From e495746c4c6229e0779b713c91bd397b1818cf63 Mon Sep 17 00:00:00 2001
From: Arthur Flam <arthur.flam@gmail.com>
Date: Thu, 20 Jan 2022 16:46:57 +0200
Subject: [PATCH] Fix: openseadragon 3.0 API

In openseadragon 3.0 viewer.buttons was renamed to viewer.buttonGroup
https://github.com/openseadragon/openseadragon/commit/0ede8992de954e2a1641b7ce60fb865d3c3849a8
---
 src/imagefilters.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/imagefilters.js b/src/imagefilters.js
index 258f661..d5147e3 100644
--- a/src/imagefilters.js
+++ b/src/imagefilters.js
@@ -120,7 +120,7 @@
         $.extend(true, this.navImages, this.viewer.navImages);
 
         var prefix = this.prefixUrl || this.viewer.prefixUrl || '';
-        var useGroup = this.viewer.buttons && this.viewer.buttons.buttons;
+        var useGroup = this.viewer.buttonGroup && this.viewer.buttonGroup.buttons;
 
         if (this.showControl) {
             this.toggleButton = new $.Button({
@@ -136,8 +136,8 @@
             });
 
             if (useGroup) {
-                this.viewer.buttons.buttons.push(this.toggleButton);
-                this.viewer.buttons.element.appendChild(this.toggleButton.element);
+                this.viewer.buttonGroup.buttons.push(this.toggleButton);
+                this.viewer.buttonGroup.element.appendChild(this.toggleButton.element);
             }
             if (this.toggleButton.imgDown) {
                 this.buttonActiveImg = this.toggleButton.imgDown.cloneNode(true);