Fonts are graphical resources that can be accessed with a call to ej.microui.display.Font.getFont(). Fonts are declared in Classpath *.fonts.list files (or in *.fontsext.list for an external resource, see External Fonts).

digraph D {

    internalFont [shape=diamond, label="internal?"]
    fontsList [shape=box, label="*.fonts.list"]
    fontsExt [shape=box, label="*.fontsext.list"]
    subgraph cluster_font {
        label ="Font"
        internalFont -> fontsList [label="yes"]
        internalFont -> fontsExt [label="no=external"]

The file format is a standard Java properties file, each line representing a / separated resource path relative to the Classpath root referring to a Font file (usually with a .ejf file extension). The resource may be followed by optional parameters which define :

  • some ranges of characters to embed in the final raw file;
  • the required pixel depth for transparency.

By default, all characters available in the input font file are embedded, and the pixel depth is 1 (i.e 1 bit-per-pixel). Example:

# The following font is embedded with all characters
# without transparency

# The following font is embedded with only the latin
# unicode range without transparency

# The following font is embedded with all characters
# with 2 levels of transparency

Font files conventionally end with the .ejf suffix and are created using the Font Designer (see Font Designer).

Configuration File

Here is the format of the *.fonts.list files.

ConfigFile          ::= Line [ 'EOL' Line ]*
Line                ::= FontPath [ ':' [ Ranges ] [ ':' BitsPerPixel ] ]
FontPath            ::= Identifier [ '/' Identifier ]*
Ranges              ::= Range [ ';' Range ]*
Range               ::= CustomRangeList | KnownRange
CustomRangeList     ::= CustomRange [ ',' CustomRange ]*
CustomRange         ::= Number | Number '-'  Number
KnownRange          ::= Name [ SubRangeList ]?
SubRangeList        ::= '(' SubRange [ ',' SubRange ]* ')'
SubRange            ::= Number | Number - Number
Identifier          ::= 'a-zA-Z_$' [ 'a-zA-Z_$0-9' ]*
Number              ::= Number16 | Number10
Number16            ::= '0x' [ Digit16 ]+
Number10            ::= [ Digit10 ]+
Digit16             ::= 'a-fA-F0-9'
Digit10             ::= '0-9'
BitsPerPixel        ::= '1' | '2' | '4' | '8'

Font Range

The first parameter is for specifying the font ranges to embed. Selecting only a specific set of characters to embed reduces the memory footprint. If unspecified, all characters of the font are embedded.

Several ranges can be specified, separated by ;. There are two ways to specify a character range: the custom range and the known range.

Custom Range

Allows the selection of raw Unicode character ranges.


  • myfont:0x21-0x49: Defines one range: embed all characters from 0x21 to 0x49 (included);
  • myfont:0x21-0x49,0x55-0x75: Defines a set of two ranges: embed all characters from 0x21 to 0x49 and from 0x55 to 0x75.
  • myfont:0x21-0x49,0x55: Defines a set of one range and one character: embed all characters from 0x21 to 0x49 and character 0x55.

Known Range

A known range is a range available in the following table.


  • myfont:basic_latin: Embed all Basic Latin characters;
  • myfont:basic_latin;arabic: Embed all Basic Latin characters, and all Arabic characters.

The following table describes the available list of ranges and sub-ranges (processed from the “Unicode Character Database” version 9.0.0 available on the official unicode website ).

