Projects:Go Bible/SymScroll

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Symmetric Scrolling Branch

New page under development.

Raison d'être

The motivation for developing the SymScroll branch of Go Bible was to provide support for touch screen only phones that have Java ME. For touch screen phones with a hardware menu button, using SymScroll you can safely get rid of the on-screen virtual keypad and retain full Go Bible functionality, thus taking advantage of the full area of the screen for the application display.

As a sensible prelude for this task, the source code has been refactored. The SymScroll branch of GoBibleCore has been subdivided into many more Java classes than the previous release.


Enhanced/changed features

  • Symmetrical scrolling
  • Smooth scrolling
  • Touch screen full support

New features

  • Text added by translators can be displayed (e.g. in italics)
  • Line breaks
  • Psalm titles & other headings
  • Personal names & name of deity
  • OT quotations
  • Other numeral systems (e.g. Arabic, Devanagari, Thai)
  • Search next & search more
  • Key settings (e.g. for phones with QWERTY keyboard)
  • Font attributes (if available in the phone firmware)


  1. Search results are limited to 50 verses. 'Search Next' finds the next 50 verses containing the search text.
  2. One of the keys can be assigned to 'Search Next' in a different sense. It goes to the next search result.
  3. If no search has yet been done, the same key initates a new search.


Several software improvements were implemented in the SymScroll branch.

  • The painting code has been reworked. It is much faster than the previous code.

Technical details:

  • The original code measured the length of each line character by character, giving speed n (n = number of characters in a verse).
  • Because of look ahead and caching, at first the SymScroll branch repeated the above process about 4x, on top of other overheads, slowing it down by about the same factor.
  • Now, the code defers measuring any length until an entire word is read, speeding the code up by a factor equal to the average word length.
  • For Chinese script, where there is no concept of words and spaces, the code is does a binary search (i.e. log_2(n) ) to find the best breaking point.

Remarks within

  • The file allows remarks to be included. Any line that begins with the hash symbol # is treated as a remark.

Bug fixes

Some existing software bugs are being fixed. Details will be included in the release notes.

Implementation details

Symmetrical scrolling

Pressing 'up' now goes up by one screen, and pressing 'down' still goes down by one screen. This should be much more intuitive than the previous method. [1]

The previous method had its merits, namely speed, which this branch assumes is less relevant in the era of phones that can emulate Nintendo Gameboys.

  1. In which 'up' went up to the start of the previous verse.

Smooth scrolling

Touch screen scrolling needed to be smooth. Smooth scrolling is abandonned when a proper 'up' or 'down' key is pressed, after which the application reverts to the original discrete scrolling method.

Touch screen support

The Biblical text display now includes simple book and chapter headings, such that during continued scrolling, there is a better visual feedback for navigating. Horizontal touch screen scrolling navigates to next/previous chapter. The Go Bible Menu is accessed by touching anywhere in the top bar.

Key settings

This new feature facilitates remapping keys to the Go Bible navigation functions, thus making it possible for the user of a phone with a QUERTY keyboard (for example) to assign keys more conveniently. This feature requires several new UI properties.

The new Search Next feature is by default assigned to the previously unused "0" key.

Font attributes

GoBibleCore can now display text with font attributes such as italics or oblique or small caps, providing these attributes are supported by the phone firmware, and providing such attributes make sense for the language's alphabet.

In addition, the user can select alternative rendering methods such as underline, suitable for fonts that don't include italics.

Other numeral systems

The new UI property called UI-Digits facilitates using a different numeral system for chapter and verse numbers. The method is to specify a ten character string corresponding to the digits 0 through 9. Examples:

Default (if omitted):

UI-Digits: 0123456789

Eastern Arabic numerals:

UI-Digits: ٠١٢٣٤٥٦٧٨٩

Farsi numerals:

UI-Digits: ۰۱۲۳۴۵۶۷۸۹

Devanagari numerals:

UI-Digits: ०१२३४५६७८९

Thai numerals:

UI-Digits: ๐๑๒๓๔๕๖๗๘๙

Khmer numerals:

