qml: refactor loading view in MainViewLoader for clarity

modules/gui/qt/maininterface/qml/MainViewLoader.qml

@@ -119,7 +119,7 @@ Widgets.StackViewExt {
         _updateView()
 
         // NOTE: This call is useful to avoid a binding loop on currentComponent.
-        currentComponentChanged.connect(function() { _updateView() })
+        currentComponentChanged.connect(_updateView)
     }
 
     onModelChanged: resetFocus()
@@ -169,16 +169,17 @@ Widgets.StackViewExt {
     function _updateView() {
         // NOTE: When the currentItem is null we default to the StackView focusReason.
         if (currentItem && currentItem.activeFocus)
-            _applyView(currentItem.focusReason)
+            _loadView(currentItem.focusReason)
         else if (activeFocus)
-            _applyView(focusReason)
+            _loadView(focusReason)
         else
-            replace(null, currentComponent)
+            _loadView()
     }
 
-    function _applyView(reason) {
+    function _loadView(reason) {
         replace(null, currentComponent)
 
-        setCurrentItemFocus(reason)
+        if (typeof reason !== "undefined")
+            setCurrentItemFocus(reason)
     }
 }