@antv/x6/src/view/cache.ts

JavaScript diagramming library that uses SVG and HTML for rendering.

import { Dictionary } from '../common'
import { JSONObject, Dom } from '../util'
import { Line, Rectangle, Ellipse, Polyline, Path, Segment } from '../geometry'
import { CellView } from './cell'

export class Cache {
  protected elemCache: Dictionary<Element, Cache.Item>

  public pathCache: {
    data?: string
    length?: number
    segmentSubdivisions?: Segment[][]
  }

  constructor(protected view: CellView) {
    this.clean()
  }

  clean() {
    if (this.elemCache) {
      this.elemCache.dispose()
    }
    this.elemCache = new Dictionary()
    this.pathCache = {}
  }

  get(elem: Element) {
    const cache = this.elemCache
    if (!cache.has(elem)) {
      this.elemCache.set(elem, {})
    }
    return this.elemCache.get(elem)!
  }

  getData(elem: Element) {
    const meta = this.get(elem)
    if (!meta.data) {
      meta.data = {}
    }
    return meta.data
  }

  getMatrix(elem: Element) {
    const meta = this.get(elem)
    if (meta.matrix == null) {
      const target = this.view.rotatableNode || this.view.container
      meta.matrix = Dom.getTransformToElement(elem as any, target as SVGElement)
    }

    return Dom.createSVGMatrix(meta.matrix)
  }

  getShape(elem: Element) {
    const meta = this.get(elem)
    if (meta.shape == null) {
      meta.shape = Dom.toGeometryShape(elem as SVGElement)
    }
    return meta.shape.clone()
  }

  getBoundingRect(elem: Element) {
    const meta = this.get(elem)
    if (meta.boundingRect == null) {
      meta.boundingRect = Dom.getBBox(elem as SVGElement)
    }
    return meta.boundingRect.clone()
  }
}

export namespace Cache {
  export interface Item {
    data?: JSONObject
    matrix?: DOMMatrix
    boundingRect?: Rectangle
    shape?: Rectangle | Ellipse | Polyline | Path | Line
  }
}