- From: Stephen Deach <sdeach@adobe.com>
- Date: Fri, 23 Sep 2005 07:28:50 -0700
- To: fantasai <fantasai.lists@inkedblade.net>, Rotan Hanrahan <Rotan.Hanrahan@MobileAware.com>
- Cc: www-international@w3.org, www-di@w3.org, bidi@unicode.org
At 2005.09.22-22:36(-0400), fantasai wrote: >Rotan Hanrahan wrote: >>* Western text (e.g. english) uses bullet lists that have the bullets on the >>left, the text running horizontally and the list growing downward >>(vertically). What is the case for languages that write text vertically? Or >>Right-to-Left (RTL)? > >The layout is the exactly the same if you are using a relative directional >system (before/after, start/end of line instead of top/bottom, left/right of >line). So, for RTL, the bullets and indentation are on the right edge, for >TTB vertical layout they are along the top edge. The bullets are generally drawn on the start edge of the predominant writing system for either the document or for the whole list. >>* Western text requires several characters per word. So the information is >>dense vertically, but not so dense horizontally. What is the information >>density for other languages? Idiographics etc? For example, in english, the >>phrase "Home Page" fits into a few pixels high, and many more pixels wide, >>but how does the sample phrase in Chinese compare? > >Chinese words average 2 characters long. Japanese and Korean are, I believe, >a bit longer due to inflection (but I have not studied these languages). > >>* Are there any special considerations for word-wrapping of vertical text? > >Same as in horizontal. There are special considerations for CJK in general, >however. There are differences in the line-breaking rules for clusters of languages/scripts, especially when/if hyphenation is allowed. Japanese have a well described set of rules for linebreaking, C & K have similar rules though not as well documented. Thai has no wordspaces, so linebreaking requires a dictionary. If a German word has a s-set followed by an s or has a syllable that should end in a single s followed by a syllable that begins with an s, the last s is suppressed when the word is written together, but shown when the word is hyphenated. Similar rules apply to the Skandinavian languages. etc, etc. >>* Are there special text layout considerations for ruby annotations? > >There must be enough leading between the lines to accomodate ruby annotations. >And of course, your layout engine must support ruby annotations. :) Well, not just for ruby, but in general ideographic scripts have wider spacing between the lines than is common for latin scripts. >>* Western text often uses coloured underlining to indicate a hyperlink. What >>is the norm for languages where such lines might not be easy to notice? Are >>there such languages? > >Putting out a wild guess here, but I think underlining is generally positioned >such that it is noticeable. In Japanese, at least, the underlining for vertical text is generally drawn on the before (right) edge rather than on the after (left) edge (at least for the ideographic text and full-width latin text, it should probably be drawn below the baseline for the rotated roman halfidth/proportional text). >>* If users could choose, would they prefer portrait or landscape layouts? How >>would the rules of their written text influence their preference? > >A vertically-set document would be reasonably readable only if > - it scrolls only horizontally >or > - it scrolls only vertically, but it's multicol and the columns are > no broader and no longer than the viewport In general a document is readable if it is re-flowed so that the full line fits in the size of the screen/window and only one direction of scrolling is necessary to read the column/galley of text. -or- if broken into pages that fit in the screen/window so that no scrolling is necessary. >It is analogous to saying that a horizontally-set document would be >reasonably readable only if > - it scrolls only vertically >or > - it scrolls only horizontally, but it's multicol and the columns > are no wider and no taller than the viewport > >In print, most aspects of vertical layout are analogous to horizontal >layout. The differences are mainly in the details. (Vertical layout >usually has more separation between lines, Chinese uses a different >set of quotation marks, you can use a vertically-compacted font style, >etc.) Another thing to note is that Japanese magazines make frequent >use of mixed layout pages: pages with some boxes laid out horizontally >and others vertically. > >One major difference between vertical and horizontal layout is that >vertical layout can stack its lines from right to left (as for CJK) >or from left to right (as for Mongolian and Manchu), whereas horizontal >layout never goes from bottom to top. There are cases in historic/ancient languages and limited specialized usages such as signage. AHEAD SCHOOL SLOW >~fantasai All of the above should be considered "common practice" or "rules of thumb", a document designer may choose to violate any or all such practices. ---Steve Deach sdeach@adobe.com
Received on Friday, 23 September 2005 14:29:46 UTC