[Cyan]<CedarChest6.0>Tajo>TajoMenusImpl.mesa!1

TajoMenusImpl.mesa

Last edited by Eric Nickell, March 29, 1985 2:33:50 pm PST

DIRECTORY

PopUpMenu USING [RequestSelection],

Rope USING [Cat, Equal, Substr],

SymTab USING [Create, Fetch, Insert, Ref],

TajoMenus

;

TajoMenusImpl: CEDAR PROGRAM

IMPORTS PopUpMenu, Rope, SymTab

EXPORTS TajoMenus

= BEGIN

OPEN TajoMenus;

TajoSystem: TYPE ~ REF TajoSystemRec;

TajoSystemRec: PUBLIC TYPE ~ RECORD [

x: SymTab.Ref ← SymTab.Create[]

];

PopUp: TYPE ~ REF PopUpRec;

PopUpRec: TYPE ~ RECORD [

list: LIST OF ROPE ← NIL,

action: SEQUENCE len:NAT OF REF

];

DuplicateName: PUBLIC ERROR ~ CODE;

filler: ROPE ~ " "; --Lots of spaces

CreateTajoSystem: PUBLIC PROC [menus: LIST OF TajoMenu] RETURNS [ts: TajoSystem] ~ {

ring: LIST OF ROPE ← LIST[menus.first.title];

ringTail: LIST OF ROPE ← ring;

nMenus: CARDINAL ← 0; --Number of menus

ts ← NEW[TajoSystemRec];

Choose first default menu as the first one listed

defaultTitle ← menus.first.title;

Count number of main menus

FOR each: LIST OF TajoMenu ← menus, each.rest UNTIL each=NIL DO

nMenus ← nMenus + 1;

ENDLOOP;

Create a ring of ROPEs from the original list

FOR each: LIST OF TajoMenu ← menus.rest, each.rest UNTIL each=NIL DO

ringTail ← ringTail.rest ← LIST[each.first.title];

ENDLOOP;

ringTail.rest ← ring; --Close the ring

Set up the PopUp menu for each of the main entries

FOR eachMenu: LIST OF TajoMenu ← menus, eachMenu.rest UNTIL eachMenu=NIL DO

AppendToPopUp: PROC [r: ROPE] ~ {

tail ← tail.rest ← LIST[r];

};

optionList: LIST OF ROPE ← LIST["Dummy"]; --The actual list of rope for this menu

tail: LIST OF ROPE ← optionList; --Always points to tail of optionList

popUp: PopUp;

nEntries: CARDINAL ← 0; --Will contain the number of entries exclusive to this menu

tempEntry: LIST OF TajoEntry ← eachMenu.first.options;

Count the number of entries

FOR eachEntry: LIST OF TajoEntry ← eachMenu.first.options, eachEntry.rest UNTIL eachEntry=NIL DO

nEntries ← nEntries+1;

ENDLOOP;

Create the PopUp record

popUp ← NEW[PopUpRec[nMenus+nEntries+1]];

popUp.action[0] ← NIL;

Add the other menu titles to the PopUp menu to be presented for this TajoMenu

UNTIL Rope.Equal[ringTail.first, eachMenu.first.title] DO --Point ringTail at our title

ringTail ← ringTail.rest;

ENDLOOP;

FOR index: CARDINAL IN [1..nMenus] DO

rope: ROPE;

ringTail ← ringTail.rest; --Set up title name

rope ← Rope.Cat[Rope.Substr[base: filler, len: (nMenus-index)*2], ringTail.first];

IF index=nMenus THEN rope ← Rope.Cat[rope, "-----------"];

popUp.action[index] ← ringTail.first;

AppendToPopUp[rope];

ENDLOOP;

Add the menu entries to the PopUp menu

FOR index: CARDINAL IN [1..nEntries] DO

ref: REF ← IF tempEntry.first.action=NIL THEN tempEntry.first.rope ELSE tempEntry.first.action;

AppendToPopUp[tempEntry.first.rope];

popUp.action[nMenus+index] ← ref;

tempEntry ← tempEntry.rest;

ENDLOOP;

Install the popUp menu into the TajoSystem

popUp.list ← optionList.rest;

IF ~SymTab.Insert[ts.x, eachMenu.first.title, popUp] THEN ERROR DuplicateName[];

ENDLOOP;

};

defaultTitle: ROPE ← NIL; --Remembers last title brought up

Select: PUBLIC PROC [ts: TajoSystem, title: ROPE ← NIL] RETURNS [action: REF] ~ {

IF title=NIL THEN title ← defaultTitle;

DO --This is an iterative process

popUp: PopUp;

found: BOOLEAN;

ref: REF;

choice: CARDINAL;

[found, ref] ← SymTab.Fetch[ts.x, title];

IF ~found THEN RETURN [title]; --This is where ROPEs are returned from

Here, we have found a menu to bring up.

defaultTitle ← title; --Remember this menu as the new default

popUp ← NARROW[ref];

choice ← PopUpMenu.RequestSelection[choice: popUp.list];

action ← popUp.action[choice];

WITH action SELECT FROM

r: ROPE => title ← r;

ENDCASE => RETURN [action];

ENDLOOP;

};

END.