IMPLEMENTATION MODULE NumInput;
(*
 *  REPERTOIRE
 *  Release 1.6
 *  By Charles Bradford and Cole Brecheen
 *  (c) Copyright 1985-1992 PMI
 *  Green Bay, Wisconsin
 *  All rights reserved
 *  (414) 468-6040
 *
 *  $Header:   D:/logfiles/mods/numinput.mov   1.4   10 Mar 1991 15:35:32   coleb  $
 *
 *)


(*
Author:     Mike Carter
Description:
  Enter or edit a numeric field.
  Replacement for PMI StrInput.ReadNumeric.  Note that parameters
  are slightly different:
    1.  PMI FloatingPoint and InDecimals parameters have been
        removed. They simply have no meaning the way real number
        input is now handled.
    2.  minusOK has been added - see below.
    3.  The meaning of DecimalPlaces has been changed - see
        below.

  Some of the features of this version:
    * General editing functions are very close to PMI string
      input. (Keys like Ins, Del, Home, End, PgUp, PgDn, Left and
      Right Arrows, Up and Down Arrows, Backspace, Tab, Shift
      Tab, etc. work almost the same way as they do in string
      fields).
    * Numbers are entered from left to right, then right-
      justified on field exit.
    * Both insert and overstrike modes are supported.
    * The number of digits after the decimal place is strictly
      enforced. The user is beeped if too many are entered; if
      two few are entered, zeroes are appended.  If there is not
      enough room in the field, the rightmost character is thrown
      out, the decimal point repositioned, and the user beeped.

  Notes on parameters:
    * A new field was added in ScrnTypes.InputFieldRecord called
      "decimalPlace", with corresponding type DecimalPlaceType.
      This was designed to be passed to this routine: a -1 value
      indicates user-specified decimal points (or none); a 0
      means no digits after the decimal point, a 1 one digit,
      etc.
    * The value of minusOK determines whether negative numbers
      are allowed; this can be set from rMin, iMin within
      UserOps.  Must be FALSE for strings that are later to be
      interpreted as CARDINAL.

  Notes on Methodology:
    NumInput combines state transition tables with a series of
    rules.  The three state tables reflect the current input mode
    and the character that the cursor is under; they generate
    actions to be taken based on each key that may be hit as well
    as the next state.  The tables are:
      InputTable = entry on top of blanks.
      EditOverTable = overstrike mode.
      EditInsertTable = insert mode.
    The entries in the state tables are formed by three-character
    sequences. (See the initialization code at the end of this
    module).

    (1) The first character is a non-mnemonic that stands for a
        sequence of actions to be taken if a key in that keyclass
        is hit.  See the KeyAction procedure guts to see which
        procedures are executed for which letters. Generally,
        these procedures are qualifying procedures that determine
        whether or not a keystroke is legal from a given state.
    (2) The next character specifies the action to take if the
        qualifications are met.  "I" stands for insert; "E"
        stands for error.
    (3) The last character in the state table triplet is the next
        state. You'll notice that this is missing in many cases -
        that is because of the fact that during editing, the next
        state must be dynamically re-computed from the numeric
        string AFTER the change has been made.

    The state tables are difficult to understand without
    diagrams, from which they were created (state transition
    diagrams).

    The rules referred to above are generally conditions that
    would have caused the state tables to grow exponentially had
    they been included. InsertCharacter contains a number of
    these rules, such as what to do when you are on the last
    character in the field under a number of circumstances.

*)

IMPORT BigSets;
IMPORT ErrorManager;
IMPORT KbdInput;
IMPORT Key;
IMPORT LowLevel;
IMPORT M2Strings;
IMPORT Numbers;
IMPORT PosUtils;
IMPORT ScrnTypes;
IMPORT Spkr;
IMPORT StrConv;
IMPORT StrEdit;
IMPORT UserOps;
IMPORT SYSTEM;
IMPORT VWindows;

VAR
  Initialized : BOOLEAN;


TYPE
  TableIndexType = (InputTable, EditOverTable, EditInsertTable);
    (* InputTable = entry on top of blanks *)
    (* EditOverTable = overstrike mode *)
    (* EditInsertTable = insert mode *)
  KeyClassType = (DigitsClass, MinusClass, DecimalPointClass, DollarClass);

CONST
  ActionLetters = 2;    (* state table action letters + next state - 1 *)
  MaxStates = 6;        (* max number of states in table *)

VAR
  stateTable      : ARRAY [InputTable..EditInsertTable],
                          [DigitsClass..DollarClass],
                          [0..MaxStates * (ActionLetters+1)] OF CHAR;
                                       (* actions and next states *)

