maplair/src/layer/vector/Renderer.getRenderer.js

JavaScript library for mobile-friendly interactive maps

import {Canvas} from './Canvas.js';
import {SVG} from './SVG.js';

// Registers `getRenderer()` and related methods on the given map class, called by `MaplairMap` itself.
export function register(MaplairMap) {
	MaplairMap.include({
		// @namespace MaplairMap; @method getRenderer(layer: Path): Renderer
		// Returns the instance of `Renderer` that should be used to render the given
		// `Path`. It will ensure that the `renderer` options of the map and paths
		// are respected, and that the renderers do exist on the map.
		getRenderer(layer) {
			// @namespace Path; @option renderer: Renderer
			// Use this specific instance of `Renderer` for this path. Takes
			// precedence over the map's [default renderer](#map-renderer).
			// If set, it will override the `pane` option of the path.
			let renderer = layer.options.renderer ?? this._getPaneRenderer(layer.options.pane) ?? this.options.renderer ?? this._renderer;

			if (!renderer) {
				renderer = this._renderer = this._createRenderer();
			}

			if (!this.hasLayer(renderer)) {
				this.addLayer(renderer);
			}
			return renderer;
		},

		_getPaneRenderer(name) {
			if (name === 'overlayPane' || name === undefined) {
				return;
			}

			let renderer = this._paneRenderers[name];
			if (renderer === undefined) {
				renderer = this._createRenderer({pane: name});
				this._paneRenderers[name] = renderer;
			}
			return renderer;
		},

		_createRenderer(options) {
			// @namespace MaplairMap; @option preferCanvas: Boolean = false
			// Whether `Path`s should be rendered on a `Canvas` renderer.
			// By default, all `Path`s are rendered in a `SVG` renderer.
			return (this.options.preferCanvas && new Canvas(options)) || new SVG(options);
		}
	});
}