list_counter

A Counter class that follows the specification outlined at https://www.w3.org/TR/css-lists-3/#auto-numbering.

The CounterStyle class represents styles that can be used to generate a text representation of the given counter's value (such as a 'iv' for 4, or 'β' for 2).

See https://www.w3.org/TR/css-counter-styles-3/#counter-styles for more details.

Getting started

Getting started is simple:

dependencies:
                  list_counter: ^1.0.2
                

Usage

void main() {
                  final counter = Counter('named_counter'); //You can also start a counter at a specific integer value with Counter('name', VALUE);
                  final listStyle = PredefinedCounterStyle.upperRoman;
                  
                  counter.increment(); // Adds 1 to the counter
                  print(listStyle.generateMarkerContent(counter.value));
                  // Prints "I. "
                 
                  counter.increment(2021); // Now the counter is at 2022
                  print(listStyle.generateMarkerContent(conter.value));
                  // Prints "MMXXII. "
                 
                  // Optionally, you can just print the result of the algorithm without any suffixes:
                  print(listStyle.generateCounterContent(counter.value));
                  // Prints "MMXXII"
                }
                

Predefined Counter Styles

A lengthy list of predefined counter styles is included!

Some of the most basic include:

• PredefinedCounterStyle.decimal (A simple ordered list)
• PredefinedCounterStyle.disc (A simple bulleted/unordered list)
• PredefinedCounterStyle.circle (A bulleted list with open circles)
• PredefinedCounterStyle.square (A bulleted list with square bullets)
• PredefinedCounterStyle.lowerAlpha (a, b, c, ..., z, aa, ab)

As well as dozens of language-specific number/alphabet systems, such as:

• PredefinedCounterStyle.cjkDecimal (〇 一 二 三 四 五 六 七 八 九 ...)
• PredefinedCounterStyle.cambodian (០ ១ ២ ៣ ៤ ៥ ៦ ៧ ៨ ៩ ...)
• PredefinedCounterStyle.katakana (ア イ ウ エ オ カ キ ク ...)
• PredefinedCounterStyle.koreanHangulFormal (일천일백일십일, etc.)
• PredefinedCounterStyle.simpChineseFormal (壹仟壹佰壹拾壹, etc.)

See https://www.w3.org/TR/css-counter-styles-3/#predefined-counters for the full list.

Custom Counter Styles

Or, you can define your own style:

// Sample additive style taken from https://www.w3.org/TR/css-counter-styles-3/#additive-system
                final diceStyle = CounterStyle.define(
                  name: 'dice-style',
                  system: System.additive,
                  additiveSymbols: {6: '⚅', 5: '⚄', 4: '⚃', 3: '⚂', 2: '⚁', 1: '⚀'},
                  suffix: " ",
                );
                

diceStyle will then produce lists that look like:

⚀  One
                ⚁  Two
                ⚂  Three
                ...
                ⚅⚄  Eleven
                ⚅⚅  Twelve
                ⚅⚅⚀  Thirteen
                

Using the CounterStyleRegistry

If wanted, you can also dynamically manage a library of CounterStyles using the static CounterStyleRegistry. It is automatically filled with all the predefined styles.

Here's how it can be used:

void main() {
                  // Optionally register your own styles:
                  CounterStyleRegistry.register(myCustomStyle);
                  // You can also overwrite any of the predefined styles:
                  CounterStyleRegistry.register(customDisc); 
                  // customDisc Has name "disc" to overwrite the default style in the registry
                  
                  // Elsewhere...
                  
                  // Lookup your custom style by its name to use it:
                  CounterStyleRegistry.lookup('my-custom-style');
                  // or lookup a predefined style:
                  CounterStyleRegistry.lookup('ethiopic-numeric');
                  
                  // Optionally...
                  CounterStyleRegistry.remove('my-custom-style');
                }
                

1.0.2

• Update README.md

1.0.1

• Add static CounterStyleRegistry to keep track of available styles
• Cleaned up files

1.0.0

• Add Chinese and Ethiopic number systems
• Extensive testing to ensure stability
• Graduate to production!

0.5.0

• Add more complex additive number systems (Korean/Japanese)

0.1.0

• Add example and additional documentation

0.0.1

• Initial release