Oberon/A2/Oberon.Out1.Mod

(* ETH Oberon, Copyright 2001 ETH Zuerich Institut fuer Computersysteme, ETH Zentrum, CH-8092 Zuerich.
Refer to the "General ETH Oberon System Source License" contract available at: http://www.oberon.ethz.ch/ *)

MODULE Out IN Oberon; (** portable *)	(* based on module from "Programming in Oberon" *)

(** Simple output routines for writing text into the Oberon log or a separate viewer. *)

IMPORT Texts, Viewers, Oberon, MenuViewers, TextFrames;

CONST
  StandardMenu = "System.Close System.Copy System.Grow Edit.Search Edit.Store";

TYPE Appender = PROCEDURE();

VAR T: Texts.Text; W: Texts.Writer; Append: Appender;

PROCEDURE TA(); BEGIN Texts.Append(T, W.buf) END TA;

PROCEDURE AppendImmediate*(); BEGIN Append := TA END AppendImmediate;

PROCEDURE Null(); BEGIN END Null;

PROCEDURE AppendDelayed*(); BEGIN Append := Null END AppendDelayed;

(** Write character. *)
PROCEDURE Char*(ch: CHAR);
BEGIN
	Texts.Write(W, ch); Append()
END Char;

(** Write a string. *)
PROCEDURE String*(str: ARRAY OF CHAR);
BEGIN
	Texts.WriteString(W, str); Append()
END String;

(** Write the integer i in n field positions. *)
PROCEDURE Int*(i, n: LONGINT);
BEGIN
	Texts.WriteInt(W, i, n); Append()
END Int;

(** Write the integer i in hexadecimal with a leading space. *)
PROCEDURE Hex*(i: LONGINT);
BEGIN
	Texts.WriteHex(W, i); Append()
END Hex;

(** Write the real x in n field positions. *)
PROCEDURE Real*(x: REAL; n: INTEGER);
BEGIN
	Texts.WriteReal(W, x, n); Append()
END Real;

(** Write the real x in n field positions in fixed point notation with f fraction digits. *)
PROCEDURE RealFix*(x: REAL; n, f: INTEGER);
BEGIN
	Texts.WriteRealFix(W, x, n, f, 0); Append()
END RealFix;

(** Write the longreal x in n field positions. *)
PROCEDURE LongReal*(x: LONGREAL; n: INTEGER);
BEGIN
	Texts.WriteLongReal(W, x, n); Append()
END LongReal;

(** Write the longreal x in n field positions in fixed point notation with f fraction digits. *)
PROCEDURE LongRealFix*(x: LONGREAL; n, f: INTEGER);
BEGIN
	Texts.WriteLongRealFix(W, x, n, f, 0); Append()
END LongRealFix;

(** Write a carriage return (CR or end-of-line). *)
PROCEDURE Ln*;
BEGIN
	Texts.WriteLn(W); Texts.Append(T, W.buf)
END Ln;

(** Open a separate viewer for output. *)
PROCEDURE Open*;
  VAR V: Viewers.Viewer;
    X, Y: INTEGER;
BEGIN
	IF T = Oberon.Log THEN NEW(T); Texts.Open(T, "") END;
	Oberon.AllocateUserViewer(400, X, Y);
	V := MenuViewers.New(
		TextFrames.NewMenu("Out.Text", StandardMenu),
		TextFrames.NewText(T, 0),
		TextFrames.menuH, X, Y) 
	(*
	Oberon.OpenText("Out.Text", T, 400, 200)
	*)
END Open;

(** Revert output to the system log. *)
PROCEDURE Close*;
BEGIN
	T := Oberon.Log
END Close;

BEGIN
	Texts.OpenWriter(W);  T := Oberon.Log; AppendDelayed()
END Out.

(** Remarks:

1. Out uses a Writer from module Texts to write output to the log. 
After AppendImmediate(), Out is slow because the log is updated after 
every procedure call.  After AppendDelayed, updating is delayed to the 
end of the line and performance is better.  Best performance is when 
Texts is used directly.

2. Out.Open creates a new text and viewer for output.  Once this is 
done, output can be sent to the system log again by executing Close.
*)