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From: ott@piyopiyo.hatori.t.u-tokyo.JUNET (ott)
Newsgroups: comp.lang.smalltalk
Subject: Smalltalk/V286: moving cursor in Texteditor
Message-ID: <16@piyopiyo.hatori.t.u-tokyo.JUNET>
Date: 16 Jun 89 01:39:43 GMT
Reply-To: ott@piyopiyo.hatori.t.u-tokyo.JUNET (max)
Organization: Hatori Lab., Department of Electrical Engineering, Univesity of Tokyo
Lines: 44

I finally got 286/V (or the other way around) running yesterday and
started to transfer some of my methods for enhancing the texteditor
from the PC version.

Things have changed a lot and late at night I ran into the following
problem I just cant explain.

I want to move the cursor (I-beam) with the keyboard. Left, right, up
and down works fine, but using the same method I can't properly move
it to the end or beginning of a line.

A stripped down version of the method I added to TextPane:

selectBeginningOfLine
	| curPosition |
	curPosition := selection origin.
	selection selectBefore: ( curPosition x: 1).

It leaves a copy of the cursor at curPosition, moves the cursor to the
beginning and reverses the part of the line between. It does not
select that area, as the reverse part stays.

To move it to the end (only changed 'curPosition x: lastColumn')
things are a bit different. A copy of the old cursor remains, the
cursor is moved to the end, but invisible as a 2nd permanent copy of
the cursor shape is copied to this position as well.

In both cases the cursor is shifted to the right place and character
input appears at the right place as well. But the move creates those
strange artifacts.

Has anyone figured out where exactly the cursor gets moved and
the big idea behind TextSelection.

I am quite lost and would appreciate any help.

Thanks

-max
------------------------------------------------------------------------------
Max Ott			     e-mail:
Hatori Laboratory             ott@piyopiyo.hatori.t.u-tokyo.junet@relay.cs.net
Dept. of E.E.; U of Tokyo             I am not a tourist, I live here, but
+(81)-(03) 812 2111 Ext. 6761         would not mind being one.