脚麻是什么病的前兆| 铎读什么| 真相是什么意思| 左下腹疼痛是什么原因| 包皮手术后吃什么伤口愈合快| 什么味道| 病人化疗期间吃什么好| 紫荆花代表什么生肖| 厚植是什么意思| 粉红色泡沫样痰是什么病| 香槟玫瑰花语是什么意思| 跳蚤怕什么东西| 什么什么的荷叶| 女性睾酮高说明什么| 荤菜是什么意思| 血脂高低看什么指标| 尚书是什么官| 护理部主任是什么级别| ml是什么单位| 金骏眉茶是什么茶| 人发胖的原因是什么引起的| 中国梦是什么意思| 韧带拉伤用什么药好| 多吃洋葱有什么好处| 高血糖适合吃什么主食| 中国国酒是什么| 兰花叶子发黄是什么原因| 鸡眼用什么药| 没有料酒用什么去腥| 枸杞泡水喝有什么作用和功效| 石足念什么| 什么是认知障碍| 152是什么意思| 鱼石脂是什么| 蛋白粉吃了有什么好处| igg是什么意思| 五脏六腑是什么意思| 孩子一直咳嗽不好是什么原因| 做肠镜要做什么准备| 骞字五行属什么| tags是什么意思| 厘清和理清的区别是什么| 胃溃疡是什么意思| 怀孕前三个月需要注意什么| 什么是抽动症| 钟鸣鼎食是什么意思| 节瓜是什么瓜| 落成是什么意思| 寅木是什么木| 洛阳有什么好玩的| 敲定是什么意思| 电灯泡什么意思| 韭菜有什么功效| 清洁度lv是什么意思| 吃什么通便| 避孕套有什么牌子| 逆钟向转位什么意思| 战战兢兢的意思是什么| 红细胞是什么| 脚背有痣代表什么| 心脏病是什么原因引起的| qty什么意思| 病理会诊是什么意思| 笑靥如花是什么意思| 验大便能查出什么| 女人左下眼皮跳是什么预兆| 梦见黄瓜是什么意思| 夜字五行属什么| 为什么高血压| 慢性肠胃炎吃什么药| 一什么宝石| 枉是什么意思| 烧酒是什么酒| 什么是量子力学| 出柜是什么意思| 1m是什么意思| 3月18是什么星座| 什么的森林| 五色土有什么风水作用| 瑗字五行属什么| 什么是阴虚| 长期戴耳机有什么危害| 尼可刹米别名叫什么| 性激素六项什么时候查最准确| 白领是什么| 多囊卵巢综合征是什么意思| 火碱是什么东西| 吃什么药降尿酸快| 为什么会长瘊子| 集成灶什么品牌最好| 易胖体质是什么原因造成的| 什么是海市蜃楼| 是什么日子| 天秤座什么象星座| 什么奶粉好啊| 断奶吃什么药| 耳垂长痘痘是什么原因| 均质是什么意思| 梦见蛇代表什么| 吃螃蟹不能喝什么饮料| 野鸭子吃什么| 梦见鬼是什么意思| 贝母和川贝有什么区别| 血管炎吃什么药| 靠北是什么意思| 性生活是什么感觉| 湿疹吃什么药好| 心火旺吃什么| 蔬菜有什么| 帕金森看什么科室| 葛根是什么| 黄晓明和杨颖什么时候结婚的| 精不液化是什么原因导致的| 性激素六项什么时候查最准确| 脸色苍白没有血色是什么原因| 耳鸣是什么| 胰腺炎是什么症状| 99朵玫瑰花代表什么| 十二朵玫瑰花代表什么意思| 蘑菇是什么| 任什么任什么| 女孩什么时辰出生最好| p是什么意思| kamagra是什么药| 黄油可以用什么代替| cp是什么意思| 嘴唇发黑是什么症状| 两只小船儿孤孤零零是什么歌| 发烧呕吐吃什么药| 血栓是什么意思| 梦见卖衣服是什么意思| 床上为什么会有跳蚤| gly是什么氨基酸| 毛片是什么| 补肾益精是什么意思| 