source: branches/ByteArray/Devices/Serial.pas

unit Serial;

interface

uses
  Classes, SysUtils, Device, Int, Channel, syncobjs;

type
  { TSerial }

  TSerial = class(TDevice)
  private
    FLock: TCriticalSection;
    FOnInput: TNotifyEvent;
    FOnOutput: TNotifyEvent;
    InputBuffer: string;
    OutputBuffer: string;
    function ReadData(Size: TIntSize): TInt;
    function ReadInputBufferCount(Size: TIntSize): TInt;
    function ReadOutputBufferCount(Size: TIntSize): TInt;
    procedure WriteData(Size: TIntSize; Value: TInt);
    procedure WriteInputBufferCount(Size: TIntSize; Value: TInt);
    procedure WriteOutputBufferCount(Size: TIntSize; Value: TInt);
  public
    constructor Create;
    destructor Destroy; override;
    function ReadOutputBuffer: string;
    procedure WriteInputBuffer(Text: string);
    function GetHandlers: THandlers; override;
    property OnOutput: TNotifyEvent read FOnOutput write FOnOutput;
    property OnInput: TNotifyEvent read FOnInput write FOnInput;
  end;


implementation

{ TSerial }

function TSerial.ReadData(Size: TIntSize): TInt;
begin
  FLock.Acquire;
  try
    if Length(InputBuffer) > 0 then begin
      Result := Ord(InputBuffer[1]);
      Delete(InputBuffer, 1, 1);
    end;
  finally
    FLock.Release;
  end;
end;

function TSerial.ReadInputBufferCount(Size: TIntSize): TInt;
begin
  FLock.Acquire;
  try
    Result := Length(InputBuffer);
  finally
    FLock.Release;
  end;
end;

function TSerial.ReadOutputBufferCount(Size: TIntSize): TInt;
begin
  FLock.Acquire;
  try
    Result := Length(OutputBuffer);
  finally
    FLock.Release;
  end;
end;

procedure TSerial.WriteData(Size: TIntSize; Value: TInt);
begin
  FLock.Acquire;
  try
    OutputBuffer := OutputBuffer + Chr(Value);
  finally
    FLock.Release;
  end;
end;

procedure TSerial.WriteInputBufferCount(Size: TIntSize; Value: TInt);
begin
  FLock.Acquire;
  try
    InputBuffer := '';
  finally
    FLock.Release;
  end;
end;

procedure TSerial.WriteOutputBufferCount(Size: TIntSize; Value: TInt);
begin
  FLock.Acquire;
  try
    OutputBuffer := '';
  finally
    FLock.Release;
  end;
end;

constructor TSerial.Create;
begin
  FLock := TCriticalSection.Create;
  OutputBuffer := '';
  InputBuffer := '';
end;

destructor TSerial.Destroy;
begin
  FreeAndNil(FLock);
  inherited;
end;

function TSerial.ReadOutputBuffer: string;
begin
  FLock.Acquire;
  try
    Result := OutputBuffer;
    OutputBuffer := '';
  finally
    FLock.Release;
  end;
end;

procedure TSerial.WriteInputBuffer(Text: string);
begin
  FLock.Acquire;
  try
    InputBuffer := InputBuffer + Text;
  finally
    FLock.Release;
  end;
end;

function TSerial.GetHandlers: THandlers;
begin
  Result := THandlers.Create;
  Result.ReadHandlers.Add(ReadData);
  Result.ReadHandlers.Add(ReadOutputBufferCount);
  Result.ReadHandlers.Add(ReadOutputBufferCount);
  Result.WriteHandlers.Add(WriteData);
  Result.WriteHandlers.Add(WriteInputBufferCount);
  Result.WriteHandlers.Add(WriteOutputBufferCount);
end;

end.