ひらがなとカタカナのトラッキングクラス

LetterTracking.coffee

class LetterTracking
	constructor: ($target) ->
		$target.each((i, elem)=>
			$elem = $(elem)
			aTag = $elem.find('a');
			if (@hasATag(aTag))
				$elem = aTag

			text = $elem.text()
			spanText = @wrapSpan(text)
			$elem.html(spanText)
		)

	hasATag:(aTag)->
		return aTag.length > 0


	wrapSpan:(text)->
		textLength = text.length
		spanText = ''
		for i in [0..textLength]
			letter = text.charAt(i)
			if (@notLast(i, textLength))
				spanText += @getSpan letter, text.charAt(i + 1)
			else
				spanText += letter
		return spanText

	notLast: (i, textLength)->
		return i <= textLength - 1

	getSpan: (letter, nextString)->
		code = nextString.charCodeAt(0)
		if @isKigou(letter.charCodeAt(0))
			result = "<span class='kigou'>#{letter}</span>"
		else if @isHiraganaOrKatakana(code)
			result = "<span>#{letter}</span>"
		else
			result = letter
		return result

	isHiraganaOrKatakana: (code)->
		return @hiragana(code) || @katakana(code) || @isKigou(code)

	hiragana:(code)->
		return 0x3040 <= code <= 0x309f

	katakana:(code)->
		return 0x30a0 <= code <= 0x30ff

	#いまのところ句読点→、。だけ
	isKigou:(code)->
		return 12289 <= code <= 12290



window.LetterTracking = LetterTracking

text.less

.postTitle {
	font-size: 250%;
	line-height: 1.25;
	word-wrap: break-word;

	span {
		letter-spacing: -0.13em;
		&.kigou {
			letter-spacing: -0.23em;
		}
	}

	
}