[Oberon] Revision of a Text vs. update of display in a Gadget.

[Joerg]

CutLines does not move any byte in memory. („Insert“ does not move bytes!!)
But on every „n“ characters „Insert“ updates the screen. It’s true that updating the screen is rather slow.

The Wrap code is the exact opposite: it moves around a lot of bytes in memory (copy buffers) but I couldn’t find any screen update.

br
Jörg

> Am 08.03.2020 um 06:06 schrieb peter at easthope.ca:
> 
> Joerg, 
>  thanks for replying.
> 
> From:    Joerg <joerg.straube at iaeth.ch>
> Date:    Sun, 8 Mar 2020 01:51:50 +0100
>> To analyze your case you should explain a little more in detail, under 
>> what conditions you observed the behaviour and what you did with what 
>> Gadget.
> 
> It's a sporadic consequence when 
>    Mail.Wrap 70 ^ 
> is applied to some lines of Text separated by an empty line.  
> 
> Wrap is described here, including a link to the source. 
> https://en.wikibooks.org/wiki/Talk:Oberon/A2/Oberon.Mail.Mod#CutLines_vs._Wrap
> Near the end of Oberon.Mail, following CutLines.
> 
> The observation is that in rare cases an empty line (separation of 
> paragraphs) appears to be removed. Apparent damage can be worse in 
> more rare cases. Only in a Document viewer; not in a plain Text 
> viewer. Scrolling out of view and back in view makes the empty line 
> visible again. Storing the viewer to a file and opening again also 
> restores the correct view.  That's why I hypothesize that an update is 
> needed in my code. 
> 
> When another case turns up I might find a way to transmit it so that 
> you see directly.
> 
> Thanks again,                          ... Lyall E.
> 
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> Tel: +1 604 670 0140            Bcc: peter at easthope. ca
> 
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