Re: Editing and formatting characters

[Derek Simkowiak <dereks realloc net>]

->    HEBREW TEXT [HYPHEN] [RLM] 1234
->                        ^     ^
->                        A     B
[...]
-> I think the correct cursor position is at B - that is, the mark should
-> be associated with the logically-preceding character.

	Question: Why does the 'B' position correspond to the
"logically-preceding character"?  It would seem to me that 'A' would be
logically preceding...?


->    [RLE] HEBREW TEXT [HYPHEN] [PDF] 1234
->                                    ^
->                                    B
-> 
-> Again the cursor cursor position should be at B, but when we delete at
-> B, we don't want to simply delete the PDF, we instead want to delete
-> the HYPHEN and leave the [PDF]. Then when we get to:
->  
->    [RLE] H [PDF] 1234
->                 ^
->                 B
-> 
-> Hitting delete would then delete PDF, H and RLE.

	I didn't quite understand your first example, but for this second
example, I would argue that the cursor position should be at 'A', not 'B':

    [RLE] HEBREW TEXT [HYPHEN] [PDF] 1234
                              ^     ^
                              A     B

	This is how the markup tags within Microsoft Word (and most other
English word processors, albeit left to right), and it's quite intuitive.

	By putting the cursor at 'A', we don't need any special-case
delete rules for when the cursor is right next to a [PDF].  Hitting delete
would delete [HYPHEN], just as one would expect, and just like any other
character.  New characters would be inserted between the [RLE] and [PDF].

	In this case:

    [RLE] H [PDF] 1234
           ^
           A

	...if you hit delete, the H would disappear, but the [RLE] and
[PDF] would remain:

    [RLE] [PDF] 1234
         ^
         A

	The cursor is now in a special state; if you enter a new
character, it would be between the [RLE] and [PDF], but if you hit delete,
both of them would disappear (along with the visible character that the
delete would normally apply to).  Or, if you hit an arrow key, then the
[RLE]/[PDF] pair would disappear, and the cursor would move to the
appropriate visible character.  Again, this is modelled on English word
processors.



--Derek Simkowiak
  dereks realloc net