Description
Report SAPTLIST_TREE_CONTROL_DEMO demonstrates the use of the list treecontrol (class CL_GUI_LIST_TREE).
One node of the tree is described with dictionary structure TREEV_NODE.The NODE_KEY field contains the node key.
Each node of the tree can own items. An item is described by thedictionary structure TREEV_ITEM, to which the user of the tree controlmust add the character field TXT (any desired length). In the samplereport, TREEV_ITEM is included in structure MTREEITM, in order to inserta field with the name TEXT. The NODE_KEY field dictates to which node anitem belongs. The ITEM_NAME field contains the name of this item. Onlyintegers greater than or equal to 1 are allowed. The items in a node areoutput from left to right.
The example demonstrates some important characteristics of the list treecontrol, which is explained using some of the items as follows:

• Item "Objects": This item has proportional font (ITEM-FONT =
CL_GUI_LIST_TREE=>ITEM_FONT_PROP). The use of a proportional font onlymakes sense for items if the width of the item is automatically matchedto the text string that is received (so that the string alway s fits).To do so, the value CL_GUI_LIST_TREE=>ALIGN_AUTO must be written intothe item's ALIGNMENT field.

• A table structure is created for the items in the nodes that are third
and fourth from the top. In this case, it is necessary for the firstthree items of both nodes to have fixed lengths. (ITEM-ALIGNMENT =CL_GUI_LIST_TREE=>ALIGN_LEFT, ITEM-LENGTH = ...). A fixed font(ITEM-FONT = ITEM_FONT_FIXED) must be used for these items.

Selection
The items of a node can be selected individually. A click on the folderor page symbol of a node selects the entire node.
You can also set the selection behavior of the tree so that one clickalways selects the entire node (ITEM_SELECTION-Set the parameter for theconstructor to initial).

Events
The events that occur appear on the right side of the screen. In thesample program, you can trigger the following events:

node_dbl_clk (node double-click)
A node is double-clicked. In the sample program, you can do so bydouble-clicking on the folder or page symbol. If ITEM_SELECTION is setto SPACE, this event is triggered if any section of the node isdouble-clicked.

item_dbl_click (item double-click)
An item in the tree was double-clicked. This event can only occur whenITEM_SELECTION = X.

expand_nc (expand no children)
A node can have the characteristic that it displays a plus symbol (+)for a folder or page, even when there are no lower-level nodes(children). To make this setting, use the expander field in TREEV_NODE.If users click on one of these nodes, the EXPAND_NC event is triggered.In the example, node Program has this characteristic. The sampleprogram reacts to these events by copying two new nodes to the control.

button_click
The user clicked a button.

link_click
The user clicked a link item.