21 Commits

Author SHA1 Message Date
Vadim Namniak ffcaf3425c Update README.md 2015-01-25 15:27:49 -05:00
Vadim Namniak 365bd4e24c Update README.md 2015-01-25 15:27:19 -05:00
Vadim Namniak 96001e64df Update README.md 2015-01-25 15:26:14 -05:00
Vadim Namniak 49fea5c2bb Update README.md 2015-01-25 15:23:53 -05:00
Vadim Namniak 020d1dee52 Update README.md 2015-01-25 15:22:28 -05:00
Vadim Namniak c75fae5ea0 Update README.md 2015-01-25 15:18:39 -05:00
Vadim Namniak 9b2c460a69 v0.3.0 justifyLines, lineHeight and allowNewLine 2015-01-25 14:53:51 -05:00
Vadim Namniak 055cdaeb13 version updates 2014-10-12 11:04:53 -04:00
Vadim Namniak cfdccc0c61 version update 2014-10-12 11:03:27 -04:00
Vadim Namniak bb707cd508 Update README.md 2014-10-12 10:49:45 -04:00
Vadim Namniak 8dda2cb645 Update README.md 2014-10-12 10:37:29 -04:00
Vadim Namniak 7e3d425769 Update README.md 2014-10-12 01:57:56 -04:00
Vadim Namniak 6e03f629ce Merge pull request #3 from gmjosack/master
Add the ability to stroke text.
2014-10-12 01:32:44 -04:00
Gary M. Josack ebb8908812 Add the ability to stroke text.
This is useful in scenarios where a background is many colors.
2014-10-11 21:33:06 -07:00
Vadim Namniak 30c326ed36 Update README.md 2014-10-08 23:03:57 -04:00
Vadim Namniak f464af8c5d context fixes + default font size added 2014-10-08 22:53:50 -04:00
Vadim Namniak 5b7a7f9cfe Merge pull request #2 from peeinears/master
Added sizeToFill option for resizing text to fill its padded container
2014-10-08 21:34:52 -04:00
Ian Pearce 45a2b83782 Do not break text when sizeToFill is on 2014-10-06 12:15:49 +08:00
Ian Pearce 43c8775359 Run grunt 2014-10-06 03:07:23 +08:00
Ian Pearce 4924f6f06a Slightly DRYer 2014-10-06 03:05:27 +08:00
Ian Pearce 60c009b432 Added sizeToFill option for resizing text to fill its container 2014-10-06 03:00:53 +08:00
6 changed files with 309 additions and 199 deletions
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examples
examples/
.idea/
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/*! CanvasTextWrapper (https://github.com/namniak/CanvasTextWrapper)
* Version: 0.1.0
*
/*! CanvasTextWrapper
* https://github.com/namniak/CanvasTextWrapper
* Version: 0.3.0
* MIT License (http://www.opensource.org/licenses/mit-license.html)
* Copyright (c) 2014 Vadim Namniak
*/
(function() {
'use strict';
'use strict';
var defaultOptions = {
font: '18px Arial, sans-serif',
textAlign: 'left', // each line of text is aligned left
verticalAlign: 'top', // text lines block is aligned top
paddingX: 0, // zero px left & right text padding relative to canvas or parent
paddingY: 0, // zero px top & bottom text padding relative to canvas or parent
fitParent: false, // text is tested to fit canvas width
lineBreak: 'auto' // text fills the element's (canvas or parent) width going to a new line on a whole word
};
var EL_WIDTH,EL_HEIGHT,MAX_TXT_WIDTH,MAX_TXT_HEIGHT;
window.CanvasTextWrapper = function(canvas, text, opts) {
var defaults = {
font: '18px Arial, sans-serif',
sizeToFill: false, // text is resized to fill the container (given font size is ignored)
lineHeight: 1, // default line height equivalent of '100%'
allowNewLine: true, // breaks text on every new line character '\n'
lineBreak: 'auto', // text fills the element's (canvas or parent) width going to a new line on a whole word
textAlign: 'left', // each line of text is aligned left
verticalAlign: 'top', // text lines block is aligned top
justifyLines: false, // lines are not justified
paddingX: 0, // 0px left & right text padding relatively to canvas or its container
paddingY: 0, // 0px top & bottom text padding relatively to canvas or its container
fitParent: false, // text is set to fit canvas width
