koroeskohr / canvas-text-wrapper

Split canvas text into lines on specified rule with optional alignment, padding, and more. Supports HDPI screens.

canvas-text-wrapper

Syntax

CanvasTextWrapper(HTMLCanvasElement, String [, options]);

Options

Option	Value	Description
font	String	Text style that includes font size (in px), font weight, font family, etc.
lineHeight	String or Number	Number - 'n' times font size where 1 is equivalent to '100%'. Also the property can be set in '%' or 'px'.
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) that is equally set on left and right sides.
paddingY	Number	Vertical padding (in px) that is equally set on top and bottoms.
fitParent	Boolean	Fit canvas' container size instead of its own size.
lineBreak	"auto" "word"	"auto" - text goes to the next line on a whole word when there's no room "word" - each next word is placed on a new line
sizeToFill	Boolean	Ignore given font size and line height and resize text to fill its padded container.
maxFontSizeToFill	Number	If above option is true text won't be bigger than set.
strokeText	Boolean	Allow text outline based on canvas context configuration.
justifyLines	Boolean	All lines will try to match the same width with flexed spaces between the words.
allowNewLine	Boolean	Text breaks on a new line character "\n". Note it doesn't support multiple new lines, so "\n\n\n" will be rendered the same as a single "\n".
renderHDPI	Boolean	Text is rendered based on device pixel ratio.
textDecoration	"none" "underline"	Text is underlined according to context.strokeStyle and context.lineWidth

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.

Default options

   { 
        font: '18px Arial, sans-serif',
        lineHeight: 1,
        textAlign: 'left',
        verticalAlign: 'top',
        paddingX: 0,
        paddingY: 0,
        fitParent: false,
        lineBreak: 'auto',
        strokeText: false
        sizeToFill: false,
        maxFontSizeToFill: false,
        allowNewLine: true,
        justifyLines: false,
        renderHDPI: true,
        textDecoration: 'none'
    }

Usage

Configure context properties such as fillStyle, lineWidth, strokeStyle etc. before passing it to CanvasTextWrapper like so:

var CanvasTextWrapper = require('canvas-text-wrapper').CanvasTextWrapper;

var canvas = document.getElementById('#canvasText');
canvas.width = 200;
canvas.height = 200;
context = canvas.getContext('2d');
context.lineWidth = 2;
context.strokeStyle = '#ff0000';

CanvasTextWrapper(canvas, 'Hello', {strokeText: true});

Test

Run npm t NOTE: Test requires beefy to be installed globally

Examples

see here

Install

npm i canvas-text-wrapper --save
bower install canvas-text-wrapper