heli-agri/lib/render/canvas/BuilderGroup.js

HeliAgri is a high-performance, feature-packed library for creating interactive maps on the web. It can display map tiles, vector data and markers loaded from any source on any web page. OpenLayers has been developed to further the use of geographic infor

/**
 * @module ol/render/canvas/BuilderGroup
 */

import Builder from './Builder.js';
import ImageBuilder from './ImageBuilder.js';
import LineStringBuilder from './LineStringBuilder.js';
import PolygonBuilder from './PolygonBuilder.js';
import TextBuilder from './TextBuilder.js';

/**
 * @type {Object<import("../canvas.js").BuilderType, typeof Builder>}
 */
const BATCH_CONSTRUCTORS = {
  'Circle': PolygonBuilder,
  'Default': Builder,
  'Image': ImageBuilder,
  'LineString': LineStringBuilder,
  'Polygon': PolygonBuilder,
  'Text': TextBuilder,
};

class BuilderGroup {
  /**
   * @param {number} tolerance Tolerance.
   * @param {import("../../extent.js").Extent} maxExtent Max extent.
   * @param {number} resolution Resolution.
   * @param {number} pixelRatio Pixel ratio.
   */
  constructor(tolerance, maxExtent, resolution, pixelRatio) {
    /**
     * @private
     * @type {number}
     */
    this.tolerance_ = tolerance;

    /**
     * @private
     * @type {import("../../extent.js").Extent}
     */
    this.maxExtent_ = maxExtent;

    /**
     * @private
     * @type {number}
     */
    this.pixelRatio_ = pixelRatio;

    /**
     * @private
     * @type {number}
     */
    this.resolution_ = resolution;

    /**
     * @private
     * @type {!Object<string, !Object<import("../canvas.js").BuilderType, Builder>>}
     */
    this.buildersByZIndex_ = {};
  }

  /**
   * @return {!Object<string, !Object<import("../canvas.js").BuilderType, import("./Builder.js").SerializableInstructions>>} The serializable instructions
   */
  finish() {
    const builderInstructions = {};
    for (const zKey in this.buildersByZIndex_) {
      builderInstructions[zKey] = builderInstructions[zKey] || {};
      const builders = this.buildersByZIndex_[zKey];
      for (const builderKey in builders) {
        const builderInstruction = builders[builderKey].finish();
        builderInstructions[zKey][builderKey] = builderInstruction;
      }
    }
    return builderInstructions;
  }

  /**
   * @param {number|undefined} zIndex Z index.
   * @param {import("../canvas.js").BuilderType} builderType Replay type.
   * @return {import("../VectorContext.js").default} Replay.
   */
  getBuilder(zIndex, builderType) {
    const zIndexKey = zIndex !== undefined ? zIndex.toString() : '0';
    let replays = this.buildersByZIndex_[zIndexKey];
    if (replays === undefined) {
      replays = {};
      this.buildersByZIndex_[zIndexKey] = replays;
    }
    let replay = replays[builderType];
    if (replay === undefined) {
      const Constructor = BATCH_CONSTRUCTORS[builderType];
      replay = new Constructor(
        this.tolerance_,
        this.maxExtent_,
        this.resolution_,
        this.pixelRatio_
      );
      replays[builderType] = replay;
    }
    return replay;
  }
}

export default BuilderGroup;