#659: Fixed delay in FireFox + Delay browser compatibility fixes

README.md

@@ -235,6 +235,7 @@ Demo: https://jsbin.com/jayedig/edit?js,output
 
 #### `delay` option
 Time in milliseconds to define when the sorting should start.
+Unfortunately, due to browser restrictions, delaying is not possible on IE or Edge with native drag & drop.
 
 Demo: https://jsbin.com/zosiwah/edit?js,output
 

Sortable.js

@@ -94,7 +94,7 @@
 
 		IE11OrLess = !!navigator.userAgent.match(/(?:Trident.*rv[ :]?11\.|msie|iemobile)/i),
 		Edge = !!navigator.userAgent.match(/Edge/i),
-		// FireFox = !!navigator.userAgent.match(/firefox/i),
+		FireFox = !!navigator.userAgent.match(/firefox/i),
 		Safari = !!(navigator.userAgent.match(/safari/i) && !navigator.userAgent.match(/chrome/i) && !navigator.userAgent.match(/android/i)),
 
 		CSSFloatProperty = Edge || IE11OrLess ? 'cssFloat' : 'float',
@@ -117,6 +117,7 @@
 
 		abs = Math.abs,
 		min = Math.min,
+		max = Math.max,
 
 		savedInputChecked = [],
 
@@ -249,9 +250,6 @@
 					x = evt.clientX,
 					y = evt.clientY,
 
-					winWidth = window.innerWidth,
-					winHeight = window.innerHeight,
-
 					scrollThisInstance = false;
 
 				// Detect scrollEl
@@ -575,6 +573,11 @@
 		// Setup drag mode
 		this.nativeDraggable = options.forceFallback ? false : supportDraggable;
 
+		if (this.nativeDraggable) {
+			// Touch start threshold cannot be greater than the native dragstart threshold
+			this.options.touchStartThreshold = 1;
+		}
+
 		// Bind events
 		if (options.supportPointer) {
 			_on(el, 'pointerdown', this._onTapStart);
@@ -806,10 +809,11 @@
 				dragStartFn = function () {
 					// Delayed drag has been triggered
 					// we can re-enable the events: touchmove/mousemove
-					_this._disableDelayedDrag();
+					_this._disableDelayedDragEvents();
 
-					// Make the element draggable
-					dragEl.draggable = _this.nativeDraggable;
+					if (!FireFox && _this.nativeDraggable) {
+						dragEl.draggable = true;
+					}
 
 					// Bind the events: dragstart/dragend
 					_this._triggerDragStart(evt, touch);
@@ -834,7 +838,14 @@
 					_on(ownerDocument, 'touchcancel', _this._onDrop);
 				}
 
-				if (options.delay) {
+				// Make dragEl draggable (must be before delay for FireFox)
+				if (FireFox && this.nativeDraggable) {
+					this.options.touchStartThreshold = 4;
+					dragEl.draggable = true;
+				}
+
+				// Delay is impossible for native DnD in Edge or IE
+				if (options.delay && (!this.nativeDraggable || !(Edge || IE11OrLess))) {
 					// If the user moves the pointer or let go the click or touch
 					// before the delay has been reached:
 					// disable the delayed drag
@@ -854,17 +865,22 @@
 
 		_delayedDragTouchMoveHandler: function (/** TouchEvent|PointerEvent **/e) {
 			var touch = e.touches ? e.touches[0] : e;
-			if (min(abs(touch.clientX - this._lastX), abs(touch.clientY - this._lastY))
-					>= this.options.touchStartThreshold
+			if (max(abs(touch.clientX - this._lastX), abs(touch.clientY - this._lastY))
+					>= Math.floor(this.options.touchStartThreshold / (this.nativeDraggable && window.devicePixelRatio || 1))
 			) {
 				this._disableDelayedDrag();
 			}
 		},
 
 		_disableDelayedDrag: function () {
-			var ownerDocument = this.el.ownerDocument;
-
+			dragEl && _disableDraggable(dragEl);
 			clearTimeout(this._dragStartTimer);
+
+			this._disableDelayedDragEvents();
+		},
+
+		_disableDelayedDragEvents: function () {
+			var ownerDocument = this.el.ownerDocument;
 			_off(ownerDocument, 'mouseup', this._disableDelayedDrag);
 			_off(ownerDocument, 'touchend', this._disableDelayedDrag);
 			_off(ownerDocument, 'touchcancel', this._disableDelayedDrag);