unit PrinterComponent;

interface

uses
  Windows, Messages, SysUtils, Classes, Printers, DesignEditors, DesignIntf;

type
  TPrinterNameProperty = class(TStringProperty)
  public
    function GetAttributes: TPropertyAttributes; override;
    procedure GetValueList(List: TStrings); virtual;
    procedure GetValues(Proc: TGetStrProc); override;
  end;

  TPrinterComponent = class(TComponent)
  private
    FPrinterName: string;
    function GetPrinters: TStrings;
  public
    function IsPrinterInList(const PrinterName: string): Boolean;
    property Printers: TStrings read GetPrinters;
  published
    property PrinterName: string read FPrinterName write FPrinterName;
  end;

procedure Register;

implementation

procedure Register;
begin
  RegisterComponents('Beispiele', [TPrinterComponent]);
  RegisterPropertyEditor(
   TypeInfo(string), TPrinterComponent, 'PrinterName', TPrinterNameProperty);
end;

{ TPrinterComponent }

function TPrinterComponent.GetPrinters: TStrings;
begin
  Result := Printer.Printers;
end;

{ TZStringProperty }

function TPrinterNameProperty.GetAttributes: TPropertyAttributes;
begin
  Result := [paValueList, paSortList];
end;

procedure TPrinterNameProperty.GetValueList(List: TStrings);
begin
  List.Assign((GetComponent(0) as TPrinterComponent).Printers);
end;

procedure TPrinterNameProperty.GetValues(Proc: TGetStrProc);
var
  i: Integer;
  Values: TStringList;
begin
  Values := TStringList.Create;
  try
    GetValueList(Values);
    for i := 0 to Pred(Values.Count) do
      Proc(Values[i]);
  finally
    Values.Free;
  end;
end;

function TPrinterComponent.IsPrinterInList(const PrinterName: string): Boolean;
begin
  Result := GetPrinters.IndexOf(PrinterName) > -1;
end;

end.