<<>>
<<JaMImagerContextsImpl.mesa>>
    <<Copyright Ó 1985, 1992 by Xerox Corporation.  All rights reserved.>>
<<Last change by Bill Paxton,  2-Feb-82 12:50:27>>
<<Last changed by Rick Beach, July 1, 1982 11:29 am>>
<<Last changed by Ken Pier, March 22, 1983 4:36 pm>>
<<Last Edited by: Stone, January 30, 1984 1:26:03 pm PST>>
    <<Tim Diebert: July 18, 1985 3:27:27 pm PDT>>


    DIRECTORY
        Imager USING [Context],
        JaMIPrivate,
        JaMImagerContexts;

    JaMIContextsImpl: CEDAR MONITOR
        IMPORTS 
        EXPORTS JaMIPrivate, JaMImagerContexts =
        BEGIN OPEN JaMImagerContexts;

        InfoList: TYPE = REF InfoListRec;
        InfoListRec: TYPE = RECORD [info: Info, rest: InfoList];
        list: InfoList¬ NIL;
        State: TYPE = JaMIPrivate.State;
        Info: TYPE = JaMIPrivate.Info;

        NotFound: PUBLIC SIGNAL = CODE;
        CreateInfo: PUBLIC ENTRY PROC [state: State] RETURNS [info: Info] = {
            ENABLE UNWIND => NULL;
            info ¬ NEW[JaMIPrivate.InfoRec];
            info.state ¬ state;
            FOR l:InfoList ¬ list, l.rest UNTIL l=NIL DO
                IF l.info.state=state THEN ERROR;
                ENDLOOP;
            list ¬ NEW[InfoListRec ¬ [info,list]] };

        ForgetInfo: PUBLIC ENTRY PROC [state: State] = {
            ENABLE UNWIND => NULL;
            pred: InfoList;
            IF list=NIL THEN RETURN;
            IF list.info.state=state THEN { list ¬ list.rest; RETURN };
            pred ¬ list;
            FOR l:InfoList ¬ list.rest, l.rest UNTIL l=NIL DO
                IF l.info.state=state THEN { pred.rest ¬ l.rest; RETURN };
                pred ¬ l; ENDLOOP };

        GetInfo: PUBLIC ENTRY PROC [state: State] RETURNS [info: Info] = {
            ENABLE UNWIND => NULL;
            FOR l:InfoList ¬ list, l.rest UNTIL l=NIL DO
                IF l.info.state=state THEN RETURN [l.info];
                ENDLOOP;
            RETURN [NIL] };

        AddContext: PUBLIC ENTRY PROC [state: State, context: Context, callMe: CallMe, name: ATOM, enabled: BOOLEAN ¬ TRUE] = {
            ENABLE UNWIND => NULL;
            end,new: JaMImagerContexts.DCList ¬ NIL;
            found: BOOLEAN ¬ FALSE;
            FOR l:InfoList ¬ list, l.rest UNTIL l=NIL DO
                IF l.info.state=state THEN {
                    FOR dl: JaMImagerContexts.DCList ¬ l.info.dcList, dl.next UNTIL dl=NIL DO
                        IF dl.name=name THEN {
                            dl.callMe ¬callMe;  dl.dc ¬ context; 
                            dl.enabled ¬ enabled;
                            found ¬ TRUE;
                            };
                        end ¬ dl;
                        ENDLOOP;
                    IF ~found THEN new ¬ NEW[JaMImagerContexts.DCRec ¬
                        [next: NIL, callMe: callMe, dc: context,  enabled: enabled, name: name]];
                    IF end=NIL THEN l.info.dcList ¬ new ELSE end.next ¬ new;
                    RETURN};
                ENDLOOP;
            };

        RemoveContext: PUBLIC ENTRY PROC [state: State, name: ATOM] RETURNS [context: Imager.Context]= {
            ENABLE UNWIND => NULL;
            prev: JaMImagerContexts.DCList ¬ NIL;
            FOR l:InfoList ¬ list, l.rest UNTIL l=NIL DO
                IF l.info.state=state THEN 
                    FOR dl: JaMImagerContexts.DCList ¬ l.info.dcList, dl.next UNTIL dl=NIL DO
                        IF dl.name=name THEN {
                            IF prev=NIL THEN l.info.dcList ¬ dl.next
                            ELSE prev.next ¬ dl.next;
                            RETURN[dl.dc];
                            };
                        prev ¬ dl;
                        ENDLOOP;
                ENDLOOP;
            SIGNAL NotFound;
            RETURN[NIL];
            };

        EnableContext: PUBLIC PROC [state: State, name: ATOM] = {
            ENABLE UNWIND => NULL;
            FOR l:InfoList ¬ list, l.rest UNTIL l=NIL DO
                IF l.info.state=state THEN 
                    FOR dl: JaMImagerContexts.DCList ¬ l.info.dcList, dl.next UNTIL dl=NIL DO
                        IF dl.name=name THEN {dl.enabled ¬ TRUE; RETURN};
                        ENDLOOP;
                ENDLOOP;
            SIGNAL NotFound;
            };

        DisableContext: PUBLIC PROC [state: State, name: ATOM] = {
            ENABLE UNWIND => NULL;
            FOR l:InfoList ¬ list, l.rest UNTIL l=NIL DO
                IF l.info.state=state THEN 
                    FOR dl: JaMImagerContexts.DCList ¬ l.info.dcList, dl.next UNTIL dl=NIL DO
                        IF dl.name=name THEN {dl.enabled ¬ FALSE; RETURN};
                        ENDLOOP;
                ENDLOOP;
            SIGNAL NotFound;
            };

        ForAllDCs: PUBLIC PROC [list: JaMImagerContexts.DCList, proc: JaMImagerContexts.GProc] = {
            FOR l: JaMImagerContexts.DCList ¬ list, l.next UNTIL l=NIL DO
                IF l.enabled THEN proc[l.dc]; 
                ENDLOOP;
                };


        END...