PROCEDURE ReadNumericField
        (    WindowHandle : VWindows.AWindowHandle;    (* in *)
          VAR TheStr       : ARRAY OF CHAR;   (* in/out - field contents *)
              col1         : CARDINAL;        (* in - field loc *)
              row1         : CARDINAL;        (* in - field loc *)
              FieldWidth   : CARDINAL;        (* in - # chars. in field *)
              DecimalPlaces: ScrnTypes.DecimalPlaceType;
                                              (* in - # digits after . *)
              minusOK      : BOOLEAN;         (* in - "-" permitted *)
          VAR LastKey      : CARDINAL;        (* in/out - last key hit *)
          VAR ExitKeys     : KbdInput.KeyNumSet  (* in - keys to exit on *)
        );
  (*
  This is a general-purpose numeric input routine that replaces the PMI
  StrInput.ReadNumeric procedure.  The parameters are slightly different.
  *)

  CONST
    Minus = ORD('-');                  (* numerics required due to LastKey *)
    DecimalKey = ORD('.');
    DollarSignKey = ORD('$');
    ZeroKey = ORD('0');
    NineKey = ORD('9');
    CurrencySymbol = '$';
    blank = ' ';
    periodChar = '.';
    minusChar = '-';
    zeroChar = '0';
    MaxFieldSize = 255;
    ErrorState = 9999;    (* arbitrary error state *)
    LeaveLast = TRUE;     (* last character in field can't be overstruck *)
  VAR
    (* old PMI variables still used *)
    SavedHeight : CARDINAL;

    curPos          : CARDINAL;                (* index to TheStr *)
    curTable        : TableIndexType;          (* current state table *)
    editInProgress  : BOOLEAN;                 (* TRUE if editing started *)
    escapeHit       : BOOLEAN;                 (* ESC restores string *)
    fieldEnd        : CARDINAL;                (* FieldWidth - 1 *)
    originalStr     : ARRAY [0..MaxFieldSize] OF CHAR;
                                               (* copy to restore by ESC *)
    periodOK        : BOOLEAN;                 (* FALSE for INT and CARD *)
    states          : ARRAY [InputTable..EditInsertTable] OF CARDINAL;
                                               (* state for each table *)

(*
  The following group of procedures supports editing functions and are
  NOT involved with the state tables.
*)
  PROCEDURE DeleteCharacter;
    (* Delete the character at the current cursor position *)
    (* Any characters to the right of curPos move left *)
    (* Implements part of DEL key.  Doesn't move cursor position. *)
    VAR
      shiftIndex : CARDINAL;
  BEGIN (* procedure DeleteCharacter *)
    IF curPos < fieldEnd THEN
      FOR shiftIndex := curPos TO fieldEnd DO
        TheStr[ shiftIndex ] := TheStr[ shiftIndex + 1 ];
      END; (* for shiftIndex *)
    END; (* if curPos *)
    TheStr[ fieldEnd ] := blank;
    escapeHit := FALSE;
  END DeleteCharacter; (* procedure *)

  PROCEDURE PreviousContents;
    (* replace current contents of field with original contents *)
    (* Be sure to recompute table state afterwards *)
    (* Implements ESC key in part. *)
  BEGIN (* procedure PreviousContents *)
    StrEdit.AssignStr( originalStr, TheStr );
    curPos := 0;
  END PreviousContents; (* procedure *)

  PROCEDURE BlankOutField( startPos : CARDINAL );
    (* Replace the designated portion of the field with blanks. *)
    VAR
      strIndex : CARDINAL;
  BEGIN (* procedure BlankOutField *)
    FOR strIndex := startPos TO fieldEnd DO
      TheStr[ strIndex ] := blank;
    END; (* for strIndex *)
  END BlankOutField; (* procedure *)


  PROCEDURE CleanUpTheStr(): BOOLEAN;
    (* "Cleans up" the string in the field that the user wants to leave *)
    (* This procedure is meant to be executed whenever field movement keys *)
    (* have been hit.  E.g. TAB, PgUp, PgDn, Shift TAB, etc. *)
    (* Actions performed: *)
    (*    Leading Zeroes stripped. *)
    (*    Decimal point forced in if not there. *)
    (*    Trailing Zeroes added after decimal point without enough *)
    (*       digits after it. *)
    (*    Decimal point with too many digits after it causes truncation *)
    (*       of extra digits, beep, and cursor left in field. *)
    (*    Fields with no numeric digits are blanked out. *)
    (* Be sure to recompute table state afterwards *)
    VAR
      strIndex, decSpot, decDigits : CARDINAL;
      anyNumerics : BOOLEAN;       (* TRUE if field contains any digits *)

    PROCEDURE StopFieldExit;
      (* An adjustment to the field has been made that requires user's *)
      (* attention - prevent exit from the field (aborting key action). *)
    BEGIN (* procedure StopFieldExit *)
      (* Don't allow the field to be exited - set up as just entered *)
      StrEdit.LeftJustify( TheStr, FieldWidth );
      LastKey := 0;
      curPos := 0;
      (* And try to wake up the user that this has happened! *)
      Spkr.Noise( Spkr.Beep, Spkr.High, Spkr.Medium );
    END StopFieldExit; (* procedure *)

