[SOLVED] Qt: Signal and slot with different parameters

[akudewan]

Hello,

I'm making a Sudoku (solving/generating) program in Qt. Now, I'm just a beginner as a programmer, and I have no experience with Qt. I'm stuck in a strange situation. I want to connect a signal and slot with different parameters.

My grid is made up of an array of QLineEdits, and here's how I'm making the connections:


/* Making connections */
for(minigrid=0;minigrid<9;minigrid++)
{
for(row=0;row<3;row++)
{
for(column=0;column<3;column++)
{
connect(box[minigrid][row][column], SIGNAL(returnPressed()), this, SLOT(checkInput(int, int int)));
}
}
}


The 3 parameters of checkInput() are the minigrid, row and column numbers of the respective box in the grid. Qt doesn't accept Signals and Slots with different parameters, so how do I go about doing this?
Do I:
1) Overload returnPressed() of QLineEdit ? Is this even possible?
2) Create my own Signal in the Grid class? If so, how do I connect this signal to returnPressed() ? (if I do, then both will need to have void parameters. What how do I get the values of minigrid, row and column then?)
3) Change the structure of my grid? Use 81 connect statements ?
4) Can I subclass QLineEdit, and make my own signal in it?

Any help with this will be greatly appreciated...

[the_unforgiven]

The easiest way is to subclass QLineEdit and write a custom signal in it.
Other way would be to find a better alternative to QLineEdit. I don't know anything about your code, so I cannot comment on what would be an alternative.

HTH ;)

[akudewan]

The easiest way is to subclass QLineEdit and write a custom signal in it.
Other way would be to find a better alternative to QLineEdit. I don't know anything about your code, so I cannot comment on what would be an alternative.

HTH ;)

Thanks mate!

I made a subclass of QLineEdit, and included the data members minigrid, row & column that tell the position of the box. Then I used a Slot that simply emits the signal with the parameters I need.



/* the subclass */
class SLineEdit: public QLineEdit
{
Q_OBJECT
public:
int minigrid, row, column;
void setPosition(int, int, int);
SLineEdit(QWidget *parent = 0);
private slots:
void dataEntered();
signals:
void sendForCheck(int, int, int);
};




/* its implementation */
SLineEdit::SLineEdit(QWidget *parent) : QLineEdit(parent)
{
}

void SLineEdit::setPosition(int mg, int r, int c)
{
this->minigrid = mg;
this->row = r;
this->column = c;
}

void SLineEdit::dataEntered()
{
emit sendForCheck(this->minigrid, this->row, this->column);
}




/*and the connections */
for(int minigrid=0;minigrid<9;minigrid++)
{
for(int row=0;row<3;row++)
{
for(int column=0;column<3;column++)
{
connect(box[minigrid][row][column], SIGNAL(returnPressed()), box[minigrid][row][column], SLOT(dataEntered()));

connect(box[minigrid][row][column], SIGNAL(sendForCheck(int, int, int)), this, SLOT(checkInput(int, int, int)));

}
}
}


It feels so good to finally get this working after breaking my head over it for 2 days...
:)

[the_unforgiven]

Sounds good. Congrats ;)

[ihavenoname]

thanks for posting your solution this has helped me out.