buddhism/uni_modules/lime-echart/components/l-echart/canvas.js

const cacheChart = {}
const fontSizeReg = /([\d\.]+)px/
class EventEmit {
  constructor() {
    this.__events = {}
  }
  on(type, listener) {
    if (!type || !listener) {
      return
    }
    const events = this.__events[type] || []
    events.push(listener)
    this.__events[type] = events
  }
  emit(type, e) {
    if (type.constructor === Object) {
      e = type
      type = e && e.type
    }
    if (!type) {
      return
    }
    const events = this.__events[type]
    if (!events || !events.length) {
      return
    }
    events.forEach(listener => {
      listener.call(this, e)
    })
  }
  off(type, listener) {
    const __events = this.__events
    const events = __events[type]
    if (!events || !events.length) {
      return
    }
    if (!listener) {
      delete __events[type]
      return
    }
    for (let i = 0, len = events.length; i < len; i++) {
      if (events[i] === listener) {
        events.splice(i, 1)
        i--
      }
    }
  }
}
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
  }
}
class OffscreenCanvas {
  constructor(ctx, com, canvasId) {
    this.tagName = 'canvas'
    this.com = com
    this.canvasId = canvasId
    this.ctx = ctx
  }
  set width(w) {
    this.com.offscreenWidth = w
  }
  set height(h) {
    this.com.offscreenHeight = h
  }
  get width() {
    return this.com.offscreenWidth || 0
  }
  get height() {
    return this.com.offscreenHeight || 0
  }
  getContext(type) {
    return this.ctx
  }
  getImageData() {
    return new Promise((resolve, reject) => {
      this.com.$nextTick(() => {
        uni.canvasGetImageData(
          {
            x: 0,
            y: 0,
            width: this.com.offscreenWidth,
            height: this.com.offscreenHeight,
            canvasId: this.canvasId,
            success: res => {
              resolve(res)
            },
            fail: err => {
              reject(err)
            },
          },
          this.com
        )
      })
    })
  }
}
export class Canvas {
  constructor(ctx, com, isNew, canvasNode = {}) {
    cacheChart[com.canvasId] = { ctx }
    this.canvasId = com.canvasId
    this.chart = null
    this.isNew = isNew
    this.tagName = 'canvas'
    this.canvasNode = canvasNode
    this.com = com
    if (!isNew) {
      this._initStyle(ctx)
    }
    this._initEvent()
    this._ee = new EventEmit()
  }
  getContext(type) {
    if (type === '2d') {
      return this.ctx
    }
  }
  setAttribute(key, value) {
    if (key === 'aria-label') {
      this.com['ariaLabel'] = value
    }
  }
  setChart(chart) {
    this.chart = chart
  }
  createOffscreenCanvas(param) {
    if (!this.children) {
      this.com.isOffscreenCanvas = true
      this.com.offscreenWidth = param.width || 300
      this.com.offscreenHeight = param.height || 300
      const com = this.com
      const canvasId = this.com.offscreenCanvasId
      const context = uni.createCanvasContext(canvasId, this.com)
      this._initStyle(context)
      this.children = new OffscreenCanvas(context, com, canvasId)
    }
    return this.children
  }
  appendChild(child) {
    console.log('child', child)
  }
  dispatchEvent(type, e) {
    if (typeof type == 'object') {
      this._ee.emit(type.type, type)
    } else {
      this._ee.emit(type, e)
    }
    return true
  }
  attachEvent() {}
  detachEvent() {}
  addEventListener(type, listener) {
    this._ee.on(type, listener)
  }
  removeEventListener(type, listener) {
    this._ee.off(type, listener)
  }
  _initCanvas(zrender, ctx) {
    // zrender.util.getContext = function() {
    // 	return ctx;
    // };
    // zrender.util.$override('measureText', function(text, font) {
    // 	ctx.font = font || '12px sans-serif';
    // 	return ctx.measureText(text, font);
    // });
  }
  _initStyle(ctx, child) {
    const styles = [
      'fillStyle',
      'strokeStyle',
      'fontSize',
      'globalAlpha',
      'opacity',
      'textAlign',
      'textBaseline',
      'shadow',
      'lineWidth',
      'lineCap',
      'lineJoin',
      'lineDash',
      'miterLimit',
      // 'font'
    ]
    const colorReg = /#([0-9a-fA-F])([0-9a-fA-F])([0-9a-fA-F])\b/g
    styles.forEach(style => {
      Object.defineProperty(ctx, style, {
        set: value => {
          // if (style === 'font' && fontSizeReg.test(value)) {
          // 	const match = fontSizeReg.exec(value);
          // 	ctx.setFontSize(match[1]);
          // 	return;
          // }
          if (style === 'opacity') {
            ctx.setGlobalAlpha(value)
            return
          }
          if (
            (style !== 'fillStyle' && style !== 'strokeStyle') ||
            (value !== 'none' && value !== null)
          ) {
            // #ifdef H5 || APP-PLUS || MP-BAIDU
            if (typeof value == 'object') {
              if (value.hasOwnProperty('colorStop') || value.hasOwnProperty('colors')) {
                ctx['set' + style.charAt(0).toUpperCase() + style.slice(1)](value)
              }
              return
            }
            // #endif
            // #ifdef MP-TOUTIAO
            if (colorReg.test(value)) {
              value = value.replace(colorReg, '#$1$1$2$2$3$3')
            }
            // #endif
            ctx['set' + style.charAt(0).toUpperCase() + style.slice(1)](value)
          }
        },
      })
    })
    if (!this.isNew && !child) {
      ctx.uniDrawImage = ctx.drawImage
      ctx.drawImage = (...a) => {
        a[0] = a[0].src
        ctx.uniDrawImage(...a)
      }
    }
    if (!ctx.createRadialGradient) {
      ctx.createRadialGradient = function () {
        return ctx.createCircularGradient(...[...arguments].slice(-3))
      }
    }
    // 字节不支持
    if (!ctx.strokeText) {
      ctx.strokeText = (...a) => {
        ctx.fillText(...a)
      }
    }
    // 钉钉不支持
    if (!ctx.measureText) {
      const strLen = str => {
        let len = 0
        for (let i = 0; i < str.length; i++) {
          if (str.charCodeAt(i) > 0 && str.charCodeAt(i) < 128) {
            len++
          } else {
            len += 2
          }
        }
        return len
      }
      ctx.measureText = (text, font) => {
        let fontSize = ctx?.state?.fontSize || 12
        if (font) {
          fontSize = parseInt(font.match(/([\d\.]+)px/)[1])
        }
        fontSize /= 2
        let isBold = fontSize >= 16
        const widthFactor = isBold ? 1.3 : 1
        return {
          width: strLen(text) * fontSize * widthFactor,
        }
      }
    }
  }

