Send real time data from another class to MainWindow Label

Isidro Perla

Hello!, I need help to send data from my OpenGLWidget class to a label in my MainWindow class, here is my code

#include "mainwindow.h"
#include "ui_mainwindow.h"

//MainWindow.cpp
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);

MyOpenGLWidget *a = new MyOpenGLWidget;

connect(a, SIGNAL(textChanged(QString)),ui->lb_ax, SLOT(setText(QString)));

a->someFunctionThatChangesText("");

QApplication::processEvents();
QWidget::repaint();

update();

}

MainWindow::~MainWindow()
{
delete ui;
}

//MainWindow.h
#ifndef MYOPENGLWIDGET_H
#define MYOPENGLWIDGET_H

#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <GL/gl.h>
#include <mainwindow.h>
#include <QObject>
#include <signal.h>

class MyOpenGLWidget : public QOpenGLWidget, public QOpenGLFunctions
{
Q_OBJECT
public:
MyOpenGLWidget(QWidget *parent = nullptr);
float tiempo = 0;

signals:
void textChanged(QString);
public:
void someFunctionThatChangesText(const QString& newtext);

public slots:
void funcionActivacionTimer();

protected:
void initializeGL() override;
void paintGL() override;
void resizeGL(int w, int h) override;

virtual void mousePressEvent(QMouseEvent *event);
virtual void mouseMoveEvent(QMouseEvent *event);
virtual void mouseReleaseEvent(QMouseEvent *event);

};

#endif // MYOPENGLWIDGET_H

//MyOpenglGlWidget.cpp
#include "myopenglwidget.h"
#include <GL/gl.h>
#include <QDebug>
#include <math.h>
#include <QMouseEvent>
#include <mainwindow.h>
#include <ui_mainwindow.h>
#include <QTimer>

float xM=0;
float yM=0;
float w=0; //Variable que guarda el ancho del OpenGL widget.
float h=0; //Variable que guarda el alto del OpenGL widget.

float m=20;
float k=20;
float a=0;
float x=0;

float A=0;

float xP=0;
float t=0;

int cont=0; //Almacena el mismo valor que el contador.

bool m_is_dragging=false; //Variable boleaana que indica si se clickea el mouse.
bool act=false;

MyOpenGLWidget::MyOpenGLWidget(QWidget *parent)
: QOpenGLWidget {parent}
{
QTimer *cronometro=new QTimer(this);
connect(cronometro, SIGNAL(timeout()), this, SLOT(funcionActivacionTimer()));
cronometro->start(50); //Se actualiza cada 50 milisegundos.
}

void MyOpenGLWidget::funcionActivacionTimer(){
if(t<=20 && m_is_dragging==false && act==true){
tiempo+=0.1f;
t=tiempo;
}if(t==20){
t=0;
act=false;
}
}

void MyOpenGLWidget::mousePressEvent(QMouseEvent *event){ //Función que detecta si se ha o esta clickeando el mouse (hace a esa variable true).

if(event->button() == Qt::LeftButton){ //Esta variable boleana se hace true si se mantiene apretado el click izquierdo del mouse.
    m_is_dragging = true;
    act=true;
}

}

void MyOpenGLWidget::mouseMoveEvent(QMouseEvent event){ //Se obtine el ancho y el alto del openGL widget (w,h).
if(m_is_dragging==true){
A=(event->pos().rx())(10/w)-5;
}
}

void MyOpenGLWidget::mouseReleaseEvent(QMouseEvent *event){ //Función que detecta si se ha dejado clickear el mouse (hace a esa variable false).
m_is_dragging = false; //Esta variable boleana se hace false si se no esta apretado el click izquierdo del mouse.
}

void caja(float l, float x, float y){
glPushMatrix();
glTranslatef(x,y,0);
if(m_is_dragging==true){
glTranslatef(xM-4,0,0);
}else if(m_is_dragging==false){
glTranslatef(xP,0,0);
}
glColor3f(1,0,0);
glBegin(GL_POLYGON);
glVertex2f((-l/2),(l/2));
glVertex2f((-l/2),(-l/2));
glVertex2f((l/2),(-l/2));
glVertex2f((l/2),(l/2));
glEnd();
glPopMatrix();
}

void posicionDeEquilibrio(void){

glColor3f(0,0,0);
glBegin(GL_LINES);
for(float i=0.25; i<=10; i+=0.5){
    glVertex2f(5,i-0.25);
    glVertex2f(5,i);
}
glEnd();