    PROCEDURE NoDecimalPoint;
      (* Process a string that has no decimal point.  For Reals only. *)

      PROCEDURE InsertLeftJustified
                (    insChar   : CHAR;           (* character to insert *)
                     pos       : CARDINAL        (* position in TheStr *)
                );
        (* puts insChar into TheStr at location pos; rightmost char gone *)
        VAR
          strIndex : CARDINAL;
      BEGIN (* procedure InsertLeftJustified *)
        (* move what's there over; forget the leftmost character *)
        IF fieldEnd > 0 THEN
          FOR strIndex := fieldEnd-1 TO pos BY -1 DO
            TheStr[ strIndex+1 ] := TheStr[ strIndex ];
          END; (* for strIndex *)
          TheStr[ pos ] := insChar;
        END; (* if fieldEnd *)
      END InsertLeftJustified; (* procedure *)

      VAR
        decPointPos : CARDINAL;        (* where the decimal point goes *)
        rightSubStr : ARRAY [0..80] OF CHAR;     (* str in front of dec pt. *)
        trailingDig : BOOLEAN;         (* true if digits after dec. point *)

    BEGIN (* procedure NoDecimalPoint *)
      (* note that TheStr does not necessarily have length = FieldWidth! *)
      StrEdit.LeftJustify( TheStr, FieldWidth );
      (* if necessary, sacrifice the last digit to make room for '.' *)
      decPointPos := FieldWidth-VAL(CARDINAL,DecimalPlaces)-1;
      InsertLeftJustified( periodChar, decPointPos );
      (* right justify with period as a boundary *)
      IF decPointPos > 0 THEN
        M2Strings.Copy( TheStr, 0, decPointPos, rightSubStr );
        StrEdit.RightJustify( rightSubStr, decPointPos );
        StrEdit.OverWrite( rightSubStr, TheStr, 0 );  (* put back in, shifted *)
      END; (* if decPointPos *)
      (* Fill in any gaps with zeroes. *)
      trailingDig := FALSE;
      FOR strIndex := decPointPos+1 TO fieldEnd DO
        IF TheStr[ strIndex ] = blank THEN
          TheStr[ strIndex ] := zeroChar;
        ELSE
          trailingDig := TRUE;
        END; (* if TheStr *)
      END; (* for strIndex *)

      (* Alert the user only if dec. point was added in middle of digits *)
      IF trailingDig THEN
        StopFieldExit;
      END; (* if trailingDig *)
    END NoDecimalPoint; (* procedure *)


  BEGIN (* procedure CleanUpTheStr *)
    (* Blank fields ignored *)
    IF PosUtils.IsBlank( TheStr ) THEN
      RETURN( TRUE );
    END; (* if PosUtils.IsBlank *)

    (* Another check - if there were no numeric digits, blank out. *)
    anyNumerics := FALSE;
    FOR strIndex := 0 TO fieldEnd DO
      anyNumerics := anyNumerics OR
                  PosUtils.IsNumericChar( TheStr[ strIndex ] )
    END; (* for strIndex *)
    IF NOT anyNumerics THEN
      BlankOutField( 0 );
      RETURN( TRUE );        (* not much point in doing anything else *)
    END; (* if NOT *)

    (* First, out with the leading zeroes.  Leave last one. *)
    (* Note also removes zeroes for -00.33 or $00.33 *)
    strIndex := 0;
    LOOP
      IF TheStr[ strIndex ] = zeroChar  THEN
        TheStr[ strIndex ] := blank;
      END; (* if TheStr *)
      IF (strIndex = fieldEnd) OR (TheStr[strIndex] = periodChar) OR
         ((TheStr[strIndex] # zeroChar) AND     (* stop on non-zero digit *)
         PosUtils.IsNumericChar( TheStr[strIndex] ))
      THEN
        EXIT;
      END; (* if strIndex *)
      INC( strIndex );
    END; (* loop *)
    (* Don't leave just a period in the field, though *)
    IF (TheStr[strIndex] = periodChar) AND
       (NOT PosUtils.IsNumericChar( TheStr[strIndex+1] )) THEN
      StrEdit.InsertRightJustified( zeroChar, TheStr, strIndex );
    END; (* if TheStr *)
    IF PosUtils.IsBlank( TheStr ) THEN
      TheStr[ 0 ] := zeroChar;                    (* at least one there *)
    END; (* if PosUtils.IsBlank *)
    (* Get rid of any blanks after punctuation ($  33.) *)
    StrEdit.DeleteChar( blank, TheStr );       (* trailing gone too *)

