TAtlasGrid

Create constructor

constructor Create(AOwner: TComponent); override;

Creates a 640 x 320 grid with one fixed header row, no fixed column, 28-pixel rows, grid lines, column sizing, editing, Tab navigation, thumb tracking, a white background and double buffering.

Destroy destructor

destructor Destroy; override;

Detaches from the table, then destroys the grid.

Col property

property Col;

The current column, the same index as the table column. Setting it moves the cursor and commits a pending edit first.

Row property

property Row;

The current grid row. Row 0 is the header, so the table view row is Row - 1; check (Row >= 1) and (Row <= Table.RowCount) before using it. Setting it moves the cursor and commits a pending edit first, raising EAtlasDataError if that edit is invalid.

if (Grid.Row >= 1) and (Grid.Row <= Grid.Table.RowCount) then
  Grid.Table.DeleteRow(Grid.Row - 1);

EditorMode property

property EditorMode;

True while the in-place editor is open. Setting it to False closes the editor and keeps its text as the pending edit; call CommitEdit next to store it at once.

Table property

property Table: TAtlasTable read FTable write SetTable;

The table to show and edit, or nil. The grid follows the table through a listener and a free notification: freeing the table sets Table to nil. Assigning another table cancels a pending edit.

HeaderColor property

property HeaderColor: TColor read FHeaderColor write SetHeaderColor default $003D2C1E;

Background of the header row; the header text is white and bold. Default $003D2C1E, a dark blue.

AlternateColor property

property AlternateColor: TColor read FAlternateColor write SetAlternateColor default $00F8F5F2;

Background of odd grid rows (the first, third, fifth ... data rows). Default $00F8F5F2, a light grey.

Align property

property Align;

Standard VCL property, published by this class.

Anchors property

property Anchors;

Standard VCL property, published by this class.

Color property

property Color;

Standard VCL property, published by this class.

Font property

property Font;

Standard VCL property, published by this class.

ParentFont property

property ParentFont;

Standard VCL property, published by this class.

TabOrder property

property TabOrder;

Standard VCL property, published by this class.

TabStop property

property TabStop;

Standard VCL property, published by this class.

Enabled property

property Enabled;

Standard VCL property, published by this class.

Visible property

property Visible;

Standard VCL property, published by this class.

PopupMenu property

property PopupMenu;

Standard VCL property, published by this class.

OnClick event

property OnClick;

Standard VCL event, published by this class.

OnDblClick event

property OnDblClick;

Standard VCL event, published by this class.

OnEnter event

property OnEnter;

Standard VCL event, published by this class.

OnExit event

property OnExit;

Standard VCL event, published by this class.

OnKeyDown event

property OnKeyDown;

Standard VCL event. It also fires for keys pressed in the in-place editor, except Escape, which the grid handles itself.

CommitEdit method

procedure CommitEdit;

Validates the pending edit, writes it to the table cell under the cursor and closes the editor. Does nothing when there is no pending edit. Raises EAtlasDataError when the value does not fit the column; the edit then stays pending. Call it before your own code sorts, filters or changes the table.

Grid.CommitEdit;
Grid.Table.Sort(2, False);

CancelEdit method

procedure CancelEdit;

Discards the pending edit and closes the in-place editor. If the editor was open, closing it hands its text back as a new pending edit, so to discard what is being typed call CancelEdit twice. The grid calls it itself on every table change.

Grid.CancelEdit;
Grid.CancelEdit; // the editor was open

Show a table and sort it from code

The grid follows the table; commit a pending edit before code moves rows. Prints ascending: b a, view row 0 and descending: a b in the example run.

uses Vcl.Forms, Vcl.Controls, Atlas.Data, Atlas.Grid;

function ShowTable(Form: TForm; Table: TAtlasTable): TAtlasGrid;
begin
  Result := TAtlasGrid.Create(Form);
  Result.Parent := Form;
  Result.Align := alClient;
  Result.HeaderColor := $00503A28;
  Result.AlternateColor := $00F4F1EE;
  Result.Table := Table; // the grid now follows every change of the table
end;

procedure SortByColumn(Grid: TAtlasGrid; Column: Integer);
begin
  Grid.CommitEdit; // store a pending edit before the rows move
  Grid.Table.Sort(Column, (Grid.Table.SortColumn <> Column) or not Grid.Table.Ascending);
end;

function CurrentViewRow(Grid: TAtlasGrid): Integer;
begin
  // Grid row 0 is the header; -1 when the cursor is not on a data row.
  if (Grid.Row >= 1) and (Grid.Row <= Grid.Table.RowCount) then
    Result := Grid.Row - 1
  else
    Result := -1;
end;

Make Enter and Escape act at once

A form-level key handler (the form sees keys first because KeyPreview is True) that makes Enter store the value immediately and Escape really discard it. Verified with simulated keystrokes: Enter commits, an invalid value raises on Enter, Escape restores the old value, and arrow keys still commit.

uses Winapi.Windows, System.Classes, Vcl.Forms, Vcl.Controls, Atlas.Grid;

type
  TGridForm = class(TForm)
  public
    Grid: TAtlasGrid;
    constructor Create(AOwner: TComponent); override;
    procedure FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
  end;

constructor TGridForm.Create(AOwner: TComponent);
begin
  inherited CreateNew(AOwner);
  KeyPreview := True;        // the form sees keys before the grid's in-place editor
  OnKeyDown := FormKeyDown;
  Grid := TAtlasGrid.Create(Self);
  Grid.Parent := Self;
  Grid.Align := alClient;
end;

procedure TGridForm.FormKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
begin
  if (ActiveControl <> Grid) or not Grid.EditorMode then
    Exit;
  if Key = VK_RETURN then
  begin
    Grid.EditorMode := False; // hand the editor text to the grid
    Grid.CommitEdit;          // validate and store it now, or raise EAtlasDataError
  end
  else if Key = VK_ESCAPE then
  begin
    Grid.CancelEdit;          // closing the editor keeps its text pending...
    Grid.CancelEdit;          // ...so the second call discards it
    Key := 0;
  end;
end;