Bugfixes: don't select dirs and don't crash on write settings

Only select files when archiving pics from filemanager. While at it, I
noticed a crash on close when no item is selected in PicturesWidget. So
check if MappingData is valid on writing settings. Best way is
MappingData::isValid(), and for that I needed a explicit constructor.

1 files changed, 3 insertions, 1 deletions

diff --git a/pictureswidget.cpp b/pictureswidget.cpp
index 92b0490..54d86e2 100644
--- a/pictureswidget.cpp
+++ b/pictureswidget.cpp
@@ -64,7 +64,9 @@ void PicturesWidget::showPicViewer(bool toggled){
 void PicturesWidget::writeSettings(){
     QSettings s;
     MappingData selected = mMappingTree->selectedItem();
-    s.setValue("ui/selectedmapping", selected.path.first());
+    if(selected.isValid()){
+        s.setValue("ui/selectedmapping", selected.path.first());
+    }
     mPictureView->writeHeaderConfig();
 }