AntV X6源码简析

前端 | AntV X6源码探究简析.png

前言

AntV是蚂蚁金服全新一代数据可视化解决方案，其中X6主要用于解决图编辑领域相关的解决方案，其是一款图编辑引擎，内置了一下编辑器所需的功能及组件等，本文旨在通过简要分析x6源码来对图编辑领域的一些底层引擎进行一个大致了解，同时也为团队中需要进行基于X6编辑引擎进行构建的图编辑器提供一些侧面了解，在碰到问题时可以较快的找到问题点。

架构

图片

图片

X6整体是基于MVVM的架构进行设计的，对外整体暴露Graph的类，其中的Node、Edge、Port等都有对外暴露的方法，可以单独使用，其中提供了类Jquery的一些dom操作方法，整体的Graph基于了一个事件基类，对事件进行的整体的处理，其中使用了dispose来对实例进行显示判定。

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图片

整体设计符合SOLID原则，提供事件机制进行发布订阅解耦，对于扩展性结构则提供注册机制，进行扩展性插件组织

目录

整体采用monorepo进行源码的仓库管理

• packages
  • x6
    • addon
    • common
    • geometry
    • global
    • graph
    • layout
    • model
    • registry
    • shape
    • style
    • types
    • util
    • view
  • x6-angular-shape
  • x6-geometry
    • angle
    • curve
    • ellipse
    • line
    • point
    • polyline
    • rectangle
  • x6-react
  • x6-react-components
  • x6-react-shape
  • x6-vector
  • x6-vue-shape

源码

从架构层次可以看出，整体对外暴露的就是Graph这么一个大类，因而在分析源码调用过程中，我们抓住Graph进行逐步的往外拓展，从而把握整体的一个设计链路，避免陷入局部无法抽离

Graph

Graph类提供了整体所有结构的汇总，从而暴露给用户

class Graph extends Basecoat {
  public readonly options: GraphOptions.Definition
  public readonly css: CSSManager
  public readonly model: Model
  public readonly view: GraphView
  public readonly hook: HookManager
  public readonly grid: Grid
  public readonly defs: Defs
  public readonly knob: Knob
  public readonly coord: Coord
  public readonly renderer: ViewRenderer
  public readonly snapline: Snapline
  public readonly highlight: Highlight
  public readonly transform: Transform
  public readonly clipboard: Clipboard
  public readonly selection: Selection
  public readonly background: Background
  public readonly history: History
  public readonly scroller: Scroller
  public readonly minimap: MiniMap
  public readonly keyboard: Shortcut
  public readonly mousewheel: Wheel
  public readonly panning: Panning
  public readonly print: Print
  public readonly format: Format
  public readonly size: SizeManager
  
  // 拿到需要加载的container
  public get container() {
    return this.view.container
  }

  protected get [Symbol.toStringTag]() {
    return Graph.toStringTag
  }

  constructor(options: Partial) {
    super()

    this.options = GraphOptions.get(options)
    this.css = new CSSManager(this)
    this.hook = new HookManager(this)
    this.view = this.hook.createView()
    this.defs = this.hook.createDefsManager()
    this.coord = this.hook.createCoordManager()
    this.transform = this.hook.createTransformManager()
    this.knob = this.hook.createKnobManager()
    this.highlight = this.hook.createHighlightManager()
    this.grid = this.hook.createGridManager()
    this.background = this.hook.createBackgroundManager()
    this.model = this.hook.createModel()
    this.renderer = this.hook.createRenderer()
    this.clipboard = this.hook.createClipboardManager()
    this.snapline = this.hook.createSnaplineManager()
    this.selection = this.hook.createSelectionManager()
    this.history = this.hook.createHistoryManager()
    this.scroller = this.hook.createScrollerManager()
    this.minimap = this.hook.createMiniMapManager()
    this.keyboard = this.hook.createKeyboard()
    this.mousewheel = this.hook.createMouseWheel()
    this.print = this.hook.createPrintManager()
    this.format = this.hook.createFormatManager()
    this.panning = this.hook.createPanningManager()
    this.size = this.hook.createSizeManager()
  }
}

Shape

实现各种类型方法的中间解耦层，用于包裹属性等

// shape的基类，标记shape的各种属性，如标签等
class Base<
  Properties extends Node.Properties = Node.Properties,
> extends Node {
  get label() {
    return this.getLabel()
  }

  set label(val: string | undefined | null) {
    this.setLabel(val)
  }

  getLabel() {
    return this.getAttrByPath('text/text')
  }

  setLabel(label?: string | null, options?: Node.SetOptions) {
    if (label == null) {
      this.removeLabel()
    } else {
      this.setAttrByPath('text/text', label, options)
    }

    return this
  }

  removeLabel() {
    this.removeAttrByPath('text/text')
    return this
  }
}

// 创建shape的方法
function createShape(
  shape: string,
  config: Node.Config,
  options: {
    noText?: boolean
    ignoreMarkup?: boolean
    parent?: Node.Definition | typeof Base
  } = {},
) {
  const name = getName(shape)
  const defaults: Node.Config = {
    constructorName: name,
    attrs: {
      '.': {
        fill: '#ffffff',
        stroke: 'none',
      },
      [shape]: {
        fill: '#ffffff',
        stroke: '#000000',
      },
    },
  }

  if (!options.ignoreMarkup) {
    defaults.markup = getMarkup(shape, options.noText === true)
  }

  const base = options.parent || Base
  return base.define(
    ObjectExt.merge(defaults, config, { shape: name }),
  ) as typeof Base
}

