SWMM5 Delphi GUI Dcontrol.pas Summary

 The Dcontrol unit is part of the EPA SWMM project and provides the user interface for editing Rule-Based Controls in SWMM. This form contains a TMemo control where users can modify control rules written in a text format.

Key Features of the Dcontrol Unit:

1. Text Editing for Control Rules:

   • The form contains a TMemo control (Memo1) where the user can view and edit rule-based controls. These rules are stored in Project.ControlRules, which is a string list.

2. Loading and Saving Control Rules:

   • When the form is created (FormCreate), the Memo1 control is populated with the current control rules from Project.ControlRules. The user can then modify the contents.
   • The BtnOKClick handler saves the modified rules back into Project.ControlRules. If any blank lines are found at the end of the rules, they are removed before saving.

3. Status Bar and Notifications:

   • A TStatusBar (StatusBar1) is used for displaying messages or notifications about the current status, though it’s not actively updated in the provided code snippet.

4. Search and Focus:

   • The StartRule string can be set to a specific rule. If StartRule is not empty, the form will search for this rule within the memo text and select it (FormShow). This helps the user quickly navigate to a specific rule in a long list.

5. Help Button:

   • The BtnHelpClick procedure is linked to the Help button, which opens a specific help context for editing control rules. This allows users to get help related to the rule-based controls.

Constants and Properties:

• StartRule: A string used to specify a rule to focus on when the form is shown.
• Modified: A boolean flag to track if any changes were made to the control rules.
• Memo1: The TMemo control used for displaying and editing the control rules.
• Project.ControlRules: A string list that holds the control rules, which is loaded into the memo on form creation and saved on clicking OK.

Main Methods:

1. FormCreate:

   • Initializes the memo with existing control rules and sets the Modified flag to false.

2. FormShow:

   • If StartRule is provided, it searches for the rule within the memo and selects it to give focus to the rule. This helps in directly navigating to a specific rule.

3. BtnOKClick:

   • Saves the edited control rules back to Project.ControlRules. If the content of the memo has been modified, it updates the list and removes any blank lines from the end.

4. BtnHelpClick:

   • Displays the help for editing control rules by using the help system (HELP_CONTEXT, 210740).

5. FormKeyDown:

   • Handles the key press event to trigger help when the F1 key is pressed.

Summary:

The Dcontrol unit enables the user to edit rule-based controls in SWMM. It provides a simple text editor interface where users can add, modify, or remove control rules. The form also allows for quick navigation to a specific rule and provides help functionality to assist users in understanding the syntax and usage of control rules.