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11 | 11 |
|
12 | 12 | export default class SVGConvert{ |
13 | 13 |
|
14 | | - /** |
15 | | - * Converts the SVG image from the source element into a raster image with the given size and format |
16 | | - * and inserts the resulting data URI into the src attribute of the given destination image element. |
17 | | - * |
18 | | - * @param {SVGElement|HTMLImageElement} source |
19 | | - * @param {HTMLImageElement} destination |
20 | | - * @param {Number<int>} width |
21 | | - * @param {Number<int>} height |
22 | | - * @param {String} format |
23 | | - * @return {void} |
24 | | - */ |
25 | | - static toDataURI(source, destination, width, height, format){ |
26 | | - // format is whatever the fuck the specification allows: |
27 | | - // @see https://html.spec.whatwg.org/multipage/canvas.html#dom-canvas-todataurl-dev |
28 | | - format = (format || 'image/png'); |
29 | | - |
30 | | - if(!destination instanceof HTMLImageElement){ |
31 | | - throw new Error('destination is not an instance of HTMLImageElement'); |
32 | | - } |
33 | | - |
34 | | - if(source instanceof HTMLImageElement){ |
35 | | - source = SVGConvert.base64Decode(source); |
36 | | - } |
37 | | - |
38 | | - SVGConvert.toCanvas(source, width, height) |
39 | | - .then(canvas => destination.src = canvas.toDataURL(format)) |
40 | | - .catch(error => console.log('(╯°□°)╯彡┻━┻ ', error)); |
41 | | - } |
42 | | - |
43 | | - /** |
44 | | - * Draws the given SVG source on a canvas of the given size and returns the canvas element |
45 | | - * |
46 | | - * @param {SVGElement} source |
47 | | - * @param {Number<int>} width |
48 | | - * @param {Number<int>} height |
49 | | - * @return {Promise<HTMLCanvasElement>} |
50 | | - */ |
51 | | - static toCanvas(source, width, height){ |
52 | | - return new Promise((resolve, reject) => { |
53 | | - |
54 | | - if(!source instanceof SVGElement){ |
55 | | - throw new Error('source is not an instance of SVGElement'); |
56 | | - } |
57 | | - |
58 | | - // the source SVG element needs to be visible |
59 | | - source.style.display = 'inline-block'; |
60 | | - source.style.visibility = 'visible'; |
61 | | - |
62 | | - // add/fix the width/height of the SVG element |
63 | | - // @see https://bugzilla.mozilla.org/show_bug.cgi?id=700533#c39 |
64 | | - source.width.baseVal.valueAsString = width; |
65 | | - source.height.baseVal.valueAsString = height; |
66 | | - |
67 | | - try{ |
68 | | - // stringify the SVG element and create an object URL for it |
69 | | - let svgString = new XMLSerializer().serializeToString(source); |
70 | | - let svgBlob = new Blob([svgString], {type: 'image/svg+xml;charset=utf-8'}); |
71 | | - let tempUrl = URL.createObjectURL(svgBlob); |
72 | | - // create a temporary image |
73 | | - let tempImg = new Image(width, height); |
74 | | - // trigger the onLoad event with the temporary blob URL |
75 | | - tempImg.src = tempUrl; |
76 | | - // process the conversion in the onLoad event |
77 | | - tempImg.onload = function(){ |
78 | | - // create a canvas element to draw the SVG on |
79 | | - let canvas = document.createElement('canvas'); |
80 | | - canvas.width = width; |
81 | | - canvas.height = height; |
82 | | - canvas.getContext('2d').drawImage(tempImg, 0, 0); |
83 | | - // revoke the temporary blob |
84 | | - URL.revokeObjectURL(tempUrl); |
85 | | - // return the PNG image as data URI |
86 | | - resolve(canvas); |
87 | | - }; |
88 | | - } |
89 | | - catch(error){ |
90 | | - reject(error.message); |
91 | | - } |
92 | | - }); |
93 | | - } |
94 | | - |
95 | | - /** |
96 | | - * Converts the given SVG base64 data URI into a DOM element |
97 | | - * |
98 | | - * @param {HTMLImageElement} image |
99 | | - * @return {SVGElement} |
100 | | - */ |
101 | | - static base64Decode(image){ |
102 | | - |
103 | | - if(!image instanceof HTMLImageElement){ |
104 | | - throw new Error('image is not an instance of HTMLImageElement'); |
105 | | - } |
106 | | - |
107 | | - if(!image.src || !image.src.includes('base64,')){ |
108 | | - throw new Error('invalid image source'); |
109 | | - } |
110 | | - |
111 | | - return new DOMParser().parseFromString(atob(image.src.split(',')[1]), 'image/svg+xml').firstChild; |
