Problems with connect() and some classes

brunoluiz · wrote on 30 Apr 2012, 21:19

Good night,

I'm writing some code here but I'm getting this error:

@Object::connect: No such slot gaugeView::updateValues(30) in ..\teste2\mainwindow.cpp:43
Object::connect: No such slot gaugeView::updateValues(30) in ..\teste2\mainwindow.cpp:44@

I tried everything I found at Google, but I can't find the error. The code of the class are:

Main Window.cpp:
@#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "gaugeview.h"
#include <QFileDialog>
#include <QTimer>

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

int ra = rand();
while(ra > 200)
ra = rand();

gaugeView * gauge1 = new gaugeView(centralWidget());
ref = gauge1;
QString pointerFile = ":/pointer.png";
QString backgroundFile = ":/background.png";

gauge1->setPointer(pointerFile);
gauge1->setBackground(backgroundFile);
gauge1->setPosition(0,0);
gauge1->setDimensions(272,272);
gauge1->create();
gauge1->update(ra);

ra = rand();
while(ra > 200)
ra = rand();

gaugeView * gauge2 = new gaugeView(centralWidget());

gauge2->setPointer(pointerFile);
gauge2->setBackground(backgroundFile);
gauge2->setPosition(0,271);
gauge2->setDimensions(272,272);
gauge2->create();
gauge2->update(ra);

QTimer * timerRand = new QTimer;
connect(timerRand,SIGNAL(timeout()),gauge1,SLOT(updateValues(30)));
connect(timerRand,SIGNAL(timeout()),gauge2,SLOT(updateValues(30)));
timerRand->start(2000);
}

MainWindow::~MainWindow()
{
delete ui;
}
//void MainWindow::updateValues(gaugeView obj, int num)
//{
// obj.update(num);
//}
@

MainWindow.h
@#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include "gaugeview.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();

private:
Ui::MainWindow *ui;
gaugeView * ref;

//public slots:
// void updateValues(int);
};

#endif // MAINWINDOW_H
@

gaugeview.h
@#ifndef GAUGEVIEW_H
#define GAUGEVIEW_H

#include <QWidget>
#include <QGraphicsScene>
//#include <QPixmap>

class gaugeView : public QWidget
{
Q_OBJECT
public:
explicit gaugeView(QWidget *parent = 0);
void update(int);
void create();
void setPointer(QString);
void setBackground(QString);
void setPosition(int,int);
void setDimensions(int,int);
bool setDigital(bool);

private:
QPixmap pixPointer;
QPixmap pixBackground;
int posx, posy;
int actualWidth,actualHeight;
int actualValue, pastValue;
bool showDigital;
QGraphicsView * gp;
QGraphicsScene * actualScene;
void createDigital(void);

public slots:
void updateValues(int);
};

#endif // GAUGEVIEW_H
@

gaugeview.cpp
@#include "gaugeview.h"
#include <QPainter>
#include <QGraphicsView>
#include <QBrush>

gaugeView::gaugeView(QWidget *parent) :
QWidget(parent)
{
gp = new QGraphicsView(parentWidget());
gp->move(0,0);
gp->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
gp->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
gp->lower();
}

void gaugeView::setPointer(QString fileLocation)
{
pixPointer.fill(Qt::transparent);
pixPointer.load(fileLocation);
}

void gaugeView::setBackground(QString fileLocation)
{
pixBackground.fill(Qt::transparent);
pixBackground.load(fileLocation);
}

void gaugeView::setPosition(int x = 0,int y = 0)
{
posx = x;
posy = y;
gp->move(posx,posy);
}

bool gaugeView::setDigital(bool checkCond)
{
showDigital = checkCond;
return checkCond;
}

void gaugeView::createDigital()
{

}

void gaugeView::setDimensions(int width,int height)
{
actualWidth = width;
actualHeight = height;
pixPointer = pixPointer.scaled(actualWidth, actualHeight);
pixBackground = pixBackground.scaled(actualWidth, actualHeight);
}

void gaugeView::create()
{
QBrush brushBackground;
brushBackground.setTexture(pixBackground);

actualScene = new QGraphicsScene();
actualScene->clear();
actualScene->addPixmap(pixPointer);

gp->setBackgroundBrush(brushBackground);
gp->setScene(actualScene);
gp->show();
}

void gaugeView::update(int value)
{
pastValue = actualValue;
actualValue = value;

QSize size = pixPointer.size();
QPixmap rotatedPixmap(size);
rotatedPixmap.fill(Qt::transparent);

QPainter * p = new QPainter(&rotatedPixmap);
p->setRenderHint(QPainter::SmoothPixmapTransform);
p->translate(size.width()/2,size.height()/2);
p->rotate(actualValue);
p->translate(-size.width()/2,-size.height()/2);
p->drawPixmap(0,0,pixPointer);
p->end();
delete p;

actualScene->clear();
actualScene->addPixmap(rotatedPixmap);

gp->setScene(actualScene);
gp->move(posx,posy);
gp->show();
}

void gaugeView::updateValues(int num = 0)
{
this->update(num);
}
@

If someone have an idea of what is happening, please, post it.

dbzhang800 · wrote on 30 Apr 2012, 21:29

You slot should be
@
updateValues(int)
@

instead of
@
updateValues(30)
@

dbzhang800 · wrote on 30 Apr 2012, 21:32

However,

following statement still wrong
@
connect(timerRand,SIGNAL(timeout()),gauge1,SLOT(updateValues(int)));
@

params provided by signal should >= params needed by your slot.

Read the manual carefully. http://doc-snapshot.qt-project.org/4.8/signalsandslots.html

brunoluiz · wrote on 30 Apr 2012, 21:34

So, in this logic, how I can update my gauges with QTimer?

mlong · wrote on 30 Apr 2012, 21:59

Make your gauges member variables so they are accessible throughout your class.

Then create a slot to do that specific task. For instance:

@
// slot:
void setValuesOnTimeout() {
gauge1->updateValues(30);
gauge2->updateValues(30);
}
@

Then connect like:
@
connect(timerRand,SIGNAL(timeout()),this,SLOT(setValuesOnTimeout()));
@

Edit:

Alternately... (I think this might work, but I haven't tried it...)

Make the default values on your updateValues slots = 30.

Then just connect:
@
// These will use the default value of 30
connect(timerRand,SIGNAL(timeout()),gauge1,SLOT(updateValues()));
connect(timerRand,SIGNAL(timeout()),gauge2,SLOT(updateValues()));
@

brunoluiz · wrote on 30 Apr 2012, 22:59

Thank you! It worked.

[quote author="mlong" date="1335823162"]Make your gauges member variables so they are accessible throughout your class.