Syntax10.Scn.Fnt
Syntax10i.Scn.Fnt
StampElems
Alloc
3 May 96
Syntax10m.Scn.Fnt
Syntax12i.Scn.Fnt
LineElems
Alloc
MODULE Host;	(** SHML 19 Mar 96, 
		This module encapsulates all system_dependent variables and procedures of an Oberon System V4.
		This is the version for Oberon for Amiga.
		Created by Stefan H._M. Ludwig, Institute for Computer Systems, ETH Zurich, ludwig@inf.ethz.ch, 19 Mar 96
	IMPORT Input, Display, Modules, Bitmaps;
		Host-: ARRAY 32 OF CHAR;	(** string identifying the host machine *)
		TimeUnit-: LONGINT;	(** resolution of Input.Time(), TimeUnit ticks happen per second *)
		OptionChar-: CHAR;	(** character used by command interpreters for specifying options *)
		PathChar-: CHAR;	(** character used in file names for separating subdirectories *)
		backup: Bitmaps.Bitmap;
	(* Support *) 
	PROCEDURE Append(VAR to(*inout*): ARRAY OF CHAR; this: ARRAY OF CHAR);
		(* append this to to, trim this to space left in to *)
		VAR toLen, i, j: LONGINT;
	BEGIN
		i := -1;
		REPEAT INC(i) UNTIL to[i] = 0X;
		toLen := LEN(to)-1; j := 0;
		WHILE (i # toLen) & (this[j] # 0X) DO to[i] := this[j]; INC(i); INC(j) END;
		to[i] := 0X
	END Append;
	(* Exported procedures *) 
	PROCEDURE Backup*(X, Y, W, H: INTEGER);
		(** Backup screen area X, Y, W, H; (must not be followed by Backup) *)
	BEGIN
		backup := Bitmaps.New(W, H);
		Bitmaps.CopyBlock(Bitmaps.Disp, backup, X, Y, W, H, 0, 0, Display.replace)
	END Backup;
	PROCEDURE Restore*(X, Y, W, H: INTEGER);
		(** Restore screen area X, Y, W, H; (must be preceded by Backup) *)
	BEGIN
		IF backup # NIL THEN Bitmaps.CopyBlock(backup, Bitmaps.Disp, 0, 0, W, H, X, Y, Display.replace) END
	END Restore;
	PROCEDURE IsFileNameChar*(ch: CHAR): BOOLEAN;	(** Is ch part of a valid file name? *)
	BEGIN
		CASE ch OF
		| "A".."Z", "a".."z", "0".."9", ".", "/", "_", ":": RETURN TRUE
		ELSE RETURN FALSE
		END
	END IsFileNameChar;
	PROCEDURE CallError*(command: ARRAY OF CHAR; res: INTEGER; VAR msg(*out*): ARRAY OF CHAR);
		(** Translate error message when the call of command fails; (res # 0, 100); (LEN(msg) >= 32, 101) *)
		VAR i, j: INTEGER;
	BEGIN
		ASSERT(res # 0, 100); ASSERT(LEN(msg) >= 32, 101);
		IF res > 0 THEN
			COPY("Call error: ", msg); Append(msg, Modules.importing);
			IF res = 1 THEN Append(msg, " not found")
			ELSIF res = 2 THEN Append(msg, " not an obj-file")
			ELSIF res = 3 THEN
				Append(msg, " imports ");
				Append(msg, Modules.imported); Append(msg, " with bad key")
			ELSIF res = 4 THEN Append(msg, " corrupted obj file")
			ELSIF res = 5 THEN Append(msg, command); Append(msg, " command not found")
			ELSIF res = 6 THEN Append(msg, " has too many imports")
			ELSIF res = 7 THEN Append(msg, " not enough space")
			END
		ELSIF res < 0 THEN
			i := -1;
			REPEAT INC(i) UNTIL (command[i] = ".") OR (command[i] = 0X);
			IF command[i] = 0X THEN i := -1 END;
			j := -1; 
			REPEAT INC(i); INC(j); msg[j] := command[i] UNTIL command[i] = 0X;	(* copy procedure name *)
			Append(msg, " not found")
		END
	END CallError;
BEGIN
	Host := "Amiga";
	OptionChar := "\"; PathChar := "/";
	TimeUnit := Input.TimeUnit
END Host.