Fix getting drawer width

aas-gui/Frontend/aas-web-gui/src/components/MainWindow.vue

@@ -123,15 +123,12 @@ export default defineComponent({
         let screenWidth = document.getElementsByTagName('html')[0].clientWidth;                                   // the width of the screen (Window) excluding the scrollbar
         let navigationDrawer: any = document.getElementsByClassName('leftMenu')[0];                               // the width of the navigation drawer
         let isDrawerOpen: boolean = navigationDrawer.style.transform == 'translateX(0px)';                        // checks if the navigation drawer is open
-        screenWidth = screenWidth - (isDrawerOpen ? navigationDrawer[0].clientWidth : 0);                         // if the navigation drawer is open subtract the width of the navigation drawer from the screen width
+        screenWidth = screenWidth - (isDrawerOpen ? navigationDrawer.clientWidth : 0);                         // if the navigation drawer is open subtract the width of the navigation drawer from the screen width
         let diffX = parseInt(e.pageX) - pageX;                                                                    // amount the header was dragged (minus - left, plus - right)
         let minimalColWith = 200;
-        if ((curColWidth + diffX) >= minimalColWith
-          && (nxtColWidth - diffX) >= minimalColWith) {
-
+        if ((curColWidth + diffX) >= minimalColWith && (nxtColWidth - diffX) >= minimalColWith) {
           if(curCol) curCol.style.width = (100 - ((screenWidth - (curColWidth + diffX)) / screenWidth) * 100) + '%';  // scale the current Column (Window)
           if(nxtCol) nxtCol.style.width = (100 - ((screenWidth - (nxtColWidth - diffX)) / screenWidth) * 100) + '%';  // scale the next Column (Window) if it exists
-
         }
 			});
       // Eventlistener to clear the local Variables mouse up