MODULE Connect232 ;
 
(*)
 *  A communications routine via the RS232 line to another host.
 *  Parameters are:
 *
 *      EscChar         The "escape" character, when this character is read
 *                      from the keyboard return to caller.
 *      HalfDuplex      The state of the host's connection, if HalfDuplex is
 *                      true echo the keyboard characters locally.
 *      TabletOk        If true, the yellow button on the puck causes an
 *                      exit too.
                        5-Oct-83. Change cursor shape and allow ANY puck button
                        to cause an exit.
 *      RETURN:         ConCharExit    if <EscChar> caused exit,
 *                      ConButtonExit  for puck button.
(*)
 
EXPORTS    (*-------------*)
 
IMPORTS IO_Unit   FROM IO_Unit;
IMPORTS IOErrors  FROM IOErrors;
 
TYPE
    (* What caused "Connect" to exit *)
    ConExitFlag = (ConCharExit, ConButtonExit) ;


FUNCTION Connect( EscChar: Char; HalfDuplex, TabletOk: Boolean ) : ConExitFlag;
 
 
PRIVATE   (*---------------*)
 
IMPORTS Screen    FROM Screen ;
IMPORTS System    FROM System ;
IMPORTS IO_Others FROM IO_Others;

FUNCTION Connect( EscChar: Char; HalfDuplex, TabletOk: Boolean ) : ConExitFlag;
   CONST
      NUL =   Chr(#000) ;
      BS  =   Chr(#010) ;
      TAB =   Chr(#011) ;
      LF  =   Chr(#012) ;
      CR  =   Chr(#015) ;
      CtrlQ = Chr(#021) ;
      CtrlS = Chr(#023) ;
   VAR
      hpos:  Integer ;   (* current position in the line (for tabs) *)
      oldX, oldY: Integer ;    (* Old cursor offsets *)
      quit:  Boolean ;         (* loop control *)
      LineChr, KeyChr:  Char;  (* current RS232 and keyboard characters *)
      OldCurs, NewCurs: CurPatPtr ;  (* Old and New cursors (if TabletOk) *)
      return: ConExitFlag ;    (* the exit flag *)
 
   PROCEDURE WriteChr( c: Char ) ;
      BEGIN
         SPutChr( c ) ;
         Hpos := Hpos + 1
      END ;
 
   HANDLER CtlC ;
      BEGIN
      END ;
 
   BEGIN  (*-Connect-*)

      (* Allocate cursor space *)
      New( 0, 4, NewCurs) ;
      New( 0, 4, OldCurs) ;

      (* Clear the cursor area *)
      RasterOp(RXor, 64, 64, 0, 0, 4, RECAST(NewCurs, RasterPtr),
                             0, 0, 4, RECAST(NewCurs, RasterPtr) ) ;
 
(* Cursor values from file: Connect3.Cursor *)
      NewCurs^[ 0,0] := #40 ;
      NewCurs^[ 1,0] := #120 ;
      NewCurs^[ 1,1] := #1642 ;
      NewCurs^[ 1,2] := #167000 ;
      NewCurs^[ 2,0] := #210 ;
      NewCurs^[ 2,1] := #1024 ;
      NewCurs^[ 2,2] := #42000 ;
      NewCurs^[ 3,0] := #404 ;
      NewCurs^[ 3,1] := #1610 ;
      NewCurs^[ 3,2] := #42000 ;
      NewCurs^[ 4,0] := #1002 ;
      NewCurs^[ 4,1] := #1024 ;
      NewCurs^[ 4,2] := #42000 ;
      NewCurs^[ 5,0] := #404 ;
      NewCurs^[ 5,1] := #1642 ;
      NewCurs^[ 5,2] := #162000 ;
      NewCurs^[ 6,0] := #2211 ;
      NewCurs^[ 7,0] := #5122 ;
      NewCurs^[ 7,1] := #100000 ;
      NewCurs^[ 8,0] := #10444 ;
      NewCurs^[ 8,1] := #40000 ;
      NewCurs^[ 9,0] := #20210 ;
      NewCurs^[ 9,1] := #20000 ;
      NewCurs^[10,0] := #40120 ;
      NewCurs^[10,1] := #10000 ;
      NewCurs^[11,0] := #20210 ;
      NewCurs^[11,1] := #20000 ;
      NewCurs^[12,0] := #10444 ;
      NewCurs^[12,1] := #40000 ;
      NewCurs^[13,0] := #5122 ;
      NewCurs^[13,1] := #100000 ;
      NewCurs^[14,0] := #2211 ;
      NewCurs^[15,0] := #404 ;
      NewCurs^[16,0] := #1002 ;
      NewCurs^[17,0] := #404 ;
      NewCurs^[18,0] := #210 ;
      NewCurs^[19,0] := #120 ;
      NewCurs^[20,0] := #40 ;
 

