from what little i know about this sort of thing characters have direction attached to them and the first character in a sequence dictates the prevailing / main direction, so if a char that is a right to left char starts then that should be the established norm throughout that text, so what you describe below does not look good.

maybe this list would be helpful: <http://www.lists.apple.com/mailman/listinfo/carbon-development>


On Sunday, July 6, 2003, at 03:33 pm, Theodore H. Smith wrote:



Hi people,


I'm having a real headache trying to code for Arabic/Hebrew text editing for the Mac. I'm developing a generalised editfield, of course I'd like it to edit Japanese too, but Japanese can run in the English direction, so that makes it a lot simpler!

I really am in need of some kind of forum or group with programmers specialising in Arabic or Hebrew development on the Mac. I am running into problems that seem very hard to solve, especially with the lack of information and coverage on this.

The problem may be conceptual, I am having a hard time visualising ATSUI's (MacOS's unicode display/edit API) modelling sometimes. I'm finding in fact visualising reverse direction text a headache. Especially seeing as I haven't seen code for working with it like a proper text editor should do, yet.

Things like how does the paragraph selection work? This I find really very awkward... Heres an example (pretend these numbers and letters are Arabic, \r means return, ignore the spaces):

In RAM: 12356789 \r abcdefg \r xyz

Screen: 987654321 \r gfedcba \r zyx

So if I select the onscreen from 2 to \r, which looks perfectly in order, then I am actually selecting a discontinuous range! But that doesn't seem right! There should be no need to, right? Is an arabic UTF document really backwards? So the first character in an arabic UTF document is actually the last onscreen?

What really is going on here? What should be going on? Is my example wrong? I really can't do any coding on reverse direction text till I work out how these paragraphs are meant to be working. Its all really rather twisted to me.

I do appreciate the problems here, in fact I made a theoretical exploration and found that if we ordered in visual order instead of logical, we'd just get a different set of headaches, not really less. Such is computing for real-world problems!

Reply directly to me if you can please? At [EMAIL PROTECTED]


-- Theodore H. Smith - Macintosh Consultant / Contractor. My website: <www.elfdata.com/>






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