Text-svg元素详解

Text-svg元素详解

http://www.eramx.com/forum/printthread.php?p=2494

Text-svg元素详解
 

本文为Scalable Vector Graphics (SVG) 1.1 Specification中text部分，学习笔记。

http://www.w3.org/TR/SVG11/text.html#TextElement

1.The 'text' element

主要属性有：x,y,dx,dy,rotate,textLength,lengthAdjust

x,y表示文本的横纵坐标。

dx,dy表示移动的横纵坐标。

rotate表示旋转的度数。

Example text01 : 
<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="10cm" height="3cm" viewBox="0 0 1000 300"
xmlns="http://www.w3.org/2000/svg" version="1.1">
<desc>Example text01 - 'Hello, out there' in blue</desc>
<text x="250" y="150" 
font-family="Verdana" font-size="55" fill="blue" >
Hello, out there
</text>
<!-- Show outline of canvas using 'rect' element -->
<rect x="1" y="1" width="998" height="298"
fill="none" stroke="blue" stroke-width="2" />
</svg>



效果展示：http://www.w3.org/TR/SVG11/images/text/text01.svg

2.tspan元素

Within a 'text' element, text and font properties and the current text position can be adjusted with absolute or relative coordinate values by including a 'tspan' element.

主要属性有：x,y,dx,dy,rotate,textLength,lengthAdjust

属性解释同上。

Example tspan01 

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="10cm" height="3cm" viewBox="0 0 1000 300"
xmlns="http://www.w3.org/2000/svg" version="1.1">
<desc>Example tspan01 - using tspan to change visual attributes</desc>
<g font-family="Verdana" font-size="45" >
<text x="200" y="150" fill="blue" >
You are
<tspan font-weight="bold" fill="red" >not</tspan>
a banana.
</text>
</g>
<!-- Show outline of canvas using 'rect' element -->
<rect x="1" y="1" width="998" height="298"
fill="none" stroke="blue" stroke-width="2" />
</svg>


效果展示：http://www.w3.org/TR/SVG11/images/text/tspan01.svg

Example tspan02 

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="10cm" height="3cm" viewBox="0 0 1000 300"
xmlns="http://www.w3.org/2000/svg" version="1.1">
<desc>Example tspan02 - using tspan's dx and dy attributes 
for incremental positioning adjustments</desc>
<g font-family="Verdana" font-size="45" >
<text x="200" y="150" fill="blue" >
But you
<tspan dx="2em" dy="-50" font-weight="bold" fill="red" >
are
</tspan>
<tspan dy="100">
a peach!
</tspan>
</text>
</g>
<!-- Show outline of canvas using 'rect' element -->
<rect x="1" y="1" width="998" height="298"
fill="none" stroke="blue" stroke-width="2" />
</svg>

效果展示：http://www.w3.org/TR/SVG11/images/text/tspan02.svg

3.tref元素

The textual content for a 'text' can be either character data directly embedded within the 'text' element or the character data content of a referenced element, where the referencing is specified with a 'tref' element

文本内容可以用text元素直接包含进来，或者用tref元素引用进来。

主要属性有：x,y,dx,dy,rotate,textLength,lengthAdjust,xlink:href

xlink:href属性指定引用的url。其他属性同上。

Example tref01 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="10cm" height="3cm" viewBox="0 0 1000 300"
xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink">
<defs>
<text id="ReferencedText">
Referenced character data
</text>
</defs>
<desc>Example tref01 - inline vs reference text content</desc>
<text x="100" y="100" font-size="45" fill="blue" >
Inline character data
</text>
<text x="100" y="200" font-size="45" fill="red" >
<tref xlink:href="#ReferencedText"/>
</text>
<!-- Show outline of canvas using 'rect' element -->
<rect x="1" y="1" width="998" height="298"
fill="none" stroke="blue" stroke-width="2" />
</svg>


<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="10cm" height="3cm" viewBox="0 0 1000 300"
xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink">
<defs>
<text id="ReferencedText">
Referenced character data
</text>
</defs>
<desc>Example tref01 - inline vs reference text content</desc>
<text x="100" y="100" font-size="45" fill="blue" >
Inline character data
</text>
<text x="100" y="200" font-size="45" fill="red" >
<tref xlink:href="#ReferencedText"/>
</text>
<!-- Show outline of canvas using 'rect' element -->
<rect x="1" y="1" width="998" height="298"
fill="none" stroke="blue" stroke-width="2" />
</svg>

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="10cm" height="3cm" viewBox="0 0 1000 300"
xmlns="http://www.w3.org/2000/svg" version="1.1"
xmlns:xlink="http://www.w3.org/1999/xlink">
<defs>
<text id="ReferencedText">
Referenced character data
</text>
</defs>
<desc>Example tref01 - inline vs reference text content</desc>
<text x="100" y="100" font-size="45" fill="blue" >
Inline character data
</text>
<text x="100" y="200" font-size="45" fill="red" >
<tref xlink:href="#ReferencedText"/>
</text>
<!-- Show outline of canvas using 'rect' element -->
<rect x="1" y="1" width="998" height="298"
fill="none" stroke="blue" stroke-width="2" />
</svg>

效果展示：http://www.w3.org/TR/SVG11/images/text/tref01.svg

4.Text layout

'writing-mode' lr-tb | rl-tb | tb-rl | lr | rl | tb | inherit 
本属性仅仅用于text元素，在 'tspan', 'tref', 'altGlyph' 和 'textPath'自元素中将忽略。 
当文字竖排时，可以用'glyph-orientation-vertical' 属性来具体设置 
'glyph-orientation-vertical' auto | <angle> | inherit 
当文字横排时，可以用'glyph-orientation-horizontal' 属性来具体设置 
'glyph-orientation-horizontal' <angle> | inherit 
以上两属性的angle只能是90的倍数 

