Entity: predicate

tree_box(Handle, Parent, Tree_func, _, X, Y, Width, Height)

Creates a list box control.
Handle handle. Use _ if you don't need it. 
Parent handle of the parent window. Use _ for default.
Tree_func predicate which will receive edit messages
X,Y coordinates of upper left corner
Width, Height  size of the window

Look at tree box methods:

L is get_tree_length(Tree_Box)
S is get_tree_selected(Tree_Box)
R is tree_parent(Tree_Box, Item)
R is tree_child(Tree_Box, Item)
R is tree_next_brother(Tree_Box, Item)
insert_tree_item(Tree_Box, Item_Handle, Parent, After, Text, Icon1, Icon2)
delete_tree_item(Tree_Box, Item)
get_tree_item(Tree_Box, Item, Text, Icon1, Icon2)
set_tree_item(Tree_Box, Item, Text, Icon1, Icon2)
set_tree_icons(Tree_Box, Icon1, Icon2, ...)

You can use this predicate to change the stile of your Tree_Box. The information which you need for this is how bits in the style are connect to list box features.

Here is the list of important bits:
 buttons (for opening of the item with children)   set 
 lines (connecting items)  set 
 root lines  set 
 in place edit   

in place edit
If you want to support in place edit then you should to set this style (it is not set by default) and to proceed the message edit(Item, Text). This message is send when some one tries to edit the label of some of the tree items and contain the handle of the edited item and the new text. The following example shows how this can be done:

  window( _, _, win_func(_), "Tree Demo", 100, 50, 370, 420).

win_func(init) :-
  tree_box(G_Tree_Box, _, tree_func, _, 10, 10, 150, 350),
  change_style(G_Tree_Box, 0, 0, 8),
  insert_tree_item(G_Tree_Box, _, root, first, "First", _, _).

  yes_no("Tree Demo","Are you sure that you want to change this text.", ?),
  set_tree_item(G_Tree_Box, Item, Text, _, _).

See also:
tree box methods

Look at the example:
Tree Box.spj (in folder Examples)