hi,
I am writing a simple converter application here when we give a decimal number (0-255) then its convert in hex and binary or hex is convert decimal and binary ..., all are synchronize using signal-slot. i use validator for control use input. but it not showing me desired result.

Thanks in advance

ByteConvertorDialog.h
Qt Code: 
  1. #ifndef BYTECONVERTERDIALOG_H
  2. #define BYTECONVERTERDIALOG_H
  3.  
  4. #include <QWidget>
  5.  
  6. class QLineEdit; //forward declartion
  7.  
  8. class ByteConverterDialog : public QWidget
  9. {
  10.     Q_OBJECT
  11. public:
  12.     ByteConverterDialog();
  13. private:
  14.     QLineEdit* decEdit;
  15.     QLineEdit* hexEdit;
  16.     QLineEdit* binEdit;
  17. private slots:
  18.     void decChanged(const QString&);
  19.     void hexChanged(const QString&);
  20.     void binChanged(const QString&);
  21. };
  22.  
  23. #endif // BYTECONVERTERDIALOG_H
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ByteConvertorDialog.cpp
Qt Code: 
  1. #include <QLineEdit>
  2. #include <QLabel>
  3. #include <QPushButton>
  4. #include <QVBoxLayout>
  5. #include <QHBoxLayout>
  6. #include <QGridLayout>
  7. #include <QIntValidator>
  8. #include <QRegExpValidator>
  9. #include "ByteConverterDialog.h"
  10.  
  11. ByteConverterDialog::ByteConverterDialog()
  12. {
  13.     QVBoxLayout *mainLayout = new QVBoxLayout(this);
  14.     QGridLayout *editLayout = new QGridLayout;
  15.     QHBoxLayout *buttonLayout = new QHBoxLayout;
  16.  
  17.     mainLayout->addLayout(editLayout);
  18.     mainLayout->addStretch();
  19.     mainLayout->addLayout(buttonLayout);
  20.  
  21.     QLabel *decLabel = new QLabel(tr("Decimal"));
  22.     QLabel *hexLabel = new QLabel(tr("Hex"));
  23.     QLabel *binLabel = new QLabel(tr("Binary"));
  24.     decEdit = new QLineEdit;
  25.     hexEdit = new QLineEdit;
  26.     binEdit = new QLineEdit;
  27.  
  28.     editLayout->addWidget(decLabel,0,0);
  29.     editLayout->addWidget(decEdit,0,1);
  30.     editLayout->addWidget(hexLabel,1,0);
  31.     editLayout->addWidget(hexEdit,1,1);
  32.     editLayout->addWidget(binLabel,2,0);
  33.     editLayout->addWidget(binEdit,2,1);
  34.  
  35.     QPushButton *exitButton = new QPushButton(tr("Quit"));
  36.  
  37.     buttonLayout->addStretch();
  38.     buttonLayout->addWidget(exitButton);
  39.  
  40.     exitButton->setDefault(true);
  41.  
  42.     this->setWindowTitle("Byte Converter");
  43.  
  44.     QIntValidator* decValidator = new QIntValidator(0,255,decEdit);
  45.     decEdit->setValidator(decValidator);
  46.  
  47.     QRegExpValidator* hexValidator = new QRegExpValidator(QRegExp("[0-9A-Fa-f]{1,2}"),hexEdit);
  48.     hexEdit->setValidator(hexValidator);
  49.  
  50.     QRegExpValidator* binValidator = new QRegExpValidator(QRegExp("[01]{1,8}"),binEdit);
  51.     binEdit->setValidator(binValidator);
  52.  
  53.     connect(exitButton,SIGNAL(clicked()),this,SLOT(close()));
  54.     connect(decEdit,SIGNAL(textChanged(QString)),this,SLOT(decChanged(QString)));
  55.     connect(hexEdit,SIGNAL(textChanged(QString)),this,SLOT(hexChanged(QString)));
  56.     connect(binEdit,SIGNAL(textChanged(QString)),this,SLOT(binChanged(QString)));
  57. }
  58.  
  59. void ByteConverterDialog::decChanged(const QString& newValue)
  60. {
  61.     bool ok;
  62.     int num = newValue.toInt(&ok);
  63.     if(ok)
  64.     {
  65.         hexEdit->setText(QString::number(num,16));
  66.         binEdit->setText(QString::number(num,2));
  67.     }
  68.     else
  69.     {
  70.         hexEdit->setText("");
  71.         binEdit->setText("");
  72.     }
  73. }
  74.  
  75. void ByteConverterDialog::hexChanged(const QString& newValue)
  76. {
  77.     bool ok;
  78.     int num = newValue.toInt(&ok);
  79.     if(ok)
  80.     {
  81.         decEdit->setText(QString::number(num));
  82.         binEdit->setText(QString::number(num,2));
  83.     }
  84.     else
  85.     {
  86.         decEdit->setText("");
  87.         binEdit->setText("");
  88.     }
  89. }
  90.  
  91. void ByteConverterDialog::binChanged(const QString& newValue)
  92. {
  93.     bool ok;
  94.     int num = newValue.toInt(&ok);
  95.     if(ok)
  96.     {
  97.         decEdit->setText(QString::number(num));
  98.         hexEdit->setText(QString::number(num,16));
  99.     }
  100.     else
  101.     {
  102.         decEdit->setText("");
  103.         hexEdit->setText("");
  104.     }
  105. }
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main.cpp
Qt Code: 
  1. #include <QApplication>
  2. #include "ByteConverterDialog.h"
  3.  
  4. int main(int argc,char *argv[])
  5. {
  6.     QApplication app(argc,argv);
  7.     ByteConverterDialog bc;
  8.     bc.setAttribute(Qt::WA_QuitOnClose);
  9.     bc.show();
  10.     return app.exec();
  11. }
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