
    <<NodePropsImpl.mesa>>
        <<Copyright © 1985, 1986 by Xerox Corporation.  All rights reserved.>>
        <<written by Paxton.  January 1981>>
        <<Michael Plass, May 28, 1986 3:38:28 pm PDT>>
        <<Rick Beach, March 28, 1985 9:57:47 am PST>>
        <<Russ Atkinson (RRA) August 19, 1985 4:17:41 pm PDT>>
        <<Doug Wyatt, September 12, 1986 7:08:21 pm PDT>>
        <<>>
    DIRECTORY
        Atom USING [DottedPairNode, GetPName, MakeAtom, PropList],
        Basics USING [BoundsCheckHighHalf, DoubleShiftLeft, NonNegative],
        IO USING [atom, int, PutFR],
        List USING [Length, Sort],
        MessageWindow USING [Append, Blink],
        RefTab USING [Create, Fetch, Ref, Store],
        Rope USING [Concat, Equal, Fetch, FromChar, FromRefText, IsEmpty, ROPE, Size, Substr],
        Rosary USING [FromProcProc, MapRuns, ROSARY, Size],
    Tioga USING [MapPropsAction, Node, PropCopier, PropReader, Props, PropsBody, PropWriter];

    NodePropsImpl: CEDAR MONITOR
    IMPORTS Atom, Basics, IO, List, MessageWindow, RefTab, Rope, Rosary
    EXPORTS Tioga
    ~ BEGIN

        ROSARY: TYPE = Rosary.ROSARY;
        ROPE: TYPE = Rope.ROPE;
        Node: TYPE = Tioga.Node;
        Prop, Props: TYPE = Tioga.Props;
        PropsBody: TYPE = Tioga.PropsBody;

        MapPropsAction: TYPE = Tioga.MapPropsAction;
        PropReader: TYPE = Tioga.PropReader;
        PropWriter: TYPE = Tioga.PropWriter;
        PropCopier: TYPE = Tioga.PropCopier;

        commentAtom: ATOM = $Comment;
        formatAtom: ATOM = $Format;
        styleDefAtom: ATOM = $StyleDef;
        prefixAtom: ATOM = $Prefix;
        postfixAtom: ATOM = $Postfix;
        charpropsAtom: ATOM = $CharProps;
        charsetsAtom: ATOM = $CharSets;
        artworkAtom: ATOM = $Artwork;

        refBool: ARRAY BOOL OF REF BOOL _ [FALSE: NEW[BOOL _ FALSE], TRUE: NEW[BOOL _ TRUE]];
        RefBool: PUBLIC PROC [b: BOOL] RETURNS [REF BOOL] ~ { RETURN[refBool[b]] };

        ReadComment: PropReader ~ {
            comment: BOOL ~ Rope.Equal[specs, "TRUE", FALSE];
            RETURN [refBool[comment]];
            };

        WriteComment: PropWriter ~ {
            comment: BOOL _ FALSE;
            WITH value SELECT FROM
                x: REF BOOL => comment _ x^;
                ENDCASE => NULL; 
            RETURN [IF comment THEN "TRUE" ELSE "FALSE"];
            };


        ReadFormat: PropReader ~ {
            RETURN[IF Rope.IsEmpty[specs] THEN NIL ELSE Atom.MakeAtom[specs]];
            };

        WriteFormat: PropWriter ~ {
            IF value=NIL THEN RETURN[""];
            WITH value SELECT FROM
                atom: ATOM => RETURN[Atom.GetPName[atom]];
                ENDCASE => RETURN[NIL];
            };


        ReadCharSets: PropReader ~ {
            <<Raises a bounds fault if invalid specs are provided.>>
            <<Encoding is (<repeatCount><charSet>)*, where <repeatCount> is encoded with the variable-length integer encoding scheme described 
            in FileOps, and <charSet> is just encoded as a byte.>>
            p: PROC [q: PROC [REF, INT]] ~ {
                i: INT _ 0;
                size: INT _ Rope.Size[specs];
                GetByte: PROC RETURNS [b: [0..256)] ~ {b _ Rope.Fetch[specs, i]-'\000; i _ i + 1};
                Combine: PROC [a: INT, b: [0..128)] RETURNS [INT] ~ {
                    bnd: NAT ~ LAST[NAT]/128+1;
                    RETURN [Basics.DoubleShiftLeft[[li[Basics.BoundsCheckHighHalf[a, bnd]]], 7].li + b];
                    };
                GetInt: PROC RETURNS [int: INT _ 0] ~ {
                    b: [0..256) _ GetByte[];
                    WHILE b > 127 DO
                        int _ Combine[int, b-128];
                        b _ GetByte[];
                        ENDLOOP;
                    int _ Combine[int, b];
                    };
                UNTIL i = size DO
                    repeat: INT ~ GetInt[];
                    charSet: [0..256) ~ GetByte[];
                    IF charSet=0 THEN q[NIL, repeat] ELSE q[NEW[[0..256) _ charSet], repeat];
                    ENDLOOP;
                };
            RETURN [Rosary.FromProcProc[p]];
            };

