Last night I has asked for a validator to for checking if a number was an int and I got a good hand. One of my co-workers told me they're going to need a double. The code will throw an error for white space and for special characters so I'm not sure what the approach is. Thanks for the clarificatioin

Qt Code: 
  1. double GateOverlapFactor::on_okButton_clicked()
  2. {
  3.     QString isNumber = m_ui->lineEdit->text();
  4.     QString trueNumber = "";    
  5.     QString str = m_ui->lineEdit->text();
  6.     double returnDouble;
  7.  
  8.     foreach(QChar c, str)
  9.     {
  10.         if(c.isNumber()) //check numeric input
  11.         {
  12.             trueNumber = m_ui->lineEdit->text();
  13.  
  14.             close();
  15.         }
  16.         if(isspace(true))  // Check for whitespace
  17.         {
  18.             m_ui->messageLbl->setText(m_ui->lineEdit->text() + "Enter a Numeric Value");            
  19.         }
  20.         else // not numeric?, throw error
  21.         {
  22.         m_ui->messageLbl->setText(m_ui->lineEdit->text() + ":  Is Invalid.  Enter a Numeric Value");
  23.  
  24.         }
  25.     }
  26.  
  27.     returnDouble = trueNumber.toDouble();
  28.  
  29.     return returnDouble;
  30. }
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