
    <<CharDisplays.Mesa>>
<<Last Edited by: Spreitzer, February 19, 1986 9:02:41 pm PST>>

    DIRECTORY IO, Rope, ViewerClasses;

    CharDisplays: CEDAR DEFINITIONS = {

        ROPE: TYPE = Rope.ROPE;
        Viewer: TYPE = ViewerClasses.Viewer;

        DisplayDestroyed: ERROR [cd: CharDisplay];

        CharDisplay: TYPE = REF CharDisplayRep;
        CharDisplayRep: TYPE = RECORD [
            class: CharDisplayClass,
            det: DisplayDetails,
            name: ROPE,
            viewer: Viewer _ NIL,
            fromDisplay: IO.STREAM _ NIL,
            line, col: INT _ 0,
            emphs: Emphs,
            otherInstanceData: REF ANY _ NIL];

        DisplayDetails: TYPE = RECORD [
            lines: NAT _ 24,
            columns: NAT _ 80,
            autoMargins, scrolls: BOOL _ TRUE,
            autoMarginsVariable, scrollsVariable: BOOL _ FALSE];

        CharDisplayClass: TYPE = REF CharDisplayClassRep;
        CharDisplayClassRep: TYPE = RECORD [
            name: ROPE,
            Init: PROC [cd: CharDisplay, initData: REF ANY],
            ChangeDetails: PROC [cd: CharDisplay, new: DisplayDetails],
            DeleteChar: PROC [cd: CharDisplay],
            TakeChar: PROC [cd: CharDisplay, char: CHAR, insert: BOOL --_ FALSE--],
            CursorMove: PROC [cd: CharDisplay, line, col: INT, relative: BOOL --_ FALSE--, doLine, doCol: BOOL --_ TRUE--],
            Line: PROC [cd: CharDisplay, insert: BOOL],
                <<Insert/Delete>>
            ClearTo: PROC [cd: CharDisplay, where: Where],
            ClearAll: PROC [cd: CharDisplay],
            SetEmph: PROC [cd: CharDisplay, emph: Emph, on: BOOL],
            Emphasize: PROC [cd: CharDisplay, emph: Emph, on: BOOL],
                <<Apply to char at cursor>>
            SetFont: PROC [cd: CharDisplay, font: ROPE],
            Beep: PROC [cd: CharDisplay],
            Flush: PROC [cd: CharDisplay] _ NIL,
                <<Notifes display that nothing more will be done to it for a while.>>
                <<Flush may be falsely called, but must be called when it becomes true.>>
            Destroyed: PROC [cd: CharDisplay] RETURNS [BOOL]
            ];

        SimplyChange: PROC [cd: CharDisplay, new: DisplayDetails];

        Where: TYPE = {EndOfLine, EndOfScreen};

        Emph: TYPE = {underline, bold, italic, inverse};
        Emphs: TYPE = ARRAY Emph OF BoolDefaultsFalse;
        BoolDefaultsFalse: TYPE = BOOL _ FALSE;
        EmphOp: TYPE = {add, subtract, set};

        GetClass: PROC [name: ROPE] RETURNS [cdc: CharDisplayClass];
        RegClass: PROC [cdc: CharDisplayClass];

        Create: PROC [class: CharDisplayClass, name: ROPE _ NIL, det: DisplayDetails _ [], initData: REF ANY _ NIL] RETURNS [cd: 
        CharDisplay];

        Split: PROC [l: CharDisplayList, name: ROPE _ NIL] RETURNS [s: CharDisplay];

        CharDisplayList: TYPE = LIST OF CharDisplay;

        }.