From 617abf7afedbc910a3549138b15ae885e5782dd7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Du=C5=A1an=20Poizl?= <nou.spiro@gmail.com>
Date: Fri, 28 Feb 2025 10:42:39 +0100
Subject: [PATCH] Better handling of FITS loading error

---
 imageringlist.cpp   | 11 ++++++++++-
 imageringlist.h     |  1 +
 imagescrollarea.cpp |  2 +-
 loadimage.cpp       | 38 +++++++++++++++++++++++---------------
 4 files changed, 35 insertions(+), 17 deletions(-)

diff --git a/imageringlist.cpp b/imageringlist.cpp
index e36b193..8d4794e 100644
--- a/imageringlist.cpp
+++ b/imageringlist.cpp
@@ -85,6 +85,11 @@ void Image::clearThumbnail()
     m_thumbnail.reset();
 }
 
+bool Image::isLoading() const
+{
+    return m_loading;
+}
+
 void Image::imageLoaded(std::shared_ptr<RawImage> rawImage, ImageInfoData info)
 {
     m_loading = false;
@@ -200,7 +205,7 @@ void ImageRingList::increment()
     if(m_images.size())
     {
         //don't increment if current image was not loaded yet
-        if(!(*m_currImage)->rawImage())
+        if((*m_currImage)->isLoading())
             return;
 
         (*m_firstImage)->release();
@@ -216,6 +221,10 @@ void ImageRingList::decrement()
 {
     if(m_images.size())
     {
+        //don't decrement if current image was not loaded yet
+        if((*m_currImage)->isLoading())
+            return;
+
         (*m_lastImage)->release();
         m_firstImage = decrement(m_firstImage);
         m_currImage = decrement(m_currImage);
diff --git a/imageringlist.h b/imageringlist.h
index 229ce6e..d75efa5 100644
--- a/imageringlist.h
+++ b/imageringlist.h
@@ -38,6 +38,7 @@ public:
     bool isCurrent() const;
     int number() const;
     void clearThumbnail();
+    bool isLoading() const;
 signals:
     void pixmapLoaded(Image *ptr);
     void thumbnailLoaded(Image *ptr);
diff --git a/imagescrollarea.cpp b/imagescrollarea.cpp
index 260a416..b4c41c1 100644
--- a/imagescrollarea.cpp
+++ b/imagescrollarea.cpp
@@ -110,7 +110,7 @@ void ImageScrollArea::oneToOne()
 
 void ImageScrollArea::imageLoaded(Image *image)
 {
-    if(image && image->rawImage())
+    if(image)
     {
         m_imageWidget->setImage(image->rawImage(), image->number());
         m_imageWidget->setWCS(image->info().wcs);
diff --git a/loadimage.cpp b/loadimage.cpp
index 14e5b9c..1bc71aa 100644
--- a/loadimage.cpp
+++ b/loadimage.cpp
@@ -86,19 +86,31 @@ bool loadFITS(const QString path, ImageInfoData &info, std::shared_ptr<RawImage>
     fitsfile *file;
     int status = 0;
     int type = -1;
-    fits_open_diskfile(&file, path.toLocal8Bit().data(), READONLY, &status);
     int num = 0;
+    long naxes[3] = {0};
+
+    auto checkError = [&info, &status]()
+    {
+        char err[100];
+        fits_get_errstatus(status, err);
+        info.info.append({QObject::tr("Error"), QString(err)});
+        qDebug() << "Failed to load FITS file" << err;
+        return false;
+    };
+
+    fits_open_diskfile(&file, path.toLocal8Bit().data(), READONLY, &status);
+    if(status)return checkError();
     fits_get_num_hdus(file, &num, &status);
+    if(status)return checkError();
 
     int imgtype;
     int naxis;
-    long naxes[3] = {0};
     for(int i=1; i <= num; i++)
     {
-        fits_movabs_hdu(file, i, IMAGE_HDU, &status);
-        fits_get_hdu_type(file, &type, &status);
-        fits_get_img_param(file, 3, &imgtype, &naxis, naxes, &status);
-        fits_get_img_equivtype(file, &imgtype, &status);
+        fits_movabs_hdu(file, i, IMAGE_HDU, &status);if(status)return checkError();
+        fits_get_hdu_type(file, &type, &status);if(status)return checkError();
+        fits_get_img_param(file, 3, &imgtype, &naxis, naxes, &status);if(status)return checkError();
+        fits_get_img_equivtype(file, &imgtype, &status);if(status)return checkError();
 
         if(type == IMAGE_HDU && naxis >= 2 && naxis <= 3 && status == 0)
         {
@@ -150,6 +162,7 @@ bool loadFITS(const QString path, ImageInfoData &info, std::shared_ptr<RawImage>
             {
                 fpixel[2] = i;
                 fits_read_pix(file, fitstype, fpixel, size, NULL, data + img.size() * RawImage::typeSize(type) * (i-1), NULL, &status);
+                if(status)return checkError();
             }
             if(fitstype == TSHORT)
             {
@@ -169,7 +182,10 @@ bool loadFITS(const QString path, ImageInfoData &info, std::shared_ptr<RawImage>
     }
 noload:
     if(file)
-        loadFITSHeader(file, info);
+    {
+        status = loadFITSHeader(file, info);
+        if(status)return checkError();
+    }
 
     if(image)
     {
@@ -181,14 +197,6 @@ noload:
     }
 
     fits_close_file(file, &status);
-    if(status)
-    {
-        char err[100];
-        fits_get_errstatus(status, err);
-        info.info.append({QObject::tr("Error"), QString(err)});
-        qDebug() << "Failed to load FITS file" << err;
-    }
-
     return true;
 }