UI-Digits: ០១២៣៤៥៦៧៨៩


  1. Limitations: Currently, there is no error message. Go Bible does not check for uniqueness of characters.
  2. If there are less than 10 characters, it will revert to default. If there are more than 10 characters, the extra characters will be ignored (since no digits are larger than 9).
  3. The transformation is done at the individual digit level for decimal notation.
  4. The transformation applies only to chapter and verse numbers as used by the application, not to any numbers as might be found within the text of some Bible translations.
  5. In numeral systems with further special symbols for 20, 30, 50, etc; these are not catered for.
  6. For right to left languages, how different phones handle the bidirectional algorithm when the numeral system is not the default is outside the control of Go Bible software.
  7. Some languages do not have a symbol for numerical zero. See [2] which tabulates Numerals in Unicode.
  8. Some phones may display South East Asian numerals with a peculiar font size, relative to the normal text. This is not a Go Bible software issue.
  9. No semantic check is performed by Go Bible Creator. i.e. The following would be accepted, even though it makes no sense.
UI-Digits: 9876543210

Red Letters for Words of Jesus

This is in additional option under Preferences. It allows the user to switch Red Letters On or Off for any Go Bible applications made from source text that included the required markup.

Custom Verse Numbering

New feature still under development.

The latest code snapshot (2011-06-29) supports custom verse numbering (including out-of-order verses).

This was achieved by creating an additional file under Bible Data/ to store mapping data (mapping one verse number to another).

Details to be added later.

Go Bible Creator

The SymScroll branch of Go Bible Creator supports several new features.

  • Some new command line options have been added.
  • The command line option for update has been extended.
  • Some new UI properties have been defined.
  • Some further properties are available for use in collections text files.

Command line options

Options are now available by which one can choose a baseline Manifest file template, a baseline template, and even the GoBibleCore binaries. This should make GoBibleCreator a bit easier to use with different versions of GoBibleCore.

Usage: (java -jar GoBibleCreator) [ options ] CollectionsFilePath
	-b (path) - Path to GoBibleCore binaries (.jar)
	-m (path) - Path to Manifest file template
	-p (path) - Path to template
	-dh - Show some debug output
	-u - Update only
	-d - Set base source text directory

Note: The update only option has been extended to permit the main argument to be an existing GoBibleJARfilePath. This enables any Go Bible application to be upgraded to use the latest binaries, without requiring access to the source text file or a collections text file. Example:

java -jar GoBibleCreator.jar -u <old_gobible>.jar

This will convert an old Go Bible application to the SymScroll edition. Localized UI translations would lack the additional UI items, so these would default to the English UI properties. Yet that would be a spur to urge the user to supply the translations for these, so it becomes a "win-win" situation.

New UI properties

Here is a list of the new and re-used user interface (UI) properties:

UI-Key-Settings: Key Settings
UI-Assign-Key: Assign Key
UI-Unassign-Key: Unassign Key

UI-Action-Next-Book: Next Book
UI-Action-Next-Chapter: Next Chapter
UI-Action-Next-Screen: Next Screen
UI-Action-Next-Verse: Next Verse
UI-Action-Next-3-Lines: Next 3 Lines
UI-Action-Next-1-Line: Next Line

UI-Action-Previous-Book: Previous Book
UI-Action-Previous-Chapter: Previous Chapter
UI-Action-Previous-Screen: Previous Screen
UI-Action-Previous-Verse: Previous Verse
UI-Action-Previous-3-Lines: Previous 3 Lines
UI-Action-Previous-1-Line: Previous Line

UI-Book: Book
UI-Chapter: Chapter
UI-Verse: Verse
UI-Chapter-Reference-%1: Chapter %1
UI-Search-More: Search More
UI-Search-Next: Search Next
UI-Set-Range: Set Range ...
UI-From-Book: From Book
UI-To-Book: To Book

UI-Delete-All-Bookmarks-Alert: Delete all bookmarks?
UI-Delete-All: Delete All

UI-Delete-History-Entry: Delete history
UI-Delete-All-History-Entries: Delete all history
UI-Delete-History-Entry-Alert: Delete this history?
UI-Delete-All-History-Entries-Alert: Delete all history?

