SWMM5 Delphi GUI Ftable.pas Summary

 Below is a high-level summary of Ftable.pas, a Delphi unit within the EPA SWMM 5 application. This unit implements TTableForm, an MDI child form that displays tabular time series results of a SWMM simulation using a TDrawGrid component.

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1. Purpose of Ftable.pas

The Ftable.pas unit defines a form (TTableForm) that provides a time series data table for SWMM's simulation results. Depending on the user’s selection (described by a TReportSelection record), the table can display:

1. Table by Variable: Time series for a single variable (e.g., flow, depth, or subcatchment runoff) across multiple objects.
2. Table by Object: Time series for one object (a single node, link, subcatchment, or the system) across several variables.

The table is populated with results from SWMM’s binary output file. When a new simulation is completed, calling RefreshTable re-queries the output file for the selected data and redraws the table.

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2. Key Elements of TTableForm

1. TTableForm class:

   • Inherits from TForm and acts as an MDI child window inside SWMM.

2. Grid1: TDrawGrid:

   • The main grid where data is displayed (time along rows; variables/objects along columns).
   • Each cell is rendered in the Grid1DrawCell event.

3. Edit1: TEdit (invisible at runtime):

   • Provides a reference for consistent row/column heights.

4. Table: TReportSelection:

   • Stores the user’s selection parameters (object type, variable indices, date/time display mode, etc.).

5. ColLabel[]: array:

   • Holds the string labels (headers) for each column.

6. Methods:

   • CreateTable(aReportSelection):
     Receives a TReportSelection describing what data to display, sets up column headers, and calls RefreshTable.
   • RefreshTable:
     Retrieves data from SWMM’s output results, populates the column headings, and sets the row count. Updates Grid1 display.
   • Grid1DrawCell:
     Custom drawing of each table cell (including date/time in columns 0-1, and fetched simulation data in columns 2+).
   • CopyTo:
     Launches the "Copy To" dialog (in Dcopy.pas) and calls CopyToString to copy the current selection to file or clipboard.
   • Print:
     Prints the grid across multiple pages if necessary (using Xprinter.pas).

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3. Work Flow

1. Creation: When a user requests a Table by Object or Table by Variable, SWMM builds a TReportSelection and calls TableForm.CreateTable(ReportSelection).
2. Setup: The form uses the TReportSelection to configure:
   • The number of columns,
   • Column headers (object IDs or variable names + units),
   • Row count (matches number of time steps).
3. Population: Each time step is placed in row 1..N, and each item (object/variable) in columns 2..M. Rows 0 or columns 0-1 are for headings.
4. Interaction:
   • Sorting is limited (only partial).
   • Copying is done by selecting a block of cells or the entire table, then calling CopyTo.
   • Printing goes column by column to fit across multiple pages.

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4. Integration with SWMM

• The table obtains results from Uoutput.Get*ValStr functions which read from SWMM’s binary results file.
• Date/time and simulation indexing come from Uglobals fields like StartDateTime, DeltaDateTime, ReportStep, etc.

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5. Summary

In Ftable.pas, TTableForm is the MDI child window that displays time series data in tabular form, fetches SWMM output results for each time step and item, renders them in a TDrawGrid, and provides copying/printing functionalities. This is part of SWMM’s user interface for analyzing and exporting simulation results in tabular format.