I've found the default Popup positioning tends to be unreliable, but fortunately you can override the default behavior by assigning a function to the alignment property. I've modified the aforementioned sample below with what my apps use. In particular, I added lines 52-80, and also the reference to reactiveUtils on line 35.
<html lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<title>Intro to popups | Sample | ArcGIS Maps SDK for JavaScript 4.28</title>
<style>
html,
body,
#viewDiv {
padding: 0;
margin: 0;
height: 100%;
width: 100%;
}
#instruction {
z-index: 99;
position: absolute;
top: 15px;
left: 50%;
padding: 5px;
margin-left: -175px;
height: 30px;
width: 355px;
background: rgba(25, 25, 25, 0.8);
color: white;
}
</style>
<link rel="stylesheet" href="https://js.arcgis.com/4.28/esri/themes/light/main.css" />
<script src="https://js.arcgis.com/4.28/"></script>
<script>
require(["esri/rest/locator", "esri/Map", "esri/views/MapView", "esri/core/reactiveUtils"], (locator, Map, MapView, reactiveUtils) => {
// Set up a locator url using the world geocoding service
const locatorUrl = "https://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer";
// Create the Map
const map = new Map({
basemap: "streets-navigation-vector"
});
// Create the MapView
const view = new MapView({
container: "viewDiv",
map: map,
center: [-71.6899, 43.7598],
zoom: 12
});
reactiveUtils.watch(() => view.popup?.id, function() {
view.popup.alignment = function() {
var location = this.location;
var view = this.view;
if ((location) && (view)) {
var viewPoint = view.toScreen(location);
var y2 = view.height / 2;
var x2 = view.width / 3;
var x3 = x2 * 2;
if (viewPoint.y >= y2) {
if (viewPoint.x < x2)
return "top-right";
else if (viewPoint.x > x3)
return "top-left";
} else {
if (viewPoint.x < x2)
return "bottom-right";
else if (viewPoint.x > x3)
return "bottom-left";
else
return "bottom-center";
}
}
return "top-center";
};
});
/*******************************************************************
* This click event sets generic content on the popup not tied to
* a layer, graphic, or popupTemplate. The location of the point is
* used as input to a reverse geocode method and the resulting
* address is printed to the popup content.
*******************************************************************/
view.popupEnabled = false;
view.on("click", (event) => {
// Get the coordinates of the click on the view
const lat = Math.round(event.mapPoint.latitude * 1000) / 1000;
const lon = Math.round(event.mapPoint.longitude * 1000) / 1000;
view.openPopup({
// Set the popup's title to the coordinates of the location
title: "Reverse geocode: [" + lon + ", " + lat + "]",
location: event.mapPoint // Set the location of the popup to the clicked location
});
const params = {
location: event.mapPoint
};
// Display the popup
// Execute a reverse geocode using the clicked location
locator
.locationToAddress(locatorUrl, params)
.then((response) => {
// If an address is successfully found, show it in the popup's content
view.popup.content = response.address;
})
.catch(() => {
// If the promise fails and no result is found, show a generic message
view.popup.content = "No address was found for this location";
});
});
});
</script>
</head>
<body>
<div id="viewDiv"></div>
<div id="instruction" class="esri-widget">Click any location on the map to see its street address</div>
</body>
</html>