林黛玉和贾宝玉是什么关系| 男性尿频尿急吃什么药| 强的松又叫什么| 7月18号是什么日子| 为什么脖子上会长痘痘| 肛门瘙痒看什么科| 结石吃什么好| 什么食物降血压| 女人绝经一般在什么年龄段| 英纳格手表什么档次| 讹诈是什么意思| 甲状腺炎有什么症状| 红日是什么意思| x射线是什么| 白茶泡出来是什么颜色| 969368是什么电话| 上日下成念什么| 五三年属什么生肖| 金是什么结构的字| 腚什么意思| 雨水是什么意思| 不等是什么意思| 姊妹是什么意思| 甲状腺在什么位置| 米虫长什么样| 乳头痒什么原因| 过早是什么意思| mm代表什么| 结婚28年是什么婚| 北齐是什么朝代| 口腔溃疡是缺什么| 什么是偏旁什么是部首| 右眼一直跳是什么原因| 六味地黄丸什么牌子的好| 嘴角起痘是什么原因| 前列腺炎吃什么药效果好见效快| 陈真属什么生肖| 9月3号是什么节日| 孕妇什么时候吃dha效果比较好| 青蛙吃什么东西| 吃羊肉不能吃什么| 眼睛疲劳用什么眼药水| 税号是什么| 韧带和筋有什么区别| 川芎有什么功效与作用| 风声鹤唳的意思是什么| 身体素质是什么意思| 拉不出来屎是什么原因| 大兴安岭属于什么市| 4.28是什么星座| 30岁以上适合用什么牌子的护肤品| 阿咖酚散是什么| 谷丙转氨酶高吃什么药| 随喜功德是什么意思| 深入交流是什么意思| 蜈蚣长什么样子| 目敢念什么| 摩羯后面是什么星座| 开瑞坦是什么药| 铁剂什么时候吃最好| 同病相怜什么意思| 无名指比中指长代表什么| 子痫是什么病| 饭后胃疼是什么原因| 喉咙痛喝什么饮料| 职业年金什么时候领取| 5月7日什么星座| 小狗可以吃什么| 性激素检查是查什么| 樱花的花语是什么| 钟馗是什么人物| 皮囊炎用什么药膏| 胎位左枕前是什么意思| 听调不听宣什么意思| 晚上吃什么饭| 幼儿贫血吃什么补血最快| 手上起小水泡是什么原因| 显赫是什么意思| hcy是什么意思| 办身份证要穿什么衣服| 尿潜血是什么原因造成的| 正常高压是什么意思| 兰州人为什么要戴头巾| 痰多吃什么好| 肚子痛什么原因| 沉鱼落雁闭月羞花是什么意思| 煮茶叶蛋用什么茶| 头发掉什么原因| 茶叶水洗脸有什么好处| bug是什么意思网络用语| 海虹是什么| 雷达是什么| 3月7日什么星座| 血红蛋白低吃什么| 星链是什么| 牛肉和什么菜炒好吃| 左氧氟沙星是什么药| 刘玄德属什么生肖| 梦见自己来月经了什么预兆| 性激素六项挂什么科| 咖啡喝多了有什么危害| 蛇和什么相冲| 经常腿抽筋是什么原因| 圣女果是什么水果| 通房是什么意思| 补肾吃什么药| 耐克属于什么档次| btc是什么货币| 深海鱼油的作用是什么| http什么意思| 来例假可以吃什么水果| 猫屎为什么那么臭| 口腔老是出血是什么原因| 扫把星什么意思| 棺材一般用什么木头| 突然视力模糊是什么原因引起的| 尿酸高吃什么降的快| 经常放屁是什么原因造成的| 陷阱是什么意思| 为什么会长疤痕疙瘩| 不到长城非好汉的下一句是什么| b族维生素什么人不能吃| 零点是什么意思| 农历5月25日是什么星座| 顺字五行属什么| 伊朗是什么派| 三月八号什么星座| 肚脐中间疼是什么原因| 肝内低密度影是什么意思| 百度

