1+ const { createCanvas, registerFont } = require ( 'canvas' ) ;
2+
3+ // this is text-to-image v5.2 package included directly in oxygen for easier control over canvas and nan versions
4+
5+ const defaults = {
6+ bgColor : '#fff' ,
7+ customHeight : 0 ,
8+ bubbleTail : { width : 0 , height : 0 } ,
9+ fontFamily : 'Arial' ,
10+ fontPath : '' ,
11+ fontSize : 18 ,
12+ fontWeight : 'normal' ,
13+ lineHeight : 28 ,
14+ margin : 10 ,
15+ maxWidth : 400 ,
16+ textAlign : 'left' ,
17+ textColor : '#000' ,
18+ verticalAlign : 'top' ,
19+ } ;
20+
21+ const createTextData = ( text , config , canvas ) => {
22+ const { bgColor, fontFamily, fontPath, fontSize, fontWeight, lineHeight, maxWidth, textAlign, textColor, } = config ;
23+ if ( fontPath ) {
24+ registerFont ( fontPath , { family : fontFamily } ) ;
25+ }
26+ const textCanvas = canvas || createCanvas ( maxWidth , 100 ) ;
27+ const textContext = textCanvas . getContext ( '2d' ) ;
28+ let textX = 0 ;
29+ let textY = 0 ;
30+ if ( [ 'center' ] . includes ( textAlign . toLowerCase ( ) ) ) {
31+ textX = maxWidth / 2 ;
32+ }
33+ if ( [ 'right' , 'end' ] . includes ( textAlign . toLowerCase ( ) ) ) {
34+ textX = maxWidth ;
35+ }
36+ textContext . textAlign = textAlign ;
37+ textContext . fillStyle = bgColor ;
38+ textContext . fillRect ( 0 , 0 , textCanvas . width , textCanvas . height ) ;
39+ textContext . fillStyle = textColor ;
40+ textContext . font = `${ fontWeight } ${ fontSize } ${ fontFamily } ;
41+ textContext . textBaseline = 'top' ;
42+ const words = text . split ( ' ' ) ;
43+ let wordCount = words . length ;
44+ let line = '' ;
45+ const addNewLines = [ ] ;
46+ for ( let n = 0 ; n < wordCount ; n += 1 ) {
47+ let word = words [ n ] ;
48+ if ( / \n / . test ( words [ n ] ) ) {
49+ const parts = words [ n ] . split ( '\n' ) ;
50+ word = parts . shift ( ) || '' ;
51+ addNewLines . push ( n + 1 ) ;
52+ words . splice ( n + 1 , 0 , parts . join ( '\n' ) ) ;
53+ wordCount += 1 ;
54+ }
55+ const testLine = `${ line } ${ word } . replace ( / ^ + / , '' ) . replace ( / + $ / , '' ) ;
56+ const testLineWidth = textContext . measureText ( testLine ) . width ;
57+ if ( addNewLines . indexOf ( n ) > - 1 || ( testLineWidth > maxWidth && n > 0 ) ) {
58+ textContext . fillText ( line , textX , textY ) ;
59+ line = word ;
60+ textY += lineHeight ;
61+ }
62+ else {
63+ line = testLine ;
64+ }
65+ }
66+ textContext . fillText ( line , textX , textY ) ;
67+ const height = textY + Math . max ( lineHeight , fontSize ) ;
68+ return {
69+ textHeight : height ,
70+ textData : textContext . getImageData ( 0 , 0 , maxWidth , height ) ,
71+ } ;
72+ } ;
73+
74+ const createImageCanvas = ( content , conf ) => {
75+ const { textHeight } = createTextData ( content , {
76+ maxWidth : conf . maxWidth - conf . margin * 2 ,
77+ fontSize : conf . fontSize ,
78+ lineHeight : conf . lineHeight ,
79+ bgColor : conf . bgColor ,
80+ textColor : conf . textColor ,
81+ fontFamily : conf . fontFamily ,
82+ fontPath : conf . fontPath ,
83+ fontWeight : conf . fontWeight ,
84+ textAlign : conf . textAlign ,
85+ } ) ;
86+ const textHeightWithMargins = textHeight + conf . margin * 2 ;
87+ if ( conf . customHeight && conf . customHeight < textHeightWithMargins ) {
88+ console . warn ( 'Text is longer than customHeight, clipping will occur.' ) ;
89+ }
90+ const height = conf . customHeight || textHeightWithMargins ;
91+ const canvas = createCanvas ( conf . maxWidth , height + conf . bubbleTail . height ) ;
92+ const { textData } = createTextData ( content , {
93+ maxWidth : conf . maxWidth - conf . margin * 2 ,
94+ fontSize : conf . fontSize ,
95+ lineHeight : conf . lineHeight ,
96+ bgColor : conf . bgColor ,
97+ textColor : conf . textColor ,
98+ fontFamily : conf . fontFamily ,
99+ fontPath : conf . fontPath ,
100+ fontWeight : conf . fontWeight ,
101+ textAlign : conf . textAlign ,
102+ } , canvas ) ;
103+ const ctx = canvas . getContext ( '2d' ) ;
104+ ctx . clearRect ( 0 , 0 , canvas . width , canvas . height ) ;
105+ ctx . globalAlpha = 1 ;
106+ ctx . fillStyle = conf . bgColor ;
107+ ctx . fillRect ( 0 , 0 , canvas . width , height ) ;
108+ if ( conf . bubbleTail . width && conf . bubbleTail . height ) {
109+ ctx . beginPath ( ) ;
110+ ctx . moveTo ( canvas . width / 2 - conf . bubbleTail . width / 2 , height ) ;
111+ ctx . lineTo ( canvas . width / 2 , canvas . height ) ;
112+ ctx . lineTo ( canvas . width / 2 + conf . bubbleTail . width / 2 , height ) ;
113+ ctx . closePath ( ) ;
114+ ctx . fillStyle = conf . bgColor ;
115+ ctx . fill ( ) ;
116+ }
117+ const textX = conf . margin ;
118+ let textY = conf . margin ;
119+ if ( conf . customHeight && conf . verticalAlign === 'center' ) {
120+ textY =
121+ ( conf . customHeight - textData . height ) / 2 +
122+ Math . max ( 0 , ( conf . lineHeight - conf . fontSize ) / 2 ) ;
123+ }
124+ ctx . putImageData ( textData , textX , textY ) ;
125+ return canvas ;
126+ } ;
127+
128+ const generate = async ( content , config ) => {
129+ const conf = { ...defaults , ...config } ;
130+ const canvas = createImageCanvas ( content , conf ) ;
131+ return canvas . toDataURL ( ) ;
132+ } ;
133+
134+ const generateSync = ( content , config ) => {
135+ const conf = { ...defaults , ...config } ;
136+ const canvas = createImageCanvas ( content , conf ) ;
137+ return canvas . toDataURL ( ) ;
138+ } ;
139+
140+ exports . generate = generate ;
141+ exports . generateSync = generateSync ;
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