Loading image from subclass QGraphicsview

[2lights]

How do I upload an image to a graphicsview from a subclass of QGraphicsview

I created new class "TestGV" as a child class of QGraphicsView
I promoted my graphicsView widget on form to "TestGV" class

Where do I create the scene in the mainwindow class or the "TestGV" class
This is what i got, but does not work

definitions in public "TesGv Class"
    QGraphicsScene *scene;
    QGraphicsPixmapItem *newImage;

definitions in public "TesGv Class"
    QGraphicsScene *scene;
    QGraphicsPixmapItem *newImage;

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//In mainWindow Class -> PushButton "Upload Image"
    ui->graphicsView->getImageFileName(); // call function in subclass to get and set image
    ui->graphicsView->scene = new QGraphicsScene(this);
    ui->graphicsView->setScene(ui->graphicsView->scene)

//In mainWindow Class -> PushButton "Upload Image"
    ui->graphicsView->getImageFileName(); // call function in subclass to get and set image
    ui->graphicsView->scene = new QGraphicsScene(this);
    ui->graphicsView->setScene(ui->graphicsView->scene)

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//In subClass "TestGV" "getImageFileName
     QFileDialog dialog(this, "Upload");
    dialog.setNameFilter(tr("Images (*.png *.jpg *.bmp *)"));
    dialog.setViewMode(QFileDialog::Detail);
    QString imageFileName1;
    if(dialog.exec())
    {
        imageFileName1 = dialog.selectedFiles().first();
    }
 
    image1.load(imageFileName1);
    image1 = image1.convertToFormat(QImage::Format_RGB32);
 
    QRgb colour;
    for (int f1=0; f1<image1.width(); f1++) {
        for (int f2=0; f2<image1.height(); f2++) {
            colour = image1.pixel(f1, f2);
            image1.setPixel(f1, f2, QColor((qRed(colour) + qGreen(colour) + qBlue(colour))/3).rgb());
        }
    }
    QPixmap pixmap;
    pixmap.fromImage(image1);
    scene = new QGraphicsScene(this);
    newImage = scene->addPixmap(pixmap);

//In subClass "TestGV" "getImageFileName
     QFileDialog dialog(this, "Upload");
    dialog.setNameFilter(tr("Images (*.png *.jpg *.bmp *)"));
    dialog.setViewMode(QFileDialog::Detail);
    QString imageFileName1;
    if(dialog.exec())
    {
        imageFileName1 = dialog.selectedFiles().first();
    }

    image1.load(imageFileName1);
    image1 = image1.convertToFormat(QImage::Format_RGB32);

    QRgb colour;
    for (int f1=0; f1<image1.width(); f1++) {
        for (int f2=0; f2<image1.height(); f2++) {
            colour = image1.pixel(f1, f2);
            image1.setPixel(f1, f2, QColor((qRed(colour) + qGreen(colour) + qBlue(colour))/3).rgb());
        }
    }
    QPixmap pixmap;
    pixmap.fromImage(image1);
    scene = new QGraphicsScene(this);
    newImage = scene->addPixmap(pixmap);

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The above code does display Dialogbox & user can select image of choice
But nothing is uploaded
How do I set the scene from the subClass "testGV"
And do the uploading also from "TestGV"

Kindly provide me with example code

Kind Regards

[Santosh Reddy]

//In mainWindow Class -> PushButton "Upload Image"
ui->graphicsView->scene = new QGraphicsScene(this);
ui->graphicsView->setScene(ui->graphicsView->scene)
ui->graphicsView->getImageFileName(); // call function in subclass to get and set image

//In mainWindow Class -> PushButton "Upload Image"
ui->graphicsView->scene = new QGraphicsScene(this);
ui->graphicsView->setScene(ui->graphicsView->scene)
ui->graphicsView->getImageFileName(); // call function in subclass to get and set image

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//In subClass "TestGV" "getImageFileName
QFileDialog dialog(this, "Upload");
dialog.setNameFilter(tr("Images (*.png *.jpg *.bmp *)"));
dialog.setViewMode(QFileDialog::Detail);
QString imageFileName1;
if(dialog.exec())
{
    imageFileName1 = dialog.selectedFiles().first();
}
 
image1.load(imageFileName1);
image1 = image1.convertToFormat(QImage::Format_RGB32);
 
QRgb colour;
for (int f1=0; f1<image1.width(); f1++) {
    for (int f2=0; f2<image1.height(); f2++) {
        colour = image1.pixel(f1, f2);
        image1.setPixel(f1, f2, QColor((qRed(colour) + qGreen(colour) + qBlue(colour))/3).rgb());
    }
}
 
QPixmap pixmap;
pixmap.fromImage(image1);
//scene = new QGraphicsScene(this);
newImage = scene->addPixmap(pixmap);

//In subClass "TestGV" "getImageFileName
QFileDialog dialog(this, "Upload");
dialog.setNameFilter(tr("Images (*.png *.jpg *.bmp *)"));
dialog.setViewMode(QFileDialog::Detail);
QString imageFileName1;
if(dialog.exec())
{
    imageFileName1 = dialog.selectedFiles().first();
}

image1.load(imageFileName1);
image1 = image1.convertToFormat(QImage::Format_RGB32);

QRgb colour;
for (int f1=0; f1<image1.width(); f1++) {
    for (int f2=0; f2<image1.height(); f2++) {
        colour = image1.pixel(f1, f2);
        image1.setPixel(f1, f2, QColor((qRed(colour) + qGreen(colour) + qBlue(colour))/3).rgb());
    }
}

QPixmap pixmap;
pixmap.fromImage(image1);
//scene = new QGraphicsScene(this);
newImage = scene->addPixmap(pixmap);

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[2lights]

Thanks,


Based on QDebug output on width & height of image
my QImage works
my QPixmap does not get initialised at all

pixmap.fromImage(image1);

pixmap.fromImage(image1);

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Loading from QImage directly... works

newImage = scene->addPixmap(QPixmap::fromImage(image1));

newImage = scene->addPixmap(QPixmap::fromImage(image1));

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not sure if i'll need Qpixmap later though
Would like to know why QPixmap is not working accordingly


Kind Regards
Thanks

[Santosh Reddy]

fromImage() is a static member function, you need to copy the converted pixmap into a variable (you might have ignored the compiler warning, or may be even disabled them). Anyways this will work

QPixmap pixmap;
pixmap = pixmap.fromImage(image1);

QPixmap pixmap;
pixmap = pixmap.fromImage(image1);

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and even better is this

QPixmap pixmap;
pixmap = QPixmap::fromImage(image1);

QPixmap pixmap;
pixmap = QPixmap::fromImage(image1);

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