Intro

If you’re developing in Delphi and looking for a powerful, flexible, and highly customizable data grid solution, then TMS FNC Data Grid is the perfect choice. In this blog, we continue on our journey with the TMS FNC Data Grid. The TMS FNC Data Grid offers developers advanced tools for presenting and interacting with data. A key feature is its support for built-in calculations on rows and columns. This functionality allows developers to perform summary operations such as sums, averages, counts, minimum, and maximum values directly within the grid, without the need for external code or complex calculations.

Built-In Calculation Functions

The Grid provides methods to perform calculations on rows and columns, either across the entire dataset or for specific ranges. These functions return values that can be displayed directly or processed further as needed.

Row Calculation Functions

Each row calculation function operates on a specific row and can target all columns or a specified range. Here’s a quick overview:

• RowAverage: Returns the average of cell values in a row.
• RowDistinct: Counts unique values in a row.
• RowMax: Finds the maximum value.
• RowMin: Finds the minimum value.
• RowStandardDeviation: Calculates the standard deviation.
• RowSum: Computes the sum of values in the row.
• RowCustomCalculation: Allows for a custom calculation, triggered via the OnCustomRowCalculation event.

Column Calculation Functions

These functions operate on columns, similar to the row functions but targeting a specific column index:

• ColumnAverage: Computes the average of values.
• ColumnDistinct: Counts distinct values in the column.
• ColumnMin: Finds the minimum value.
• ColumnMax: Finds the maximum value.
• ColumnStandardDeviation: Calculates the standard deviation.
• ColumnSum: Sums up all values in the column.
• ColumnCustomCalculation: Executes custom calculation logic, triggered via the OnCustomColumnCalculation event.

Tracking Calculations

A convenient feature of the grid is its support for tracking calculations displayed in a fixed row or column.

To enable these calculations, use the ColumnCalculations or RowCalculations property, where each column / row can have a unique calculation type:

• gcmSum: Displays the column sum.
• gcmAverage: Displays the average of the column.
• gcmCount: Shows the row count.
• gcmMin: Displays the minimum value.
• gcmMax: Displays the maximum value.
• gcmCustom: Displays a custom calculation result.
• gcmDistinct: Shows the count of distinct values.
• gcmStandardDeviation: Displays the standard deviation.

These calculations provide real-time insights and summarize key metrics without needing additional code.

Example: Setting Up Column Calculations

Here’s how to initialize a grid with several rows and set up basic column calculations for SUM, AVERAGE, MIN, and MAX:

Grid.Clear;
Grid.DefaultColumnWidth := 150;
Grid.RowCount := 20;
Grid.FixedBottomRowCount := 1; // Reserve a footer row for calculations
Grid.RandomFill(False, 100); // Fill the grid with random values for testing

// Setting up column calculations in the footer row
Grid.ColumnCalculations[0, 'SUM'] := [CreateNormalColumnCalculation(gcmSum)];
Grid.ColumnCalculations[1, 'AVERAGE'] := [CreateNormalColumnCalculation(gcmAvg)];
Grid.ColumnCalculations[2, 'MIN'] := [CreateNormalColumnCalculation(gcmMin)];
Grid.ColumnCalculations[3, 'MAX'] := [CreateNormalColumnCalculation(gcmMax)];

// Update calculations to reflect initial data in the grid
Grid.UpdateCalculations;

Grid.Clear;
Grid.Options.Column.Stretching.Enabled := True;
Grid.RowCount := 40;
Grid.ColumnCount := 5;
Grid.LoadSampleData;
Grid.Group(3);
Grid.GroupCount(1);
Grid.GroupAverage(4);