车讯:搭载新动力系统 新款Macan有望今年亮相

百度 项目总面积近17000平方米。

This article gives a high level summary of various typographic strategies for fully justifying text on a line and in a paragraph for a variety of scripts, and offers some advice to authors and implementers.

Since the amount of content on a line tends to vary, even if minutely, from line to line within a paragraph, typographers have come up with various methods for effective full justification – causing the text to completely fill the line – in order to create visual alignment on both edges of a paragraph.

Typographic conventions for full text justification depend on the writing system, the content language, and the calligraphic style of the text. Results also tend to vary based on the capabilities of the layout engine and a given typographer’s preferences for weighing its various detrimental effects on typographic color and readability.

This article provides a hint at some of the different strategies used in different writing systems, but the devil is very much in the detail. Furthermore, other factors such as line-break rules, hyphenation, and other inline features, have to be taken into account during justification.

For more detailed information about how justification happens in various scripts, see the International text layout and typography index.

A survey of script behaviors

Chinese Writing System (Han Ideographs)

Historically, Chinese was written as Han ideographs, with no punctuation. Under this system, justification was automatic, as the characters fit perfectly into a square grid, and lines could wrap between any two characters. However, the introduction of punctuation in recent centuries, along with its accompanying line-breaking restrictions, plus the increase in mixed-script text (such as the inclusion of European numbers and/or words, phrases, names, and trademarks) has created a need for adjustments within a line.

Punctuation introduced line-breaking restrictions such as not starting a line with a period or closing parentheses; and Latin text, while sometimes typeset in a full-width character style with Chinese-style line-breaking, is also frequently typeset with proportional fonts and line-wrapped or hyphenated according to its usual rules, breaking the Chinese grid. These newer developments thus open up space at the end of a line, which justification needs to deal with.

Chinese notably does not use word spaces, so these do not provide a justification opportunity within the lines; thus justification techniques focus on adjustments to spacing around punctuation, script-change boundaries, and inter-character spacing.

Japanese Writing System

Like Chinese, Japanese was historically written in Han ideographs; however it has since developed its own phonetic scripts Hiragana and Katakana (collectively, Kana). While pure kana texts do exist, particularly in children’s literature, Han ideographs (Kanji, in Japanese) continue to be an integral part of normal Japanese text, and are interspersed with kana within a sentence.

Like Chinese, Japanese embraced European-inspired punctuation, numerals, and other foreign snippets that don’t conform to the standard full-width character grid. The Japanese writing system also does not use word spaces, and similarly focuses on adjustments to spacing around punctuation, script-change boundaries, and inter-character spacing, with a notable preference for compression of intra-glyph spacing over expansion between glyphs.

Example of Japanese justification.
Examples of Japanese justification (from jlreq)

Punctuation normally fits in the same square glyph as ideographic and kana characters, but typically leaves a substantial part of that square blank. When attempting to justify text on a line, justification may reduce the blank space in such glyphs first, before attempting other strategies.

Korean Writing System

Like Japanese, Korean was historically written in pure Han ideographs, but long ago developed its own phonetic script, Hangul, which has mostly supplanted ideographs in modern Korean writing.

While Han ideographs (Hanja, in Korean) were kept as part of the writing system, they have become increasingly scarce over time such that many documents are written in pure Hangul, and some only use Hanja in a limited way for things such as proper nouns, or dates, or as inline annotations for disambiguation among homophones rather than as part of the main text. However, Hanja and Hangul together remain important components of Korean writing.

Like Japanese, Korean adopted punctuation and numerals. However, unlike Japanese, Korean also adopted word spaces, and tends towards narrow (Western-style, rather than full-width) punctuation.

The word spaces allow Korean to use inter-word justification: as in English publications, this method adjusts the spaces between words in order to fill the line. However, unlike English, modern Korean normally wraps characters rather than whole words to a new line when the end of a line is reached. This can to some extent reduce the difficulty of justifying text.