UI-Digits: 0123456789

UI-Red-Letter: Red Letters for words of Jesus


  1. This list may still be incomplete – (e.g. UI properties for selecting font attributes).
  2. Parameter %1 in UI-Chapter-Reference-%1 is a placeholder for the numerical value. This facilitates having a different position for the number in the displayed chapter headings.
  3. In version 2.4.x, displaying "Delete All" under Bookmarks was a kludge using "UI-Delete" and "UI-All".
  4. "From Book" and "To Book" are back in use. When the "Set Range" option is chosen for Search, these labels appear at the head of the lists of available booknames.
  5. "Search-More" relates to displaying the next set of search results.
  6. "Search-Next" relates to jumping to the next search result in the text.

Here is the file for the SymScroll branch complete with remark lines.

# BibleCanvas Menu Items
UI-Goto: Go to
UI-Search: Search
UI-Search-Next: Search Next
UI-Search-Results: Search Results
UI-Set-Range: Choose Range...
UI-Add-Bookmark: Add Bookmark
UI-Bookmarks: Bookmarks
UI-History: History
UI-Send-MMS: Send MMS
UI-Send-SMS: Send SMS
UI-Preferences: Preferences
UI-Key-Settings: Key Settings
UI-About: About
UI-Exit: Exit
UI-Cancel: Cancel
# BibleCanvas Display Elements
## UI-Of... Matthew 1:4 [of] 25
UI-Of: of
# Numerals for chapter & verse numbers (example below is Devanagari)
## UI-Digits: ०१२३४५६७८९
UI-Digits: 0123456789
## UI-Chapter-Reference-%1: Used at the start of chapters.
## e.g. The Gospel according to Matthew // [Chapter 1]
UI-Chapter-Reference-%1: Chapter %1
# Key Settings Keys
UI-Assign-Key: Assign Key
UI-Unassign-Key: Unassign Key
UI-Unassigned-Label: (unassigned)
UI-Action-Next-1-Line: Next Line
UI-Action-Next-3-Lines: Next 3 Lines
UI-Action-Next-Book: Next Book
UI-Action-Next-Chapter: Next Chapter
UI-Action-Next-Screen: Next Screen
UI-Action-Next-Verse: Next Verse
UI-Action-Previous-1-Line: Previous Line
UI-Action-Previous-3-Lines: Previous 3 Lines
UI-Action-Previous-Book: Previous Book
UI-Action-Previous-Chapter: Previous Chapter
UI-Action-Previous-Screen: Previous Screen
UI-Action-Previous-Verse: Previous Verse
# Search Actions
UI-Stop: Stop
## UI-Found: [Searching]: // [Found] nn // [Please Wait...]
UI-Searching: Searching
UI-Results: Results
UI-Found: Found
UI-Please-Wait: Please wait
# Theme Settings
## UI-Themes: Title of form
UI-Themes: Themes
## UI-Theme-*: Names of themes
UI-Theme-Blue: Blue
UI-Theme-Computer: Computer
UI-Theme-Floral: Floral
UI-Theme-Natural: Natural
UI-Theme-Paper: Paper
UI-Theme-Sunshine: Sunshine
# Other Settings
UI-Change: Change
UI-Font-Size: Font size
UI-Font-Style: Font style
UI-Full-Screen: Full screen
UI-Red-Letter: Red Letters for words of Jesus
UI-Reverse-Characters: Reverse Characters
UI-Reverse-Colours: Reverse Colours
UI-Save: Save
UI-Select: Select
UI-Theme: Theme
# Font Size Settings
UI-Small: Small
UI-Medium: Medium
UI-Large: Large
# Font Style Settings
UI-Bold: Bold
UI-Plain: Plain
# Full screen settings / Reverse colors settings
UI-On: On
UI-Off: Off
# Search Options
UI-Search-Text: Search Text
UI-Books: Books
UI-All: All
UI-Define-Range: Set Range...
UI-New-Testament: New Testament
UI-Old-Testament: Old Testament
UI-Gospels: Gospels
UI-Pauls-Letters: Paul's Letters
UI-Other-Letters: Other Letters
UI-Books-Of-Moses: Books of Moses
UI-Historical: Historical
UI-Poetic: Poetic
UI-Major-Prophets: Major Prophets
UI-Minor-Prophets: Minor Prophets
# New option available in Search Results 
## This finds the next set of [50] results
## The number of displayed results is determined by the 
## optional collections file property Go-Bible-Max-Results
UI-Search-More: Search More
# Send SMS
UI-Send-Verses: Send Verses
UI-Select-Verses-To-Send: Select verses to send
UI-Send: Send
## UI-To: Send from (book, chapter, verse) [to] (verse number)
UI-To: to
UI-Message-Too-Large-To-Be-Sent: Message too large to be sent
UI-Verse-Does-Not-Exist: Verse does not exist
UI-Phone-Number: Phone Number
## ??
UI-Back: Back
# Goto form:
UI-Book: Book
UI-Verse: Verse
UI-Chapter: Chapter
# Bookmarks
UI-View: View
UI-Delete: Delete
UI-Delete-Bookmark: Delete Bookmark
UI-Delete-Bookmark-Alert: Delete the selected bookmark?
UI-Delete-All-Bookmarks-Alert: Delete all bookmarks?
UI-Delete-All: Delete All
# History
UI-Delete-History-Entry: Delete history
UI-Delete-All-History-Entries: Delete all history
UI-Delete-History-Entry-Alert: Delete this history?
UI-Delete-All-History-Entries-Alert: Delete all history?
# Other
UI-Error: Error
# Obsolete
## Search settings, first and last book to search
UI-From-Book: From Book
UI-To-Book: To Book
## Displayed when chapter/ book is loaded as it takes some time to load
UI-Loading: Loading
## ??