    (* find decimal point (if real type) *)
    (* User-specified decimal points not enforced (DecimalPlaces=-1) *)
    IF DecimalPlaces > 0 THEN
      IF PosUtils.PresentPos( periodChar, TheStr, decSpot ) THEN
        (* count the number of digits after the decimal point *)
        decDigits := 0;
        FOR strIndex := decSpot+1 TO fieldEnd DO
          IF PosUtils.IsNumericChar( TheStr[ strIndex ] ) THEN
            INC( decDigits );
          END; (* if PosUtils.IsNumericChar *)
        END; (* for strIndex *)
        IF VAL(INTEGER,decDigits) < DecimalPlaces THEN
          (* not enough digits after decimal point *)
          (* so force-feed the zeroes *)
          FOR strIndex := decSpot+decDigits+1 TO
              Numbers.Min( decSpot+VAL(CARDINAL,DecimalPlaces), fieldEnd ) DO
            TheStr[ strIndex ] := zeroChar;
          END; (* for strIndex *)
          IF (fieldEnd - decSpot) < VAL(CARDINAL,DecimalPlaces) THEN
            (* not enough room in field for required decimal places *)
            (* take out the decimal point and shift it as necessary *)
            StrEdit.DeleteChar( periodChar, TheStr );
            NoDecimalPoint;
            RETURN( FALSE );
          END; (* if fieldEnd *)
        ELSIF VAL(INTEGER,decDigits) > DecimalPlaces THEN
          (* they typed in too many digits after the decimal point - remove *)
          FOR strIndex := decSpot+VAL(CARDINAL,DecimalPlaces)+1 TO
              decSpot+decDigits+1 DO
            TheStr[ strIndex ] := blank;
          END; (* for strIndex *)
          StopFieldExit;
          RETURN( FALSE );             (* Something typed was lost - notify *)
        END; (* if decDigits *)
      ELSE
        NoDecimalPoint;
      END; (* if PosUtils.PresentPos *)
    END; (* if DecimalPlaces *)

    RETURN( TRUE );                (* OK to go ahead and leave field *)
  END CleanUpTheStr; (* procedure *)


  PROCEDURE ComputeNextState;
    (* Used to switch state tables from the various modes *)
    (* (Numeric Entry, Insert Editing, Overstrike Editing) *)
    (* Called after keys that move the cursor in editing modes *)
  BEGIN (* procedure ComputeNextState *)
    CASE curTable OF
      InputTable:
        IF NOT((TheStr[ curPos ] = blank) OR (curPos = fieldEnd)) THEN
          (* Must change to an edit mode *)
          IF UserOps.InsertMode THEN
            curTable := EditInsertTable;
          ELSE
            curTable := EditOverTable;
          END; (* if UserOps.InsertMode *)
        END; (* if not *)
    | EditInsertTable, EditOverTable:
      (* change to InputTable if cursor is on a blank *)
        IF (TheStr[ curPos ] = blank) THEN
          curTable := InputTable;
        ELSIF NOT UserOps.InsertMode THEN
          curTable := EditOverTable;
        ELSE
          curTable := EditInsertTable;
        END; (* if TheStr *)
    END; (* case curTable *)
    (* Now, have to figure out which state we are left in *)
    (* This is because the editing actions change the states *)
    (* NOTE: This is where the states are documented.  Each state *)
    (* is represented by three character positional substrings in the *)
    (* third dimension of the stateTable array. *)
    CASE curTable OF
      InputTable:
        IF PosUtils.IsBlank( TheStr ) THEN
          states[ InputTable ] := 0;     (* back to initial *)
        ELSIF PosUtils.Present( periodChar, TheStr ) THEN
          states[ InputTable ] := 4;     (* after period *)
        ELSIF PosUtils.Present( CurrencySymbol, TheStr )  THEN
          states[ InputTable ] := 3;     (* after currency *)
        ELSIF PosUtils.Present( minusChar, TheStr ) THEN
          IF PosUtils.IsNumericChar( TheStr[curPos] ) THEN
            states[ InputTable ] := 5;     (* no currency can follow *)
          ELSE
            states[ InputTable ] := 2;     (* bare - *)
          END; (* if PosUtils.IsNumber *)
        ELSE
          states[ InputTable ] := 1;     (* numbers only so far *)
        END; (* if IsBlank *)
      | EditInsertTable, EditOverTable:       (* same 4 states for both *)
        CASE ORD( TheStr[curPos] ) OF
          ZeroKey..NineKey   : states[ curTable ] := 0;
          | Minus            : states[ curTable ] := 1;
          | DollarSignKey    : states[ curTable ] := 2;
          | DecimalKey       : states[ curTable ] := 3;
        ELSE
          states[ curTable ] := ErrorState;
        END; (* case TheStr *)
    END; (* case curTable *)
  END ComputeNextState; (* procedure *)


  PROCEDURE FirstSpaceOrEnd;
    (* position cursor on first space or at end of field *)
  BEGIN (* procedure FirstSpaceOrEnd *)
    IF NOT( PosUtils.PresentPos( blank, TheStr, curPos )) THEN
      curPos := fieldEnd;
    END; (* if NOT *)
  END FirstSpaceOrEnd; (* procedure *)


