CoreText - the approach

I have been looking at the text in Cello in some detail. The approach that have decided to take is to change the fundamental text object so that it is a thin wrapper on a NS/CFAttributedString. Doing this gives me RTF import and Unicode support at a basic level. On top of this the CTFrame fits quite naturally into one of the Cello classes.

The fact that the PC version of cello is fundamentally based on RTF and that I can use core text as an RTF engine is a bit of a result. What it means is that I can deploy a unicode text editing engine (unicode character set, bidirectional text). This just has to be projected into the UI - but it a way basing things on core text and doing the UI in cocoa give or take the international input it is probably hard not to do.

The remaining piece in the multi-lingual text equation is vertical text - but this is not hard to do in core text - but it is not pressing.

Within Cello there are also classes that represent character and paragraph styles. I will try and preserve these but make them thin wrappers. The paragraph style would seem to map naturally onto the CTParagrahStyle, and the Character style as a NS/CFDictionary of values for the attributed string.