custom widget update() and repaint() will not work

[AI_Messiah]

So I have a widget for an image. I know that it does work in relation to the first call of the paint event but when I send in an image I can't get this to happen again

header:

#ifndef IMAGEDISPLAY_H
#define IMAGEDISPLAY_H

#include <QWidget>
#include <QImage>

class QPaintEvent;

class ImageDisplay : public QWidget
{
    Q_OBJECT
public:
    explicit ImageDisplay(QWidget *parent = nullptr);

    virtual void paintEvent(QPaintEvent* event);
    void setImage(QImage img);
signals:

private:
    QImage toShow;
};

#endif // IMAGEDISPLAY_H

source

#include "imagedisplay.h"
#include <QtGui>

ImageDisplay::ImageDisplay(QWidget *parent)
    : QWidget{parent}
{
    //toShow = QImage(":/Images/Images/Columbine-Flower-Colors-768x768-tile.jpg");

}

void ImageDisplay::paintEvent(QPaintEvent *event)
{
    QPainter painter(this);
    painter.setPen(QColor::fromRgb(255, 255, 255, 255));
    QBrush solid = QBrush(QColor::fromRgb(255, 255, 255, 255), Qt::BrushStyle::SolidPattern);
    auto size = this->size();
    auto offset = 4;
    painter.drawImage(QRect(0, 0, 768, 768), toShow);

}

void ImageDisplay::setImage(QImage img)
{
    toShow = img;
    this->repaint();
}

[ChrisW67]

"Will not work" is not a good description of what is happening versus what was expected.
Does it behave differently if you call QWidget::update() rather than QWidget::repaint()?

void ImageDisplay::setImage(const QImage &img)
{
    toShow = img;
    update();
}

Without code we cannot see if you are doing something that blocks the event loop or painting.

[SGaist]

@AI_Messiah hi,

Might be a silly question but since you don't seem to be anything special with the image, why not use QLabel ?