  PROCEDURE LeftMove() : BOOLEAN;
    (* Move the cursor to the left - TRUE if can do within field *)
  BEGIN (* procedure LeftMove *)
    IF curPos = 0 THEN
      (* Change of plans - you're headed out of the field! *)
      LastKey := Key.BackTab;          (* get out of the field *)
      IF NOT CleanUpTheStr() THEN
        ComputeNextState;
      ELSE
        StrEdit.RightJustify( TheStr, FieldWidth );
      END; (* if NOT *)
      RETURN( FALSE );
    ELSE
      DEC( curPos );
      RETURN( TRUE );
    END; (* if curPos *)
  END LeftMove; (* procedure *)

  PROCEDURE RightMove;
    (* Move the cursor to the right *)
  BEGIN (* procedure RightMove *)
    IF curPos = fieldEnd THEN
      (* go to the next frame! *)
      LastKey := Key.Tab;
      StrEdit.RightJustify( TheStr, FieldWidth );
    ELSE
      INC( curPos );
    END; (* if curPos *)
  END RightMove; (* procedure *)


(*
  Well, at last we've reached the end of the edit-oriented
  procedures. What follows are the procedures to support the
  stateTable actions and transitions.  These substrings are coded
  "AAT" in the stateTable, where AA are characters indicating
  actions to take and T is an optional next state.  Next states
  have to be computed for both EditOver and EditInsert tables.
*)

  PROCEDURE KeyAction( keyClass : KeyClassType );
    (* process the key struck - keyClass indicates type of key struck *)
    (* The current table, the current state, and the key class all *)
    (* determine the actions to take and the next state, if any, to go to. *)
    (*
       Next state is only provided in input table; the edit tables
       must compute the next state based on the character that the
       cursor is on after the edit action; they are not input-driven.
    *)
    CONST
      MaxProcs = 3;          (* max number of letters for one state *)
    VAR
      whichLetter : CARDINAL;
      procLetters : ARRAY [0..MaxProcs] OF CHAR;
      passedTests : BOOLEAN;         (* used during edit modes *)
      nextState : CARDINAL;


    PROCEDURE ErrorInKeyStroke;
      (* What to do when an error occurs - also used for parsing errors *)
      (* Called by 'E' command. *)
    BEGIN (* procedure ErrorInKeyStroke *)
      Spkr.Noise( Spkr.Beep, Spkr.Normal, Spkr.Short );
      nextState := states[ curTable ];         (* stay where you are *)
    END ErrorInKeyStroke; (* procedure *)

    PROCEDURE InsertCharacter;
      (* Put the keystroke into TheStr at curPos *)
      (* If any tests done previous have failed, refuse character and beep. *)
      (* Called by 'I' command. *)
      VAR
        targetPos : CARDINAL;        (* for moving characters *)
    BEGIN (* procedure InsertCharacter *)
      (* not OK to shift out characters *)
      IF passedTests AND NOT(UserOps.InsertMode AND (TheStr[ fieldEnd ] # blank))
      THEN
        IF UserOps.InsertMode THEN              (* insert mode *)
          (* move string to the right by 1, then put in character *)
          (* NOT OK to shift right on out of the field *)
          IF (FieldWidth >= 2) AND (curPos < fieldEnd) THEN
            FOR targetPos := FieldWidth-2 TO curPos BY -1 DO
              TheStr[ targetPos+1 ] := TheStr[ targetPos ];
            END; (* for targetPos *)
          END; (* if FieldWidth *)
        END; (* if UserOps.InsertMode *)
        IF (curPos = FieldWidth - 1) AND (TheStr[ curPos ] # blank)
           AND (UserOps.InsertMode AND LeaveLast)
        THEN
          (* Don't replace character if you're on the last field position, *)
          (* a non-blank character is already there, and the constant *)
          (* LeaveLast is TRUE, and you're in insert mode. *)
          ErrorInKeyStroke;
        ELSE  (* All other combinations generate replacement *)
          IF (curPos = FieldWidth - 1) AND (TheStr[ curPos ] # blank) THEN
            (* You're on the last character in the field *)
            Spkr.Noise( Spkr.Beep, Spkr.Normal, Spkr.Short );
          END; (* if curPos *)
          (* replace character under cursor and move cursor right *)
          TheStr[ curPos ] := VAL( CHAR, LastKey );
          INC( curPos );
          IF curPos >= FieldWidth THEN
            curPos := FieldWidth - 1;
          END; (* if curPos *)
        END; (* if curpos *)
      ELSE
        ErrorInKeyStroke;
      END; (* if passedTests *)
    END InsertCharacter; (* procedure *)

    PROCEDURE PresentChar;
      (* tests to see if the key struck is already present - fails if so. *)
      (* Called by 'P', 'A', 'B', 'F', 'G', 'H', 'J', and 'K' commands. *)
      VAR
        strKey : ARRAY [0..1] OF CHAR;
    BEGIN (* procedure PresentChar *)
      strKey[0] := CHR(LastKey);
      strKey[1] := CHR(0);
      passedTests := passedTests AND
                    (NOT (PosUtils.Present( strKey, TheStr )));
    END PresentChar; (* procedure *)