  1. This example may not be completely up to date.

Collections text file properties

Here is a list of the new collections text file properties:

MIDlet-Description: A brief description of the Go Bible application
Go-Bible-Max-Results: 50


  1. MIDlet-Description: is a required property for JAD files. Previous versions of Go Bible omitted this. Use this for a brief description. Use the existing Info: property to provide a verbose description.
  2. The value specified for Go-Bible-Max-Results: relates to how many search results are displayed at once. The default is now 50. Using a lower number may improve how Go Bible works on some older phone models. cf. Prior to SymScroll, maximum search results was fixed at 200.
  3. Corrections to how some existing properties appear in the JAD file are also being tackled. See issue 133 for further details.

Custom manifest file template properties

Go Bible Creator supports using different manifest files. Here is an example of the default manifest template for LTR scripts.

Manifest-Version: 1.0
Go-Bible-Align: Left
Go-Bible-Render-Faux-Italic: yes
Go-Bible-Render-Faux-Underlined: yes
Go-Bible-Render-Faux-Bold: yes
Go-Bible-Line-Height: 1.05
Nokia-MIDlet-On-Screen-Keypad: no


If you have the Go-Bible-Render-Faux-Italic option set in the manifest, all italics will be rendered in grey[1] with dotted underline.[2] Otherwise, the program will use the default Italic font.[3]

  1. The current code uses 67% normal text colour, 33% background colour. This should be sufficient for all the preset themes. For words of Jesus, the predefined 'red' colour overrides the grey.
  2. Dotted underlines are a drop-in replacement for italics. This follows the convention used in various Chinese Bibles for the words tagged (in USFM) as translators' additions.
  3. This method can therefore be used to build a separate Go Bible application for phones that do not support italics, yet without requiring a different collections text file.

Support for XHTML_TE

The SymScroll branch of Go Bible Creator incorporates the extension to specify XHTML_TE as the source text format. The code is as provided by one of the programmers at SIL in Dallas. It was designed to support their FieldWorks Translation Editor, and is used internally by their Pathway publication tool.