strokeText: false // text is stroked according to context configuration
};
if (!(this instanceof CanvasTextWrapper)) {
throw new TypeError('CanvasTextWrapper constructor failed. Use "new" keyword when instantiating.');
}
var CanvasTextWrapper = function(canvas,text,options) {
if (!(this instanceof CanvasTextWrapper)) {
return new CanvasTextWrapper(canvas,text,options);
}
this.canvas = canvas;
this.text = text;
this.canvas = canvas;
this.text = text;
this.context = this.canvas.getContext('2d');
this.context.font = this.font;
this.context.textBaseline = 'bottom';
// set options to specified or default values
for (var property in defaultOptions) {
this[property] = (opts && opts[property]) ? opts[property] : defaultOptions[property];
}
for (var property in defaults) {
if (defaults.hasOwnProperty(property)) {
this[property] = (options && options[property]) ? options[property] : defaults[property];
}
}
// extract font size
this.lineHeight = parseInt(this.font.replace(/^\D+/g, ''), 10);
EL_WIDTH = (this.fitParent === false) ? this.canvas.width : this.canvas.parentNode.clientWidth;
EL_HEIGHT = (this.fitParent === false) ? this.canvas.height : this.canvas.parentNode.clientHeight;
MAX_TXT_WIDTH = EL_WIDTH - (this.paddingX * 2);
MAX_TXT_HEIGHT = EL_HEIGHT - (this.paddingY * 2);
// validate all set properties
this.validate();
this._init();
};
// basic context settings
this.context = this.canvas.getContext('2d');
this.context.font = this.font;
this.context.textBaseline = 'bottom';
CanvasTextWrapper.prototype = {
_init: function() {
this.fontSize = parseInt(this.font.replace(/^\D+/g,''),10) || 18;
this.textBlockHeight = 0;
this.lines = [];
this.newLineIndexes = [];
this.textPos = {x: 0,y: 0};
this.drawText();
};
this._setFont(this.fontSize);
this._setLineHeight();
this._validate();
this._render();
},
CanvasTextWrapper.prototype = {
_render: function() {
if (this.sizeToFill) {
var numWords = this.text.trim().split(/\s+/).length;
var fontSize = 0;
drawText: function() {
var canvas = this.canvas;
var context = canvas.getContext('2d');
do {
this._setFont(++fontSize);
this.lineHeight = this.fontSize;
this._wrap();
} while (this.textBlockHeight < MAX_TXT_HEIGHT && (this.lines.join(' ').split(/\s+/).length == numWords));
var elementWidth = (this.fitParent === false) ? canvas.width : canvas.parentNode.clientWidth;
var maxTextLength = elementWidth - (this.paddingX * 2);
this._setFont(--fontSize);
this.lineHeight = this.fontSize;
} else {
this._wrap();
}
var words = this.text.split(/\s+/);
var lines = [];
var textPos = {
x: 0,
y: 0
};
if (this.justifyLines && this.lineBreak === 'auto') {
this._justify();
}
this.checkWordsLength(context, words, maxTextLength);
this.breakTextIntoLines(context, lines, words, maxTextLength);
this._setAlignY();
this._drawText();
},
// height of the broken down into lines text
var textBlockHeight = lines.length * this.lineHeight;
_setFont: function(fontSize) {
var fontParts = (!this.sizeToFill) ? this.font.split(/\b\d+px\b/i) : this.context.font.split(/\b\d+px\b/i);
this.context.font = fontParts[0] + fontSize + 'px' + fontParts[1];
this.fontSize = fontSize;
},
// set vertical align for the whole text block
this.setTextVerticalAlign(textPos, textBlockHeight);
_setLineHeight: function() {
if (!isNaN(this.lineHeight)) {
this.lineHeight = this.fontSize * this.lineHeight;
} else if (this.lineHeight.toString().indexOf('px') !== -1) {
this.lineHeight = parseInt(this.lineHeight);
} else if (this.lineHeight.toString().indexOf('%') !== -1) {
this.lineHeight = (parseInt(this.lineHeight) / 100) * this.fontSize;
}
},
for (var i = 0; i < lines.length; i++) {
this.setTextHorizontalAlign(context, textPos, elementWidth, lines[i]);
