relayout when a tabButton changes visibility

declarativeimports/plasmacomponents/qml/TabButton.qml

@@ -100,6 +100,7 @@ Item {
             //TabBar is the granparent
             root.parent.parent.currentTab = root
         }
+        onVisibleChanged: root.parent.childrenChanged()
     }
 
     QtObject {

declarativeimports/plasmacomponents/qml/private/TabBarLayout.qml

@@ -106,16 +106,29 @@ Item {
 
         function layoutChildren() {
             var childCount = root.children.length
+            var visibleChildCount = childCount
             var contentWidth = 0
             var contentHeight = 0
             if (childCount != 0) {
-                var itemWidth = (root.width - (childCount-1)*10) / childCount
+                //not too much efficient but the loop over children needs to be done two times to get the proper child width
+                for (var i = 0; i < childCount; ++i) {
+                    if (!root.children[i].visible) {
+                        --visibleChildCount
+                    }
+                }
+                var itemWidth = (root.width - (childCount-1)*10) / visibleChildCount
                 var itemIndex = mirrored ? childCount - 1 : 0
                 var increment = mirrored ? - 1 : 1
+                var visibleIndex = 0
 
                 for (var i = 0; i < childCount; ++i, itemIndex += increment) {
                     var child = root.children[itemIndex]
-                    child.x = i * itemWidth + i*10
+                    if (!child.visible) {
+                        continue
+                    }
+
+                    child.x = visibleIndex * itemWidth + visibleIndex*10
+                    ++visibleIndex
                     child.y = 0
                     child.width = itemWidth
                     child.height = root.height