From 1f73dde983d1b1aafcc408e5f2d9fa7d2799d9e1 Mon Sep 17 00:00:00 2001
From: Luis Nieto <luis.nieto.pala@gmail.com>
Date: Fri, 9 Jul 2021 16:09:46 -0500
Subject: [PATCH] Move change image source's methods inside viewer

Added the methods inside the extend function, so that they appear
as properties. Since we cannot reference properties of an object inside
said object, we extract them as properties when needed.
---
 src/viewer.js | 61 ++++++++++++++++++++++++++++++++-------------------
 1 file changed, 38 insertions(+), 23 deletions(-)

diff --git a/src/viewer.js b/src/viewer.js
index 03276a7b..e6f116bc 100644
--- a/src/viewer.js
+++ b/src/viewer.js
@@ -1646,8 +1646,8 @@ $.extend( $.Viewer.prototype, $.EventSource.prototype, $.ControlDock.prototype,
         //////////////////////////////////////////////////////////////////////////
         var onFocusHandler          = $.delegate( this, onFocus ),
             onBlurHandler           = $.delegate( this, onBlur ),
-            onNextHandler           = $.delegate( this, onNext ),
-            onPreviousHandler       = $.delegate( this, onPrevious ),
+            onNextHandler           = $.delegate( this, this['goToNextPage'] ),
+            onPreviousHandler       = $.delegate( this, this['goToPreviousPage'] ),
             navImages               = this.navImages,
             useGroup                = true;
 
@@ -2316,7 +2316,40 @@ $.extend( $.Viewer.prototype, $.EventSource.prototype, $.ControlDock.prototype,
             this.world.resetItems();
             this.forceRedraw();
         }
-    }
+    },
+
+    /**
+     * Sets the image source to the source with index equal to
+     * currentIndex - 1. Changes current image in sequence mode.
+     * If specified, wraps around (see navPrevNextWrap in
+     * {@link OpenSeadragon.Options})
+     *
+     * @method
+     */
+
+    goToPreviousPage: function () {
+        var previous = this._sequenceIndex - 1;
+        if(this.navPrevNextWrap && previous < 0){
+            previous += this.tileSources.length;
+        }
+        this.goToPage( previous );
+    },
+
+    /**
+     * Sets the image source to the source with index equal to
+     * currentIndex + 1. Changes current image in sequence mode.
+     * If specified, wraps around (see navPrevNextWrap in
+     * {@link OpenSeadragon.Options})
+     *
+     * @method
+     */
+    goToNextPage: function () {
+        var next = this._sequenceIndex + 1;
+        if(this.navPrevNextWrap && next >= this.tileSources.length){
+            next = 0;
+        }
+        this.goToPage( next );
+    },
 });
 
 
@@ -2783,10 +2816,10 @@ function onCanvasKeyPress( event ) {
               event.preventDefault = true;
               break;
             case 106: //j - previous image source
-              onPrevious.bind(this)();
+              this.goToPreviousPage();
               break;
             case 107: //k - next image source
-              onNext.bind(this)();
+              this.goToNextPage();
               break;
             default:
                 // console.log( 'navigator keycode %s', event.keyCode );
@@ -3677,22 +3710,4 @@ function onFlip() {
    this.viewport.toggleFlip();
 }
 
-function onPrevious(){
-    var previous = this._sequenceIndex - 1;
-    if(this.navPrevNextWrap && previous < 0){
-        previous += this.tileSources.length;
-    }
-    this.goToPage( previous );
-}
-
-
-function onNext(){
-    var next = this._sequenceIndex + 1;
-    if(this.navPrevNextWrap && next >= this.tileSources.length){
-        next = 0;
-    }
-    this.goToPage( next );
-}
-
-
 }( OpenSeadragon ));