Name Tag Start End
Basic Latin basic_latin 0x0 0x7f
Latin-1 Supplement latin-1_supplement 0x80 0xff
Latin Extended-A latin_extended-a 0x100 0x17f
Latin Extended-B latin_extended-b 0x180 0x24f
IPA Extensions ipa_extensions 0x250 0x2af
Spacing Modifier Letters spacing_modifier_letters 0x2b0 0x2ff
Combining Diacritical Marks combining_diacritical_marks 0x300 0x36f
Greek and Coptic greek_and_coptic 0x370 0x3ff
Cyrillic cyrillic 0x400 0x4ff
Cyrillic Supplement cyrillic_supplement 0x500 0x52f
Armenian armenian 0x530 0x58f
Hebrew hebrew 0x590 0x5ff
Arabic arabic 0x600 0x6ff
Syriac syriac 0x700 0x74f
Arabic Supplement arabic_supplement 0x750 0x77f
Thaana thaana 0x780 0x7bf
NKo nko 0x7c0 0x7ff
Samaritan samaritan 0x800 0x83f
Mandaic mandaic 0x840 0x85f
Arabic Extended-A arabic_extended-a 0x8a0 0x8ff
Devanagari devanagari 0x900 0x97f
Bengali bengali 0x980 0x9ff
Gurmukhi gurmukhi 0xa00 0xa7f
Gujarati gujarati 0xa80 0xaff
Oriya oriya 0xb00 0xb7f
Tamil tamil 0xb80 0xbff
Telugu telugu 0xc00 0xc7f
Kannada kannada 0xc80 0xcff
Malayalam malayalam 0xd00 0xd7f
Sinhala sinhala 0xd80 0xdff
Thai thai 0xe00 0xe7f
Lao lao 0xe80 0xeff
Tibetan tibetan 0xf00 0xfff
Myanmar myanmar 0x1000 0x109f
Georgian georgian 0x10a0 0x10ff
Hangul Jamo hangul_jamo 0x1100 0x11ff
Ethiopic ethiopic 0x1200 0x137f
Ethiopic Supplement ethiopic_supplement 0x1380 0x139f
Cherokee cherokee 0x13a0 0x13ff
Unified Canadian Aboriginal Syllabics unified_canadian_aboriginal_syllabics 0x1400 0x167f
Ogham ogham 0x1680 0x169f
Runic runic 0x16a0 0x16ff
Tagalog tagalog 0x1700 0x171f
Hanunoo hanunoo 0x1720 0x173f
Buhid buhid 0x1740 0x175f
Tagbanwa tagbanwa 0x1760 0x177f
Khmer khmer 0x1780 0x17ff
Mongolian mongolian 0x1800 0x18af
Unified Canadian Aboriginal Syllabics Extended unified_canadian_aboriginal_syllabics_extended 0x18b0 0x18ff
Limbu limbu 0x1900 0x194f
Tai Le tai_le 0x1950 0x197f
New Tai Lue new_tai_lue 0x1980 0x19df
Khmer Symbols khmer_symbols 0x19e0 0x19ff
Buginese buginese 0x1a00 0x1a1f
Tai Tham tai_tham 0x1a20 0x1aaf
Combining Diacritical Marks Extended combining_diacritical_marks_extended 0x1ab0 0x1aff
Balinese balinese 0x1b00 0x1b7f
Sundanese sundanese 0x1b80 0x1bbf
Batak batak 0x1bc0 0x1bff
Lepcha lepcha 0x1c00 0x1c4f
Ol Chiki ol_chiki 0x1c50 0x1c7f
Cyrillic Extended-C cyrillic_extended-c 0x1c80 0x1c8f
Sundanese Supplement sundanese_supplement 0x1cc0 0x1ccf
Vedic Extensions vedic_extensions 0x1cd0 0x1cff
Phonetic Extensions phonetic_extensions 0x1d00 0x1d7f
Phonetic Extensions Supplement phonetic_extensions_supplement 0x1d80 0x1dbf
Combining Diacritical Marks Supplement combining_diacritical_marks_supplement 0x1dc0 0x1dff
Latin Extended Additional latin_extended_additional 0x1e00 0x1eff
Greek Extended greek_extended 0x1f00 0x1fff
General Punctuation general_punctuation 0x2000 0x206f
Superscripts and Subscripts superscripts_and_subscripts 0x2070 0x209f
Currency Symbols currency_symbols 0x20a0 0x20cf
Combining Diacritical Marks for Symbols combining_diacritical_marks_for_symbols 0x20d0 0x20ff
Letterlike Symbols letterlike_symbols 0x2100 0x214f
Number Forms number_forms 0x2150 0x218f
Arrows arrows 0x2190 0x21ff
Mathematical Operators mathematical_operators 0x2200 0x22ff
Miscellaneous Technical miscellaneous_technical 0x2300 0x23ff
Control Pictures control_pictures 0x2400 0x243f
Optical Character Recognition optical_character_recognition 0x2440 0x245f
Enclosed Alphanumerics enclosed_alphanumerics 0x2460 0x24ff
Box Drawing box_drawing 0x2500 0x257f
Block Elements block_elements 0x2580 0x259f
Geometric Shapes geometric_shapes 0x25a0 0x25ff
Miscellaneous Symbols miscellaneous_symbols 0x2600 0x26ff
Dingbats dingbats 0x2700 0x27bf
Miscellaneous Mathematical Symbols-A miscellaneous_mathematical_symbols-a 0x27c0 0x27ef
Supplemental Arrows-A supplemental_arrows-a 0x27f0 0x27ff