        WriteCharSets: PropWriter ~ {
            text: REF TEXT ~ NEW[TEXT[48]];
            Fold: PROC ~ {specs _ Rope.Concat[specs, Rope.FromRefText[text]]; text.length _ 0};
            PutByte: PROC [b: [0..256)] ~ {
                IF text.length = text.maxLength THEN Fold[];
                text[text.length] _ VAL[b];
                text.length _ text.length + 1;
                };
            PutInt: PROC [int: INT, more: BOOLEAN _ FALSE] ~ {
                IF int > 127 THEN {PutInt[int/128, TRUE]; int _ int MOD 128};
                IF more THEN int _ int + 128;
                PutByte[int];
                };
            charSet: [0..256) _ 0;
            charSetRepeat: INT _ 0;
            FlushRun: PROC ~ {
                IF charSetRepeat > 0 THEN {PutInt[charSetRepeat]; PutByte[charSet]; charSetRepeat _ 0};
                };
            Action: PROC [item: REF, repeat: INT] RETURNS [quit: BOOL _ FALSE] ~ {
                new: [0..256) _ WITH item SELECT FROM
                    r: REF [0..256) => r^,
                    ENDCASE => 0;
                IF charSetRepeat > 0 AND new#charSet THEN FlushRun[];
                charSet _ new;
                charSetRepeat _ charSetRepeat + repeat;
                };
            specs _ NIL;
            [] _ Rosary.MapRuns[[NARROW[value]], Action];
            FlushRun[];
            Fold[];
            IF specs#NIL AND Rope.Size[specs]=0 THEN specs _ NIL;
            };


        ReadCharProps: PropReader ~ {
            <<Raises a bounds fault if invalid specs are provided.>>
            <<Encoding is>>
                <<(<repeatCount><propsCount>(<atomLen><atomBytes><valueLen><valueBytes>)*)*,>>
            <<where the counts and lengths are encoded with the variable-length integer encoding scheme described in FileOps.>>
            p: PROC [q: PROC [REF, INT]] ~ {
                i: INT _ 0;
                size: INT _ Rope.Size[specs];
                GetByte: PROC RETURNS [b: [0..256)] ~ {b _ Rope.Fetch[specs, i]-'\000; i _ i + 1};
                Combine: PROC [a: INT, b: [0..128)] RETURNS [INT] ~ {
                    bnd: NAT ~ LAST[NAT]/128+1;
                    RETURN [Basics.DoubleShiftLeft[[li[Basics.BoundsCheckHighHalf[a, bnd]]], 7].li + b];
                    };
                GetInt: PROC RETURNS [int: INT _ 0] ~ {
                    b: [0..256) _ GetByte[];
                    WHILE b > 127 DO
                        int _ Combine[int, b-128];
                        b _ GetByte[];
                        ENDLOOP;
                    int _ Combine[int, b];
                    };
                GetRope: PROC RETURNS [rope: ROPE _ NIL] ~ {
                    len: INT ~ GetInt[];
                    rope _ Rope.Substr[specs, i, len];
                    i _ i + len;
                    [] _ Basics.NonNegative[size-i];
                    };
                UNTIL i = size DO
                    repeatCount: INT ~ GetInt[];
                    propsCount: INT ~ GetInt[];
                    propList: Atom.PropList _ NIL;
                    THROUGH [0..propsCount) DO
                        atom: ATOM ~ Atom.MakeAtom[GetRope[]];
                        valueSpecs: ROPE ~ GetRope[];
                        value: REF ~ ReadProp[atom, valueSpecs];
                        propList _ CONS[NEW[Atom.DottedPairNode _ [key: atom, val: value]], propList];
                        ENDLOOP;
                    q[propList, repeatCount];
                    ENDLOOP;
                };
            RETURN [Rosary.FromProcProc[p]];
            };

