help to roGridScreen fast loading content

Sub showMoviesScreen()
   dlg = CreateObject("roOneLineDialog")
   dlg.setTitle("Loading Collection")
   dlg.showBusyAnimation()
   dlg.show()
    screen = CreateObject("roGridScreen")
    port = CreateObject("roMessagePort")
    screen.SetMessagePort(port)
    screen.SetGridStyle("flat-portrait") 
    screen.SetDescriptionVisible(true)
   screen.SetBreadcrumbText("Movies", "Session")
    
    categoryList = getCategoryListMovies()
    categoryCount = categoryList.count()
   
    seriesList = CreateObject("roList")
        
    screen.SetupLists(categoryCount)
   screen.show()
    screen.setListNames(categoryList)
    
    for i = 0 to categoryCount-1
        tmpMoviesList = getMoviesByCategory(categoryList[i])
        screen.SetContentList(i,tmpMoviesList)
        seriesList.AddTail(tmpMoviesList)
      screen.show()
    end for
    
    screen.show()
   
    dlg.close()
    while true  
        msg = wait(0, port)
      
        if msg <> invalid and type(msg) = "roGridScreenEvent" then
            if msg.isScreenClosed() then
                exit while 
           else if msg.isListItemFocused()
                print "Focused msg: ";msg.GetMessage();"row: ";msg.GetIndex();
                print " col: ";msg.GetData()
            else if msg.isListItemSelected() then  
                 print "Selected msg: ";msg.GetMessage();"row: ";msg.GetIndex();         
                'selection = seriesList.GetEntry(msg.GetIndex())[msg.GetData()]
            
                list = seriesList.GetEntry(msg.GetIndex())
                if list <> invalid then
                  selection = list[msg.GetData()]
                end if
            
            if selection.Title = "Search"
            searchMovies()
            else if selection.Title = "Favorites"
            FavoritesMovies()
            else
                showSpringboardScreenMovies(selection)
            end if
         
            end if
        end if
    end while
    
End Sub

Function getCategoryListMovies() as object
    jsonAsString = CreateObject("roUrlTransfer")
    jsonAsString.SetURL(UrlServidor()+"/category.php?t=movies")
    json = ParseJson(jsonAsString.GetToString())
    return json
End Function


Function getMoviesByCategory(category)
    jsonAsString = CreateObject("roUrlTransfer")
    jsonAsString.SetURL(UrlServidor()+"/movies.php?cat="+category)
    json = ParseJson(jsonAsString.GetToString())
    return json.Videos
   
End Function