g-list-store-insert (store position item)

store -- a g-list-store object
position -- an unsigned integer with the position at which to insert the new item
item -- a g-object object with the new item

Inserts the item into the list store at position. The item must be of type item-type type or derived from it. The position argument must be smaller than the length of the list store, or equal to it to append.

This function takes a ref on item.

Use the g-list-store-splice function to insert multiple items at the same time efficiently.