DBGrid компонент, который отображает разными цветами удалённые, обновлённые и добавленные записи

unit atcDBGrid;
(*
  (c) Aveen Tech
  2001 - 2002

  FileName: atcDBGrid.pas

  Version        Date            Author              Comment
  1.0            13/06/2000      Majid Vafai Jahan  Create.

OVERVIEW
  - This grid is inherited from DBGrid and add some required functionality to it.

Functionality:
  - Record type are all records that may be modified, unmodified, inserted, deleted.
  - Coloring according to Record type.
  - show selected Record Type.

*)

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  Grids, DBGrids, dbTables, db;
const
  AlignFlags : array [TAlignment] of Integer =
    ( DT_LEFT or DT_WORDBREAK or DT_EXPANDTABS or DT_NOPREFIX,
      DT_RIGHT or DT_WORDBREAK or DT_EXPANDTABS or DT_NOPREFIX,
      DT_CENTER or DT_WORDBREAK or DT_EXPANDTABS or DT_NOPREFIX );
  RTL: array [Boolean] of Integer = (0, DT_RTLREADING);
type
  TCachedShow = (csModify, csUnModify, csRemoved, csInserted, csAll, csNormal);
  TatcDBGrid = class(TDBGrid)
  private
    FCachedShow: TCachedShow;
    FModifiedColor: TColor;
    FInsertedColor: TColor;
    FDeletedColor: TColor;
    procedure SetCachedShow(const Value: TCachedShow);
  protected
    procedure DrawDataCell(const Rect: TRect; Field: TField;
      State: TGridDrawState); override;
    procedure DrawColumnCell(const Rect: TRect; DataCol: Integer;
      Column: TColumn; State: TGridDrawState); override;
  public
    constructor Create(AOwner: TComponent); override;
  published
    property atcCachedShow: TCachedShow read FCachedShow write SetCachedShow;
    property atcDeletedColor: TColor read FDeletedColor write FDeletedColor;
    property atcInsertedColor: TColor read FInsertedColor write FInsertedColor;
    property atcModifiedColor: TColor read FModifiedColor write FModifiedColor;
  end;

procedure Register;

implementation

(******************************************************************************)
procedure Register;
begin
  RegisterComponents('ATC DB Compo', [TatcDBGrid]);
end;

(******************************************************************************)
constructor TatcDBGrid.Create(AOwner: TComponent);
(*
  Description: Record Type Showing is All except Deletes.
*)

begin
  inherited;
  FCachedShow := csNormal;
  FDeletedColor := clGray;
  FInsertedColor := clAqua;
  FModifiedColor := clRed;
end;

(******************************************************************************)
procedure TatcDBGrid.DrawColumnCell(const Rect: TRect; DataCol: Integer;
  Column: TColumn; State: TGridDrawState);
(*
  Description: On Drawing Column Color Updated Records.
*)
var
  ARect: TRect;
begin
  inherited;
  if not Assigned(Column.Field) then
    exit;
  // Copy Rect into Variable.
  CopyRect(ARect, Rect);
  if Assigned(DataLink) and (DataLink.Active) and (DataLink.DataSet <> nil) then
  begin
    // если текущая запись изменена
    if DataLink.DataSet.UpdateStatus = usModified then
    begin
      Canvas.Brush.Color := atcModifiedColor;
      Canvas.Font.Color := clBlack;
      Canvas.FillRect(Rect);
      DrawText(Canvas.Handle, PChar(Column.Field.Text), Length(Column.Field.Text), ARect,
       AlignFlags[Column.Alignment] or RTL[UseRightToLeftAlignmentForField(Column.Field, Column.Alignment)]);
    end
    // если текущая запись добавлена.
    else if DataLink.DataSet.UpdateStatus = usInserted then
    begin
      Canvas.Brush.Color := atcInsertedColor;
      Canvas.Font.Color := clBlack;
      Canvas.FillRect(Rect);
      DrawText(Canvas.Handle, PChar(Column.Field.Text), Length(Column.Field.Text), ARect,
       AlignFlags[Column.Alignment] or RTL[UseRightToLeftAlignmentForField(Column.Field, Column.Alignment)]);
    end
    // если текущая запись удалена.
    else if DataLink.DataSet.UpdateStatus = usDeleted then
    begin
      Canvas.Brush.Color := atcDeletedColor;
      Canvas.Font.Color := clWhite;
      Canvas.FillRect(Rect);
      DrawText(Canvas.Handle, PChar(Column.Field.Text), Length(Column.Field.Text), ARect,
       AlignFlags[Column.Alignment] or RTL[UseRightToLeftAlignmentForField(Column.Field, Column.Alignment)]);
    end;
  end;
end;