        WriteCharProps: PropWriter ~ {
            curRope: ROPE _ NIL;
            Grab: PROC RETURNS [rope: ROPE] ~ {rope _ curRope; curRope _ NIL};
            PutByte: PROC [b: [0..256)] ~ {curRope _ Rope.Concat[curRope, Rope.FromChar[VAL[b]]]};
            PutRope: PROC [rope: ROPE] ~ {curRope _ Rope.Concat[curRope, rope]};
            PutInt: PROC [int: INT, more: BOOLEAN _ FALSE] ~ {
                IF int > 127 THEN {PutInt[int/128, TRUE]; int _ int MOD 128};
                IF more THEN int _ int + 128;
                PutByte[int];
                };
            rept: INT _ 0;
            itemSpecs: ROPE _ NIL;
            FlushRun: PROC ~ { IF rept > 0 THEN {PutInt[rept]; PutRope[itemSpecs]; rept _ 0} };
            PutItem: PROC [newItemSpecs: ROPE, repeat: INT] ~ {
                IF NOT Rope.Equal[newItemSpecs, itemSpecs] THEN FlushRun[];
                itemSpecs _ newItemSpecs;
                rept _ rept + repeat;
                };
            Action: PROC [item: REF, repeat: INT] RETURNS [quit: BOOL _ FALSE] ~ {
                save: ROPE ~ Grab[];
                SpecsList: PROC [propList: Atom.PropList] RETURNS [s: LIST OF REF _ NIL] ~ {
                    FOR p: Atom.PropList _ propList, p.rest UNTIL p = NIL DO
                        atom: ATOM ~ NARROW[p.first.key];
                        v: ROPE ~ WriteProp[atom, p.first.val];
                        IF v # NIL THEN {
                            a: ROPE ~ Atom.GetPName[atom];
                            PutInt[Rope.Size[a]]; PutRope[a]; PutInt[Rope.Size[v]]; PutRope[v];
                            s _ CONS[Grab[], s];
                            };
                        ENDLOOP;
                    };
                specList: LIST OF REF _ List.Sort[SpecsList[NARROW[item]]];
                newItemSpecs: ROPE;
                PutInt[List.Length[specList]];
                UNTIL specList = NIL DO
                    t: LIST OF REF _ specList;
                    PutRope[NARROW[t.first]];
                    specList _ t.rest;
                    t.rest _ NIL;
                    ENDLOOP;
                newItemSpecs _ Grab[];
                curRope _ save;
                PutItem[newItemSpecs, repeat];
                };
            [] _ Rosary.MapRuns[[NARROW[value]], Action];
            FlushRun[];
            specs _ Grab[];
            IF specs#NIL AND Rope.Size[specs]=0 THEN specs _ NIL;
            };


        FindName: PROC [n: Node, name: ATOM, remove: BOOL] RETURNS [prop: Prop] ~ {
            lst, prev: Props;
            IF n=NIL THEN RETURN [NIL];
            lst _ n.props;
            prop _ NIL; prev _ NIL;
            WHILE lst#NIL DO
                IF lst.name = name THEN { prop _ lst; EXIT };
                prev _ lst;  lst _ lst.next;
                ENDLOOP;
            IF prop#NIL AND remove THEN {
                IF prev#NIL THEN prev.next _ prop.next
                ELSE n.props _ prop.next;
                };
            };

        PutProp: PUBLIC PROC [n: Node, name: ATOM, value: REF] ~ {
            prop: Prop _ FindName[n, name, FALSE];
            IF name = charpropsAtom OR name = charsetsAtom THEN {
                value _ CheckRosarySize[NARROW[value], n, name];
                };
            IF value = NIL THEN {
                IF prop#NIL THEN prop.value _ NIL;
                SELECT name FROM
                    styleDefAtom => n.hasstyledef _ FALSE;
                    prefixAtom => n.hasprefix _ FALSE;
                    postfixAtom => n.haspostfix _ FALSE;
                    formatAtom => n.formatName _ NIL;
                    commentAtom => n.comment _ FALSE;
                    charpropsAtom => n.hascharprops _ FALSE;
                    charsetsAtom => n.hascharsets _ FALSE;
                    artworkAtom => n.hasartwork _ FALSE;
                    ENDCASE;
                RETURN 
                };
            SELECT name FROM
                styleDefAtom => n.hasstyledef _ TRUE;
                prefixAtom => n.hasprefix _ TRUE;
                postfixAtom => n.haspostfix _ TRUE;
                formatAtom => {
                    n.formatName _ NARROW[value];
                    RETURN;
                    };
                commentAtom => { -- simply set the bit in the node
                    n.comment _ NARROW[value, REF BOOL]^;
                    RETURN;
                    };
                charpropsAtom => n.hascharprops _ TRUE;
                charsetsAtom => n.hascharsets _ TRUE;
                artworkAtom => n.hasartwork _ TRUE;
                ENDCASE;
            IF prop#NIL THEN prop.value _ value
            ELSE n.props _ NEW[PropsBody _ [name: name, value: value, next: n.props]];
            };

