Give save filter only formats that are supported

src/mainwindow.cpp

@@ -18,6 +18,7 @@
 #include <QThreadPool>
 #include <QStatusBar>
 #include <QImageReader>
+#include <QImageWriter>
 #include <QMimeDatabase>
 #include <QDesktopServices>
 #include <QJsonDocument>
@@ -57,12 +58,18 @@ MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
     for(auto format : supportedFormats)
     {
         QMimeType mimeType = db.mimeTypeForName(format);
-        _saveFilter.append(mimeType.filterString() + ";;");
         _openFilter.append("*.");
         _openFilter.append(mimeType.suffixes().join(" *."));
         _openFilter.append(" ");
         nameFilter.append(mimeType.suffixes());
     }
+    auto supportedWrite = QImageWriter::supportedMimeTypes();
+    for(auto format : supportedWrite)
+    {
+        QMimeType mimeType = db.mimeTypeForName(format);
+        _saveFilter.append(mimeType.filterString() + ";;");
+    }
+
     _openFilter.append("*.fit *.fits *.fts *.fz *.xisf *.cr2 *.cr3 *.nef *.dng)");
     _openFilter.append(tr(";;All files (*)"));
     nameFilter.append({"fit", "fits", "fts", "fz", "xisf", "cr2", "cr3", "nef", "dng"});
@@ -618,7 +625,7 @@ void MainWindow::saveAs()
                                  _lastDir,
                                  _saveFilter,
                                  &selectedFilter);
-    auto filterToFormat = [](const QString &file, const QString &filter) -> const char*
+    auto filterToFormat = [](const QString &file, const QString &filter) -> const QString
     {
         QString suffix = QFileInfo(file).suffix();
         if(!suffix.compare("jpg", Qt::CaseInsensitive) || !suffix.compare("jpeg", Qt::CaseInsensitive))return "jpeg";
@@ -628,6 +635,10 @@ void MainWindow::saveAs()
         if(filter.contains("png"))return "png";
         if(filter.contains("fits"))return "fits";
         if(filter.contains("xisf"))return "xisf";
+        QRegularExpression suf("\\(\\*\\.([a-zA-Z]+).*\\)");
+        auto match = suf.match(filter);
+        if(match.hasMatch())
+            return match.captured(1);
         return "jpeg";
     };
 
@@ -643,7 +654,7 @@ void MainWindow::saveAs()
         {
             QImage img = m_image->renderToImage();
             if(!img.isNull())
-                img.save(file, filterToFormat(file, selectedFilter));
+                img.save(file, filterToFormat(file, selectedFilter).toLatin1().data());
         }
     }
 }