source: branches/bigint/Console.pas

unit Console;

interface

uses
  Classes, SysUtils, Device, Int;

type

  { TConsole }

  TConsole = class(TDevice)
  private
    FOnRead: TNotifyEvent;
    FOnWrite: TNotifyEvent;
    procedure WriteChar(Data: TInt);
    function ReadChar: TInt;
    function ReadInputBufferSize: TInt;
  public
    InputBuffer: string;
    OutputBuffer: string;
    function GetHandlers: THandlers; override;
    property OnWrite: TNotifyEvent read FOnWrite write FOnWrite;
    property OnRead: TNotifyEvent read FOnRead write FOnRead;
  end;


implementation

{ TConsole }

function TConsole.GetHandlers: THandlers;
begin
  Result := THandlers.Create;
  Result.ReadHandlers.Add(ReadChar);
  Result.ReadHandlers.Add(ReadInputBufferSize);
  Result.WriteHandlers.Add(WriteChar);
end;

procedure TConsole.WriteChar(Data: TInt);
begin
  OutputBuffer := OutputBuffer + Chr(Data);
  if Assigned(FOnWrite) then FOnWrite(Self);
end;

function TConsole.ReadChar: TInt;
begin
  if Length(InputBuffer) > 0 then begin
    Result := Ord(InputBuffer[1]);
    Delete(InputBuffer, 1, 1);
  end else Result := 0;
end;

function TConsole.ReadInputBufferSize: TInt;
begin
  Result := Length(InputBuffer);
end;

end.