        CheckRosarySize: PROC [rosary: ROSARY, n: Node, what: ATOM]
        RETURNS [ROSARY] ~ {
            IF rosary # NIL THEN {
                rosarySize: INT ~ Rosary.Size[rosary];
                ropeSize: INT ~ Rope.Size[n.rope];
                IF rosarySize # ropeSize THEN {
                    msg: ROPE ~ IO.PutFR["NodePropsImpl: %g property discarded because its size (%g) differed from rope size (%g).", IO.atom[what], 
                    IO.int[rosarySize], IO.int[ropeSize]];
                    MessageWindow.Append[msg, TRUE];
                    MessageWindow.Blink[];
                    RETURN [NIL];
                    };
                };
            RETURN [rosary];
            };

        GetProp: PUBLIC PROC [node: Node, name: ATOM] RETURNS [value: REF _ NIL] ~ {
            IF node#NIL THEN {
                prop: Prop ~ FindName[node, name, FALSE];
                IF prop#NIL THEN value _ prop.value
                ELSE SELECT name FROM
                    commentAtom => value _ refBool[node.comment];
                    formatAtom => IF node.formatName#NIL THEN value _ node.formatName;
                    ENDCASE;
                };
            };

        RemProp: PUBLIC PROC [n: Node, name: ATOM] ~ {
            [] _ FindName[n, name, TRUE]; -- removes the value
            SELECT name FROM
                styleDefAtom => n.hasstyledef _ FALSE;
                prefixAtom => n.hasprefix _ FALSE;
                postfixAtom => n.haspostfix _ FALSE;
                formatAtom => n.formatName _ NIL;
                commentAtom => n.comment _ FALSE;
                charpropsAtom => n.hascharprops _ FALSE;
                charsetsAtom => n.hascharsets _ FALSE;
                artworkAtom => n.hasartwork _ FALSE;
                ENDCASE;
            };

        MapProps: PUBLIC PROC [node: Node, action: MapPropsAction,
        formatFlag, commentFlag: BOOL _ TRUE] RETURNS [quit: BOOL] ~ {
            <<apply the action to each name & value pair for the node>>
            <<returns true if&when an action returns true>>
            IF node#NIL THEN {
                props: Props _ node.props;
                IF formatFlag AND node.formatName#NIL AND action[formatAtom, node.formatName] THEN RETURN [TRUE];
                IF commentFlag AND action[commentAtom, refBool[node.comment]] THEN RETURN [TRUE];
                UNTIL props=NIL DO
                    next: Props ~ props.next; -- get it now in case action deletes current prop
                    IF props.value#NIL AND action[props.name, props.value] THEN RETURN [TRUE];
                    props _ next;
                    ENDLOOP;
            };
            RETURN [FALSE]
            };

<<Read, Write, Copy Props>>
    PropProcs: TYPE ~ REF PropProcsRep;
    PropProcsRep: TYPE ~ RECORD [reader: PropReader, writer: PropWriter, copier: PropCopier];

    propProcsTable: RefTab.Ref _ RefTab.Create[];

    RegisterProp: PUBLIC PROC [name: ATOM,
    reader: PropReader, writer: PropWriter, copier: PropCopier] ~ {
        <<registers these procs for this variety of node>>
        <<they will be called by DoSpecs, GetSpecs, and CopyInfo >>
        IF name#NIL THEN {
            procs: PropProcs ~ NEW[PropProcsRep _ [reader: reader, writer: writer, copier: copier]];
            [] _ RefTab.Store[propProcsTable, name, procs];
            };
        };

    NullRead: PUBLIC PropReader ~ { RETURN [NIL] };
    NullWrite: PUBLIC PropWriter ~ { RETURN [NIL] };
    NullCopy: PUBLIC PropCopier ~ { RETURN [NIL] };

    ReadProp: PUBLIC PropReader ~ {
        <<used when reading files>>
        <<calls the registered reader for this property name>>
        <<returns specs if no reader is registered>>
        reader: PropReader _ NIL;
        WITH RefTab.Fetch[propProcsTable, name].val SELECT FROM
            procs: PropProcs => reader _ procs.reader;
            ENDCASE;
        IF reader#NIL THEN RETURN[reader[name, specs]]
        ELSE RETURN[specs];
        };