Model

提供了Node、Cell、Edge、Prot等的处理方法

class Model extends Basecoat {
  public readonly collection: Collection
  protected readonly batches: KeyValue = {}
  protected readonly addings: WeakMap = new WeakMap()
  public graph: Graph | null
  protected nodes: KeyValue = {}
  protected edges: KeyValue = {}
  protected outgoings: KeyValue = {}
  protected incomings: KeyValue = {}

  protected get [Symbol.toStringTag]() {
    return Model.toStringTag
  }

  constructor(cells: Cell[] = []) {
    super()
    this.collection = new Collection(cells)
    this.setup()
  }
}

Renderer

渲染Model相关的数据

class Renderer extends Base {
  protected views: KeyValue
  protected zPivots: KeyValue
  protected updates: Renderer.Updates
  protected init() {}
  protected startListening() {}
  protected stopListening() {}
  protected resetUpdates() {}
  protected onSortModel() {}
  protected onModelReseted() {}
  protected onBatchStop() {}
  protected onCellAdded() {}
  protected onCellRemove() {}
  protected onCellZIndexChanged() {}
  protected onCellVisibleChanged() {}
  protected processEdgeOnTerminalVisibleChanged() {}
  protected isEdgeTerminalVisible() {}
}

Store

数据的公共存储仓库，与renderer进行交互

class Store extends Basecoat>{
  protected data: D
  protected previous: D
  protected changed: Partial
  protected pending = false
  protected changing = false
  protected pendingOptions: Store.MutateOptions | null
  protected mutate() {}
  constructor(data: Partial = {}) {
    super()
    this.data = {} as D
    this.mutate(ObjectExt.cloneDeep(data))
    this.changed = {}
  }
  get() {}
  set() {}
  remove() {}
  clone() {}
}

View

聚合EdgeView、CellView等，使用了jQuery的相关DOM操作

abstract class View extends Basecoat {
  public readonly cid: string
  public container: Element
  protected selectors: Markup.Selectors

  public get priority() {
    return 2
  }

  constructor() {
    super()
    this.cid = Private.uniqueId()
    View.views[this.cid] = this
  }
}

Geometry

提供几何图形的操作处理，包括Curve、Ellipse、Line、Point、PolyLine、Rectangle、Angle等

abstract class Geometry {
  abstract scale(
    sx: number,
    sy: number,
    origin?: Point.PointLike | Point.PointData,
  ): this

  abstract rotate(
    angle: number,
    origin?: Point.PointLike | Point.PointData,
  ): this

  abstract translate(tx: number, ty: number): this

  abstract translate(p: Point.PointLike | Point.PointData): this

  abstract equals(g: any): boolean

  abstract clone(): Geometry

  abstract toJSON(): JSONObject | JSONArray

  abstract serialize(): string

  valueOf() {
    return this.toJSON()
  }

  toString() {
    return JSON.stringify(this.toJSON())
  }
}

Registry

提供注册中心的机制，

class Registry<
  Entity,
  Presets = KeyValue,
  OptionalType = never,
> {
  public readonly data: KeyValue
  public readonly options: Registry.Options

  constructor(options: Registry.Options) {
    this.options = { ...options }
    this.data = (this.options.data as KeyValue) || {}
    this.register = this.register.bind(this)
    this.unregister = this.unregister.bind(this)
  }

  get names() {
    return Object.keys(this.data)
  }

  register() {}
  unregister() {}
  get() {}
  exist() {}
}

Events

提供事件的监听(发布订阅)机制

class Events {
    private listeners: { [name: string]: any[] } = {}

    on() {}
    once() {}
    off() {}
    trigger() {}
    emit() {}
}

总结

整体我们看到，要想实现一款底层的图编辑引擎，需要做好整体的架构设计及解构，通常不外乎MVC的结构的变种，因而我们在选择Model层、View层、Controller层的过程中，可以综合考虑软件工程中不同的设计方案来处理，比如对事件系统的设计、插件机制的设计等等，另外在底层渲染方面，毕竟作为图可视化领域的前端方案，对SVG、HTML、Canvas等不同方案的选择也需要针对性考虑，以上。可视化领域深度与广度探索起来不仅仅局限于前端侧，希望能够在这方面能够系统的学习与实践，从而探索出在前端领域的一些机会，共勉！！！

参考

• X6官网
• Antv/X6<图编辑引擎>
• x6源码
• antvis G6 vs X6 vs Topology 源码统计分析
• X6 1.0 抱歉来晚
• XFlow 1.0：专业的图编辑应用解决方案
• X6：深度打磨，日臻完善
• AntV 旗下图编辑引擎 X6