From 6901be9ee00a441f49a2e4b56763809885371d06 Mon Sep 17 00:00:00 2001
From: jwasilgeo <jwasilkowski@esri.com>
Date: Tue, 28 Jul 2020 09:10:31 -0500
Subject: [PATCH] reverting changes introduced in pr #1011

---
 src/Layers/BasemapLayer.js | 58 +-------------------------------------
 1 file changed, 1 insertion(+), 57 deletions(-)

diff --git a/src/Layers/BasemapLayer.js b/src/Layers/BasemapLayer.js
index 0ba26d70b..40e86ba3e 100644
--- a/src/Layers/BasemapLayer.js
+++ b/src/Layers/BasemapLayer.js
@@ -1,6 +1,5 @@
 import { TileLayer, Util } from 'leaflet';
 import { pointerEvents } from '../Support';
-import { request } from '../Request';
 import {
   setEsriAttribution,
   _getAttributionData,
@@ -104,9 +103,7 @@ export var BasemapLayer = TileLayer.extend({
         urlTemplate: tileProtocol + '//{s}.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}',
         options: {
           minZoom: 1,
-          maxZoom: 22,
-          maxNativeZoom: 22,
-          downsampled: false,
+          maxZoom: 19,
           subdomains: ['server', 'services'],
           attribution: 'DigitalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community',
           attributionUrl: 'https://static.arcgis.com/attribution/World_Imagery'
@@ -250,21 +247,12 @@ export var BasemapLayer = TileLayer.extend({
 
     map.on('moveend', _updateMapAttribution);
 
-    // Esri World Imagery is cached all the way to zoom 22 in select regions
-    if (this._url === BasemapLayer.TILES.Imagery.urlTemplate) {
-      map.on('zoomanim', _fetchTilemap, this);
-    }
-
     TileLayer.prototype.onAdd.call(this, map);
   },
 
   onRemove: function (map) {
     map.off('moveend', _updateMapAttribution);
 
-    if (this._url === BasemapLayer.TILES.Imagery.urlTemplate) {
-      map.off('zoomanim', _fetchTilemap, this);
-    }
-
     TileLayer.prototype.onRemove.call(this, map);
   },
 
@@ -284,50 +272,6 @@ export var BasemapLayer = TileLayer.extend({
   }
 });
 
-function _fetchTilemap (evt) {
-  var map = evt.target;
-  if (!map) { return; }
-
-  var oldZoom = map.getZoom();
-  var newZoom = evt.zoom;
-  var newCenter = map.wrapLatLng(evt.center);
-
-  if (newZoom > oldZoom && newZoom > 13 && !this.options.downsampled) {
-    // convert wrapped lat/long into tile coordinates and use them to generate the tilemap url
-    var tilePoint = map.project(newCenter, newZoom).divideBy(256).floor();
-
-    // use new coords to determine the tilemap url
-    var tileUrl = Util.template(this._url, Util.extend({
-      s: this._getSubdomain(tilePoint),
-      x: tilePoint.x,
-      y: tilePoint.y,
-      z: newZoom
-    }, this.options));
-
-    // 8x8 grids are cached
-    var tilemapUrl = tileUrl.replace(/tile/, 'tilemap') + '/8/8';
-
-    // an array of booleans in the response indicate missing tiles
-    request(tilemapUrl, {}, function (err, response) {
-      if (!err) {
-        for (var i = 0; i < response.data.length; i++) {
-          if (!response.data[i]) {
-            // if necessary, resample a lower zoom
-            this.options.maxNativeZoom = newZoom - 1;
-            this.options.downsampled = true;
-            break;
-          }
-          // if no tiles are missing, reset the original maxZoom
-          this.options.maxNativeZoom = 22;
-        }
-      }
-    }, this);
-  } else if (newZoom < 13) {
-    // if the user moves to a new region, time for a fresh test
-    this.options.downsampled = false;
-  }
-}
-
 export function basemapLayer (key, options) {
   return new BasemapLayer(key, options);
 }