Problem with slot

[wysota]

Please read this topic: Using a Component in Your Application

You shouldn't add any code to the ui_*.h files, they are generated and all your code will be overwritten next time uic runs. Instead use one of the inheritance approaches described in the manual and add your code there.

[stefek]

#include "calc.h"
#include "ui_calc.h"
 
Calc::Calc(QWidget *parent)
    : QDialog(parent), ui(new Ui::Calc)
{
     value = 0;
     ui->setupUi(this);
     this->setWindowTitle("Calqta");
 
     QSignalMapper *signalMapper = new QSignalMapper();
 
     connect(ui->firstButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->firstButton, "1");
 
     connect(ui->secondButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->secondButton, "2");
 
     connect(ui->thirdButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->thirdButton, "3");
 
     connect(ui->fourthButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->fourthButton, "4");
 
     connect(ui->fifthButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->fifthButton, "5");
 
     connect(ui->sixthButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->sixthButton, "6");
 
     connect(ui->seventhButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->seventhButton, "7");
 
     connect(ui->eighthButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->eighthButton, "8");
 
     connect(ui->ninethButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->ninethButton, "9");
 
     connect(ui->zeroButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->zeroButton, "0");
 
 
     connect(signalMapper, SIGNAL(mapped(const QString &)), this, SLOT(changeValue(const QString &)));
     connect(ui->sqrtButton, SIGNAL(clicked()), this, SLOT(square()));
 
     connect(ui->clearButton, SIGNAL(clicked()), this, SLOT(clear()));
 
 
 
 
}
 
Calc::~Calc()
{
    delete ui;
}
void Calc::add(const QString &val){
 
     str+=val;
 
}
void Calc::changeValue(const QString &val){
 
     Calc::add(val);
     value=str.toInt();
     display(value);
 
 
}
 
void Calc::display(const int &val){
 
     ui->lcdNumber->display(val);
}
void Calc::square(){ //works
 
 
     value = std::sqrt(value);
     display(value);
     str.remove(0, str.length());
     Calc::changeValue(QString::number(value));
 
 
}
void Calc::clear(){ //works
 
     value = 0;
     str.remove(0, str.length());
     display(value);
}

#include "calc.h"
#include "ui_calc.h"

Calc::Calc(QWidget *parent)
    : QDialog(parent), ui(new Ui::Calc)
{
     value = 0;
     ui->setupUi(this);
     this->setWindowTitle("Calqta");

     QSignalMapper *signalMapper = new QSignalMapper();

     connect(ui->firstButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->firstButton, "1");

     connect(ui->secondButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->secondButton, "2");

     connect(ui->thirdButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->thirdButton, "3");

     connect(ui->fourthButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->fourthButton, "4");

     connect(ui->fifthButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->fifthButton, "5");

     connect(ui->sixthButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->sixthButton, "6");

     connect(ui->seventhButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->seventhButton, "7");

     connect(ui->eighthButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->eighthButton, "8");

     connect(ui->ninethButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->ninethButton, "9");

     connect(ui->zeroButton, SIGNAL(clicked()), signalMapper, SLOT(map()));
     signalMapper->setMapping(ui->zeroButton, "0");


     connect(signalMapper, SIGNAL(mapped(const QString &)), this, SLOT(changeValue(const QString &)));
     connect(ui->sqrtButton, SIGNAL(clicked()), this, SLOT(square()));

     connect(ui->clearButton, SIGNAL(clicked()), this, SLOT(clear()));




}

Calc::~Calc()
{
    delete ui;
}
void Calc::add(const QString &val){

     str+=val;

}
void Calc::changeValue(const QString &val){

     Calc::add(val);
     value=str.toInt();
     display(value);


}

void Calc::display(const int &val){

     ui->lcdNumber->display(val);
}
void Calc::square(){ //works


     value = std::sqrt(value);
     display(value);
     str.remove(0, str.length());
     Calc::changeValue(QString::number(value));


}
void Calc::clear(){ //works

     value = 0;
     str.remove(0, str.length());
     display(value);
}

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I managed that simple dialog, so I came back to my calculator. All numeric buttons work correctly - adding digit to number works. Square root also works correctly. Now I have a problem with 2 arguments operations, such as addition. I don't have an idea how can I store the second argument - first is in the variable "value". Could you give me handy tip?
Regards
Stefek

[wysota]

You are currently using a postfix notation - you first store an operand and then expect an operator. Now you have to switch to an infix notation where the operator comes inbetween operands and where the second operand may be empty. You should have storage space (variables) for at least two operands and one variable for the operator. Then it will be easy to perform calculations. Consider this mockup:

class SimpleCalculator {
public:
  enum Operator { NoOp, AddOp, SubOp, MulOp, DivOp, SqrtOp, SqrOp };
  SimpleCalculator(){ m_left = 0; m_right = 0; m_op = NoOp; }
  void setLeftOperand(int v){ m_left = v; }
  void setRightOperand(int v){ m_right = v; }
  void setOperator(Operator o){ m_op = o; }
  int calculate(){
    int result = 0;
    switch(m_op){
    case AddOp: result = m_left + m_right; break;
    case SubOp: result = m_left - m_right; break;
    ...
    case SqrOp: result = m_left*m_left;
    case NoOp: default: result = m_left;
    }
    m_op = NoOp;
    m_left = result;
    m_right = 0;
    return result;
  }
};

class SimpleCalculator {
public:
  enum Operator { NoOp, AddOp, SubOp, MulOp, DivOp, SqrtOp, SqrOp };
  SimpleCalculator(){ m_left = 0; m_right = 0; m_op = NoOp; }
  void setLeftOperand(int v){ m_left = v; }
  void setRightOperand(int v){ m_right = v; }
  void setOperator(Operator o){ m_op = o; }
  int calculate(){
    int result = 0;
    switch(m_op){
    case AddOp: result = m_left + m_right; break;
    case SubOp: result = m_left - m_right; break;
    ...
    case SqrOp: result = m_left*m_left;
    case NoOp: default: result = m_left;
    }
    m_op = NoOp;
    m_left = result;
    m_right = 0;
    return result;
  }
};

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Your next problem will be how to execute a sequence of operations but until you reach that step, first learn this one.