SWMM5 Delphi GUI Dchart.pas Summary

 The Dchart unit is a dialog form used in the EPA SWMM project to configure various charting options for visualizing simulation results. This dialog provides a comprehensive interface for users to customize the appearance and behavior of charts, including axis settings, series configurations, and legend options.

Key Features:

1. Chart Series Configuration:

   • Users can configure the appearance of the chart series, such as line style, line color, point markers, area fill styles, and pie chart properties.
   • TSeriesOptions class stores options for each chart series, which include settings for line visibility, marker style, area fill style, pie chart properties, and label visibility.

2. Axis Configuration:

   • Users can set the axis titles, scaling (minimum, maximum, and increment values), and gridlines for the X and Y axes.
   • There is support for both linear and date-time axes.
   • The dialog includes controls for configuring both the left and right Y-axes and the X-axis.

3. Legend Configuration:

   • The dialog allows users to modify the legend's position, visibility, frame, and other properties, such as shadow and transparency.

4. Graph Appearance:

   • Users can specify the background color, 3D view settings, and graph title.
   • The dialog includes options for setting up the general appearance of the chart, including font choices for various elements such as the graph title and axis labels.

5. Series Options:

   • The dialog allows the user to select the type of chart series (line, bar, point, pie, etc.) and configure properties specific to each type of series. For example, for line charts, users can modify the line width and style, and for pie charts, they can control the rotation angle and whether the pie chart is circled.

6. Auto-scaling:

   • The dialog supports auto-scaling of the axes, particularly for time-series data, by automatically adjusting the axis range based on the data.

7. Page Control for Multiple Tabs:

   • The dialog includes multiple tabs (e.g., general settings, axis settings, legend settings, and series-specific settings) for organizing the various configuration options.

Key Constants and Enumerations:

• LineStyleText: Array of available line styles (solid, dashed, etc.).
• LegendPosText: Array of available legend positions (left, right, top, bottom).
• MarkStyleText: Array of available marker styles (rectangle, circle, triangle, etc.).
• FillStyleText: Array of available fill styles for areas (solid, diagonal, etc.).
• StackStyleText: Array of available stack styles for bar charts (side, stacked, etc.).
• LabelStyleText: Array of available label styles (value, percent, label, etc.).
• DateFormats: Array of available date formats for time series data.

Methods and Event Handlers:

1. Form Initialization:

   • The FormCreate method initializes the form by loading available options for series styles, axis configurations, and other chart settings into combo boxes and other UI controls.

2. Series Configuration:

   • The SeriesComboBoxClick method is used to load the options for the selected series.
   • The SaveSeriesOptions method saves the options for the current series into the theSeries string list.

3. Axis Configuration:

   • The SetAxisOptions method assigns the user-defined axis options to the corresponding chart axis (X or Y).
   • The ValidAxisScaling method checks if the axis scaling parameters are valid (e.g., ensuring that the minimum is less than the maximum).

4. Font and Label Configuration:

   • The GraphTitleFontLabelLinkClick, AxisFontLabelLinkClick, and LegendFontLabelLinkClick methods open the font dialog to allow users to choose fonts for various elements like the graph title, axis titles, and legend.

5. Auto-scaling:

   • The AutoScaleAxis method automatically scales the selected axis based on the data range and increments.

6. Help:

   • The HelpBtnClick method opens the help documentation for chart options.
   • The FormKeyDown method enables the use of the F1 key for accessing the help.

Example Use Case:

1. A user runs a simulation in SWMM and wants to visualize the results. They open the chart options dialog and select the type of chart they want (e.g., line, bar, pie).
2. The user configures the appearance of the series (e.g., changing line styles, adding markers) and adjusts the axis scaling and legend settings.
3. After configuring the chart, the user applies the settings, and the chart is displayed with the updated appearance.

Summary:

The Dchart unit provides a powerful and flexible interface for configuring charts in EPA SWMM. Users can fine-tune the appearance of the charts, including axis labels, series styles, and legends, making it easier to interpret the results of simulations. The integration with various charting options and the ability to automatically scale axes make it a valuable tool for visualizing hydrological model outputs.