From 2d655143c31612c2139191922d51548e35962443 Mon Sep 17 00:00:00 2001
From: Frederic Junod <frederic.junod@camptocamp.com>
Date: Fri, 17 May 2019 16:45:29 +0200
Subject: [PATCH] Add an Overlay in the export-map example

---
 examples/export-map.css  | 6 ++++++
 examples/export-map.html | 3 +++
 examples/export-map.js   | 9 ++++++++-
 3 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 examples/export-map.css

diff --git a/examples/export-map.css b/examples/export-map.css
new file mode 100644
index 0000000000..9917279a2b
--- /dev/null
+++ b/examples/export-map.css
@@ -0,0 +1,6 @@
+.overlay {
+  background-color: yellow;
+  border-radius: 6px;
+  padding: 4px;
+  white-space: nowrap;
+}
diff --git a/examples/export-map.html b/examples/export-map.html
index 4ab8686cbb..9e45f5e986 100644
--- a/examples/export-map.html
+++ b/examples/export-map.html
@@ -8,5 +8,8 @@ docs: >
 tags: "export, png, openstreetmap"
 ---
 <div id="map" class="map"></div>
+<div style="display: none;">
+  <div class="overlay" id="null">Null Island</div>
+</div>
 <a id="export-png" class="btn btn-default"><i class="fa fa-download"></i> Download PNG</a>
 <a id="image-download" download="map.png"></a>
diff --git a/examples/export-map.js b/examples/export-map.js
index f402a0fa86..c3b5512347 100644
--- a/examples/export-map.js
+++ b/examples/export-map.js
@@ -1,5 +1,6 @@
 import Map from '../src/ol/Map.js';
 import View from '../src/ol/View.js';
+import Overlay from '../src/ol/Overlay.js';
 import GeoJSON from '../src/ol/format/GeoJSON.js';
 import {Tile as TileLayer, Vector as VectorLayer} from '../src/ol/layer.js';
 import {OSM, Vector as VectorSource} from '../src/ol/source.js';
@@ -25,11 +26,17 @@ const map = new Map({
   })
 });
 
+map.addOverlay(new Overlay({
+  position: [0, 0],
+  element: document.getElementById('null')
+}));
+
+
 // export options for html-to-image.
 // See: https://github.com/bubkoo/html-to-image#options
 const exportOptions = {
   filter: function(element) {
-    return element.className.indexOf('ol-control') === -1;
+    return element.className ? element.className.indexOf('ol-control') === -1 : true;
   }
 };