Traversing the hierarchy

By visually inspecting the subsystem graph, you get a high-level summary of the major components of the program. The completed subsystem hierarchy is a navigational structure for exploring and documenting the subject software. The hierarchy created for the list example can be explored when trying to understand the list program.

The simplest traversal technique is to open a node and traverse down in the hierarchy.

• Double-left-click on the ListADT subsystem node (or choose Children from the Navigate menu).

  A new Children window appears, showing the access functions and list data type within the ListADT subsystem.

You can also traverse up in the hierarchy to see the parent node(s):

1. Select the listinit Module node in the newly opened Children window.
2. Choose Parents from the Navigate menu.

   A new Parents window appears, showing the parent of listinit in the hierarchy; the original child node, listinit, is named in the window title.

Close the two windows just opened before proceeding:

• Activate each window and choose Close Active from the Window menu.

  Tip: You can also close each window through your window manager.

You can produce a projection perspective:

1. Select the ListADT and Control subsystem nodes.
2. Choose Settings from the Options menu.

   The Settings dialog appears, allowing you to change some parameters that influence various operations provided by rigiedit.

3. Adjust the Projection Depth slider to the value 1.

   The parameter change is immediate.

4. Click Done to dismiss the dialog.

   

5. Choose Projection from the Navigate menu.

   A new Projection window appears, containing a union of all nodes that are exactly one level below the selected nodes. The names of the selected nodes that were projected appear on the title of the Projection window\ (ListADT/Control).

   If the slider value is -1, the projection depth is infinite and a projection would display all the nodes in the subhierarchies rooted at the selected nodes. Leaf nodes are included in the projection if the slider value is set too deep for certain branches of the hierarchy.

   

   Note: You cannot directly modify the graph model from within a Projection window.

   You can, however, open a node or project a group of nodes from a Projection window.

To view the hierarchy rooted or starting at the ListADT subsystem node:

1. Select just the ListADT node.
2. Choose Overview from the Navigate menu.

   A new Overview window appears, presenting the subhierarchy below the ListADT node.

By default, the nodes in an Overview window are initially displayed without labels, but you can change that.

1. Select all the nodes in the ListADT Overview window.
2. Choose Filter by Selection ... from the Filter menu.

   A Filter by Selection dialog appears.

3. Click Show Names.

   The labels of the selected nodes in the active window are displayed.

   

4. Click Done to dismiss the dialog.

   

Before proceeding, close the Projection window and Overview window just opened.