}

void MyOpenGLWidget::initializeGL(){
initializeOpenGLFunctions();
glClearColor(1,1,1,1);
w = MyOpenGLWidget::width();
h = MyOpenGLWidget::height();
}

void calculos(){
a = (kabs(xM-5))/(m);
if(A<0){
xP = Acos(sqrt((k/m))t+M_PI);
}else if(A>0){
xP = Acos(sqrt((k/m))*t);
}
}

void MyOpenGLWidget::paintGL(){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

QPoint p = mapFromGlobal(QCursor::pos());
xM = (p.rx())*(10/w); //Se ontiene la posiciÃ³b en X del cursor y se convierte a coordenadas ortogonales.
yM = ((p.ry())*(20/h) -10)-8; //Se ontiene la posiciÃ³b en Y del cursor y se convierte a coordenadas ortogonales.

//qDebug() << xP;
//qDebug() << t << A << xP;

calculos();

glColor3f(0,0,0);
glBegin(GL_LINE_STRIP);
glVertex2f(0.01,5);
glVertex2f(0.01,3);
glVertex2f(10,3);
glEnd();



glPushMatrix();
if(m_is_dragging==true){
    //glTranslatef(xM,0,0);
    glScalef(xM/4,1,0);
}else if(m_is_dragging==false and act==true){
    glScalef((xP+5)/5,1,0);
}

glBegin(GL_LINE_STRIP);
//glVertex2f(-4,2);
//glVertex2f(4,2);
for(float i=0; i<5; i+=0.05){
    glVertex2f(i,sin(12*i)+4);
}
glEnd();
glPopMatrix();

caja(2,5,4);

posicionDeEquilibrio();

update();

}
void MyOpenGLWidget::resizeGL(int w, int h){
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, 10, 0, 10, 0, 10);
}

void MyOpenGLWidget::someFunctionThatChangesText(const QString& newtext){
emit textChanged(QString::number(tiempo));
qDebug()<<tiempo;
}

//MyOpenGLWidget.h
#ifndef MYOPENGLWIDGET_H
#define MYOPENGLWIDGET_H

#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <GL/gl.h>
#include <mainwindow.h>
#include <QObject>
#include <signal.h>

class MyOpenGLWidget : public QOpenGLWidget, public QOpenGLFunctions
{
Q_OBJECT
public:
MyOpenGLWidget(QWidget *parent = nullptr);
float tiempo = 0;

signals:
void textChanged(QString);
public:
void someFunctionThatChangesText(const QString& newtext);

public slots:
void funcionActivacionTimer();

protected:
void initializeGL() override;
void paintGL() override;
void resizeGL(int w, int h) override;

virtual void mousePressEvent(QMouseEvent *event);
virtual void mouseMoveEvent(QMouseEvent *event);
virtual void mouseReleaseEvent(QMouseEvent *event);

};

#endif // MYOPENGLWIDGET_H

------------------------------------------------>

I´m think that the problem is in this function

void MyOpenGLWidget::someFunctionThatChangesText(const QString& newtext){
emit textChanged(QString::number(tiempo));
qDebug()<<tiempo;
}

I want to know how to update tha var "Tiempo" because I need to send in real time that data to the la label lb_ax in MainWindow, i think that someFunctionThatChangesText is not updating the emit, some idea please????

mrjj

Hi
emit rarely fails so i would check
bool result = connect(a, SIGNAL(textChanged(QString)),ui->lb_ax, SLOT(setText(QString)));
qDebug()<<"conn;" << result;

Since you do
MyOpenGLWidget *a = new MyOpenGLWidget;
connect(a, SIGNAL(textChanged(QString)),ui->lb_ax, SLOT(setText(QString)));
a->someFunctionThatChangesText("");

It should be the MyOpenGLWidget you think it is, which else is a classic error.

Last thing that can be wrong, it that you might somehow block the event loop as you inserted
QApplication::processEvents();
QWidget::repaint();
which should not be needed.