-- File: WalnutVoiceImpl.mesa
-- Contents: operations for dealing with voice in Walnut messages

-- created September 26, 1983 by Willie-Sue
-- Last edit by:
  --  Willie-Sue on: December 29, 1983 2:33 pm

DIRECTORY
  Nuthatch USING [NuthatchUserHandle, MakeInterestEntry, RemoveInterestEntry],
  PrincOpsUtils USING [IsBound],
  Rope,
  ViewerClasses USING [Viewer],
  ViewerOps USING [AddProp],
  Walnuthatch USING [MoveTo, InitializeWalnuthatch],
  WalnutSendOps USING [userRName],
  WalnutVoice;
  
WalnutVoiceImpl: CEDAR PROGRAM
  IMPORTS
    Nuthatch, PrincOpsUtils, ViewerOps, Walnuthatch, WalnutSendOps
  EXPORTS WalnutVoice =
  
BEGIN 

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

 -- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
nuthatchHandle: Nuthatch.NuthatchUserHandle_ NIL;
nuthatchTries: INTEGER_ 0;

CheckForWalnuthatch: PUBLIC PROC RETURNS[ra: REF ANY] =
--  checks if the Nuthatch stuff is loaded and started; if loaded but there is no nuthatchUserHandle, then the initialization proc 
is called
--  returns NIL if no Nuthatch or the initialization returned NIL
  BEGIN
    success: BOOL;
    IF nuthatchHandle # NIL THEN RETURN[nuthatchHandle];
    TRUSTED {IF ~PrincOpsUtils.IsBound[Walnuthatch.InitializeWalnuthatch] THEN RETURN[NIL]};
    IF nuthatchTries > 5 THEN RETURN[NIL];
    [success, nuthatchHandle]_
            Walnuthatch.InitializeWalnuthatch[WalnutSendOps.userRName !
                    ABORTED => CONTINUE];
    IF ~success THEN nuthatchTries_ nuthatchTries + 1;
    RETURN[nuthatchHandle];
  END;

InternalCheck: PROC RETURNS[Nuthatch.NuthatchUserHandle] =
--  checks if the Nuthatch stuff is loaded and started; if loaded but there is no nuthatchUserHandle, then the initialization proc 
is called
--  returns NIL if no Nuthatch or the initialization returned NIL
  BEGIN
    success: BOOL_ FALSE;
    IF nuthatchHandle # NIL THEN RETURN[nuthatchHandle];
    TRUSTED {IF ~PrincOpsUtils.IsBound[Walnuthatch.InitializeWalnuthatch] THEN RETURN[NIL]};
    DO
      IF nuthatchTries > 5 THEN RETURN[NIL];
      [success, nuthatchHandle]_
            Walnuthatch.InitializeWalnuthatch[WalnutSendOps.userRName !
                    ABORTED => CONTINUE];
      IF success THEN RETURN[nuthatchHandle];
      nuthatchTries_ nuthatchTries + 1;
     ENDLOOP;
  END;

AddNuthatchHandleToViewer: PUBLIC PROC[v: Viewer] =
  BEGIN
    nuh: Nuthatch.NuthatchUserHandle_ InternalCheck[];
    IF nuh # NIL THEN ViewerOps.AddProp[v, $NuthatchHandle, nuh];
  END;

MakeInterestEntry: PUBLIC PROC[voiceID, gvID: ROPE] =
  BEGIN
    nuh: Nuthatch.NuthatchUserHandle_ InternalCheck[];
    IF nuh # NIL THEN
        Nuthatch.MakeInterestEntry[nuh, voiceID, gvID ! ABORTED => CONTINUE]
  END;

VoiceMoveTo: PUBLIC PROC[msgSetName, msgName: ROPE] =
  BEGIN
    nuh: Nuthatch.NuthatchUserHandle_ InternalCheck[];
    IF nuh # NIL THEN
        Walnuthatch.MoveTo[msgSetName, nuh, msgName ! ABORTED => CONTINUE];
  END;

RemoveInterestEntry: PUBLIC PROC[voiceID, gvID: ROPE] =
  BEGIN
    nuh: Nuthatch.NuthatchUserHandle_ InternalCheck[];
    IF nuh # NIL THEN
        Nuthatch.RemoveInterestEntry[nuh, voiceID, gvID ! ABORTED => CONTINUE];
  END;

-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

END.