
<<--File: IPMVStackOpsImpl.mesa>>
<<Last Edited by: CSChow, January 12, 1985 10:25:12 am PST>>
<<>>
DIRECTORY
TerminalIO,
    Rope,
    Convert,
Menus,
OrderedRefArray,
IPTop,
IPTopOps,
IPMVStackOps;

IPMVStackOpsImpl: CEDAR PROGRAM    
    IMPORTS TerminalIO, Rope,  Convert, OrderedRefArray, IPTopOps  
    EXPORTS IPMVStackOps =
BEGIN OPEN TIO: TerminalIO, IPMVStackOps;

    MenuHit: PUBLIC PROC [top: IPTop.Ref, oldPrevTrack, trackKept: LIST OF REF, command: ATOM, mouse: Menus.MouseButton, shift, 
    control: BOOL, trialSolns: OrderedRefArray.Ref] RETURNS [prevTrack: LIST OF REF, reGeom: BOOL _ FALSE, refreshFlag: BOOL _ 
    TRUE] ={
        prevTrack _ oldPrevTrack; --default
        SELECT command FROM
            $Undo =>{noOfSteps: NAT _ TIO.RequestInt["Number of Steps to Undo: "];
            TIO.WriteRope[Rope.Cat["Undoing ", Convert.RopeFromInt[noOfSteps], " steps..."]];
                WHILE noOfSteps # 0 DO
                    prevTrack _ CONS[IPTopOps.Undo1[top], prevTrack];
                    noOfSteps _ noOfSteps.PRED;
                    ENDLOOP;
            reGeom _ TRUE};
        $Un1 =>{
        TIO.WriteRope["Undo previous step..."];
        prevTrack _ CONS[IPTopOps.Undo1[top], prevTrack];
            reGeom _ TRUE};
        $ToSoln =>{
            IF trialSolns = NIL 
                THEN {TIO.WriteRope["No Solutions .. doing nothing"]; RETURN}
                ELSE {
                    solnNum: INT _ TIO.RequestInt[Rope.Cat[
                        "Select a solution in [1..",
                        Convert.RopeFromInt[OrderedRefArray.Size[trialSolns]],  
                        "]: "]];
                    value: INT;
                    soln: REF;
                    TIO.WriteRope["GettingSolution... this solution has value"];
                    [soln, value] _ OrderedRefArray.Fetch[trialSolns, solnNum];
                    prevTrack _ IPTopOps.Undo[top, IPTopOps.StackSize[top]];
                    IPTopOps.Redo[top, NARROW[soln]];
                    TIO.WriteInt[value];};
        reGeom _ TRUE};
        $Redo =>{which: NAT _ TIO.RequestSelection["OneOf: ", LIST["Previous Track", "Go to the track kept"]];
        TIO.WriteRope["Redoing.."];
            SELECT which FROM
            1 => {
            oldPrevTrack: LIST OF REF _ prevTrack;
                IF prevTrack = NIL 
                    THEN {TIO.WriteRope["previous track empty...Done"]; RETURN}
                    ELSE {prevTrack _ IPTopOps.Undo[top, IPTopOps.StackSize[top]];
                        IPTopOps.Redo[top, oldPrevTrack]};
                    };
            2 => {
                prevTrack _ IPTopOps.Undo[top, IPTopOps.StackSize[top]];
                IPTopOps.Redo[top, trackKept];};
                ENDCASE => TIO.WriteRope["..Nothing to do"];
            reGeom _ TRUE};
        $Re1 =>{
        TIO.WriteRope["Redoing ..."];
            IF prevTrack = NIL 
                THEN {TIO.WriteRope["nothing...Done"]; RETURN}
                ELSE {TIO.WriteRope["1 step.."]; IPTopOps.Redo1[top, prevTrack.first];};
        prevTrack _ prevTrack.rest;
        reGeom _ TRUE};
            $KepTrk =>{
            TIO.WriteRope["KeepingTrack.."];
            trackKept _ IPTopOps.GetTrack[top];
            refreshFlag _ FALSE;};
            $ClrStks => {
                TIO.WriteRope["Clear undo and redo stacks.."];
            prevTrack _ IPTopOps.GetTrack[top];
            trackKept _ NIL; --What was there is now meaningless--
            IPTopOps.ResetStacks[top];
            refreshFlag _ FALSE;
            };
            $StkSz =>{
            TIO.WriteRope[Rope.Cat["The Stacks size is: ", Convert.RopeFromInt[IPTopOps.StackSize[top]], "\n"]];
            refreshFlag _ FALSE;};
            ENDCASE => ERROR;

        }; --MenuHit

END.