Arabic Script Requirements in Desktop Software

(UNDER CONSTRUCTION)

Arabic Specification provides the information needed to support Arabic script in Desktop Applications such as Web Browsers, Desktop Publishing and Graphic Applications.

Text alignment is not the only problem of BiDirectional scripts (as many users/developers think so). Alignment is just the first step for supporting bidi scripts. The are many problems in shaping/joining, elongation, hyphenation, justification, etc too.

Arabic is a BiDirectional Script

Bidirectional Scripts in Desktop Software

Arabic characters need Shaping/Joining

Arabic Words and Lines need Elongation

Application needed to support elongation for Arabic words and lines.

Line Elongation

Elongating lines of a paragraph to make all lines same width is named Justification.

In Latin script, line elongation applied with inter-letter and inter-word spacing. In Arabic we have inter-word spacing, but there's no inter-letter spacing.

Word Elongation

There is no distinct way for word elongation in Arabic script, but typists usually do that with inserting Kashida (= U+0640 ARABIC TATWEEL) between joined letters. Some graphists use Latin's letter-spacing in graphic applications, but it can make joined letters disjoined; It's a misfeature and should not be used at all.

Comparison

Here are current situation of Arabic Elongation in some Software/Standards:

		Inter-word Elongation	Auto Trade-off	Word Elongation
CSS2	(Manual)	`word-space`		`letter-space`
CSS2	(Justification)	`text-align`		NONE
CSS3	(Manual)	`word-space`		NONE
CSS3	(Justification)	`text-justify=inter-word`	`text-kashida-space=%nn`	`text-justify=kashida`
MS Word	(Manual)	???		NONE
MS Word	(Justification)