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

JavaScript library for mobile-friendly interactive maps

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

Map.include({
	// @namespace Map; @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 Map; @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);
	}
});