_wrap: function() {
if (this.allowNewLine) {
var newLines = this.text.trim().split('\n');
for (var i = 0,idx = 0; i < newLines.length - 1; i++) {
idx += newLines[i].trim().split(/\s+/).length;
this.newLineIndexes.push(idx)
}
}
textPos.y = parseInt(textPos.y) + parseInt(this.lineHeight);
context.fillText(lines[i], textPos.x, textPos.y);
}
},
var words = this.text.trim().split(/\s+/);
this._checkLength(words);
this._breakText(words);
checkWordsLength: function(context, words, maxTextLength) {
for (var i = 0; i < words.length; i++) {
var testString = '';
var tokenLen = context.measureText(words[i]).width;
this.textBlockHeight = this.lines.length * this.lineHeight;
},
// check if a word exceeds the element's width
if (tokenLen > maxTextLength) {
for (var k = 0; (context.measureText(testString + words[i][k]).width <= maxTextLength) && (k < words[i].length); k++) {
testString += words[i][k];
}
_checkLength: function(words) {
var testString,tokenLen,sliced,leftover;
// break the word because it's too long
var sliced = words[i].slice(0, k);
var leftover = words[i].slice(k);
words.splice(i, 1, sliced, leftover);
}
}
},
for (var i = 0; i < words.length; i++) {
testString = '';
tokenLen = this.context.measureText(words[i]).width;
breakTextIntoLines: function(context, lines, words, maxTextLength) {
for (var i = 0, j = 0; i < words.length; j++) {
lines[j] = '';
if (tokenLen > MAX_TXT_WIDTH) {
for (var k = 0; (this.context.measureText(testString + words[i][k]).width <= MAX_TXT_WIDTH) && (k < words[i].length); k++) {
testString += words[i][k];
}
if (this.lineBreak === 'auto') {
// put as many full words in a line as can fit element
while ((context.measureText(lines[j] + words[i]).width <= maxTextLength) && (i < words.length)) {
lines[j] += words[i] + ' ';
i++;
}
lines[j] = lines[j].trim();
} else if (this.lineBreak === 'word') {
// put each next word in a new line
lines[j] = words[i];
i++;
}
}
},
sliced = words[i].slice(0,k);
leftover = words[i].slice(k);
words.splice(i,1,sliced,leftover);
}
}
},
setTextHorizontalAlign: function(context, textPos, elementWidth, line) {
if (this.textAlign === 'center') {
textPos.x = (elementWidth - context.measureText(line).width) / 2;
} else if (this.textAlign === 'right') {
textPos.x = elementWidth - context.measureText(line).width - this.paddingX;
} else {
textPos.x = this.paddingX;
}
},
_breakText: function(words) {
for (var i = 0,j = 0; i < words.length; j++) {
this.lines[j] = '';
setTextVerticalAlign: function(textPos, textBlockHeight) {
var elementHeight = (this.fitParent === false) ? this.canvas.height : this.canvas.parentNode.clientHeight;
if (this.lineBreak === 'auto') {
while ((this.context.measureText(this.lines[j] + words[i]).width <= MAX_TXT_WIDTH) && (i < words.length)) {
if (this.verticalAlign === 'middle') {
textPos.y = (elementHeight - textBlockHeight) / 2;
} else if (this.verticalAlign === 'bottom') {
textPos.y = elementHeight - textBlockHeight - this.paddingY;
} else {
textPos.y = this.paddingY;
}
},
this.lines[j] += words[i] + ' ';
i++;
validate: function() {
if (!(this.canvas instanceof HTMLCanvasElement)) {
throw new TypeError('From CanvasTextWrapper(): Element passed as the first parameter is not an instance of HTMLCanvasElement.');
}
if (typeof this.text !== 'string') {
throw new TypeError('From CanvasTextWrapper(): The second, dedicated for the text, parameter must be a string.');
}
if (isNaN(this.lineHeight)) {
throw new TypeError('From CanvasTextWrapper(): Cannot parse font size as an Integer. Check "font" property\'s value.');
}
if (this.textAlign !== 'left' && this.textAlign !== 'center' && this.textAlign !== 'right') {