Latin (Roman) Writing System

Quite possibly the writing system familiar to more people than any other, the Latin writing system derives from the Roman alphabet, including a few additional characters and diacritic marks to accommodate languages such as Icelandic and modern Vietnamese. Thanks to the Europeans in the Age of Exploration, their missionaries, and the Western-dominated global scholastic culture of the modern age, most languages in the world have one or more Latin transcriptions, even those that do not use it as their primary writing system.

The Latin alphabet is a phonetic system with disjoint letterforms, and typically uses spaces between words. This allows it to use inter-word justification, although it can and sometimes does adjust the spacing between individual letters as well. Line breaks generally occur between words, although hyphenation is also allowed to reduce the variance in line lengths.

Since text in Latin script is frequently adopted into other writing systems, it can sometimes take on characteristics of that system; for example, some styles of Japanese typesetting treat Latin letters the same as Japanese characters for the purpose of line-breaking and justification.

Ethiopic Writing System

Like Latin, the Ethiopic writing system uses an alphabet of disjoint letters and uses punctuation to indicate the break between words. Unlike Latin, Ethiopic traditionally uses a visible word separator – the ETHIOPIC WORD SPACE U+1361 ? although modern documents usually use a regular space U+0020 “ ” instead. Justification strategies are as for Latin: increasing the space at the word separator, and/or distributing space between letters.

Because the traditional word space is visible, the question arises as to whether it should stay with the previous word or be centred between words when the space between words is stretched. Both approaches are attested. A similar question arises for the ETHIOPIC FULL STOP U+1362 ?: in some cases the author may prefer that the space to the right side of the full stop is “more elastic”, rather than stretching the space around it equally.

Example
Word-bound wordspace in justified Ethiopic text (from elreq).

Arabic Writing System (and Other Cursive Systems)

Arabic is a cursive script, meaning its letters are typically joined together within a word. This creates additional challenges, and opportunities for full justification.

Since Arabic uses spaces between words, one method for justification is inter-word justification – stretching out the spaces within the line to fill it. However, Arabic writing also allows for calligraphic elongation or compression, distorting the shapes and connections between letters in order to fill the line while preserving its typographic color.

For example, baseline connections may be stretched (kashida), or alternate forms of glyphs, including ligated forms, may be used to lengthen or shorten words. There tend to be complex rules for the use of such techniques, which may depend on things such as the number of syllables in a word, or the proximity of a word to the start of the line, etc. The applicability of such techniques also tends to vary across different font styles, such as naskh, nasta?līq, and ruq?a. Ruq?a font styles avoid elongation techniques for justification.

A simplistic variant of the kashida technique inserts baseline elongation marks (U+0640 TATWEEL ?) at appropriate points in the text to produce justified lines, but the result is generally regarded as ugly. Depending on the implementation, it may also affect operations such as copy-paste, and searching. It is a particular problem for browser-based text, if content authors add tatweels to their source text, since stretching the browser window will invalidate the distribution of the tatweel characters.

Example
Simple baseline extensions used to justify Arabic script text.

Syriac and Mongolian have properties similar to Arabic, and in the absence of additional information should be given similar treatment for justification.

Tibetan Writing System

Tibetan is a Brahmic writing system related to Indic scripts like Devanagari and Gujarati; however, unlike these systems, it does not use Western-style punctuation nor spaces between words, and instead uses the TIBETAN MARK INTERSYLLABIC TSHEG U+0F0B ? between individual syllables (regardless of word boundaries), and has its own punctuation marks such as the TIBETAN MARK SHAD U+0F0D ? and TIBETAN MARK NYIS SHAD U+0F0E ?, which indicate the end of longer segments.

Justification techniques used in Tibetan include stretching the space after a shad, minutely increasing the spaces after tsheg marks, and simply filling the remaining space on a line with tsheg marks.

Example
Tsek marks used to fill line-end spaces in Tibetan.

South & Southeast Asian Writing Systems

Tamil has many very long words, and in Tamil news columns it may not be possible to fit more than a single word on a line. In such cases it is common to stretch the word to fit the whole width of the line. To do so, equal space is added between each non-connected glyph across the line. Space is inserted evenly between the unconnected glyphs, regardless of whether a glyph is part of a syllabic cluster, or even a single code point.