    WriteProp: PUBLIC PropWriter ~ {
        <<used when writing files>>
        <<calls the registered writer for this property name>>
        <<if no writer is registered, returns value if it is a rope, NIL otherwise>>
        writer: PropWriter _ NIL;
        WITH RefTab.Fetch[propProcsTable, name].val SELECT FROM
            procs: PropProcs => writer _ procs.writer;
            ENDCASE;
        IF writer#NIL THEN RETURN[writer[name, value]]
        ELSE WITH value SELECT FROM rope: ROPE => RETURN[rope]; ENDCASE => RETURN[NIL];
        };

    CopyProp: PUBLIC PropCopier ~ {
        <<used when copying nodes>>
        <<calls the registered copier for this property name>>
        <<if no copier is registered, returns value>>
        copier: PropCopier _ NIL;
        WITH RefTab.Fetch[propProcsTable, name].val SELECT FROM
            procs: PropProcs => copier _ procs.copier;
            ENDCASE;
        IF copier#NIL THEN RETURN[copier[name, value]]
        ELSE RETURN[value];
        };

<<Property Attributes>>

    attributeTable: LIST OF LIST OF ATOM _ NIL;
    DeclarePropertyAttribute: PUBLIC ENTRY PROC [name: ATOM, attribute: ATOM] ~ {
        FOR a: LIST OF LIST OF ATOM _ attributeTable, a.rest UNTIL a=NIL DO
            IF a.first.first = name THEN {
                FOR p: LIST OF ATOM _ a.first.rest, p.rest UNTIL p=NIL DO
                    IF p.first = attribute THEN RETURN;
                    ENDLOOP;
                a.first.rest _ CONS[attribute, a.first.rest];
                RETURN;
                };
            ENDLOOP;
        attributeTable _ CONS[LIST[name, attribute], attributeTable];
        };

    Is: PUBLIC ENTRY PROC [name: ATOM, attribute: ATOM] RETURNS [BOOL] ~ {
        FOR a: LIST OF LIST OF ATOM _ attributeTable, a.rest UNTIL a=NIL DO
            IF a.first.first = name THEN {
                FOR p: LIST OF ATOM _ a.first.rest, p.rest UNTIL p=NIL DO
                    IF p.first = attribute THEN RETURN [TRUE];
                    ENDLOOP;
                RETURN [FALSE];
                };
            ENDLOOP;
        RETURN [FALSE];
        };

    GetPropertyAttributes: PUBLIC ENTRY PROC [name: ATOM] RETURNS [LIST OF ATOM] ~ {
        FOR a: LIST OF LIST OF ATOM _ attributeTable, a.rest UNTIL a=NIL DO
            IF a.first.first = name THEN RETURN [a.first.rest];
            ENDLOOP;
        RETURN [NIL];
        };

    SetPropertyAttributes: PUBLIC ENTRY PROC [name: ATOM, attributes: LIST OF ATOM] ~ {
        FOR a: LIST OF LIST OF ATOM _ attributeTable, a.rest UNTIL a=NIL DO
            IF a.first.first = name THEN {a.first.rest _ attributes; RETURN};
            ENDLOOP;
        attributeTable _ CONS[CONS[name, attributes], attributeTable];
        };

<<Property Attribute Documentation>>
    <<$Visible       says whether property affects appearance>>
    <<$Inheritable    says whether property may be inherited when a new node is inserted>>
    <<$ClientOnly    asserts EditTool interface should not change the value>>
<<Initialization>>
    Init: PROC ~ {
        visible: LIST OF ATOM ~ LIST[$Visible];
        visAndInherit: LIST OF ATOM ~ CONS[$Inheritable, visible];
        visAndClient: LIST OF ATOM ~ CONS[$ClientOnly, visible];

        RegisterProp[formatAtom, ReadFormat, WriteFormat, NIL];
            SetPropertyAttributes[formatAtom, visAndInherit];

        RegisterProp[commentAtom, ReadComment, WriteComment, NIL];
            SetPropertyAttributes[commentAtom, visAndInherit];

        RegisterProp[$CharSets, ReadCharSets, WriteCharSets, NIL];
            SetPropertyAttributes[$CharSets, visAndClient];

        RegisterProp[$CharProps, ReadCharProps, WriteCharProps, NIL];
            SetPropertyAttributes[$CharProps, visAndClient];

        SetPropertyAttributes[prefixAtom, visAndInherit];
        SetPropertyAttributes[postfixAtom, visAndInherit];
        SetPropertyAttributes[$StyleDef, visAndInherit];
        SetPropertyAttributes[$Artwork, visible];
        SetPropertyAttributes[$Interpress, visible];
        SetPropertyAttributes[$Bounds, visible];
        };

    Init[];

    END.