'direction' ltr | rtl | inherit 
direction属性设置文本的排列方式。 
要使direction属性生效，'unicode-bidi' 属性的值必须为'embed' 或者 'bidi-override'. 
'unicode-bidi' normal | embed | bidi-override | inherit 
unicode-bidi属性设置文本的双向方式。 
Example layout01

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="10cm" height="5cm" viewBox="0 0 1000 500" xmlns="http://www.w3.org/2000/svg" version="1.1" xmlns:xlink="http://www.w3.org/1999/xlink"> 
<defs> 
<text id="myText">This is a test!</text>
</defs>
<desc>Example tref01 - inline vs reference text content</desc>
<text font-size="60" fill="blue" font-family="Verdana">
<tref xlink:href="#myText" x="20" y="50"/>
</text>
<!-- 文字水平排列时，利用 glyph-orientation-horizontal属性来设置文layout -->
<text font-size="60" fill="blue" font-family="Verdana">
<tref xlink:href="#myText" x="20" y="130" glyph-orientation-horizontal="180"/>
</text>
<!-- 当unicode-bidi属性值为embed或bidi-override时， 利用direction来设置文字layout -->
<text font-size="60" fill="blue" font-family="Verdana">
<tref xlink:href="#myText" x="20" y="210" direction="rtl" unicode-bidi="bidi-override"/>
</text>
<!-- 利用writing-mode属性设置文字layout -->
<text x="800" y="20" writing-mode="tb" font-size="60" fill="blue" font-family="Verdana">
This is a test!
</text> 
<!-- 文字竖直排列时， 利用glyph-orientation-vertical属性来设置文字layout --> <text x="900" y="20" font-size="60" fill="blue" font-family="Verdana" writing-mode="tb" glyph-orientation-vertical="270"> 
This is a test!
</text>
<!-- Show outline of canvas using 'rect' element -->
<rect x="1" y="1" width="998" height="498" fill="none" stroke="blue" stroke-width="2" />
</svg>
自己保存成.svg观看效果。文中有中文注释，所以可能要保存utf-8格式，方可正常显示。

5.Alignment properties

'text-anchor' start | middle | end | inherit

text-anchor设置文本的排列属性。

6.Font selection properties

'font-family' 

'font-style' normal | italic | oblique | inherit

'font-variant' normal | small-caps | inherit

'font-weight' normal | bold | bolder | lighter | 100 | 200 | 300| 400 | 500 | 600 | 700 | 800| 
900 | inherit

'font-stretch' normal | wider | narrower |ultra-condensed | extra-condensed |condensed | 
semi-condensed |semi-expanded | expanded |extra-expanded | ultra-expanded |
inherit 

'font-size' <absolute-size> | <relative-size> |<length> | <percentage> | inherit

7.Spacing properties 
'kerning' auto | <length> | inherit

'letter-spacing' normal | <length> | inherit

'word-spacing' normal | <length> | inherit

8.Text decoration

'text-decoration' none | [ underline || overline || line-through || blink ] | inherit

Example textdecoration01

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="12cm" height="4cm" viewBox="0 0 1200 400"
xmlns="http://www.w3.org/2000/svg" version="1.1">
<desc>Example textdecoration01 - behavior of 'text-decoration' property</desc>
<rect x="1" y="1" width="1198" height="398" fill="none" stroke="blue" stroke-width="2" />
<g font-size="60" fill="blue" stroke="red" stroke-width="1" >
<text x="100" y="75">Normal text</text>
<text x="100" y="165" text-decoration="line-through" > Text with line-through </text>
<text x="100" y="255" text-decoration="underline" > Underlined text </text>
<text x="100" y="345" text-decoration="underline" >
<tspan>One </tspan>
<tspan fill="yellow" stroke="purple" >word </tspan>
<tspan fill="yellow" stroke="black" >has </tspan>
<tspan fill="yellow" stroke="darkgreen" text-decoration="underline" >different </tspan>
<tspan fill="yellow" stroke="blue" >underlining</tspan>
</text>
</g>
</svg>

效果展示：http://www.w3.org/TR/SVG11/images/te...coration01.svg

9.text on path

主要属性有：startOffset,textLength,lengthAdjust,method,spacing 
startOffset设置文字开始的位置。startOffset = "<length>" 
method设置文字与路径的位置关系。method = "align | stretch" align为默认值。
spacing设置文字与路径的空间。spacing = "auto | exact" exact为默认值。
xlink:href设置绑定的路径。

Example toap01

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg width="12cm" height="3.6cm" viewBox="0 0 1000 300" version="1.1" xmlns=http://www.w3.org/2000/svg xmlns:xlink="http://www.w3.org/1999/xlink">
<defs>
<path id="MyPath"
d="M 100 200 
C 200 100 300 0 400 100
C 500 200 600 300 700 200
C 800 100 900 100 900 100" />
</defs>
<desc>Example toap02 - tspan within textPath</desc>
<use xlink:href="#MyPath" fill="none" stroke="red" />
<text font-family="Verdana" font-size="42.5" fill="blue" >
<textPath xlink:href="#MyPath">
We go 
<tspan dy="-30" fill="red" >
up
</tspan>
<tspan dy="30">
,
</tspan>
then we go down, then up again
</textPath>
</text>
<!-- Show outline of canvas using 'rect' element -->
<rect x="1" y="1" width="998" height="298"
fill="none" stroke="blue" stroke-width="2" />
</svg>

效果展示：http://www.w3.org/TR/SVG11/images/text/toap02.svg

10.White space handling

xml:space default|preserve