mapcomplete/src/Utils/pngMapCreator.ts

126 lines
4.5 KiB
TypeScript

import ThemeViewState from "../Models/ThemeViewState"
import { Utils } from "../Utils"
import { UIEventSource } from "../Logic/UIEventSource"
import { Map as MlMap } from "maplibre-gl"
import { MapLibreAdaptor } from "../UI/Map/MapLibreAdaptor"
import { AvailableRasterLayers } from "../Models/RasterLayers"
export interface PngMapCreatorOptions {
/**
* In mm
*/
readonly width: number
/**
* In mm
*/
readonly height: number
}
export class PngMapCreator {
private static id = 0
private readonly _options: PngMapCreatorOptions
private readonly _state: ThemeViewState
constructor(state: ThemeViewState, options: PngMapCreatorOptions) {
this._state = state
this._options = options
}
/**
* Creates a base64-encoded PNG image
* @constructor
*/
public async CreatePng(freeComponentId: string, status?: UIEventSource<string>): Promise<Blob> {
const div = document.createElement("div")
div.id = "mapdiv-" + PngMapCreator.id
/**
* We want a certain amount of pixels per mm² for a high print quality
* For this, we create a bigger map on the screen with a canvas, which has a pixelratio given
*
* We know that the default DPI of a canvas is 92, but to print something, we need a bit more
* So, instead, we give it PIXELRATIO more mm and let it render.
* We then draw this onto the PDF as if it were smaller, so it'll have plenty of quality there.
*
* However, we also need to compensate for this in the zoom level
*
*/
const pixelRatio = 2 // dots per mm
div.style.width = this._options.width + "mm"
div.style.height = this._options.height + "mm"
PngMapCreator.id++
try {
const layout = this._state.layout
function setState(msg: string) {
status?.setData(layout.id + ": " + msg)
}
setState("Initializing map")
const settings = this._state.mapProperties
const l = settings.location.data
document.getElementById(freeComponentId).appendChild(div)
const newZoom = settings.zoom.data + Math.log2(pixelRatio) - 1
const rasterLayerProperties =
settings.rasterLayer.data?.properties ??
AvailableRasterLayers.defaultBackgroundLayer.properties
const style = rasterLayerProperties?.style ?? rasterLayerProperties?.url
const mapElem = new MlMap({
container: div.id,
style,
center: [l.lon, l.lat],
zoom: newZoom,
pixelRatio,
})
console.log("Creating a map with size", this._options.width, this._options.height)
const map = new UIEventSource<MlMap>(mapElem)
const mla = new MapLibreAdaptor(map)
mla.zoom.setData(newZoom)
mla.location.setData(settings.location.data)
mla.rasterLayer.setData(settings.rasterLayer.data)
mla.allowZooming.setData(false)
mla.allowMoving.setData(false)
setState("Waiting for the data")
this._state?.showNormalDataOn(map)
setState("Waiting for the data")
await this._state.dataIsLoading.AsPromise((loading) => !loading)
setState("Waiting for styles to be fully loaded")
while (!map?.data?.isStyleLoaded()) {
console.log("Waiting for the style to be loaded...")
await Utils.waitFor(250)
}
// Some extra buffer...
for (let i = 0; i < 5; i++) {
setState(5 - i + " seconds pause to make sure all images are loaded...")
await Utils.waitFor(1000)
}
setState(
"Exporting png (" +
this._options.width +
"mm * " +
this._options.height +
"mm , maplibre-canvas-pixelratio: " +
pixelRatio +
")"
)
const progress = new UIEventSource<{ current: number; total: number }>(undefined)
progress.addCallbackD(({ current, total }) => {
setState(`Rendering marker ${current}/${total}`)
})
const png = await mla.exportAsPng(pixelRatio, progress)
setState("Offering as download...")
return png
} finally {
div.parentElement.removeChild(div)
}
}
}