META-INF.resources.frontend.vaadin-map.util.js Maven / Gradle / Ivy
/**
* @license
* Copyright 2000-2023 Vaadin Ltd.
*
* This program is available under Vaadin Commercial License and Service Terms.
*
* See for the full
* license.
*/
import VectorSource from 'ol/source/Vector';
/**
* Simple lookup for OL instances that are used by Map.
* This implementation will never release references, which means that OL
* instances in the lookup can never be garbage collected as long as the
* Map element exists.
* This should only be used as a fallback if a browser does not support
* weak references and finalization registry.
*/
class SimpleLookup {
constructor() {
this.map = new Map();
}
get(id) {
return this.map.get(id);
}
put(id, instance) {
this.map.set(id, instance);
}
}
/**
* Lookup for OL instances that uses weak references for storing objects.
* Using weak references allows the browser to garbage collect the OL
* instances that are not used anymore in the Map. The lookup also uses a
* finalization registry to remove weak references from the lookup when
* instances are garbage collected.
*/
class WeakReferenceLookup {
constructor() {
this.map = new Map();
// Create registry that notifies when a reference is garbage collected,
// the callback removes the WeakRef entry from the map
this.registry = new FinalizationRegistry((id) => {
this.map.delete(id);
});
}
get(id) {
const weakRef = this.map.get(id);
return weakRef ? weakRef.deref() : undefined;
}
put(id, instance) {
// Skip if reference is already tracked
if (this.map.has(id)) return;
// Store weak reference in map
const ref = new WeakRef(instance);
this.map.set(id, ref);
// Track reference for garbage collection, so that we can clean up the map entry
this.registry.register(instance, id);
}
}
const supportsWeakReferenceLookup = window.WeakRef && window.FinalizationRegistry;
/**
* Creates a lookup that is supported by the browser
* @returns {WeakReferenceLookup|SimpleLookup}
*/
export function createLookup() {
return supportsWeakReferenceLookup ? new WeakReferenceLookup() : new SimpleLookup();
}
/**
* Searches an OpenLayers map instance for the layer whose source contains a specific feature
* @param layers the array of layers configured in the map
* @param feature the feature that should be contained in the layers source
* @returns {*} the layer that contains the feature, or undefined
*/
export function getLayerForFeature(layers, feature) {
return layers.find((layer) => {
const source = layer.getSource && layer.getSource();
const isVectorSource = source && source instanceof VectorSource;
return isVectorSource && source.getFeatures().includes(feature);
});
}