  _initEvent(e) {
    this.event = {}
    const eventNames = [
      {
        wxName: 'touchStart',
        ecName: 'mousedown',
      },
      {
        wxName: 'touchMove',
        ecName: 'mousemove',
      },
      {
        wxName: 'touchEnd',
        ecName: 'mouseup',
      },
      {
        wxName: 'touchEnd',
        ecName: 'click',
      },
    ]

    eventNames.forEach(name => {
      this.event[name.wxName] = e => {
        const touch = e.touches[0]
        this.chart.getZr().handler.dispatch(name.ecName, {
          zrX: name.wxName === 'tap' ? touch.clientX : touch.x,
          zrY: name.wxName === 'tap' ? touch.clientY : touch.y,
        })
      }
    })
  }

  set width(w) {
    this.canvasNode.width = w
  }
  set height(h) {
    this.canvasNode.height = h
  }

  get width() {
    return this.canvasNode.width || 0
  }
  get height() {
    return this.canvasNode.height || 0
  }
  get ctx() {
    return cacheChart[this.canvasId]['ctx'] || null
  }
  set chart(chart) {
    cacheChart[this.canvasId]['chart'] = chart
  }
  get chart() {
    return cacheChart[this.canvasId]['chart'] || null
  }
}

export function dispatch(name, { x, y, wheelDelta }) {
  this.dispatch(name, {
    zrX: x,
    zrY: y,
    zrDelta: wheelDelta,
    preventDefault: () => {},
    stopPropagation: () => {},
  })
}
export function setCanvasCreator(echarts, { canvas, node }) {
  // echarts.setCanvasCreator(() => canvas);
  if (echarts && !echarts.registerPreprocessor) {
    return console.warn('echarts 版本不对或未传入echarts，vue3请使用esm格式')
  }
  echarts.registerPreprocessor(option => {
    if (option && option.series) {
      if (option.series.length > 0) {
        option.series.forEach(series => {
          series.progressive = 0
        })
      } else if (typeof option.series === 'object') {
        option.series.progressive = 0
      }
    }
  })
  function loadImage(src, onload, onerror) {
    let img = null
    if (node && node.createImage) {
      img = node.createImage()
      img.onload = onload.bind(img)
      img.onerror = onerror.bind(img)
      img.src = src
      return img
    } else {
      img = new Image()
      img.onload = onload.bind(img)
      img.onerror = onerror.bind(img)
      img.src = src
      return img
    }
  }
  if (echarts.setPlatformAPI) {
    echarts.setPlatformAPI({
      loadImage: canvas.setChart ? loadImage : null,
      createCanvas() {
        const key = 'createOffscreenCanvas'
        return uni.canIUse(key) && uni[key] ? uni[key]({ type: '2d' }) : canvas
      },
    })
  }
}