Денежное поле редактирования

unit CurrEdit;

interface

uses
  SysUtils,
  WinTypes,
  WinProcs,
  Messages,
  Classes,
  Graphics,
  Controls,
  Menus,
  Forms,
  Dialogs,
  StdCtrls;

type
  TCurrencyEdit = class(TCustomMemo)
  private
    DispFormat: string;
    FieldValue: Extended;
    procedure SetFormat(A: string);
    procedure SetFieldValue(A: Extended);
    procedure CMEnter(var Message: TCMEnter); message CM_ENTER;
    procedure CMExit(var Message: TCMExit); message CM_EXIT;
    procedure FormatText;
    procedure UnFormatText;
  protected
    procedure KeyPress(var Key: Char); override;
    procedure CreateParams(var Params: TCreateParams); override;
  public
    constructor Create(AOwner: TComponent); override;
  published
    property Alignment default taRightJustify;
    property AutoSize default True;
    property BorderStyle;
    property Color;
    property Ctl3D;
    property DisplayFormat: string read DispFormat write SetFormat;
    property DragCursor;
    property DragMode;
    property Enabled;
    property Font;
    property HideSelection;
    property MaxLength;
    property ParentColor;
    property ParentCtl3D;
    property ParentFont;
    property ParentShowHint;
    property PopupMenu;
    property ReadOnly;
    property ShowHint;
    property TabOrder;
    property Value: Extended read FieldValue write SetFieldValue;
    property Visible;
    property OnChange;
    property OnClick;
    property OnDblClick;
    property OnDragDrop;
    property OnDragOver;
    property OnEndDrag;
    property OnEnter;
    property OnExit;
    property OnKeyDown;
    property OnKeyPress;
    property OnKeyUp;
    property OnMouseDown;
    property OnMouseMove;
    property OnMouseUp;
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('Additional', [TCurrencyEdit]);
end;

constructor TCurrencyEdit.Create(AOwner: TComponent);
begin
  inherited Create(AOwner);
  AutoSize := True;
  Alignment := taRightJustify;
  Width := 121;
  Height := 25;
  DispFormat := '$,0.00;($,0.00)';
  FieldValue := 0.0;
  AutoSelect := False;
  WantReturns := False;
  WordWrap := False;
  FormatText;
end;

procedure TCurrencyEdit.SetFormat(A: string);
begin
  if DispFormat <> A then
  begin
    DispFormat := A;
    FormatText;
  end;
end;

procedure TCurrencyEdit.SetFieldValue(A: Extended);
begin
  if FieldValue <> A then
  begin
    FieldValue := A;
    FormatText;
  end;
end;

procedure TCurrencyEdit.UnFormatText;
var
  TmpText: string;
  Tmp: Byte;
  IsNeg: Boolean;
begin
  IsNeg := (Pos('-', Text) > 0) or (Pos('(', Text) > 0);
  TmpText := '';
  for Tmp := 1 to Length(Text) do
    if Text[Tmp] in ['0'..'9', '.'] then
      TmpText := TmpText + Text[Tmp];
  try
    FieldValue := StrToFloat(TmpText);
    if IsNeg then
      FieldValue := -FieldValue;
  except
    MessageBeep(mb_IconAsterisk);
  end;
end;

procedure TCurrencyEdit.FormatText;
begin
  Text := FormatFloat(DispFormat, FieldValue);
end;

procedure TCurrencyEdit.CMEnter(var Message: TCMEnter);
begin
  SelectAll;
  inherited;
end;

procedure TCurrencyEdit.CMExit(var Message: TCMExit);
begin
  UnformatText;
  FormatText;
  inherited;
end;

procedure TCurrencyEdit.KeyPress(var Key: Char);
begin
  if not (Key in ['0'..'9', '.', '-']) then
    Key := #0;
  inherited KeyPress(Key);
end;

procedure TCurrencyEdit.CreateParams(var Params: TCreateParams);
begin
  inherited CreateParams(Params);
  case Alignment of
    taLeftJustify: Params.Style := Params.Style or ES_LEFT and not ES_MULTILINE;
    taRightJustify: Params.Style := Params.Style or ES_RIGHT and not
      ES_MULTILINE;
    taCenter: Params.Style := Params.Style or ES_CENTER and not ES_MULTILINE;
  end;
end;

end.