From 48f15efa690b95e5b0ae5154dc57caf8088ae2f5 Mon Sep 17 00:00:00 2001
From: Pierre Ossman <ossman@cendio.se>
Date: Tue, 16 Jun 2020 14:24:00 +0200
Subject: [PATCH] Compensate for visual viewport when moving cursor

---
 core/util/cursor.js | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/core/util/cursor.js b/core/util/cursor.js
index 3f0b01bd..009bd6de 100644
--- a/core/util/cursor.js
+++ b/core/util/cursor.js
@@ -125,8 +125,16 @@ export default class Cursor {
         if (!useFallback) {
             return;
         }
-        this._position.x = clientX;
-        this._position.y = clientY;
+        // clientX/clientY are relative the _visual viewport_,
+        // but our position is relative the _layout viewport_,
+        // so try to compensate when we can
+        if (window.visualViewport) {
+            this._position.x = clientX + window.visualViewport.offsetLeft;
+            this._position.y = clientY + window.visualViewport.offsetTop;
+        } else {
+            this._position.x = clientX;
+            this._position.y = clientY;
+        }
         this._updatePosition();
         let target = document.elementFromPoint(clientX, clientY);
         this._updateVisibility(target);