SWMM5 Delphi GUI Dcopy.pas Summary

 The Dcopy unit is a dialog form in the EPA SWMM project, allowing users to specify the format and destination for copying a view, such as a chart or map, to a new file. This unit provides options for saving the view as different types of files, including bitmap files, EMF (Enhanced Metafile) files, or text files.

Key Features of the Dcopy Unit:

1. Destination and Format Selection:

   • DestGroup: A TRadioGroup allowing the user to choose the destination of the copied view. The options are either copying to a file (Save As) or other destinations defined by the application.
   • FormatGroup: Another TRadioGroup for selecting the format of the copied view. The options available are Bitmap (*.BMP), Enhanced Metafile (*.EMF), and Text file (*.TXT).

2. File Selection:

   • The form utilizes the SaveDialog control from the MainForm to allow the user to select the destination file path and name. The file type and extension depend on the user's selection from the format options.

3. File Types and Extensions:

   • The FilterTxt constant defines the available file formats (*.BMP, *.EMF, *.TXT) and their descriptions.
   • The ExtensionTxt constant defines the file extensions corresponding to each format.

4. Handling Copy As Data Option:

   • The RemoveCopyAsData procedure removes the "Copy As Data" option from the FormatGroup, which might be necessary in certain cases depending on the application context.

5. Modal Result Handling:

   • When the user clicks the "OK" button, the destination file name is obtained from the dialog, and the form returns the selected file name if a valid file path is chosen.
   • If the user cancels the action, the modal result is set to mrCancel, indicating that no changes were made.

6. Help Integration:

   • A help button (BtnHelpClick) is provided, which shows context-specific help using the HELP_CONTEXT identifier.

Key Methods and Procedures:

1. FormCreate:

   • This method initializes the form by setting its caption to reflect the current view being copied. It extracts the name of the active view and formats it as the form's title.

2. RemoveCopyAsData:

   • This method removes the "Copy As Data" option from the FormatGroup, which is useful in certain contexts where copying data directly isn't required.

3. BtnOKClick:

   • This method handles the "OK" button click event. It opens the SaveDialog to allow the user to select a file and determines the destination file name based on the format and the user’s selection.

4. BtnCancelClick:

   • This method handles the "Cancel" button click event, setting the modal result to mrCancel, which indicates that the user canceled the operation.

5. BtnHelpClick:

   • This method opens the help context related to the copy functionality, providing the user with guidance on using the dialog form.

6. FormKeyDown:

   • This method handles keyboard input, specifically allowing the user to press the F1 key to bring up the help dialog.

Summary:

The Dcopy unit provides a user interface for saving a SWMM view (such as a chart or map) in various formats (BMP, EMF, or TXT) to a specified destination file. It enables users to select the file format, destination path, and file name. The form also supports a help feature to guide users through the process and validates the input to ensure correct file paths and formats are selected.