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.