integrated_traffic_uniapp/uni_modules/lime-signature/components/l-signature/context.js

119 lines
2.3 KiB
JavaScript

export const uniContext = (canvasId, context) => {
let ctx = uni.createCanvasContext(canvasId, context)
if (!ctx.uniDrawImage) {
ctx.uniDrawImage = ctx.drawImage
ctx.drawImage = (image, ...agrs) => {
ctx.uniDrawImage(image.src, ...agrs)
}
}
if (!ctx.getImageData) {
ctx.getImageData = (x, y, width, height) => {
return new Promise((resolve, reject) => {
// #ifdef MP || VUE2
if (context.proxy) context = context.proxy
// #endif
uni.canvasGetImageData({
canvasId,
x,
y,
width,
height,
success(res) {
resolve(res)
},
fail(error) {
reject(error)
}
}, context)
})
}
}
return ctx
}
class Image {
constructor() {
this.currentSrc = null
this.naturalHeight = 0
this.naturalWidth = 0
this.width = 0
this.height = 0
this.tagName = 'IMG'
}
set src(src) {
this.currentSrc = src
uni.getImageInfo({
src,
success: (res) => {
this.naturalWidth = this.width = res.width
this.naturalHeight = this.height = res.height
this.onload()
},
fail: () => {
this.onerror()
}
})
}
get src() {
return this.currentSrc
}
}
export const createImage = () => {
return new Image()
}
export function useCurrentPage() {
const pages = getCurrentPages();
return pages[pages.length - 1];
}
export const toDataURL = (canvasId, context, options = {}) => {
// #ifdef MP-QQ
// context = context.$scope
// #endif
// #ifdef MP-ALIPAY
context = ''
// #endif
return new Promise((resolve, reject) => {
let {canvas, width, height, destWidth = 0, destHeight = 0, x = 0, y = 0} = options
// #ifdef MP-ALIPAY
const {pixelRatio} =uni.getSystemInfoSync()
if(!destWidth || !destHeight) {
destWidth = width * pixelRatio;
destHeight = height * pixelRatio;
width = destWidth;
height = destHeight;
x = x * pixelRatio
y = y * pixelRatio
}
// #endif
const params = {
...options,
canvasId,
id: canvasId,
// #ifdef MP-ALIPAY
x,
y,
width,
height,
destWidth,
destHeight,
// #endif
canvas,
success: (res) => {
resolve(res.tempFilePath)
},
fail: (err) => {
reject(err)
}
}
if(canvas && canvas.toTempFilePath) {
canvas.toTempFilePath(params)
} else {
uni.canvasToTempFilePath(params, context)
}
})
}