Horizontal scroll hides parts

I have a Pallete diagram that lists elements in a GridLayout.
As shown :

I used a Pallete in order to be able to drag the parts onto another diagram.
When i resize the DIV to the right (resizing has been implemented by kendo splitter) the parts are pushed to the right and get hidden, as shown:

Is there any way to tell GOJS that the div is fixed and cannot be moved/pushed ?

GoJS never changes the size or position of the HTML DIV element that is hosting the Diagram. You need to make sure that the DIV is sized the way you want.

Unfortunately there is no DOM event that lets GoJS know about a DIV that has changed size. Please read https://gojs.net/latest/intro/resizing.html.