From 4615f6b5ba23f497b8f43b9a38a410925d35ff91 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Fri, 23 Dec 2022 23:08:17 +0100
Subject: [PATCH] Add a Firefox workaround for animations.

---
 www/js/chessboard-0.3.0.js | 48 ++++++++++++++++++++------------------
 1 file changed, 25 insertions(+), 23 deletions(-)

diff --git a/www/js/chessboard-0.3.0.js b/www/js/chessboard-0.3.0.js
index d1d53f1..451f1a9 100644
--- a/www/js/chessboard-0.3.0.js
+++ b/www/js/chessboard-0.3.0.js
@@ -818,33 +818,35 @@ function doAnimations(a, oldPos, newPos) {
     }
   }
 
-  for (var i = 0; i < a.length; i++) {
-    // clear a piece
-    if (a[i].type === 'clear') {
-      document.getElementById(SQUARE_ELS_IDS[a[i].square]).querySelectorAll('.' + CSS.piece).forEach(
-        (piece) => fadeOut(piece, onFinish)
-      );
-    }
+  requestAnimationFrame(() => {  // Firefox workaround.
+    for (var i = 0; i < a.length; i++) {
+      // clear a piece
+      if (a[i].type === 'clear') {
+        document.getElementById(SQUARE_ELS_IDS[a[i].square]).querySelectorAll('.' + CSS.piece).forEach(
+          (piece) => fadeOut(piece, onFinish)
+        );
+      }
 
-    // add a piece (no spare pieces)
-    if (a[i].type === 'add' && cfg.sparePieces !== true) {
-      let square = document.getElementById(SQUARE_ELS_IDS[a[i].square]);
-      square.append(buildPiece(a[i].piece, true));
-      let piece = square.querySelector('.' + CSS.piece);
-      fadeIn(piece, onFinish);
-    }
+      // add a piece (no spare pieces)
+      if (a[i].type === 'add' && cfg.sparePieces !== true) {
+        let square = document.getElementById(SQUARE_ELS_IDS[a[i].square]);
+        square.append(buildPiece(a[i].piece, true));
+        let piece = square.querySelector('.' + CSS.piece);
+        fadeIn(piece, onFinish);
+      }
 
-    // add a piece from a spare piece
-    if (a[i].type === 'add' && cfg.sparePieces === true) {
-      animateSparePieceToSquare(a[i].piece, a[i].square, onFinish);
-    }
+      // add a piece from a spare piece
+      if (a[i].type === 'add' && cfg.sparePieces === true) {
+        animateSparePieceToSquare(a[i].piece, a[i].square, onFinish);
+      }
 
-    // move a piece
-    if (a[i].type === 'move') {
-      animateSquareToSquare(a[i].source, a[i].destination, a[i].piece,
-        onFinish);
+      // move a piece
+      if (a[i].type === 'move') {
+        animateSquareToSquare(a[i].source, a[i].destination, a[i].piece,
+          onFinish);
+      }
     }
-  }
+  });
 }
 
 // returns the distance between two squares
-- 
2.39.2