Refactoring

haltu · Jul 14, 2019 · 1a81026 · 1a81026
1 parent 0eed781
commit 1a81026
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Showing 3 changed files with 17 additions and 15 deletions.
diff --git a/dist/muuri.js b/dist/muuri.js
@@ -531,14 +531,10 @@
     cancel: 'cancel'
   };
 
-  var hasTouchEvents = !!(
-    'ontouchstart' in window ||
-    window.TouchEvent ||
-    (window.DocumentTouch && window.document instanceof DocumentTouch)
-  );
+  var hasTouchEvents = !!('ontouchstart' in window || window.TouchEvent);
   var hasPointerEvents = !!window.PointerEvent;
   var hasMsPointerEvents = !!window.navigator.msPointerEnabled;
-  var isAndroid = /(android)/i.test(navigator.userAgent);
+  var isAndroid = /(android)/i.test(window.navigator.userAgent);
   var listenerOptions = isPassiveEventsSupported ? { passive: true } : false;
 
   var taProp = 'touchAction';
@@ -864,7 +860,12 @@
     this._pointerId = Dragger._getEventPointerId(e);
     if (this._pointerId === null) return;
 
-    // Store the start event and trigger start (async or sync).
+    // Store the start event and trigger start (async or sync). Pointer events
+    // are emitted before touch events if the browser supports both of them. And
+    // if you try to move an element before `touchstart` is emitted the pointer
+    // events for that element will be canceled. The fix is to delay the emitted
+    // pointer events in such a scenario by one frame so that `touchstart` has
+    // time to be emitted before the element is (potentially) moved.
     this._startEvent = e;
     if (hasTouchEvents && (hasPointerEvents || hasMsPointerEvents)) {
       // Special cancelable check for Android to prevent drag procedure from

diff --git a/dist/muuri.min.js b/dist/muuri.min.js
diff --git a/src/Dragger/Dragger.js b/src/Dragger/Dragger.js
@@ -18,14 +18,10 @@ var events = {
   cancel: 'cancel'
 };
 
-var hasTouchEvents = !!(
-  'ontouchstart' in window ||
-  window.TouchEvent ||
-  (window.DocumentTouch && window.document instanceof DocumentTouch)
-);
+var hasTouchEvents = !!('ontouchstart' in window || window.TouchEvent);
 var hasPointerEvents = !!window.PointerEvent;
 var hasMsPointerEvents = !!window.navigator.msPointerEnabled;
-var isAndroid = /(android)/i.test(navigator.userAgent);
+var isAndroid = /(android)/i.test(window.navigator.userAgent);
 var listenerOptions = isPassiveEventsSupported ? { passive: true } : false;
 
 var taProp = 'touchAction';
@@ -351,7 +347,12 @@ Dragger.prototype._preStartCheck = function(e) {
   this._pointerId = Dragger._getEventPointerId(e);
   if (this._pointerId === null) return;
 
-  // Store the start event and trigger start (async or sync).
+  // Store the start event and trigger start (async or sync). Pointer events
+  // are emitted before touch events if the browser supports both of them. And
+  // if you try to move an element before `touchstart` is emitted the pointer
+  // events for that element will be canceled. The fix is to delay the emitted
+  // pointer events in such a scenario by one frame so that `touchstart` has
+  // time to be emitted before the element is (potentially) moved.
   this._startEvent = e;
   if (hasTouchEvents && (hasPointerEvents || hasMsPointerEvents)) {
     // Special cancelable check for Android to prevent drag procedure from