Show error message in main window when image fail to load

imagescrollareagl.cpp

@@ -90,14 +90,27 @@ ImageWidget::~ImageWidget()
 
 void ImageWidget::setImage(std::shared_ptr<RawImage> image, int index)
 {
-    if(image == nullptr)return;
+    m_currentImg = index;
+
+    if(!image || !image->valid())
+    {
+        m_imgWidth = 0;
+        m_imgHeight = 0;
+        m_error = tr("Failed to load image");
+        m_rawImage.reset();
+        update();
+        return;
+    }
+
+    m_error.clear();
     makeCurrent();
     m_rawImage = image;
-    m_rawImage->downscaleTo(m_maxTextureSize);
+    if((int)image->width() > m_maxTextureSize || (int)image->height() > m_maxTextureSize)
+        m_rawImage->resize(std::min(m_maxTextureSize, (int)image->width()), std::min(m_maxTextureSize, (int)image->height()));
 
     m_imgWidth = image->width();
     m_imgHeight = image->height();
-    m_currentImg = index;
+
 
     if(!m_image)return;
 
@@ -290,7 +303,7 @@ void ImageWidget::thumbnailLoaded(const Image *image)
 {
     makeCurrent();
     const RawImage *raw = image->thumbnail();
-    if(!raw)return;
+    if(!raw || !raw->valid())return;
     m_thumbnailTexture->setData(0, image->number(), QOpenGLTexture::RGBA, QOpenGLTexture::UInt16, raw->data(), m_transferOptions.get());
     float a = raw->thumbAspect();
     int sizes[3] = { std::max(1, a > 1.0f ? THUMB_SIZE : (int)(THUMB_SIZE * a)), std::max(1, a < 1.0f ? THUMB_SIZE : (int)(THUMB_SIZE / a)), image->number() };
@@ -375,6 +388,13 @@ void ImageWidget::paintGL()
             }
         }
     }
+    else if(!m_error.isEmpty())
+    {
+        QPainter painter(this);
+        painter.setPen(Qt::red);
+        painter.setFont(QFont("Sans", 24, QFont::Bold));
+        painter.drawText(0, 0, width(), height(), Qt::AlignCenter | Qt::AlignHCenter, m_error);
+    }
     else
     {
         debayer();

imagescrollareagl.h

@@ -69,6 +69,7 @@ class ImageWidget : public QOpenGLWidget
     QVector<ImageThumb> m_thumnails;
     Database *m_database = nullptr;
     QPointF m_lastPos;
+    QString m_error;
 public:
     explicit ImageWidget(Database *database, QWidget *parent = nullptr);
     ~ImageWidget() override;