    PROCEDURE DigitToLeft;
      (* Fails if there is a digit to the left of the current position *)
      (* Called by 'D', 'A', 'C', 'F', 'J', 'K' commands. *)
    BEGIN (* procedure DigitToLeft *)
      IF curPos > 0 THEN
        passedTests := passedTests AND
                    (NOT PosUtils.IsNumericChar( TheStr[curPos-1] ));
      END; (* if curPos *)
    END DigitToLeft; (* procedure *)

    PROCEDURE LeftCurrency;
      (* Fails if there is a currency symbol to the left of the cursor *)
      (* Called by 'L', 'A', and 'C' commands. *)
    BEGIN (* procedure LeftCurrency *)
      IF curPos > 0 THEN
        passedTests := passedTests AND
                    (NOT (TheStr[curPos-1] = CurrencySymbol ));
      END; (* if curPos *)
    END LeftCurrency; (* procedure *)

    PROCEDURE RightCurrency;
      (* Fails if there is a currency symbol to the right of the cursor *)
      (* Called by 'R' and 'H' commands. *)
    BEGIN (* procedure RightCurrency *)
      IF curPos < fieldEnd THEN
        passedTests := passedTests AND
                    (NOT (TheStr[curPos+1] = CurrencySymbol ));
      END; (* if curPos *)
    END RightCurrency; (* procedure *)

    PROCEDURE PeriodToTheLeft;
      (* Fails if there is a period to the left of the cursor *)
      (* Called by 'Z', 'C', and 'K' commands. *)
    BEGIN (* procedure PeriodToTheLeft *)
      IF curPos > 0 THEN
        passedTests := passedTests AND
                    (NOT (TheStr[curPos-1] = periodChar ));
      END; (* if curPos *)
    END PeriodToTheLeft; (* procedure *)

    PROCEDURE WithinDecimalPlaces;
      (* if REAL and decimal hit, have too many digits been typed? *)
      (* Called by 'W' command. *)
      VAR
        strIndex : CARDINAL;
    BEGIN (* procedure WithinDecimalPlaces *)
      IF (DecimalPlaces > 0 ) AND
          PosUtils.PresentPos( periodChar, TheStr, strIndex ) AND
          (strIndex < curPos) AND
          (VAL(INTEGER,(curPos - strIndex)) > DecimalPlaces) THEN
        passedTests := FALSE;
      END; (* if PosUtils.PresentPos *)
    END WithinDecimalPlaces; (* procedure *)

    PROCEDURE MinusOK;
      (* called only when minusChar key hit.  Fails if minusOK FALSE. *)
      (* Called by 'M', 'A', 'B', 'C', and 'F' commands. *)
    BEGIN (* procedure MinusOK *)
      passedTests := passedTests AND minusOK;
    END MinusOK; (* procedure *)

    PROCEDURE PeriodOK;
      (* called only when '.' key hit.  Fails if periodOK FALSE. *)
      (* Called by 'Y', 'G', and 'H' commands. *)
    BEGIN (* procedure PeriodOK *)
      passedTests := passedTests AND periodOK;
    END PeriodOK; (* procedure *)

    PROCEDURE GetNextState() : CARDINAL;
      (* compute the next state from the current state and state table *)
    BEGIN (* procedure GetNextState *)
      IF stateTable[ curTable ][ keyClass ][ states[curTable]*MaxProcs+2 ]
         = blank THEN
        RETURN( states[ curTable ] );  (* no change if blank *)
      ELSIF StrConv.StrToCardinal( stateTable[ curTable ][ keyClass ]
                                   [ states[curTable]*MaxProcs+2 ], 0,
                                   nextState ) THEN
        RETURN( nextState );
      ELSE
        RETURN( ErrorState );
      END; (* if stateTable *)
    END GetNextState; (* procedure *)

  BEGIN (* procedure KeyAction *)
    (* index into the state table to pick up the two action characters *)
    procLetters[0] := stateTable[ curTable ][ keyClass ]
                                [ states[curTable]*MaxProcs ];
    procLetters[1] := stateTable[ curTable ][ keyClass ]
                                [ states[curTable]*MaxProcs+1 ];
    IF states[ curTable ] = ErrorState THEN
      (* This is an internal error *)
      Spkr.Noise( Spkr.Beep, Spkr.RealHigh, Spkr.Long );
      BlankOutField( 0 );
      curPos := 0;
      ComputeNextState;
    ELSE

