gui PySide6 port: Fix access to properties for some QML components

Author: lschr

sdt/gui/SdtGui/FrameSelector.qml

@@ -48,7 +48,8 @@ T.FrameSelector {
     }
 
     onCurrentExcitationTypeChanged: {
-        for (var i = 0; i < excSel.model.length; i++) {
+        var len = excSel.model != null ? excSel.model.length : 0
+        for (var i = 0; i < len; i++) {
             if (excSel.model[i] == currentExcitationType) {
                 excSel.currentIndex = i
                 break

sdt/gui/SdtGui/ImageDisplay.qml

@@ -216,8 +216,7 @@ Item {
            early upon shutdown, which could cause
            "Type Error: Cannot read property '…' of null" and segfaults
            (Pyside6 6.4.3)
-        
-        Sdt.setQObjectParent(img, root)
         */
+        Sdt.setQObjectParent(img, root)
     }
 }

sdt/gui/SdtGui/ImageSelector.qml

@@ -96,7 +96,9 @@ Item {
                         return
                     if (roles.length > 0 &&
                             roles.filter(
-                                function(v){return model.fileRoles.includes(v)}).length <= 0)
+                                function(v){
+                                    return fileSel.model.fileRoles.includes(v)
+                                }).length <= 0)
                         return
                     openFiles()
                 }

sdt/gui/SdtGui/ImageViewer.qml

@@ -60,10 +60,9 @@ Item {
            early upon shutdown, which could cause
            "Type Error: Cannot read property '…' of null" and segfaults
            (Pyside6 6.4.3)
-
+        */
         Sdt.setQObjectParent(frameSel, root)
         Sdt.setQObjectParent(imSel, root)
         Sdt.setQObjectParent(imDisp, root)
-        */
     }
 }