[Oberon] SystemV - Viewer Scroll

Joerg joerg.straube at iaeth.ch
Tue Mar 19 18:25:49 CET 2019

My quick hack was only applicable to Files.
Assuming you have a frame, initialized a Reader "R" already and want to set
this Reader back by one position.

  Texts.OpenReader(R, f.text, Texts.Pos(R)-1);
  Texts.Read(R, ch)

-----Original Message-----
From: Oberon <oberon-bounces at lists.inf.ethz.ch> On Behalf Of Tomas Kral
Sent: Tuesday, March 19, 2019 6:15 PM
To: oberon at lists.inf.ethz.ch
Subject: Re: [Oberon] SystemV - Viewer Scroll

On Tue, 19 Mar 2019 17:27:28 +0100
Joerg <joerg.straube at iaeth.ch> wrote:

> backward
> direction":
>   Files.Set(R, Files.Base(R), Files.Pos(R)-1);
>   Files.Read(R, ch);

Possibly this?

[1] roll back No# of lines (to be determined), with the above.

[2] setting org := Files.Pos(R);
[3] do usual forward display

  Texts.OpenReader(R, F.text, org); Texts.Read(R, nextCh);
  WHILE ~L.eot & (curY >= botY) DO
    NEW(L0); DisplayLine(F, L0, R, F.X + F.left, curY, 0);
    L.next := L0; L := L0; curY := curY - lsp

Tomas Kral <thomas.kral at email.cz>
Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related systems

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