      (* Ever optimistic, set up the series of edit tests *)
      passedTests := TRUE;
      (* Execute all the procs called for in the state table *)
      FOR whichLetter := 0 TO MaxProcs-2 DO
        CASE procLetters[ whichLetter ] OF
          'A' : MinusOK;               (* MPLD *)
                PresentChar;
                LeftCurrency;
                DigitToLeft; |
          'B' : MinusOK;               (* MP *)
                PresentChar; |
          'C' : MinusOK;               (* MPLDZ *)
                PresentChar;
                LeftCurrency;
                DigitToLeft;
                PeriodToTheLeft; |
          'D' : DigitToLeft; |
          'E' : ErrorInKeyStroke; |
          'F' : MinusOK;               (* MPD *)
                PresentChar;
                DigitToLeft; |
          'G' : PeriodOK;              (* YP *)
                PresentChar; |
          'H' : PeriodOK;              (* YPR *)
                PresentChar;
                RightCurrency; |
          'I' : InsertCharacter; |
          'J' : PresentChar;           (* PD *)
                DigitToLeft; |
          'K' : PresentChar;           (* PDZ *)
                DigitToLeft;
                PeriodToTheLeft; |
          'L' : LeftCurrency; |
          'M' : MinusOK; |
          'P' : PresentChar; |
          'R' : RightCurrency; |
          'W' : WithinDecimalPlaces; |
          'Y' : PeriodOK; |
          'Z' : PeriodToTheLeft; |
          ' ' : ;                             (* do nothing on blank *)
        ELSE
          ErrorInKeyStroke;
        END; (* case ord *)
      END; (* for whichLetter *)
      escapeHit := FALSE;                     (* after a real character *)
      states[ curTable ] := GetNextState();   (* one change per keystroke *)
    END; (* if states *)
  END KeyAction; (* procedure *)


(*
  Here is the start of ReadNumericField, proper.
*)
BEGIN
  (* First we make sure the FieldWidth is okay. *)
  IF FieldWidth = 0 THEN
    FieldWidth := HIGH( TheStr ) + 1;
  ELSE
    FieldWidth := Numbers.Min( HIGH(TheStr) + 1, FieldWidth );
  END;
  FieldWidth := Numbers.Min( VWindows.EndCol(WindowHandle) - col1,
      FieldWidth );
  SavedHeight := VWindows.GetCursorHeight(WindowHandle);
  IF UserOps.InsertMode THEN
    VWindows.SetCursorHeight( WindowHandle, 6 )
  ELSE
    VWindows.SetCursorHeight( WindowHandle, 2);
  END;

  fieldEnd := FieldWidth - 1;
  (* save the original string.  ESC key will restore *)
  StrEdit.AssignStr( TheStr, originalStr );
  (* set the original states *)
  states[ InputTable ] := 0;
  states[ EditOverTable ] := 0;
  states[ EditInsertTable ] := 0;
  editInProgress := FALSE;     (* must first hit editing key to start *)
  escapeHit := TRUE;           (* allow esc exit until another key *)
  IF DecimalPlaces = 0 THEN    (* Note: Real numbers with 0 decimal places *)
    periodOK := FALSE;         (*   cannot have a decimal point in them. *)
  ELSE
    periodOK := TRUE;
  END; (* if DecimalPlaces *)
  (* initially in input mode unless there is something already there. *)
  curPos := 0;                     (* appropriate for new entry *)
  curTable := InputTable;          (* will be adjusted if required *)

  REPEAT
    VWindows.DrawStr( WindowHandle, col1, row1, SYSTEM.ADR(TheStr), 0 );
    VWindows.GotoXY( WindowHandle, col1 + curPos, row1 );
    LastKey := KbdInput.KeyHit( KbdInput.AnyKeyNum );

    IF NOT editInProgress THEN
      (* completely different actions until "editing" key hit. *)
      CASE LastKey OF
          Key.Home, Key.End, Key.Right, Key.Del, Key.Ins:
          StrEdit.LeftJustify( TheStr, FieldWidth );
          editInProgress := TRUE;
        | Key.AltD, Key.AltE, Key.Space:
          (* perform action in the next section *)
          editInProgress := TRUE;
        | ZeroKey..NineKey, Minus, DecimalKey, DollarSignKey :
          BlankOutField( 0 );
          editInProgress := TRUE;
          ComputeNextState;
      ELSE
        IF NOT BigSets.InSet( ExitKeys, LastKey ) THEN
          Spkr.Noise( Spkr.Beep, Spkr.Normal, Spkr.Short );
        END; (* if NOT *)
      END; (* case Lastkey *)
    END; (* if NOT *)

    IF editInProgress THEN
      CASE LastKey OF
        ZeroKey..NineKey: (* ASCII values of zeroChar to '9' *)
          KeyAction( DigitsClass );
          IF curTable # InputTable THEN
            ComputeNextState;
          END;  (* if curtable *)
        | Minus: (* minusChar *)
          KeyAction( MinusClass );
          IF curTable # InputTable THEN
            ComputeNextState;
          END;  (* if curtable *)
        | DecimalKey:
          KeyAction( DecimalPointClass );
          IF curTable # InputTable THEN
            ComputeNextState;
          END;  (* if curtable *)
        | DollarSignKey:
          KeyAction( DollarClass );
          IF curTable # InputTable THEN
            ComputeNextState;
          END;  (* if curtable *)