throw new TypeError('From CanvasTextWrapper(): Unsupported horizontal align value is used. Property "textAlign" can only be set to "left", "center", or "right".');
}
if (this.verticalAlign !== 'top' && this.verticalAlign !== 'middle' && this.verticalAlign !== 'bottom') {
throw new TypeError('From CanvasTextWrapper(): Unsupported vertical align value is used. Property "verticalAlign" can only be set to "top", "middle", or "bottom".');
}
if (isNaN(this.paddingX)) {
throw new TypeError('From CanvasTextWrapper(): Unsupported horizontal padding value is used. Property "paddingX" must be set to a number');
}
if (isNaN(this.paddingY)) {
throw new TypeError('From CanvasTextWrapper(): Unsupported vertical padding value is used. Property "paddingY" must be set to a number.');
}
if (typeof this.fitParent !== 'boolean') {
throw new TypeError('From CanvasTextWrapper(): Property "fitParent" must be set to a Boolean.');
}
if (this.lineBreak !== 'auto' && this.lineBreak !== 'word') {
throw new TypeError('From CanvasTextWrapper(): Unsupported line break value is used. Property "lineBreak" can only be set to "auto", or "word".');
}
}
};
if (this.allowNewLine) {
for (var k = 0; k < this.newLineIndexes.length; k++) {
if (this.newLineIndexes[k] === i) {
j++;
this.lines[j] = '';
break;
}
}
}
}
this.lines[j] = this.lines[j].trim();
} else {
this.lines[j] = words[i];
i++;
}
}
},
_justify: function() {
var maxLen,longestLineIndex,tokenLen;
for (var i = 0; i < this.lines.length; i++) {
tokenLen = this.context.measureText(this.lines[i]).width;
if (!maxLen || tokenLen > maxLen) {
maxLen = tokenLen;
longestLineIndex = i;
}
}
// fill lines with extra spaces
var numWords,spaceLength,numOfSpaces,num,filler;
var delimiter = '\u200A';
for (i = 0; i < this.lines.length; i++) {
if (i === longestLineIndex) continue;
numWords = this.lines[i].trim().split(/\s+/).length;
if (numWords <= 1) continue;
this.lines[i] = this.lines[i].trim().split(/\s+/).join(delimiter);
spaceLength = this.context.measureText(delimiter).width;
numOfSpaces = (maxLen - this.context.measureText(this.lines[i]).width) / spaceLength;
num = numOfSpaces / (numWords - 1);
filler = '';
for (var j = 0; j < num; j++) {
filler += delimiter;
}
this.lines[i] = this.lines[i].trim().split(delimiter).join(filler);
//console.log('numWords:', numWords, 'numOfSpaces:', numOfSpaces, 'num:', num);
}
},
_drawText: function() {
for (var i = 0; i < this.lines.length; i++) {
this._setAlignX(this.lines[i]);
this.textPos.y = parseInt(this.textPos.y) + this.lineHeight;
this.context.fillText(this.lines[i],this.textPos.x,this.textPos.y);
if (this.strokeText) {
this.context.strokeText(this.lines[i],this.textPos.x,this.textPos.y);
}
}
},
_setAlignX: function(line) {
if (this.textAlign == 'center') {
this.textPos.x = (EL_WIDTH - this.context.measureText(line).width) / 2;
} else if (this.textAlign == 'right') {
this.textPos.x = EL_WIDTH - this.context.measureText(line).width - this.paddingX;
} else {
this.textPos.x = this.paddingX;
}
},
_setAlignY: function() {
if (this.verticalAlign == 'middle') {
this.textPos.y = (EL_HEIGHT - this.textBlockHeight) / 2;
} else if (this.verticalAlign == 'bottom') {
this.textPos.y = EL_HEIGHT - this.textBlockHeight - this.paddingY;
} else {
this.textPos.y = this.paddingY;
}
},
_validate: function() {
if (!(this.canvas instanceof HTMLCanvasElement))
throw new TypeError('The first parameter must be an instance of HTMLCanvasElement.');
if (typeof this.text !== 'string')
throw new TypeError('The second parameter must be a string.');
if (isNaN(this.fontSize))
throw new TypeError('Cannot parse "font".');
if (isNaN(this.lineHeight))
throw new TypeError('Cannot parse "lineHeight".');
