<<>>
<<XTkInhibitableWidgetsImpl.mesa>>
<<Copyright Ó 1992 by Xerox Corporation.  All rights reserved.>>
<<Philip James, March 9, 1992 4:43 pm PST>>
<<Christian Jacobi, April 1, 1992 4:28 pm PST>>

    DIRECTORY 
        Ascii USING [BS, CR, DEL, LF],
        Rope USING [Concat, FromChar, Length, Substr, ROPE],
        Xl USING [ButtonReleaseEvent, CreateEventFilter, CreateTQ, currentTime, Details, DetailsRec, EventProcType, EventFilter, 
        KeyPressEvent, KeySym, LastTime, MatchRep, SetInputFocus, TimeStamp, XError],
        XlAscii USING [Convert],
        XTk,
        XTkButtons USING [CreateButton],
        XTkInhibitableWidgets,
        XTkLabels USING [StyleSpec, TextWidget],
        XTkShellWidgets USING [IsShell, SetFocus],
        XTkWidgets USING [GetText, SetText];

    XTkInhibitableWidgetsImpl: CEDAR MONITOR IMPORTS Rope, Xl, XlAscii, XTk, XTkButtons, XTkShellWidgets, XTkWidgets EXPORTS 
    XTkInhibitableWidgets ~ {

        InhibitableWidget: TYPE = XTkLabels.TextWidget;
        StyleSpec: TYPE = XTkLabels.StyleSpec;

        sampleBool: REF BOOLEAN ¬ NEW[BOOLEAN ¬ TRUE];

        events: Xl.EventFilter ~ Xl.CreateEventFilter[keyPress];

        Create: PUBLIC PROC [widgetSpec: XTk.WidgetSpec ¬ [], text: Rope.ROPE ¬ NIL] RETURNS [w: InhibitableWidget] ~ {
            w ¬ XTkButtons.CreateButton[widgetSpec: widgetSpec, text: text, hitProc: Hit, registerData: NEW[BOOLEAN ¬ TRUE]];
            XTk.AddPermanentMatch[w, [proc: EventProc, handles: events, tq: Xl.CreateTQ[], data: w], [keyPress: TRUE]];
            };

        flushButNoErrors: Xl.Details ¬ NEW[Xl.DetailsRec ¬ [flush: now, errorMatch: NEW[Xl.MatchRep ¬ [proc: IgnoreErrors, handles: NIL, 
        tq: Xl.CreateTQ[]]]]];
            IgnoreErrors: Xl.EventProcType = {};

        MySetFocus: PROC [field: XTk.Widget, time: Xl.TimeStamp ¬ Xl.currentTime] = {
            <<SHOULD DO CODE SHARING>>
            IF field#NIL AND field.fastAccessAllowed=ok THEN {
                root: XTk.Widget ~ XTk.RootWidget[field];
                IF time=Xl.currentTime THEN time ¬ Xl.LastTime[field.connection];
                IF root#NIL AND XTkShellWidgets.IsShell[root] 
                    THEN XTkShellWidgets.SetFocus[shell: root, time: time, child: field]
                    ELSE Xl.SetInputFocus[field.connection, field.window, parent, time, flushButNoErrors];
                };
            };

        Hit: XTk.WidgetNotifyProc ~ {
            WITH event SELECT FROM
                br: Xl.ButtonReleaseEvent => MySetFocus[widget, br.timeStamp];
                ENDCASE => {};
            };

        EventProc: Xl.EventProcType = {
            ENABLE {
                Xl.XError => GOTO oops;
                };
            widget: XTk.Widget ~ NARROW[clientData];
            WITH event SELECT FROM
                keyPress: Xl.KeyPressEvent => {
                    char: CHAR; keysym: Xl.KeySym; matched: Xl.KeySym; isModifier: BOOL;
                    [char: char, keysym: keysym, matched: matched, isModifier: isModifier] ¬ XlAscii.Convert[event.connection, keyPress.keyCode, 
                    keyPress.state];
                    IF isModifier THEN RETURN;
                    PushChar[widget, char];
                    };
                ENDCASE => {};
            EXITS oops => {};
            };

        SetEdittability: PROC [w: InhibitableWidget, edittable: BOOL] ~ {
            XTk.PutWidgetProp[w, sampleBool, NEW[BOOL ¬ edittable]]};

        Edittable: PUBLIC PROC [w: InhibitableWidget] RETURNS [BOOLEAN] ~ {
            WITH XTk.GetWidgetProp[w, sampleBool] SELECT FROM
                b: REF BOOLEAN => RETURN[b­];
                ENDCASE => RETURN[TRUE];
            };

        PushChar: PROC [widget: XTk.Widget, ch: CHAR] = {
            text: Rope.ROPE ¬ XTkWidgets.GetText[widget];
            edittable: BOOLEAN ¬ Edittable[widget];
            IF edittable THEN {
                SELECT ch FROM
                    4c, Ascii.LF, Ascii.CR, Ascii.DEL => {text ¬ NIL};
                    Ascii.BS => {
                        leng: INT ¬ Rope.Length[text];
                        IF leng>0 THEN text ¬ Rope.Substr[text, 0, leng-1];
                        }
                    ENDCASE => {
                        text ¬ Rope.Concat[text, Rope.FromChar[ch]];
                        };
                XTkWidgets.SetText[widget, text];
                };
            };

        Inhibit: PUBLIC PROC [widget: InhibitableWidget] ~ {
            SetEdittability[widget, FALSE]
            };

        Enable: PUBLIC PROC [widget: InhibitableWidget] ~ {
            SetEdittability[widget, TRUE]
            };

        }.