        | Key.Ins:
          UserOps.InsertMode := NOT UserOps.InsertMode;
          IF UserOps.InsertMode THEN
            VWindows.SetCursorHeight( WindowHandle, 6 )
          ELSE
            VWindows.SetCursorHeight( WindowHandle, 2);
          END;
        | Key.Del:
          DeleteCharacter;
          ComputeNextState;
          LastKey := 0;              (* Don't want it seen as exit key *)
        | Key.BackSpace:
          IF LeftMove() THEN
            DeleteCharacter;
            ComputeNextState;
          END; (* if LeftMove *)
        | Key.Left:            (* left arrow *)
          LastKey := 0;        (* prevent leaving field *)
          IF LeftMove() THEN
            ComputeNextState;
          END; (* if LeftMove *)
        | Key.Right:           (* right arrow *)
          LastKey := 0;        (* prevent leaving field *)
          RightMove;
          ComputeNextState;
        | Key.Escape:
          IF NOT escapeHit THEN          (* second escape gets out of frame *)
            PreviousContents;           (* restore original value *)
            ComputeNextState;
            escapeHit := TRUE;
            LastKey := 0;               (* prevent frame exit *)
            editInProgress := FALSE;    (* and take out of edit mode *)
          ELSE
            StrEdit.RightJustify( TheStr, FieldWidth );      (* allow exit *)
          END; (* if not escapeHit *)
        | Key.Home:
          curPos := 0;                   (* move to leftmost char in field *)
          ComputeNextState;
        | Key.End:
          FirstSpaceOrEnd;               (* put cursor after/on last char *)
          ComputeNextState;
        | Key.AltD, Key.Space:           (* delete entire entry *)
          BlankOutField( 0 );
          curPos := 0;
          ComputeNextState;
        | Key.AltE:                      (* erase from cursor to field end *)
          BlankOutField( curPos );
          ComputeNextState;

      ELSE
        IF NOT BigSets.InSet( ExitKeys, LastKey ) THEN
          Spkr.Noise( Spkr.Beep, Spkr.Normal, Spkr.Short );
        ELSE  (* always clean up before you can leave - might fail! *)
          (* CleanUpTheStr will change LastKey if it fails - prevent exit. *)
          IF NOT CleanUpTheStr() THEN
            ComputeNextState;
          ELSE
            StrEdit.RightJustify( TheStr, FieldWidth );
          END; (* if NOT *)
        END; (* if NOT *)
      END;
    END; (* if editInProgress *)
  UNTIL BigSets.InSet( ExitKeys, LastKey );
  VWindows.SetCursorHeight( WindowHandle, SavedHeight );
END ReadNumericField;

PROCEDURE LoadTableRow
          (    inputStr    : ARRAY OF CHAR;    (* action string for input *)
               overStr     : ARRAY OF CHAR;    (* string for overstrike  *)
               insertStr   : ARRAY OF CHAR;    (* string for insert mode *)
               keyClass    : KeyClassType      (* second dimension of table *)
          );
  (* Loads the three action strings into the state table array *)
  (* Used to initialize the array *)
BEGIN (* procedure LoadTableRow *)
  StrEdit.AssignStr( inputStr,  stateTable[ InputTable ]      [ keyClass ] );
  StrEdit.AssignStr( overStr,   stateTable[ EditOverTable ]   [ keyClass ] );
  StrEdit.AssignStr( insertStr, stateTable[ EditInsertTable ] [ keyClass ] );
END LoadTableRow; (* procedure *)

PROCEDURE InitStateTable;
  (* Initialize the state table; called once when field entered *)
  (* Invoke from the initialization section of the module *)
BEGIN (* procedure InitStateTable *)
  LoadTableRow( " I1 I1 I5 I3WI4 I5", " I RI  I  I ", " I  E  E  I ",
                                                 DigitsClass );
  LoadTableRow( "MI2 E  E  E  E  E ", "AI MI BI AI ", "CI  E FI AI ",
                                                 MinusClass );
  LoadTableRow( "YI4YI4YI4YI4 E YI4", "GI HI GI YI ", "GI  E  E  E ",
                                                 DecimalPointClass );
  LoadTableRow( " I3 E  I3 E  E  E ", "JI PI  I JI ", "KI  E  E JI ",
                                                 DollarClass );
END InitStateTable; (* procedure *)


  PROCEDURE Init();
    BEGIN
      IF Initialized THEN
        RETURN;
      ELSE
        Initialized := TRUE;
      END;
      BigSets.Init();
      ErrorManager.Init();
      KbdInput.Init();
      Key.Init();
      LowLevel.Init();
      M2Strings.Init();
      Numbers.Init();
      PosUtils.Init();
      ScrnTypes.Init();
      Spkr.Init();
      StrConv.Init();
      StrEdit.Init();
      UserOps.Init();
      VWindows.Init();

      InitStateTable();            (* load the table with action strings *)
    END Init;

BEGIN
  Initialized := FALSE;
  Init();
END NumInput.