Tree Structures
Functions and Control Elements
Pushbuttons
The function for displaying and hiding the entire tree area appear in the far left of the application toolbar. Pushbuttons that contain functions for a tree (such as expand all) usually appear on the left in the application toolbar. All the other functions appear adjacently to the right. An exception to this rule is the ALV tree, since it has its own toolbar for the functions within the tree.
The pushbutton for displaying/hiding the entire tree remains on the left in the application toolbar, since this function would otherwise disappear when the area is hidden. This button should not contain any icons, but instead the labels "<Show area>" and "<Hide area>" (short: "<Area> on" and "<Area> off"). The text must then be changed dynamically so that it always describes the current function of the pushbutton.
If the tree cannot be re-sized with a docking control or splitter control, you can add additional pushbuttons to successively increase or decrease the size of the area. In this case, the area containing the tree is increased or decreased in size by a fixed amount each time one of the buttons is pressed. These buttons always appear in the application toolbar, right next to the functions for displaying and hiding the area.
Navigation with the Mouse
The mouse is the primary navigation tool within a tree. In general, all navigation (expanding/collapsing trees) and object selection should be performed with the mouse. The following table supplies an overview of the recommended mouse actions.
| Tree object | Mouse click | Action |
|---|---|---|
+ or  |
Single left | Expand node |
- or  |
Single left | Collapse node |
| Node | Single left | Highlight node and select object |
| Node | Single right | Highlight and context menu |
| Node | Double left | Default action, such as expand node; possibly combined with actions for displaying the node contents |
| Node | Shift + Single left | Select several adjacent objects |
| Node | Ctrl + Single left | Select several non-adjacent objects |
| Page | Single left | Highlight object (and possibly display it) |
| Page | Double left | Select object and perform the default action (such as display) |
| Page | Single right | Highlight and context menu |
Table 1: Mouse Navigation in Trees
Source: SAP R/3 Style Guide