Signal Slot Question

Hi,
This must be a basic question but here it goes.

Code:

---

#include "txtedit.h"
#include "ui_txtedit.h"
 
txtEdit::txtEdit(QWidget *parent) :
    QGroupBox(parent),
    m_ui(new Ui::txtEdit)
{
    m_ui->setupUi(this);
 
    listStringList = new QStringList;
    listModel = new QStringListModel(this);
    listModel->setStringList(*listStringList);
    m_ui->listView->setModel(listModel);
...
    connect(m_ui->sortAscendingButton, SIGNAL(clicked(bool)), this, SLOT(sortStringList(bool)));
    connect(m_ui->sortDescendingButton, SIGNAL(clicked(bool)), this, SLOT(sortStringList(bool)));
}
 
...
 
 
void txtEdit::sortStringList(bool order)
{
    if(order)
        listModel->sort(0, Qt::AscendingOrder);
    else
        listModel->sort(0, Qt::DescendingOrder);
}

---

I want the buttons in lines 15 e 16 to send a true or false value to the sortStringList slot.
How do i manage this?
Thansks

Read "Advanced Signals and Slots Usage": http://doc.trolltech.com/4.5/signals...nd-slots-usage

In your special case a QButtonGroup with setExclusive(true) would do also a great job.

I wasn't able to do it with the QButtonGroup so i did this:

Code:

---

sortListSignalMapper = new QSignalMapper(this);
sortListSignalMapper->setMapping(m_ui->sortAscendingButton, QString("Ascending"));
sortListSignalMapper->setMapping(m_ui->sortDescendingButton, QString("Descending"));
connect(m_ui->sortAscendingButton, SIGNAL(clicked()), sortListSignalMapper, SLOT(map()));
connect(m_ui->sortDescendingButton, SIGNAL(clicked()), sortListSignalMapper, SLOT(map()));
connect(sortListSignalMapper, SIGNAL(mapped(QString)), this, SLOT(sortStringList(QString)));

---

Looks like i can not use bool in this situation.
Thanks

Ok,

with the mapper you can use the "int option". 1 = true and 0 = false.

Code:

---

//not tested but should work
sortListSignalMapper = new QSignalMapper(this);
sortListSignalMapper->setMapping(m_ui->sortAscendingButton, 1);
sortListSignalMapper->setMapping(m_ui->sortDescendingButton, 0);
connect(m_ui->sortAscendingButton, SIGNAL(clicked()), sortListSignalMapper, SLOT(map()));
connect(m_ui->sortDescendingButton, SIGNAL(clicked()), sortListSignalMapper, SLOT(map()));
connect(sortListSignalMapper, SIGNAL(mapped(int)), this, SLOT(sortStringList(bool)));

---

And with the button group you could simply use:

Code:

---

// use the buttonClicked(QAbstractButton *button) signal to connect to your slot
void txtEdit::sortStringList(QAbstractButton *button)
{
    if(button == m_ui->sortAscendingButton)
        listModel->sort(0, Qt::AscendingOrder);
    else
        listModel->sort(0, Qt::DescendingOrder);
}
// or if you need a bool function beside
void txtEdit::sortStringList(QAbstractButton *button)
{
    return sortStringList(button == m_ui->sortAscendingButton);
}

---

Hi,
I remember trying your first option.
I geted a ...

Code:

---

QObject::connect: Incompatible sender/receiver arguments
        QSignalMapper::mapped(int) --> txtEdit::sortStringList(bool)

---

But now you gave me an idea...

Code:

---

sortListSignalMapper = new QSignalMapper(this);
sortListSignalMapper->setMapping(m_ui->sortAscendingButton, 1);
sortListSignalMapper->setMapping(m_ui->sortDescendingButton, 0);
connect(m_ui->sortAscendingButton, SIGNAL(clicked()), sortListSignalMapper, SLOT(map()));
connect(m_ui->sortDescendingButton, SIGNAL(clicked()), sortListSignalMapper, SLOT(map()));
connect(sortListSignalMapper, SIGNAL(mapped(int)), this, SLOT(sortStringList(int)));

---

...and it worked fine.
This way order is an integer and it's value is evaluated as an "bool" in the condition.
Thanks

if you want that your code is readable (and understandable) later, you could also use Qt::AscendingOrder and Qt::DescendingOrder:

Code:

---

sortListSignalMapper = new QSignalMapper(this);
sortListSignalMapper->setMapping(m_ui->sortAscendingButton, Qt::AscendingOrder);
sortListSignalMapper->setMapping(m_ui->sortDescendingButton, Qt::DescendingOrder);
connect(m_ui->sortAscendingButton, SIGNAL(clicked()), sortListSignalMapper, SLOT(map()));
connect(m_ui->sortDescendingButton, SIGNAL(clicked()), sortListSignalMapper, SLOT(map()));
connect(sortListSignalMapper, SIGNAL(mapped(int)), this, SLOT(sortStringList(int)));
//...
void xxx::sortStringList(int order)
{
  switch(order)
  {
    case Qt::DescendingOrder:
      //...
      break;
    case Qt::AscendingOrder:
    default:
      //...
      break;
  }
}

---

EDIT:

Quote:

---

QObject::connect: Incompatible sender/receiver arguments
QSignalMapper::mapped(int) --> txtEdit::sortStringList(bool)

---

Ok, thought Qt would cast internally.:rolleyes:

You can also connect both to a slot and evaluate sender() in that slot to see which button was clicked and therefore which method to execute.

Looks like there is a warning about this subject( http://doc.trolltech.com/4.5/qobject.html#sender )

Quote:

---

Warning: This function violates the object-oriented principle of modularity. However, getting access to the sender might be useful when many signals are connected to a single slot.

---

I will try ti stick to the "principle of modularity" in order not to get lost ;)
Thanks for the tip.