if (this.textAlign.toLocaleLowerCase() !== 'left' && this.textAlign.toLocaleLowerCase() !== 'center' && this.textAlign.toLocaleLowerCase() !== 'right')
throw new TypeError('Property "textAlign" must be set to either "left", "center", or "right".');
if (this.verticalAlign.toLocaleLowerCase() !== 'top' && this.verticalAlign.toLocaleLowerCase() !== 'middle' && this.verticalAlign.toLocaleLowerCase() !== 'bottom')
throw new TypeError('Property "verticalAlign" must be set to either "top", "middle", or "bottom".');
if (typeof this.justifyLines !== 'boolean')
throw new TypeError('Property "justifyLines" must be set to a Boolean.');
if (isNaN(this.paddingX))
throw new TypeError('Property "paddingX" must be set to a Number.');
if (isNaN(this.paddingY))
throw new TypeError('Property "paddingY" must be set to a Number.');
if (typeof this.fitParent !== 'boolean')
throw new TypeError('Property "fitParent" must be set to a Boolean.');
if (this.lineBreak.toLocaleLowerCase() !== 'auto' && this.lineBreak.toLocaleLowerCase() !== 'word')
throw new TypeError('Property "lineBreak" must be set to either "auto" or "word".');
if (typeof this.sizeToFill !== 'boolean')
throw new TypeError('Property "sizeToFill" must be set to a Boolean.');
if (typeof this.strokeText !== 'boolean')
throw new TypeError('Property "strokeText" must be set to a Boolean.');
}
};
window.CanvasTextWrapper = CanvasTextWrapper;
})();
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@@ -6,53 +6,51 @@ CanvasTextWrapper
new CanvasTextWrapper(HTMLCanvasElement, String [, options]);
```
```options``` - is a JavaScript object with the following available properties and values:
```options``` - is an object with the following available properties and values:
- ```font: String``` - text style that includes font size in px (REQUIRED), weight & family, similar to CSS font shorthand property
- ```textAlign: "left" | "center" | "right"``` - horizontal alignment that applies for each line
- ```verticalAlign: "top" | "middle" | "bottom"``` - vertical alignment that applies on a whole block of text
- ```paddingX: Number``` - horizontal padding in pixels set equally on both, left and right sides of the element
- ```paddingY: Number``` - vertical padding in pixels set equally on both, top and bottom sides of the element
- ```fitParent: Boolean``` - parameter that controls which element to fit where ```true``` means fit canvas parent's width instead of canvas own width
- ```lineBreak: "auto" | "word"``` - text split rule. When using ```"auto"```, text fills the element's width going to a new line on a whole word when no more space. If ```"word"``` is set as value, each next word will be placed on a new line.
- ```font:``` (String) - text style that includes font size in px, font weight, font family, etc. Similar to CSS font shorthand property
- ```lineHeight:``` (String or Number) - Number means n times font size where 1 is equivalent to '100%'. Also the property can be set in "%" or "px" using String
- ```textAlign: "left" | "center" | "right"``` - horizontal alignment of each line
- ```verticalAlign: "top" | "middle" | "bottom"``` - vertical alignment of the whole text block
- ```paddingX:``` (Number) - horizontal padding (in px) set equally on both, left and right sides
- ```paddingY:``` (Number) - vertical padding (in px) set equally on both, top and bottom sides
- ```fitParent:``` (Boolean) - if enabled, text will fit canvas container's width instead of canvas own width
- ```lineBreak: "auto" | "word"``` - text split rule. When using ```"auto"```, text goes to a next line on a whole word when there's no more room. If ```"word"``` is set as value, each next word will be placed on a new line.
