TAtlasMemoryData

Create constructor

constructor Create(AOwner: TComponent); override;

Creates an empty source with no columns and no rows.

Destroy destructor

destructor Destroy; override;

Frees the cells. Grids bound to the source unbind themselves.

RowCount propertyinherited from TAtlasGridData

property RowCount: Integer read GetRowCount;

Number of rows.

ColumnCount propertyinherited from TAtlasGridData

property ColumnCount: Integer read GetColumnCount;

Number of columns.

Version propertyinherited from TAtlasGridData

property Version: Integer read FVersion;

Increases on every change, including each change inside a batch and once more when the batch ends. Compare two readings to tell whether anything changed.

AddColumn method

function AddColumn(const Title: string; Kind: TAtlasCellKind = ckText; ReadOnly: Boolean = False): Integer;

Adds a column and returns its index. Existing rows get a null cell in it. A ReadOnly column refuses SetCell and SetText, from code as well as from the grid; fill it through AddRow. A grid that is already bound does not add a column for it by itself: call its ResetColumns or add a grid column.

Orders.AddColumn('Order', ckNumber, True);

AddRow method

function AddRow(const Values: array of string): Integer;

Adds a row from one text per column and returns its index. Values are read with invariant settings: . as the decimal separator, ISO 8601 dates such as 2026-03-31 or 2026-03-31T14:30:00 (or invariant MM/dd/yyyy), and yes/no, true/false, y/n or 1/0 in any case. Empty text is null. The row is added whole or not at all. A wrong number of values raises A row needs n values; m given, and a value that does not fit raises "x" does not fit column "Title"; both are EAtlasGridError. Read-only columns can be filled this way.

Orders.AddRow(['Contoso', '1250.50', '2026-03-31', 'no']);

DeleteRow method

procedure DeleteRow(Row: Integer);

Removes a row; later rows move up. Raises EAtlasGridError for a row that does not exist.

ClearRows method

procedure ClearRows;

Removes every row and keeps the columns. Sends no notification when there were no rows.

ClearAll method

procedure ClearAll;

Removes every row and column. Bound grids keep their own columns; call ResetColumns on them after adding the new columns.

ColumnTitle method

function ColumnTitle(Column: Integer): string; override;

The title given to AddColumn. An index outside the columns raises the list's EArgumentOutOfRangeException.

ColumnKind method

function ColumnKind(Column: Integer): TAtlasCellKind; override;

The kind given to AddColumn.

ColumnReadOnly method

function ColumnReadOnly(Column: Integer): Boolean; override;

The read-only flag given to AddColumn.

GetCell method

function GetCell(Column, Row: Integer): TAtlasCell; override;

The stored cell. Raises EAtlasGridError outside the data.

Missing := Orders.GetCell(1, 0).IsNull;

SetCell method

procedure SetCell(Column, Row: Integer; const Cell: TAtlasCell); override;

Stores a cell of the column's kind; a null of that kind blanks it. Raises EAtlasGridError outside the data, for a read-only column (Column "Title" is read-only) and for a cell of another kind (Column "Title" holds another kind of value).

Orders.SetCell(1, 0, TAtlasCell.OfNumber(1300.75));

BeginUpdate methodinherited from TAtlasGridData

procedure BeginUpdate;

Starts a batch: the changes made until the matching EndUpdate reach watching grids as one notification. Batches nest.

Orders.BeginUpdate;

EndUpdate methodinherited from TAtlasGridData

procedure EndUpdate;

Ends a batch. When the outermost batch ends and something changed, the listeners are called once. An EndUpdate without a BeginUpdate is ignored.

Orders.EndUpdate;

AddListener methodinherited from TAtlasGridData

procedure AddListener(const Listener: TNotifyEvent);

Registers a method that is called, with the source as Sender, after every change or batch. Adding the same method twice registers it once. Grids register themselves when bound, so this is for your own code.

RemoveListener methodinherited from TAtlasGridData

procedure RemoveListener(const Listener: TNotifyEvent);

Unregisters a method. Safe during a notification and after the source has begun to be destroyed.

SetText methodinherited from TAtlasGridData

procedure SetText(Column, Row: Integer; const Text: string; const Settings: TFormatSettings);

Parses Text for the column's kind with Settings (see TAtlasCell.TryParse) and stores the result with SetCell. Raises EAtlasGridError for a cell outside the data and for text that does not parse ("abc" is not a number, is not a date, is not yes or no); the stored value is unchanged. The grid's editor and Delete key write through this method with the global FormatSettings.

Orders.SetText(1, 0, '1300.75', TFormatSettings.Invariant);

CheckCell methodinherited from TAtlasGridData

procedure CheckCell(Column, Row: Integer);

Raises EAtlasGridError Column n does not exist or Row n does not exist unless the cell lies inside the data.

Fill a memory source

Four typed columns and three rows, loaded in one batch. The third row's amount, date and paid flag are null.

uses Atlas.VGridData;

procedure FillOrders(Orders: TAtlasMemoryData);
begin
  Orders.AddColumn('Customer');
  Orders.AddColumn('Amount', ckNumber);
  Orders.AddColumn('Due', ckDateTime);
  Orders.AddColumn('Paid', ckBoolean);
  Orders.BeginUpdate;                        // one notification for the whole batch
  try
    // One text per column, read with invariant settings: '.' decimals, ISO dates.
    Orders.AddRow(['Contoso', '1250.50', '2026-03-31', 'no']);
    Orders.AddRow(['Fabrikam', '980', '2026-02-28', 'yes']);
    Orders.AddRow(['Northwind', '', '', '']);   // empty text is a null cell
  finally
    Orders.EndUpdate;
  end;
end;

Bind it to a grid

The grid creates one column per data column when it has none. See the quick start sample for sorting, filtering, totals and export.

uses Vcl.Forms, Vcl.Controls, Atlas.VGridData, Atlas.VGrid;

procedure ShowOrders(Form: TForm; Orders: TAtlasMemoryData);
var Grid: TAtlasVirtualGrid;
begin
  Grid := TAtlasVirtualGrid.Create(Form);
  Grid.Parent := Form;
  Grid.Align := alClient;
  Grid.Data := Orders;                       // no columns yet: one per data column
  Grid.FrozenColumns := 1;                   // Customer stays put when scrolling sideways
  Grid.Columns[1].Format := '#,##0.00';
  Grid.Columns[1].Total := tkSum;
  Grid.Columns[2].Format := 'yyyy-mm-dd';
  Grid.Sort(1, True);                        // largest amount first
end;