SWMM5 Delphi GUI Dculvert.pas Summary

 The Dculvert unit is a dialog form in the EPA SWMM project that allows users to select a culvert type code based on its material and inlet shape. The dialog provides an interface where users can select a specific culvert code from a tree view or manually enter a culvert code, and it validates the code entered.

Key Features of the Dculvert Unit:

1. Tree View for Culvert Selection:

   • The TreeView1 component is used to display a hierarchical list of culvert materials and inlet shapes.
   • The user can expand or collapse the tree nodes to navigate through different types of culverts.
   • Each culvert node is associated with a unique code that corresponds to the selected culvert type.

2. Code Selection and Input:

   • The user can either:
     • Select a culvert type from the tree view, or
     • Manually enter a culvert code into the Edit1 input field.
   • The Button1Click procedure validates the entered code. If the code is invalid (not within a predefined range), an error message is shown.

3. Validating the Culvert Code:

   • When the user clicks the "OK" button (Button1), the entered or selected code is validated:
     • If no code is entered, it proceeds with the default behavior.
     • If the entered code is greater than 57, it shows an error message (Uutils.MsgDlg).
     • Otherwise, the code is accepted, and the form's modal result is set to mrOk, indicating that the selection is valid.

4. Form Initialization and Selection:

   • During the form's creation (FormCreate), the TreeView1 items are populated with culvert type categories, and each item is associated with a code.
   • The SetSelection method sets the selection programmatically based on the provided code. It checks if the selected code matches one of the predefined culvert codes and highlights the corresponding tree node.
   • The GetSelection function returns the selected or entered code.

5. User Interface and Navigation:

   • The form allows users to navigate the tree of culvert types and manually enter or select the appropriate culvert code.
   • The form is centered on the PropEditForm (as seen in the FormShow procedure