

basically yes, the slot is not the shell command, but rather executes it.

class ClassA : public QObject
{
Q_OBJECT
 
public:
  ClassA();
 
signals:
  void someSignale();
};
 
class ClassB : public QObject
{
Q_OBJECT
 
public:
   ClassB();
public slots:
   someSlot()
     {
         system("some shell command");
     }
};
 
 
// somewhere else
ClassA a;
ClassB b;
 
b.connect(&a, SIGNAL(someSignal()), SLOT(someSlot()));
 
 
somewhere in ClassA:
emit someSignal();

class ClassA : public QObject
{
Q_OBJECT

public:
  ClassA();

signals:
  void someSignale();
};

class ClassB : public QObject
{
Q_OBJECT

public:
   ClassB();
public slots:
   someSlot()
     {
         system("some shell command");
     }
};


// somewhere else
ClassA a;
ClassB b;

b.connect(&a, SIGNAL(someSignal()), SLOT(someSlot()));


somewhere in ClassA:
emit someSignal();

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When ClassA emits this signal, all the slots connected to it will be executed (in an undefined order).
In a slot you may execute any code you like, e.g. call some shell command.

Read up the tutorials etc in the excellent Qt docs!

HTH.

[claudio-cit]

Very helpfull! Thank you very much.