jfjoch_viewer: Handle autocontrast better

viewer/widgets/JFJochDiffractionImage.cpp

@@ -304,11 +304,12 @@ void JFJochDiffractionImage::loadImage(std::shared_ptr<const JFJochReaderImage>
 void JFJochDiffractionImage::setAutoForeground(bool input) {
     auto_fg = input;
     if (image && auto_fg) {
-        // If auto_foreground is not set, then view stays with the current settings till these are explicitely changed
+        // If auto_foreground is not set, then view stays with the current settings till these are explicitly changed
         foreground = image->GetAutoContrastValue();
         emit foregroundChanged(foreground);
         Redraw();
     }
+    emit autoForegroundChanged(auto_fg);
 }
 
 void JFJochDiffractionImage::setResolutionRing(QVector<float> v) {
@@ -376,3 +377,9 @@ void JFJochDiffractionImage::highlightIceRings(bool input) {
     highlight_ice_rings = input;
     updateOverlay();
 }
+
+void JFJochDiffractionImage::changeForeground(float val) {
+    auto_fg = false;
+    emit autoForegroundChanged(false);
+    JFJochImage::changeForeground(val);
+}