'===========================================================================
' Subject: SIMPLE TEXT VIEWER FOR BASEC      Date: 01-20-99 (23:00)       
' Author:  The ABC Programmer                Code: BEC                    
' Origin:  voxel@edmc.net                  Packet: BASEC.ABC
'===========================================================================
'' Really really simple/useless text viewer for BASEC v0.15 [DOS]
'' By William Yu (January 20, 1999)

DIM Pointers(1 to 5000) AS LONG
DIM I AS INTEGER, A AS INTEGER, MAX AS INTEGER
DIM A$ AS STRING
DIM TotalBytes AS LONG
DIM FilePos AS INTEGER, COffset AS INTEGER
DIM FileName AS STRING

FileName = "TXTVIEW.BAS"

CLS

FileNum = FREEFILE
OPEN "B", FileNum, FileName
  IF LOF(FileNum) = 0 THEN
    CLOSE FileNum
    ?FileName;" not found."
    KILL FileName
    END
  END IF
  GOSUB DrawInterface
  Pointers(1) = 1
  I = 1
  TotalBytes = 0
  LOCATE 22,2:?"Loading..."
  DO
    A$ = SPACE$(250)
    GET #FileNum, , A$
    DO
      A = INSTR(A+1,A$, CHR$(13))
      IF A <> 0 THEN
        I = I + 1
        Pointers(I) = TotalBytes + A+2
      END IF
    LOOP UNTIL A = 0
    TotalBytes = TotalBytes + 250
  LOOP UNTIL EOF(FileNum)
  Max = I-1


  LOCATE 22,2:?CHR$(24)+CHR$(25)+CHR$(27)+CHR$(26)+"/PGUP/PGDN/HOME/END"
  FilePos = 17: COffset = 1
  GOSUB UpdateText
  DO
    A$ = INKEY$
    IF A$ = CHR$(0) + "P" THEN
      FilePos = FilePos + 1
      IF FilePos > Max+15 THEN FilePos = Max+15
      GOSUB UpdateText
    END IF
    IF A$ = CHR$(0) + "H" THEN FilePos = FilePos - 1: GOSUB UpdateText
    IF A$ = CHR$(0) + "Q" THEN
       FilePos = FilePos + 17
       IF FilePos > Max+16 THEN FilePos = Max+15
       GOSUB UpdateText
    END IF
    IF A$ = CHR$(0) + "I" THEN FilePos = FilePos - 17: GOSUB UpdateText
    IF A$ = CHR$(0) + "O" THEN FilePos = Max: GOSUB UpdateText
    IF A$ = CHR$(0) + "G" THEN FilePos = 17: GOSUB UpdateText
    IF A$ = CHR$(0) + "M" THEN COffset = COffset + 1: GOSUB UpdateText
    IF A$ = CHR$(0) + "K" THEN
      IF COffset <> 1 THEN
        COffset = COffset - 1
        GOSUB UpdateText
      END IF
    END IF
  LOOP UNTIL A$ = CHR$(27)

CLOSE FileNum

LOCATE ,,1
END


DrawInterface:
  LOCATE 2,1,0: COLOR 0,7: PRINT SPACE$(80)
  LOCATE 2,3: PRINT "Simple Text Viewer for BASIC v0.15 by William Yu"
  COLOR 7, 1
  LOCATE 3,1 : PRINT "Ú"; STRING$(78,"Ä"); "¿"
  COLOR 1,7:LOCATE 3,40-INT(LEN(FileName)/2):?" ";FileName;" "
  COLOR 7,1
  FOR I = 4 to 20
    LOCATE I,1:  ?"³"
    LOCATE I,80: ?"³"
  NEXT I
  LOCATE 21,1 : PRINT "À"; STRING$(78,"Ä"); "Ù"
  LOCATE 22,1 : COLOR 0,7: PRINT SPACE$(80)
RETURN

UpdateText:
  IF FilePos - 16 < 1 THEN FilePos = 17
  COLOR 0, 7
  LOCATE 22,50:?SPACE$(30)
  LOCATE 22,50:?"³  Line: "; FilePos-16;"...";FilePos;"    Col:";COffset
  COLOR 7, 1
  LOCATE 4
  FOR I = FilePos-16 TO FilePos
    A$ = SPACE$(Pointers(I+1) - Pointers(I)-2)
    GET #FileNum, Pointers(I), A$
    A$ = MID$(A$, COffset, 78)
    LOCATE ,2: ? A$ + SPACE$(78-LEN(A$))
  NEXT I
RETURN