Loadmore logic implementation

[Qt embedded developer]

problem: i have n session ids logs which is shown in QTreewidget using Qtreewidgetitem and qlabel. i implemented it. in each session id have n sub sessions log. which is implemented as child qtreewidget item under it.

now i not get how to implement logic such that it shows initially below it one loadmore button is there when we click on button it it expand next 14 session.

i not get how to implement above logic. please guide me.

[Qt embedded developer]

Logic: 1] maintain the session id 2] get session id which needed 3] add and remove session id on button click