Connect trouble

[marius.thorre]

Hello,
I have a main class imagedit.cpp which contains button Filter and Image. When i click to Filtre button, imagedit open a new widget which contains other button (changeBlackAndWhite button for example). I wish to connect my image with these button. That is the code:

#include "imagedit.h"
#include "ui_imagedit.h"
#include <QFileDialog>
#include <QStandardPaths>
#include <QListWidgetItem>
#include <QPushButton>
#include <QDebug>

ImagEdit::ImagEdit(QWidget *parent) : QMainWindow(parent), ui(new Ui::ImagEdit)
{
    ui->setupUi(this);
    path = new QString();
    pix = new QPixmap(*path);
}

ImagEdit::~ImagEdit()
{
    delete ui;
    delete pix;
    delete path;
}

void ImagEdit::on_open_clicked()
{
    QString cheminInitial = QStandardPaths::writableLocation(QStandardPaths::PicturesLocation);
    QString cheminFichier = QFileDialog::getOpenFileName(this, "Sélectionnez un fichier", cheminInitial);
    QFileInfo fileInfo(cheminFichier);
    QString nomFichier = fileInfo.fileName();
    QPushButton *button = new QPushButton(nomFichier, this);

    connect(button, SIGNAL(clicked()), this, SLOT(displayOnEdition()));
    *path = cheminFichier;
    QListWidgetItem *item = new QListWidgetItem;

    ui->library->addItem(item);
    ui->library->setItemWidget(item, button);
}

void ImagEdit::displayOnEdition()
{
    QPixmap pix(*path);
    pix = pix.scaled(381, 271, Qt::KeepAspectRatio);
    ui->imageLabel->setPixmap(pix);

}


void ImagEdit::on_filter_clicked()
{
    
    FilterArea *filter = new FilterArea();
    filter->setImage(pix->toImage());

    filter->show();
   
}

void ImagEdit::on_rogner_clicked()
{
    RognerArea *rogner = new RognerArea();
    rogner->show();
}

############################################

#include "filterarea.h"
#include "ui_filterarea.h"

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

}

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

void FilterArea::on_NbFilterButton_clicked()
{
    qDebug() << "NbFilterButton clicked";

    emit applyNbFilter();
}

void FilterArea::setImage(QImage image) {
    imageSelected = image;
    
//connect(ui->NbFilterButton, SIGNAL(clicked()), ImagEdit.cpp), SLOT(appliquerFiltreNoirEtBlanc()));
}

void FilterArea::appliquerFiltreNoirEtBlanc()
{

    qDebug() << "Appliquer filtre Noir et Blanc";

    if (!imageSelected.isNull()) {
        QImage imageNoirEtBlanc(imageSelected.size(), QImage::Format_Grayscale8);

        for (int y = 0; y < imageSelected.height(); ++y) {
            for (int x = 0; x < imageSelected.width(); ++x) {
                QRgb pixel = imageSelected.pixel(x, y);
                int grayValue = qGray(pixel);
                imageNoirEtBlanc.setPixel(x, y, qRgb(grayValue, grayValue, grayValue));
            }
        }

        //setImage(imageNoirEtBlanc);
    }
    else {
        qDebug() << "Erreur : Aucune image actuelle à traiter.";
    }
}

[JonB]

@marius-thorre said in Connect trouble:

//connect(ui->NbFilterButton, SIGNAL(clicked()), ImagEdit.cpp), SLOT(appliquerFiltreNoirEtBlanc()));

I don't know whether it does what you want, but are you asking for the syntax here for your "Connect trouble"? It would be

connect(ui->NbFilterButton, SIGNAL(clicked()), this, SLOT(appliquerFiltreNoirEtBlanc()));

If you intend to call FilterArea::setImage() more than once you should not put a connect() statement inside it. connect()s are usually done once in the constructor.

[marius.thorre]

@JonB I find something:

#include "imagedit.h"
#include "ui_imagedit.h"
#include <QFileDialog>
#include <QStandardPaths>
#include <QListWidgetItem>
#include <QPushButton>
#include <QDebug>

ImagEdit::ImagEdit(QWidget *parent) : QMainWindow(parent), ui(new Ui::ImagEdit)
{
    ui->setupUi(this);
    path = new QString();
    pix = new QPixmap(*path);
}

ImagEdit::~ImagEdit()
{
    delete ui;
    delete pix;
    delete path;
}

void ImagEdit::on_open_clicked()
{
    QString cheminInitial = QStandardPaths::writableLocation(QStandardPaths::PicturesLocation);
    QString cheminFichier = QFileDialog::getOpenFileName(this, "Sélectionnez un fichier", cheminInitial);
    QFileInfo fileInfo(cheminFichier);
    QString nomFichier = fileInfo.fileName();
    QPushButton *button = new QPushButton(nomFichier, this);

    connect(button, SIGNAL(clicked()), this, SLOT(displayOnEdition()));
    *path = cheminFichier;
    QListWidgetItem *item = new QListWidgetItem;

    ui->library->addItem(item);
    ui->library->setItemWidget(item, button);
}

void ImagEdit::displayOnEdition()
{
    QPixmap pix(*path);
    pix = pix.scaled(381, 271, Qt::KeepAspectRatio);
    ui->imageLabel->setPixmap(pix);

}


void ImagEdit::on_filter_clicked()
{
    FilterArea *filterarea = new FilterArea();
    //connect(filterarea, filterarea->appliquerFiltreNoirEtBlanc(pix->toImage()), this, ui->imageLabel);
    filterarea->setImage(ui->imageLabel->pixmap().toImage());
    filterarea->show();
}



void ImagEdit::on_rogner_clicked()
{
    RognerArea *rogner = new RognerArea();
    rogner->show();
}



######################################

#include "filterarea.h"
#include "ui_filterarea.h"

#include <iostream>
using namespace std;

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

}

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

void FilterArea::on_NbFilterButton_clicked()
{
    qDebug() << "NbFilterButton clicked";
    emit applyNbFilter();
}

void FilterArea::setImage(QImage image) {
    imageSelected = image;
    connect(ui->NbFilterButton, SIGNAL(clicked()), this, SLOT(appliquerFiltreNoirEtBlanc()));
}

void FilterArea::appliquerFiltreNoirEtBlanc()
{

    qDebug() << "Appliquer filtre Noir et Blanc";

    if (!imageSelected.isNull()) {
        cout << "coucou "<< imageSelected.isNull() << endl;
        QImage imageNoirEtBlanc(imageSelected.size(), QImage::Format_Grayscale8);

        for (int y = 0; y < imageSelected.height(); ++y) {
            for (int x = 0; x < imageSelected.width(); ++x) {
                QRgb pixel = imageSelected.pixel(x, y);
                int grayValue = qGray(pixel);
                imageSelected.setPixel(x, y, qRgb(grayValue, grayValue, grayValue));
            }
        }


    }
    else {
        qDebug() << "Erreur : Aucune image actuelle à traiter.";
    }
}

but i cannot change color of my picture (i check into imageSelectedIsNull and the result is 0, so it's the good image)

[JonB]

@marius-thorre said in Connect trouble:

imageSelected = image;

This copies image.

imageSelected.setPixel()

This alters the copied image.

So after copying and changing in imageSelected, where do you then show this changed image?

[marius.thorre]

@marius-thorre i was thinking it change himself