Other improvements


The source code has undergone major reorganization. The following are the new/changed Java classes:

  • USFMConverter: Supersedes USFM_Utilities. Contains all the USFM-related methods.
  • XMLConverter: Contains all the XML-related helper methods.
  • GoBibleCreator: USFM- and XML- specific code have been removed and placed in their respective Converter classes.

Go Bible data format

Go Bible data format already assigned the control character code \x01 to mark both the start and finish as the means to implement the display of red letters for Words of Jesus. As Go Bible made no standard use of control characters, it had been envisaged that any UTF-8 character up to \x1F might be used for further enhancements to the Go Bible data format.

This method has been extended as follows:

\x01 – Delimit red letters
\x02 – Delimit translators' additions (e.g. as for words shown as italics in the KJV)
\x03 – Delimit the name of deity
\x04 – Delimit quotations (e.g. OT quotations shown as oblique in the NKJV)
\x05 – Delimit a proper name

\x06 – Suppress printing the verse number, if it has not been printed, and change to boldface for titles
\x07 – Break a line, print the verse number, and resume normal data (see below)

\x0A – Line break (see below)

\x0E – Increment the verse number offset (see below)
\x0F – Decrement the verse number offset (see below)


To accommodate titles and descriptive headings without making major design changes to the data format, the following solution has been adopted. Example for canonical Psalm titles.

<VERSE INDEX 0><\x06>For the director of music. Of David.<\x07>
In the <\x03>LORD<\x03> I take refuge. How then can you say to me: ...
<VERSE INDEX 1>For look,...

To facilitate this new feature, it is apparent that the data format has been extended to permit references to verse 0 in order to accommodate canonical Psalm titles. Even so, the codes <\x06> and <\x07> can be used within other verses, such as to display the Hebrew letter stanza titles for acrostic poems such as Psalm 119.

Line breaks

Discretional line breaks are now permitted within Go Bible data format, coded as EOL marker in Unix \n (i.e. \x0A or LF ).


  1. SymScroll does not support paragraphs or poetry markup. Every verse still begins on a separate line, with the verse number at the start of the line.
  2. Therefore translations with verse range tags will still require a workaround during preprocessing.

Verse number offset

The displayed verse number = verse index + offset. Internally, when navigating to passages, or when sending SMS, only the verse index is used.


  1. This is a solution in place of what was a workaround, where empty verse tags had to be inserted in the USFM files for missing verses.

Go Bible Creator support

Table showing which markup feature is supported for each source text format. Please update this table.
Markup Feature Code USFM USFM tags[1] ThML OSIS XHTML_TE
Delimit red letters \x01 yes \wj_...\wj* yes[2] no yes
Delimit translators' additions \x02 yes \add_...\add* no no yes
Delimit the name of deity \x03 yes \nd_...\nd* no no yes
Delimit quotations \x04 yes \qt_...\qt* no no yes
Delimit a proper name \x05 yes \pn_...\pn* no no yes
Suppress printing the verse number, etc \x06 yes \s#_text...[3] no no no
Line break, print verse number, resume \x07 yes \s#_text...[4] no no no
Line break \x0A yes \p(_text...) no no no
Increment the verse number offset \x0E yes \v_#[5] no no no
Decrement the verse number offset \x0F yes \v_#[6] no no no
  1. See the User Reference available at [1]
  2. Implements <span class="red">...</span>
  3. Applied before the title.
  4. Applied after the title.
  5. The code must appear at the start of the verse. The code has to be repeated for every verse for which the numbering is not correct.
  6. See above.

Backwards compatibility

The SymScroll branch of GoBibleCore is backwards compatible with existing Go Bible applications. This means that earlier applications can be changed to SymScroll merely by replacing the file gobiblecore2.jar and using the Update option of Go Bible Creator to rebuild the application. For Go Bible applications that already have a UI translation, then ideally the new UI properties should be translated prior to the rebuild.

Development Status

The SymScroll branch is no longer being actively developed. Most of the features are already implemented. No milestoned release was ever announced. The source code for this branch of gobible-creator is available on github. It excludes the code for Go Bible Core. The original source code for gobible was exported from Google Code by lukeme.

See also