- ```sizeToFill:``` (Boolean) - ignore given font size and line height and resize text to fill its padded container
- ```strokeText:``` (Boolean) - outline text based on context configuration
- ```justifyLines:``` (Boolean) - if enabled, all lines match the same width with flexed spaces between words (one-word lines are ignored).
- ```allowNewLine:``` (Boolean) if enabled, the text breaks on every new line character "\n" otherwise it'll be considered as a space
NOTE: if a single word is too long to fit the width with specified font size, it will be broken into as many lines as required on any letter without specific word breaking rule.
NOTE: if a single word is too long to fit the width with specified font size, it will break on any letter unless ```sizeToFill``` option is enabled.
##Defaults
The default options object which values will be used if a property is not specified or no object is passed:
```
{
font: "18px Arial, sans-serif",
textAlign: "left",
verticalAlign: "top",
paddingX: 0,
paddingY: 0,
fitParent: false,
lineBreak: "auto"
}
font: "18px Arial, sans-serif",
lineHeight: 1,
textAlign: "left",
verticalAlign: "top",
paddingX: 0,
paddingY: 0,
fitParent: false,
lineBreak: "auto",
strokeText: false
sizeToFill: false,
allowNewLine: true,
justifyLines: false
}
```
##Usage
Use standard canvas text drawing methods such as "fillStyle" and "globalCompositeOperation" when needed before using CanvasTextWrapper like so:
Configure context settings properties such as "fillStyle", "lineWidth" or "strokeStyle" before using CanvasTextWrapper like so:
```
var canvas = document.createElement('canvas');
canvas.width = 300;
canvas.height = 250;
var canvas = document.getElementById("#canvasText");
canvas.width = 200;
canvas.height = 200;
context = canvas.getContext("2d");
context.fillStyle = "rgb(255, 255, 255)";
context.fillRect(0, 0, canvas.width, canvas.height);
context.globalCompositeOperation = "destination-out";
new CanvasTextWrapper(canvas, "Hi there", {
font: "normal 40px Open Sans, sans-serif",
textAlign: "center",
verticalAlign: "bottom",
paddingY: 10,
lineBreak: "word",
});
context.lineWidth = 2;
context.strokeStyle = "#ff0000";
CanvasTextWrapper(canvas,"Hello"); //default options will apply
```
##Examples
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{
"name": "canvas-text-wrapper",
"version": "0.1.0",
"ignore": [
"**/.*",
"**/*.log",
"**/*.json",
"Gruntfile.js",
"examples",
"node_modules",
"README.md"
],
"repository": {
"type": "git",
"url": "git://github.com/namniak/CanvasTextWrapper.git"
},
"homepage": "http://namniak.github.io/CanvasTextWrapper/"
"name": "canvas-text-wrapper",
"version": "0.3.0",
"ignore": [
"**/.*",
"**/*.log",
"**/*.json",
"Gruntfile.js",
"examples",
"node_modules",
"README.md"
],
"repository": {
"type": "git",
"url": "git://github.com/namniak/CanvasTextWrapper.git"
},
"homepage": "http://namniak.github.io/CanvasTextWrapper/"
}
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@@ -1,7 +1,7 @@
{
"name": "canvas-text-wrapper",
"description": "JavaScript canvas text wrapper that automatically splits a string into lines on specified rule with optional alignments and padding.",
"version": "0.1.1",
"description": "Pure JavaScript canvas text wrapper that automatically splits a string into lines on specified rule with alignment and padding.",
"version": "0.3.0",
"license": "MIT",
"main": "CanvasTextWrapper.min.js",
"homepage": "http://namniak.github.io/CanvasTextWrapper/",
@@ -13,4 +13,4 @@
"bugs": {
"url": "https://github.com/namniak/CanvasTextWrapper/issues"
}
}
}