I've been trying enhance Preselection for a while, and could add columns to the preselection tree through BAdI /SAPAPO/ATP_EST.
Now the screen should be started with all the locations unselected by default.
I tried to manually unset "CHOSEN" field value in /sapapo/if_ex_atp_est~change_tree_nodes. Although the checkboxes were correctly unchecked at first, the program behaves like they've never been unchecked and the first location in the list is selected.
With this BAdI I'm unable to manipulate the tree..
Is this the way to achieve what i'm trying to do or should I look for another BAdI/customization?