mapcomplete/Logic/State/LayerState.ts
2023-03-28 05:13:48 +02:00

70 lines
2.4 KiB
TypeScript

import { UIEventSource } from "../UIEventSource"
import { GlobalFilter } from "../../Models/GlobalFilter"
import FilteredLayer from "../../Models/FilteredLayer"
import LayerConfig from "../../Models/ThemeConfig/LayerConfig"
import { OsmConnection } from "../Osm/OsmConnection"
/**
* The layer state keeps track of:
* - Which layers are enabled
* - Which filters are used, including 'global' filters
*/
export default class LayerState {
/**
* Filters which apply onto all layers
*/
public readonly globalFilters: UIEventSource<GlobalFilter[]> = new UIEventSource(
[],
"globalFilters"
)
/**
* Which layers are enabled in the current theme and what filters are applied onto them
*/
public readonly filteredLayers: Map<string, FilteredLayer>
private readonly osmConnection: OsmConnection
/**
*
* @param osmConnection
* @param layers
* @param context: the context, probably the name of the theme. Used to disambiguate the upstream user preference
*/
constructor(osmConnection: OsmConnection, layers: LayerConfig[], context: string) {
this.osmConnection = osmConnection
this.filteredLayers = new Map()
for (const layer of layers) {
this.filteredLayers.set(
layer.id,
FilteredLayer.initLinkedState(layer, context, this.osmConnection)
)
}
layers.forEach((l) => this.linkFilterStates(l))
}
/**
* Some layers copy the filter state of another layer - this is quite often the case for 'sibling'-layers,
* (where two variations of the same layer are used, e.g. a specific type of shop on all zoom levels and all shops on high zoom).
*
* This methods links those states for the given layer
*/
private linkFilterStates(layer: LayerConfig) {
if (layer.filterIsSameAs === undefined) {
return
}
const toReuse = this.filteredLayers.get(layer.filterIsSameAs)
if (toReuse === undefined) {
throw (
"Error in layer " +
layer.id +
": it defines that it should be use the filters of " +
layer.filterIsSameAs +
", but this layer was not loaded"
)
}
console.warn(
"Linking filter and isDisplayed-states of " + layer.id + " and " + layer.filterIsSameAs
)
this.filteredLayers.set(layer.id, toReuse)
}
}