(******************************************************************************)
procedure TatcDBGrid.DrawDataCell(const Rect: TRect; Field: TField;
  State: TGridDrawState);
(*
  Описание: Рисуем ячейки
*)
var
  ARect: TRect;
begin
  inherited;
  CopyRect(ARect, Rect);

  if Assigned(DataLink) and (DataLink.Active) and (DataLink.DataSet <> nil) then
  begin
    // если текущая запись изменена
    if DataLink.DataSet.UpdateStatus = usModified then
    begin
      Canvas.Brush.Color := clRed;
      Canvas.Font.Color := clBlack;
      Canvas.FillRect(Rect);
      DrawText(Canvas.Handle, PChar(Field.Text), Length(Field.Text), ARect,
       AlignFlags[Field.Alignment] or RTL[UseRightToLeftAlignmentForField(Field, Field.Alignment)]);
    end
    // если текущая запись добавлена.
    else if DataLink.DataSet.UpdateStatus = usInserted then
    begin
      Canvas.Brush.Color := clAqua;
      Canvas.Font.Color := clBlack;
      Canvas.FillRect(Rect);
      DrawText(Canvas.Handle, PChar(Field.Text), Length(Field.Text), ARect,
       AlignFlags[Field.Alignment] or RTL[UseRightToLeftAlignmentForField(Field, Field.Alignment)]);
    end
    // если текущая запись удалена.
    else if DataLink.DataSet.UpdateStatus = usDeleted then
    begin
      Canvas.Brush.Color := clGray;
      Canvas.Font.Color := clWhite;
      Canvas.FillRect(Rect);
      DrawText(Canvas.Handle, PChar(Field.Text), Length(Field.Text), ARect,
       AlignFlags[Field.Alignment] or RTL[UseRightToLeftAlignmentForField(Field, Field.Alignment)]);
    end;
  end;
end;

(******************************************************************************)
procedure TatcDBGrid.SetCachedShow(const Value: TCachedShow);
(*
  Description: Record type for showing in grid.
  Parameters: Value cached record show.
*)

begin
  FCachedShow := Value;
  if ComponentState = [csDesigning] then
    exit;
  if not Assigned(DataSource) or not Assigned(DataSource.DataSet) then
    exit;
  // для показа только выбранного типа записей.
  if Assigned(DataLink) and Assigned(DataLink.DataSet) and (DataLink.Active) then
  begin
    case FCachedShow of
    csAll:
      TBDEDataSet(DataSource.DataSet).UpdateRecordTypes := [rtModified, rtInserted, rtDeleted, rtUnmodified];
    csModify:
      TBDEDataSet(DataSource.DataSet).UpdateRecordTypes := [rtModified];
    csUnModify:
      TBDEDataSet(DataSource.DataSet).UpdateRecordTypes := [rtUnmodified];
    csInserted:
      TBDEDataSet(DataSource.DataSet).UpdateRecordTypes := [rtInserted];
    csRemoved:
      TBDEDataSet(DataSource.DataSet).UpdateRecordTypes := [rtDeleted];
    csNormal:
      TBDEDataSet(DataSource.DataSet).UpdateRecordTypes := [rtModified, rtInserted, rtUnmodified];
    end;
  end;
end;

(******************************************************************************)
end.