      (* Debug :- %)
      Writeln('TabletOk = ', TabletOk) ;
      (% Debug    *)


      SCurOn ;  (* ? *)


      (* Set up our cursor, or turn the cursor off if we can't use a cursor *)
      IF TabletOk THEN
         BEGIN
            IOReadCursPicture( OldCurs, oldX, oldY ) ;
            IOLoadCursor( NewCurs, 0, 0) ;
            IOSetModeTablet( relTablet ) ;
            IOCursorMode( TrackCursor )
         END
      ELSE
         IOCursorMode( OffCursor ) ;  (* Turn it off *)

      return := ConCharExit ;  (* Assume the exit by escape char *)
      quit := False ;
      WHILE NOT quit DO
         BEGIN
            (*----------   RS232 Input   ----------*)
            IF (IOCRead(RS232In, LineChr)=IOEIOC)  THEN
               BEGIN
                  LineChr := Chr( Land( Ord(LineChr), #177) ) ;
                  IF (LineChr = TAB) THEN
                     BEGIN
                        WriteChr( ' ' ) ;
                        WHILE (Hpos MOD 8) <> 0 DO  WriteChr( ' ' )
                     END
                  ELSE
                     IF (LineChr = BS) THEN
                        BEGIN
                           IF Hpos > 0 THEN
                              BEGIN (* Delete the character *)
                                 SBackSpace( ' ' );
                                 SPutChr( ' ' ) ;
                                 SBackSpace( ' ' ) ;
                                 Hpos := Hpos - 1
                              END
                        END
                     ELSE
                        IF (LineChr IN [NUL, CtrlS, CtrlQ]) THEN (* NOTHING *)
                        ELSE
                           WriteChr( LineChr ) ;   (* write it *)
 
                  IF (LineChr IN [CR, LF]) THEN  Hpos := 0 ;  (* a new line *)
               END ; (* RS232 input *)
 
            (*----------   Keyboard Input   ----------*)
            IF (IOCRead(TransKey, KeyChr)=IOEIOC) THEN
               BEGIN
                  IF (KeyChr = EscChar) THEN
                     BEGIN
                        quit := True
                     END
                  ELSE
                     BEGIN
                        IF IOCWrite(RS232Out, KeyChr)<>IOEIOC THEN
                           KeyChr := Chr(#277) ;
                        IF HalfDuplex THEN WriteChr( KeyChr )
                     END
               END ; (* Keyboard input *)
 
            (*----------   Tablet Input   ----------*)
            IF TabletOk AND TabSwitch THEN
              BEGIN
                return := ConButtonExit ;
                quit := True
              END

         END ; (* while *)

      (* Restore cursor *)
      IF TabletOk THEN IOLoadCursor( OldCurs, oldX, oldY )
      ELSE IOCursorMode( TrackCursor ) ; (* I assume it was originally on *)
      Dispose( NewCurs ) ;

      Connect := return
   END .  (*-Connect-*)