openlayers/src/ol/layer/VectorTile.js

/**
 * @module ol/layer/VectorTile
 */
import {assert} from '../asserts.js';
import TileProperty from './TileProperty.js';
import BaseVectorLayer from './BaseVector.js';
import VectorTileRenderType from './VectorTileRenderType.js';
import CanvasVectorTileLayerRenderer from '../renderer/canvas/VectorTileLayer.js';
import {assign} from '../obj.js';


/**
 * @typedef {Object} Options
 * @property {number} [opacity=1] Opacity (0, 1).
 * @property {boolean} [visible=true] Visibility.
 * @property {import("../extent.js").Extent} [extent] The bounding extent for layer rendering.  The layer will not be
 * rendered outside of this extent.
 * @property {number} [zIndex] The z-index for layer rendering.  At rendering time, the layers
 * will be ordered, first by Z-index and then by position. When `undefined`, a `zIndex` of 0 is assumed
 * for layers that are added to the map's `layers` collection, or `Infinity` when the layer's `setMap()`
 * method was used.
 * @property {number} [minResolution] The minimum resolution (inclusive) at which this layer will be
 * visible.
 * @property {number} [maxResolution] The maximum resolution (exclusive) below which this layer will
 * be visible.
 * @property {import("../render.js").OrderFunction} [renderOrder] Render order. Function to be used when sorting
 * features before rendering. By default features are drawn in the order that they are created. Use
 * `null` to avoid the sort, but get an undefined draw order.
 * @property {number} [renderBuffer=100] The buffer in pixels around the tile extent used by the
 * renderer when getting features from the vector tile for the rendering or hit-detection.
 * Recommended value: Vector tiles are usually generated with a buffer, so this value should match
 * the largest possible buffer of the used tiles. It should be at least the size of the largest
 * point symbol or line width.
 * @property {import("./VectorTileRenderType.js").default|string} [renderMode='hybrid'] Render mode for vector tiles:
 *  * `'image'`: Vector tiles are rendered as images. Great performance, but point symbols and texts
 *    are always rotated with the view and pixels are scaled during zoom animations. When `declutter`
 *    is set to `true`, the decluttering is done per tile resulting in labels and point symbols getting
 *    cut off at tile boundaries.
 *  * `'hybrid'`: Polygon and line elements are rendered as images, so pixels are scaled during zoom
 *    animations. Point symbols and texts are accurately rendered as vectors and can stay upright on
 *    rotated views.
 *
 * @property {import("../source/VectorTile.js").default} [source] Source.
 * @property {import("../PluggableMap.js").default} [map] Sets the layer as overlay on a map. The map will not manage
 * this layer in its layers collection, and the layer will be rendered on top. This is useful for
 * temporary layers. The standard way to add a layer to a map and have it managed by the map is to
 * use {@link module:ol/Map#addLayer}.
 * @property {boolean} [declutter=false] Declutter images and text. Decluttering is applied to all
 * image and text styles of all Vector and VectorTile layers that have set this to `true`. The priority
 * is defined by the z-index of the layer, the `zIndex` of the style and the render order of features.
 * Higher z-index means higher priority. Within the same z-index, a feature rendered before another has
 * higher priority.
 * @property {import("../style/Style.js").StyleLike} [style] Layer style. See
 * {@link module:ol/style} for default style which will be used if this is not defined.
 * @property {boolean} [updateWhileAnimating=false] When set to `true`, feature batches will be
 * recreated during animations. This means that no vectors will be shown clipped, but the setting
 * will have a performance impact for large amounts of vector data. When set to `false`, batches
 * will be recreated when no animation is active.
 * @property {boolean} [updateWhileInteracting=false] When set to `true`, feature batches will be
 * recreated during interactions. See also `updateWhileAnimating`.
 * @property {number} [preload=0] Preload. Load low-resolution tiles up to `preload` levels. `0`
 * means no preloading.
 * @property {boolean} [useInterimTilesOnError=true] Use interim tiles on error.
 */


/**
 * @classdesc
 * Layer for vector tile data that is rendered client-side.
 * Note that any property set in the options is set as a {@link module:ol/Object~BaseObject}
 * property on the layer object; for example, setting `title: 'My Title'` in the
 * options means that `title` is observable, and has get/set accessors.
 *
 * @param {Options=} opt_options Options.
 * @extends {BaseVectorLayer<import("../source/VectorTile.js").default>}
 * @api
 */
class VectorTileLayer extends BaseVectorLayer {
  /**
   * @param {Options=} opt_options Options.
   */
  constructor(opt_options) {
    const options = opt_options ? opt_options : {};

    const baseOptions = /** @type {Object} */ (assign({}, options));
    delete baseOptions.preload;
    delete baseOptions.useInterimTilesOnError;

    super(/** @type {import("./BaseVector.js").Options} */ (baseOptions));

    const renderMode = options.renderMode || VectorTileRenderType.HYBRID;
    assert(renderMode == undefined ||
        renderMode == VectorTileRenderType.IMAGE ||
        renderMode == VectorTileRenderType.HYBRID,
    28); // `renderMode` must be `'image'` or `'hybrid'`

    /**
     * @private
     * @type {VectorTileRenderType}
     */
    this.renderMode_ = renderMode;

    this.setPreload(options.preload ? options.preload : 0);
    this.setUseInterimTilesOnError(options.useInterimTilesOnError !== undefined ?
      options.useInterimTilesOnError : true);

  }

  /**
   * Create a renderer for this layer.
   * @return {import("../renderer/Layer.js").default} A layer renderer.
   * @protected
   */
  createRenderer() {
    return new CanvasVectorTileLayerRenderer(this);
  }

  /**
   * @return {VectorTileRenderType} The render mode.
   */
  getRenderMode() {
    return this.renderMode_;
  }

  /**
   * Return the level as number to which we will preload tiles up to.
   * @return {number} The level to preload tiles up to.
   * @observable
   * @api
   */
  getPreload() {
    return /** @type {number} */ (this.get(TileProperty.PRELOAD));
  }

  /**
   * Whether we use interim tiles on error.
   * @return {boolean} Use interim tiles on error.
   * @observable
   * @api
   */
  getUseInterimTilesOnError() {
    return /** @type {boolean} */ (this.get(TileProperty.USE_INTERIM_TILES_ON_ERROR));
  }

  /**
   * Set the level as number to which we will preload tiles up to.
   * @param {number} preload The level to preload tiles up to.
   * @observable
   * @api
   */
  setPreload(preload) {
    this.set(TileProperty.PRELOAD, preload);
  }

  /**
   * Set whether we use interim tiles on error.
   * @param {boolean} useInterimTilesOnError Use interim tiles on error.
   * @observable
   * @api
   */
  setUseInterimTilesOnError(useInterimTilesOnError) {
    this.set(TileProperty.USE_INTERIM_TILES_ON_ERROR, useInterimTilesOnError);
  }
}


export default VectorTileLayer;