Braille Patterns braille_patterns 0x2800 0x28ff
Supplemental Arrows-B supplemental_arrows-b 0x2900 0x297f
Miscellaneous Mathematical Symbols-B miscellaneous_mathematical_symbols-b 0x2980 0x29ff
Supplemental Mathematical Operators supplemental_mathematical_operators 0x2a00 0x2aff
Miscellaneous Symbols and Arrows miscellaneous_symbols_and_arrows 0x2b00 0x2bff
Glagolitic glagolitic 0x2c00 0x2c5f
Latin Extended-C latin_extended-c 0x2c60 0x2c7f
Coptic coptic 0x2c80 0x2cff
Georgian Supplement georgian_supplement 0x2d00 0x2d2f
Tifinagh tifinagh 0x2d30 0x2d7f
Ethiopic Extended ethiopic_extended 0x2d80 0x2ddf
Cyrillic Extended-A cyrillic_extended-a 0x2de0 0x2dff
Supplemental Punctuation supplemental_punctuation 0x2e00 0x2e7f
CJK Radicals Supplement cjk_radicals_supplement 0x2e80 0x2eff
Kangxi Radicals kangxi_radicals 0x2f00 0x2fdf
Ideographic Description Characters ideographic_description_characters 0x2ff0 0x2fff
CJK Symbols and Punctuation cjk_symbols_and_punctuation 0x3000 0x303f
Hiragana hiragana 0x3040 0x309f
Katakana katakana 0x30a0 0x30ff
Bopomofo bopomofo 0x3100 0x312f
Hangul Compatibility Jamo hangul_compatibility_jamo 0x3130 0x318f
Kanbun kanbun 0x3190 0x319f
Bopomofo Extended bopomofo_extended 0x31a0 0x31bf
CJK Strokes cjk_strokes 0x31c0 0x31ef
Katakana Phonetic Extensions katakana_phonetic_extensions 0x31f0 0x31ff
Enclosed CJK Letters and Months enclosed_cjk_letters_and_months 0x3200 0x32ff
CJK Compatibility cjk_compatibility 0x3300 0x33ff
CJK Unified Ideographs Extension A cjk_unified_ideographs_extension_a 0x3400 0x4dbf
Yijing Hexagram Symbols yijing_hexagram_symbols 0x4dc0 0x4dff
CJK Unified Ideographs cjk_unified_ideographs 0x4e00 0x9fff
Yi Syllables yi_syllables 0xa000 0xa48f
Yi Radicals yi_radicals 0xa490 0xa4cf
Lisu lisu 0xa4d0 0xa4ff
Vai vai 0xa500 0xa63f
Cyrillic Extended-B cyrillic_extended-b 0xa640 0xa69f
Bamum bamum 0xa6a0 0xa6ff
Modifier Tone Letters modifier_tone_letters 0xa700 0xa71f
Latin Extended-D latin_extended-d 0xa720 0xa7ff
Syloti Nagri syloti_nagri 0xa800 0xa82f
Common Indic Number Forms common_indic_number_forms 0xa830 0xa83f
Phags-pa phags-pa 0xa840 0xa87f
Saurashtra saurashtra 0xa880 0xa8df
Devanagari Extended devanagari_extended 0xa8e0 0xa8ff
Kayah Li kayah_li 0xa900 0xa92f
Rejang rejang 0xa930 0xa95f
Hangul Jamo Extended-A hangul_jamo_extended-a 0xa960 0xa97f
Javanese javanese 0xa980 0xa9df
Myanmar Extended-B myanmar_extended-b 0xa9e0 0xa9ff
Cham cham 0xaa00 0xaa5f
Myanmar Extended-A myanmar_extended-a 0xaa60 0xaa7f
Tai Viet tai_viet 0xaa80 0xaadf
Meetei Mayek Extensions meetei_mayek_extensions 0xaae0 0xaaff
Ethiopic Extended-A ethiopic_extended-a 0xab00 0xab2f
Latin Extended-E latin_extended-e 0xab30 0xab6f
Cherokee Supplement cherokee_supplement 0xab70 0xabbf
Meetei Mayek meetei_mayek 0xabc0 0xabff
Hangul Syllables hangul_syllables 0xac00 0xd7af
Hangul Jamo Extended-B hangul_jamo_extended-b 0xd7b0 0xd7ff
High Surrogates high_surrogates 0xd800 0xdb7f
High Private Use Surrogates high_private_use_surrogates 0xdb80 0xdbff
Low Surrogates low_surrogates 0xdc00 0xdfff
Private Use Area private_use_area 0xe000 0xf8ff
CJK Compatibility Ideographs cjk_compatibility_ideographs 0xf900 0xfaff
Alphabetic Presentation Forms alphabetic_presentation_forms 0xfb00 0xfb4f
Arabic Presentation Forms-A arabic_presentation_forms-a 0xfb50 0xfdff
Variation Selectors variation_selectors 0xfe00 0xfe0f
Vertical Forms vertical_forms 0xfe10 0xfe1f
Combining Half Marks combining_half_marks 0xfe20 0xfe2f
CJK Compatibility Forms cjk_compatibility_forms 0xfe30 0xfe4f
Small Form Variants small_form_variants 0xfe50 0xfe6f
Arabic Presentation Forms-B arabic_presentation_forms-b 0xfe70 0xfeff
Halfwidth and Fullwidth Forms halfwidth_and_fullwidth_forms 0xff00 0xffef
Specials specials 0xfff0 0xffff


