content: function onKeyEvent(key as string, press as boolean) as boolean
      handled = false
  
      if press then
          if key = "right"
              if m.categoriesList.hasFocus() and m.subcategoriesList.visible
                  m.categoriesList.setFocus(false)
                  m.subcategoriesList.setFocus(true)
                  UpdateAllItemsFocusState(m.subcategoriesList)
                  UpdateAllItemsFocusState(m.categoriesList)
                  handled = true
              end if
          else if key = "left"
              if m.subcategoriesList.hasFocus()
                  m.subcategoriesList.setFocus(false)
                  m.categoriesList.setFocus(true)
                  UpdateAllItemsFocusState(m.subcategoriesList)
                  UpdateAllItemsFocusState(m.categoriesList)
                  handled = true
              end if
          else if key = "back"
              if m.subcategoriesList.hasFocus()
                  m.subcategoriesList.setFocus(false)
                  m.categoriesList.setFocus(true)
                  UpdateAllItemsFocusState(m.subcategoriesList)
                  UpdateAllItemsFocusState(m.categoriesList)
                  handled = true
              end if
          end if
      end if
  
      return handled
  end function