move getRandomOrder to utils

DIYgod · DIYgod · commit c590dd40803f · 2018-03-02T16:12:55.000+08:00
diff --git a/src/js/player.js b/src/js/player.js
@@ -33,7 +33,7 @@ class APlayer {
         if (!this.isMultiple() && this.mode !== 'circulation' && this.mode !== 'order') {
             this.mode = 'circulation';
         }
-        this.getRandomOrder();
+        this.randomOrder = utils.randomOrder(this.options.music.length);
 
         if (this.options.showlrc) {
             this.container.classList.add('aplayer-withlrc');
@@ -348,34 +348,6 @@ class APlayer {
         return this.options.music.length > 1;
     }
 
-    /**
-     * get random order, using Fisher&ndash;Yates shuffle
-     */
-    getRandomOrder (length = this.options.music.length) {
-        function random (min, max) {
-            if (max) {
-                max = min;
-                min = 0;
-            }
-            return min + Math.floor(Math.random() * (max - min + 1));
-        }
-        function shuffle (arr) {
-            const length = arr.length,
-                shuffled = new Array(length);
-            for (let index = 0, rand; index < length; index++) {
-                rand = random(0, index);
-                if (rand !== index) { shuffled[index] = shuffled[rand]; }
-                shuffled[rand] = arr[index];
-            }
-            return shuffled;
-        }
-        if (this.isMultiple()) {
-            this.randomOrder = shuffle([...Array(length)].map(function (item, i) {
-                return i;
-            }));
-        }
-    }
-
     /**
      * get next random number
      */
@@ -423,7 +395,7 @@ class APlayer {
         const songListLength = this.container.querySelectorAll('.aplayer-list li').length;
         this.template.list.style.height = songListLength * 33 + 'px';
 
-        this.getRandomOrder();
+        this.randomOrder = utils.randomOrder(this.options.music.length);
     }
 
     /**
diff --git a/src/js/utils.js b/src/js/utils.js
@@ -65,6 +65,24 @@ const utils = {
         dragStart: isMobile ? 'touchstart' : 'mousedown',
         dragMove: isMobile ? 'touchmove' : 'mousemove',
         dragEnd: isMobile ? 'touchend' : 'mouseup'
+    },
+
+    /**
+     * get random order, using Fisher&ndash;Yates shuffle
+     */
+    randomOrder: (length = this.options.music.length) => {
+        function shuffle (arr) {
+            for (let i = arr.length - 1; i >= 0; i--) {
+                const randomIndex = Math.floor(Math.random() * (i + 1));
+                const itemAtIndex = arr[randomIndex];
+                arr[randomIndex] = arr[i];
+                arr[i] = itemAtIndex;
+            }
+            return arr;
+        }
+        return shuffle([...Array(length)].map(function (item, i) {
+            return i;
+        }));
     }
 };
 