The second parameter is for specifying the font transparency level (1, 2, 4 or 8). If unspecified, the encoded transparency level is 1 (does not depend on transparency level encoded in EJF file).


  • myfont:latin:4: Embed all latin characters with 16 levels of transparency
  • myfont::2: Embed all characters with 4 levels of transparency

External Fonts

To fetch fonts from non-byte addressable external memory, the application must pre-register the external Font resources. The management of this kind of font may be different than the internal fonts and may require a dedicated heap. For more details about the external font management, refers to the VEE Port Guide chapter External Resources.

Font Generator Error Messages

Static Font Generator Error Messages
ID Type Description
0 Error The font generator has encountered an unexpected internal error.
1 Error The Fonts list file has not been specified.
2 Error The font generator cannot create the final, raw file.
3 Error The font generator cannot read the fonts list file.
4 Warning The font generator has found no font to generate.
5 Error The font generator cannot load the fonts list file.
6 Warning The specified font path is invalid: The font will be not converted.
7 Warning There are too many arguments on a line: the current entry is ignored.
8 Error The font generator has encountered an unexpected internal error (invalid output format).
9 Error The font generator has encountered an unexpected internal error (invalid endianness).
10 Error The specified entry is invalid.
11 Error The specified entry does not contain a list of characters.
12 Error The specified entry does not contain a list of identifiers.
13 Error The specified entry is an invalid width.
14 Error The specified entry is an invalid height.
15 Error The specified entry does not contain the characters’ addresses.
16 Error The specified entry does not contain the characters’ bitmaps.
17 Error The specified entry bits-per-pixel value is invalid.
18 Error The specified range is invalid.
19 Error There are too many identifiers. The output RAW format cannot store all identifiers.
20 Error The font’s name is too long. The output RAW format cannot store all name characters.
21 Error There are too many ranges. The output RAW format cannot store all ranges.
22 Error Output list files cannot be created.
23 Error Dynamic styles are not supported. Only a PLAIN font can be encoded.
24 Error Underlined style is not supported. Only a BOLD and ITALIC font can be set.

Default Character

The application may request the rendering of a string where some characters are not available in the selected font. In that case, a default character is drawn instead: it is the first available character in the font. For example, the first available character for a font where the range matches the ASCII printable characters (0x21-0x7E) would be the exclamation mark (0x21).

The characters of a font are referenced by their Unicode value. For a given font range, the default character is the first character of the first range. Consequently, the default character may not be the same for two given fonts of an application: it depends on the specified character range for each font.

To help developers identify quickly why a string is rendered with unexpected characters, it is recommended that the font maker sets a default character that is easy to recognize (a symbol, for example, a rectangle). This character must have the first character index (index 0 is allowed).

Caching Generated Fonts

Fonts converted using the Font Generator can be cached so that they are not rebuilt every time the application is launched. Doing so can significantly speed up the application build phase.

The cache is enabled by default. It may be disabled by setting the Application option ej.microui.fontConverter.disableCache to true.

The Font Generator obeys several rules when choosing whether a font should be converted.

  • If the cache is disabled, all fonts are generated every time the application is launched.
  • All fonts will be regenerated if the application is launched using another VEE port and the new VEE port uses a different Font Generator.
  • If the generated font does not exist, it will be generated.
  • If the source font has been modified since the last time it was converted, the font will be regenerated.
  • The font will be regenerated if the destination format or the range has been modified in the fonts.list file.

Cached fonts are stored in .cache/fonts, which is located in the application output folder. You may delete this directory to force the generation of all fonts in your application. A font that was previously generated but is no longer listed in the *.fonts.list files when the application is launched will be deleted from the cache directory.