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Revision 1.0, 07/30/2003
Questions & Comments : Please mail Prabhat Hegde

Testing Considerations For Mozilla Indic Script Support

• Introduction
• Complex Text Support
• Indic Support in Mozilla
• About Indic Scripts
• The Devanagari Alphabet
• Devanagari Shaping Issues
  

• Indic Script Input
• Inscript Keyboard Layout for Indic Languages
• Phonetic IME (Solaris specific)
  
• Indic Script Text -Edit Operations
• Testing Edit Operations
  
• Hindi Edit Operations
  
• Kannada
  
• Telugu
• Tamil
  

• Test URLs
• Hindi
• Kannada
• Telugu
• Tamil
• Gujarati
• Bengali
• Malayalam
• Oriya
• 
  
• Indic Font Issues
• Hindi Test Cases
• Hindi Testing reports
• References
  

Introduction

This document outlines key Indic language features which will be useful to test Indic (Currently Hindi) featureset in the browser. The features covered are:

1. Input
2. Output (Display & and Printing)
3. Hindi script shaping issues
4. Edit Operations.
   

Complex Text Support (CTL)

Indic Support Mozilla (*nix only)

Mozilla's supports the following features w.r.t Indic scripts:

1. Context Sensitive Shaping and Rendering on Unix platforms using non-intelligent (non-OT) fonts encoded in "sun.unicode.india-0" encoding.
2. CTLized Edit operations including Cursor positioning, Insertion, Deletion, Backspacing and Selection.
3. Printing through XPrint.
4. Features 1-3 above are available for Core-X and XFT2 backends.
5. Edit operations in the Mozilla Viewer, Composer and Mail are all covered.
6. Mail transfer is via UTF-8.
7. Currently no ISCII support in view of lack of content (as in web-sites that i know of), and lack of registry for ISCII in IANA.
   

About Indic Scripts
All Indic Scripts are derived from the ancient Brahmi script. Describing them is out-of-scope here. You may find more information at one or more of the following:

The Devanagari Alphabet

Consonants
Vowels and corresponding Matras
Signs
Numerals

Indic Script Input

Inscript Keyboard Layout
INSCRIPT Keyboard Layouts are the de-facto standard for Indic Compose/Keyboard Overlay based input. They are as under:
http://java.sun.com/products/jfc/tsc/articles/InputMethod/indiclayout.html

Phonetic Input Methods (On Solaris10 and Mad-Hatter only)

Indic Script Edit Operations

Indian Languages have their own semantics in dealing with text editing. Some text processing features which need to adapt to the new semantics are:

1. Left and Right arrow should traverse the entire display unit .
2. Caret /Cursor placement should not be in the middle of a display unit but should snap to the nearest edge.
3. <Delete>/Del key deletes the entire cluster.
4. <BKSP>/Backspace composes the cluster by character.
5. Character breaking is by a cluster or alternatively a display unit.
6. Line breaking is by danda ' '.
7. Word breaking is by space.
8. Mouse clicks need to snap to the nearest cluster boundary.
9. Selection/Cut/Copy/Paste should follow the rules mentioned above

Edit Operation Testing

As described above the following opertions must be tested:

1. Left & Right Arrow Keys
2. Left & Right Arrow Keys with <Shift>
3. Left & Right Arrow Keys with <Ctrl>
4. Mouse Operations
5. Insertion
6. Replacement
8. 
   

Id	Operation	Initial	Expected Result
1	Right Arrow
2	Right Arrow
3	<CTRL>Right Arrow
4	<Shift> Right Arrow
5	Left Arrow
6	Left Arrow
7	<CTRL>Left Arrow
8	<Shift>Left Arrow
9	Mouse SnapTo
10	Mouse Double-Click/Select Word
11	Mouse Right Cut/Paste
12	Mouse Left Cut/Paste
13	<Shift> <CTRL> Left Cut/Paste
14	<Shift> <CTRL> Right Cut/Paste
15	Select clusters in a word - Select/Cut/Paste
16	Straddle Script boundary - Select/Cut/Paste
17
18	Backspace - Delete a character (Start from end of the word)
19	Backspace
20	Backspace
21	Delete (Start from beginning of the word)
22	Delete (Start from beginning of the word)
23	Copy/Paste Repeat 11-16 above but use Copy instead of Cut
24	Replace
25	Insertion (Add a Halant at the location shown by the cursor)
26
27

Devanagari Character Shaping

Shaping is the process by which characters are rendered in the appropriate presentation forms. Some but not exhaustive set of rules to cover Devanagari Character Shaping is as below:

Id	Description/Rule	Input = Expected Output
	Conjunct formation Formed by randomly combining consonants. Consonants are written using half-forms for all consonants except the last. Not all of the conjuncts can form valid and pronouncable syllables and thereby not all combinations produced are valid. Testing of valid combination is upto the testers knowledge of the script. It is not possible to provide a list here.
	Consonant combining with Matra No Matra for अ which is implicit Matras coincide with stem for consonants having them. Matras are centered (w.r.t base consonant) for those with no stem. र is the only consonant with exceptions to the above rules. Sample combinations for letter ma illustrated.
	Re-Ordering Note the re-ordering of the choti-I matra.
	Shaping Samples of context sensitive shaping when consonants are joined together.
	Half Forms Half-forms are valid for all consonants except for र, फ and ढ Half forms of some alphabets such as ट & ठ are rendered one below the other.
	Ra Case (The first cluster is a case of ra)
	Reph Case

Indic Font Issues