112 | | - } |
| 14 | + /** |
| 15 | + * Converts the SVG image from the source element into a raster image with the given size and format |
| 16 | + * and inserts the resulting data URI into the src attribute of the given destination image element. |
| 17 | + * |
| 18 | + * @param {SVGElement|HTMLImageElement} source |
| 19 | + * @param {HTMLImageElement} destination |
| 20 | + * @param {Number<int>} width |
| 21 | + * @param {Number<int>} height |
| 22 | + * @param {String} format |
| 23 | + * @return {void} |
| 24 | + */ |
| 25 | + static toDataURI(source, destination, width, height, format){ |
| 26 | + // format is whatever the fuck the specification allows: |
| 27 | + // @see https://html.spec.whatwg.org/multipage/canvas.html#dom-canvas-todataurl-dev |
| 28 | + format = (format || 'image/png'); |
| 29 | + |
| 30 | + if(!destination instanceof HTMLImageElement){ |
| 31 | + throw new Error('destination is not an instance of HTMLImageElement'); |
| 32 | + } |
| 33 | + |
| 34 | + if(source instanceof HTMLImageElement){ |
| 35 | + source = SVGConvert.base64Decode(source); |
| 36 | + } |
| 37 | + |
| 38 | + SVGConvert.toCanvas(source, width, height) |
| 39 | + .then(canvas => destination.src = canvas.toDataURL(format)) |
| 40 | + .catch(error => console.log('(╯°□°)╯彡┻━┻ ', error)); |
| 41 | + } |
| 42 | + |
| 43 | + /** |
| 44 | + * Draws the given SVG source on a canvas of the given size and returns the canvas element |
| 45 | + * |
| 46 | + * @param {SVGElement} source |
| 47 | + * @param {Number<int>} width |
| 48 | + * @param {Number<int>} height |
| 49 | + * @return {Promise<HTMLCanvasElement>} |
| 50 | + */ |
| 51 | + static toCanvas(source, width, height){ |
| 52 | + return new Promise((resolve, reject) => { |
| 53 | + |
| 54 | + if(!source instanceof SVGElement){ |
| 55 | + throw new Error('source is not an instance of SVGElement'); |
| 56 | + } |
| 57 | + |
| 58 | + // the source SVG element needs to be visible |
| 59 | + source.style.display = 'inline-block'; |
| 60 | + source.style.visibility = 'visible'; |
| 61 | + |
| 62 | + // add/fix the width/height of the SVG element |
| 63 | + // @see https://bugzilla.mozilla.org/show_bug.cgi?id=700533#c39 |
| 64 | + source.width.baseVal.valueAsString = width; |
| 65 | + source.height.baseVal.valueAsString = height; |
| 66 | + |
| 67 | + try{ |
| 68 | + // stringify the SVG element and create an object URL for it |
| 69 | + let svgString = new XMLSerializer().serializeToString(source); |
| 70 | + let svgBlob = new Blob([svgString], {type: 'image/svg+xml;charset=utf-8'}); |
| 71 | + let tempUrl = URL.createObjectURL(svgBlob); |
| 72 | + // create a temporary image |
| 73 | + let tempImg = new Image(width, height); |
| 74 | + // trigger the onLoad event with the temporary blob URL |
| 75 | + tempImg.src = tempUrl; |
| 76 | + // process the conversion in the onLoad event |
| 77 | + tempImg.onload = function(){ |
| 78 | + // create a canvas element to draw the SVG on |
| 79 | + let canvas = document.createElement('canvas'); |
| 80 | + canvas.width = width; |
| 81 | + canvas.height = height; |
| 82 | + canvas.getContext('2d').drawImage(tempImg, 0, 0); |
| 83 | + // revoke the temporary blob |
| 84 | + URL.revokeObjectURL(tempUrl); |
| 85 | + // return the canvas element |
| 86 | + resolve(canvas); |
| 87 | + }; |
| 88 | + } |
| 89 | + catch(error){ |
| 90 | + reject(error.message); |
| 91 | + } |
| 92 | + |
| 93 | + }); |
| 94 | + } |
| 95 | + |
| 96 | + /** |
| 97 | + * Converts the given SVG base64 data URI into a DOM element |
| 98 | + * |
| 99 | + * @param {HTMLImageElement} image |
| 100 | + * @return {SVGElement} |
| 101 | + */ |
| 102 | + static base64Decode(image){ |
| 103 | + |
| 104 | + if(!image instanceof HTMLImageElement){ |
| 105 | + throw new Error('image is not an instance of HTMLImageElement'); |
| 106 | + } |
| 107 | + |
| 108 | + if(!image.src || !image.src.includes('base64,')){ |
| 109 | + throw new Error('invalid image source'); |
| 110 | + } |
| 111 | + |
| 112 | + return new DOMParser().parseFromString(atob(image.src.split(',')[1]), 'image/svg+xml').firstChild; |
| 113 | + } |
113 | 114 |
|
114 | 115 | } |
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