An example from a news column of a single word stretched to the line width (middle line).

The figure just below illustrates how this stretching is based on glyphs, and is independent of the underlying code points.

Tamil glyph separation. The vowel-signs are coloured, and on the top line the grapheme-cluster boundaries are shown with thin vertical lines. The first vowel-sign is a circumgraph (ie. a single code point that renders glyphs on more than one side of the base). The bottom line shows how this word would be expanded to fill a line. View characters.

Note the following:

  1. The sequence of three items on the far left is actually composed of only two code points, [U+0B95 TAMIL LETTER KA] followed by the circumgraph [U+0BCC TAMIL VOWEL SIGN AU]. Notice that there are spaces between the base consonant and both glyphs that make up the vowel-sign.
  2. To its immediate right, the base character and combining mark that make up the middle syllable have been split apart, so the units are codepoints rather than grapheme clusters.
  3. The last grapheme cluster (on the right) is kept intact, because the vowel-sign is joined to the base consonant.

In Southeast Asian systems such as Thai and Lao, there are no spaces between words, but spaces serve to separate larger units of text. However, lines are still broken at (invisible) word boundaries, and the text may be stretched to make the line ends flush. If there are no spaces on a line, or if expanding the spaces produces gaps that are too large, similar glyph-based algorithms may be applied to the text in order to produce the expansion needed.

Other Writing Systems

Most (but not all) writing systems not mentioned here have discrete letters, like Latin, and in the absence of more specific information may be assumed to justify in a similar manner.

Readers who wish to provide such “more specific information” are invited (and strongly encouraged) to create a github issue so that we can add information or links to this article and the typography index.

Advice for implementers and authors

In this section we provide additional advice for implementers and content authors related to justification.

Tagging content for language

Authors should use (correct) language tags in order to get the best possible typographic behavior. For example, if Japanese text is tagged as Japanese, the user agent knows to preferentially compress the space rather than expand it. If Latin text is labelled as German, the user agent knows to avoid inter-character spacing, since that may signify emphasis to German readers.

For information about how to tag HTML for language, see Language tags in HTML and XML.

Justifying untagged content

Web browsers frequently have to deal with untagged, potentially mixed-script content. The following are some implementation guidelines for designing a strategy to deal with such content.

盐碱地适合种什么农作物 九个月的宝宝吃什么辅食食谱 专柜是什么意思 感冒发烧吃点什么食物比较好 双十一从什么时候开始
为什么受伤的总是我 吃什么对前列腺有好处 苏小小属什么生肖 宫高是什么意思 吃什么可以调理肠胃
mtd是什么意思 卵巢早衰吃什么药调理最好 与生俱来是什么意思 上海有什么景点 女人腰疼是什么原因引起的
压马路是什么意思 凌晨四点醒是什么原因 吃什么东西对肺部好 什么是脊柱侧弯 女性腋臭什么年龄消失
陆家嘴为什么叫陆家嘴hcv8jop6ns2r.cn 小肚子突出是什么原因hcv8jop6ns7r.cn 刀郎和那英是什么关系hcv7jop7ns1r.cn 黑皮肤适合穿什么颜色的衣服hcv9jop7ns0r.cn 经常想吐恶心是什么原因fenrenren.com
一个西一个米念什么hcv9jop5ns7r.cn 什么是碳水化合物食物hcv7jop4ns6r.cn 11年是什么婚hcv9jop7ns0r.cn 一暴十寒什么意思cj623037.com 用你的手解我的锁是什么歌hcv9jop3ns6r.cn
画地为牢什么意思hcv9jop6ns7r.cn 蚕豆病是什么病有什么症状hcv8jop7ns2r.cn 桂花像什么hcv8jop5ns7r.cn 频繁感冒是什么原因xscnpatent.com 什么是网约车hcv9jop2ns1r.cn
狗为什么不吃饭hcv8jop8ns3r.cn aqi是什么hcv7jop5ns5r.cn 湿疹是什么病的前兆hcv9jop5ns4r.cn 为什么会闰月hcv9jop5ns7r.cn 荣辱与共是什么生肖hlguo.com
百度