QLCDNumber display double - double

Question

I'm learning visual programing in Qt by trying to create a simple calculator. I'm having trouble with the QLCDNumber because I am not able to display double numbers, it doesn't show the coma nor the decimals.
The code is pretty simple but it should do the job, but how can I show the coma?
Here is the code:
#include "mainwindow.h"
#include "ui_mainwindow.h"
using namespace std;
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
}
MainWindow::~MainWindow()
{
delete ui;
}
// VARIABLES GLOBALES
double valor1 = 0;
double valor2 = 0;
double suma = 0;
double resta = 0;
double multiplicacion = 0;
double division = 0;
double raiz = 0;
double resultado;
int contador_decimales = 0;
bool suma_presionada = 0;
bool resta_presionada = 0;
bool resultado_inicializado = 0;
// BOTÓN 1
void MainWindow::on_boton1_clicked()
{
if (contador_decimales == 0){
if (suma_presionada == 0 && resta_presionada == 0){
valor1 = valor1 * 10 + 1;
ui -> pantalla -> display(valor1);
}
else {
valor2 = valor2 * 10 + 1;
ui -> pantalla -> display(valor2);
}
} else {
if (suma_presionada == 0 && resta_presionada == 0){
valor1 = valor1 + 1/contador_decimales;
ui -> pantalla -> display(valor1);
contador_decimales = contador_decimales * 10;
}
else {
valor2 = valor2 + 1/contador_decimales;
ui -> pantalla -> display(valor2);
contador_decimales = contador_decimales * 10;
}
}
}
// BOTÓN 2
void MainWindow::on_boton2_clicked()
{
if (suma_presionada == 0 && resta_presionada == 0){
valor1 = valor1 * 10 + 2;
ui -> pantalla -> display(valor1);
}
else {
valor2 = valor2 * 10 + 2;
ui -> pantalla -> display(valor2);
}
}
// BOTÓN 3
void MainWindow::on_boton3_clicked()
{
if (suma_presionada == 0 && resta_presionada == 0){
valor1 = valor1 * 10 + 3;
ui -> pantalla -> display(valor1);
}
else {
valor2 = valor2 * 10 + 3;
ui -> pantalla -> display(valor2);
}
}
// BOTÓN SUMA
void MainWindow::on_boton_suma_clicked()
{
suma_presionada = 1;
resta_presionada = 0;
contador_decimales = 0;
}
// BOTÓN RESTA
void MainWindow::on_boton_resta_clicked()
{
suma_presionada = 0;
resta_presionada = 1;
contador_decimales = 0;
}
// BOTÓN IGUAL
void MainWindow::on_boton_igual_clicked()
{
// SUMA
if (suma_presionada == 1){
if (valor1 != NULL){
suma = valor1 + valor2;
} else {
suma = resultado + valor2;
}
ui -> pantalla -> display(suma);
resultado = ui -> pantalla -> value();
suma_presionada = 0;
contador_decimales = 0;
valor1 = NULL;
valor2 = 0;
}
// RESTA
if (resta_presionada == 1){
if (valor1 != NULL){
suma = valor1 - valor2;
} else {
suma = resultado - valor2;
}
ui -> pantalla -> display(suma);
resultado = ui -> pantalla -> value();
resta_presionada = 0;
valor1 = NULL;
valor2 = 0;
}
}
// BOTÓN DECIMAL
void MainWindow::on_boton_coma_clicked()
{
contador_decimales = 10;
ui -> pantalla -> smallDecimalPoint();
ui -> pantalla -> setSmallDecimalPoint(true);
}

Answer 1

I found the problem. It is not that the LCD doesn't display doubles, it is that I didn't have a double. I declared contador_decimales as an int, so 1/contador_decimales is an int. I tried casting it to double but it doesn't work, but if I declare contador_decimales as a double, it does.
I guess i was pretty sure it was the LDC because of how little information I found.
Sorry for the dumb question, as it turns out.