GUIX Scrollbar and Lists

Hello,

I am using an horizontal list and an horizontal scrollbar to display few pictures on my page.

I know the X position of my finger on the touchscreen (converted in screen pixel coord) and I wonder how can I scroll the list following the X position ?

I tried with no success a gx_widget_find on my GX_SCROLLBAR then scrollbar->gx_scrollbar_info.gx_scroll_value = finger_x;