Refactoring: move all code files into a src directory

src/UI/Map/OverlayMap.svelte

@@ -0,0 +1,69 @@
+<script lang="ts">
+  /**
+   * The overlay map is a bit a weird map:
+   * it is a HTML-component which is intended to be placed _over_ another map.
+   * It will align itself in order to seamlessly show the same location; but possibly in a different style
+   */
+  import MaplibreMap from "./MaplibreMap.svelte"
+  import { Store, UIEventSource } from "../../Logic/UIEventSource"
+  import { Map as MlMap } from "maplibre-gl"
+  import { MapLibreAdaptor } from "./MapLibreAdaptor"
+  import type { MapProperties } from "../../Models/MapProperties"
+  import { onDestroy } from "svelte"
+  import type { RasterLayerPolygon } from "../../Models/RasterLayers"
+
+  export let placedOverMapProperties: MapProperties
+  export let placedOverMap: UIEventSource<MlMap>
+
+  export let rasterLayer: UIEventSource<RasterLayerPolygon>
+
+  export let visible: Store<boolean> = undefined
+  let altmap: UIEventSource<MlMap> = new UIEventSource(undefined)
+  let altproperties = new MapLibreAdaptor(altmap, {
+    rasterLayer,
+    zoom: UIEventSource.feedFrom(placedOverMapProperties.zoom),
+  })
+  altproperties.allowMoving.setData(false)
+  altproperties.allowZooming.setData(false)
+
+  function pixelCenterOf(map: UIEventSource<MlMap>): [number, number] {
+    const rect = map?.data?.getCanvas()?.getBoundingClientRect()
+    if (!rect) {
+      return undefined
+    }
+    const x = (rect.left + rect.right) / 2
+    const y = (rect.top + rect.bottom) / 2
+    return [x, y]
+  }
+
+  function updateLocation() {
+    if (!placedOverMap.data || !altmap.data) {
+      return
+    }
+    altmap.data.resize()
+    const { lon, lat } = placedOverMapProperties.location.data
+    const altMapCenter = pixelCenterOf(altmap)
+    const c = placedOverMap.data.unproject(altMapCenter)
+    altproperties.location.setData({ lon: c.lng, lat: c.lat })
+  }
+
+  onDestroy(placedOverMapProperties.location.addCallbackAndRunD(updateLocation))
+  updateLocation()
+  window.setTimeout(updateLocation, 150)
+  window.setTimeout(updateLocation, 500)
+
+  if (visible) {
+    onDestroy(
+      visible?.addCallbackAndRunD((v) => {
+        if (!v) {
+          return
+        }
+        updateLocation()
+        window.setTimeout(updateLocation, 150)
+        window.setTimeout(updateLocation, 500)
+      })
+    )
+  }
+</script>
+
+<MaplibreMap map={altmap} />