From 54523943476a95157b3c3b7655472305691a58f2 Mon Sep 17 00:00:00 2001
From: Paul Gschwendtner <paulgschwendtner@me.com>
Date: Sun, 5 Jun 2016 01:08:15 +0200
Subject: [PATCH] fix(gestures): detect touch action and provide polyfill.

* On non-android browsers, touchmove events were cancelled and native scroll was disabled as well.
* touchAction is supported by the most modern-browsers and drops the cancellation of the touchmove event
* If touchAction is not supported, then we're able to use the polyfill (cancelling the touchMove event)

Fixes #7311.
---
 src/core/services/gesture/gesture.js | 42 ++++++++++++++++++++++++----
 1 file changed, 37 insertions(+), 5 deletions(-)

diff --git a/src/core/services/gesture/gesture.js b/src/core/services/gesture/gesture.js
index 4ed6893a226..5b51d9dfcdd 100644
--- a/src/core/services/gesture/gesture.js
+++ b/src/core/services/gesture/gesture.js
@@ -73,6 +73,7 @@ function MdGesture($$MdGestureHandler, $$rAF, $timeout) {
   var userAgent = navigator.userAgent || navigator.vendor || window.opera;
   var isIos = userAgent.match(/ipad|iphone|ipod/i);
   var isAndroid = userAgent.match(/android/i);
+  var touchActionProperty = getTouchAction();
   var hasJQuery =  (typeof window.jQuery !== 'undefined') && (angular.element === window.jQuery);
 
   var self = {
@@ -215,7 +216,7 @@ function MdGesture($$MdGestureHandler, $$rAF, $timeout) {
         // If we don't preventDefault touchmove events here, Android will assume we don't
         // want to listen to anymore touch events. It will start scrolling and stop sending
         // touchmove events.
-        ev.preventDefault();
+        if (!touchActionProperty && ev.type === 'touchmove') ev.preventDefault();
 
         // If the user moves greater than <maxDistance> pixels, stop the hold timer
         // set in onStart
@@ -234,7 +235,7 @@ function MdGesture($$MdGestureHandler, $$rAF, $timeout) {
      * The drag handler dispatches a drag event if the user holds and moves his finger greater than
      * <minDistance> px in the x or y direction, depending on options.horizontal.
      * The drag will be cancelled if the user moves his finger greater than <minDistance>*<cancelMultiplier> in
-     * the perpindicular direction. Eg if the drag is horizontal and the user moves his finger <minDistance>*<cancelMultiplier>
+     * the perpendicular direction. Eg if the drag is horizontal and the user moves his finger <minDistance>*<cancelMultiplier>
      * pixels vertically, this handler won't consider the move part of a drag.
      */
     .handler('drag', {
@@ -243,6 +244,18 @@ function MdGesture($$MdGestureHandler, $$rAF, $timeout) {
         horizontal: true,
         cancelMultiplier: 1.5
       },
+      onSetup: function(element, options) {
+        if (touchActionProperty) {
+          // We check for horizontal to be false, because otherwise we would overwrite the default opts.
+          this.oldTouchAction = element[0].style[touchActionProperty];
+          element[0].style[touchActionProperty] = options.horizontal === false ? 'pan-y' : 'pan-x';
+        }
+      },
+      onCleanup: function(element) {
+        if (this.oldTouchAction) {
+          element[0].style[touchActionProperty] = this.oldTouchAction;
+        }
+      },
       onStart: function (ev) {
         // For drag, require a parent to be registered with $mdGesture.register()
         if (!this.state.registeredParent) this.cancel();
@@ -253,7 +266,7 @@ function MdGesture($$MdGestureHandler, $$rAF, $timeout) {
         // If we don't preventDefault touchmove events here, Android will assume we don't
         // want to listen to anymore touch events. It will start scrolling and stop sending
         // touchmove events.
-        ev.preventDefault();
+        if (!touchActionProperty && ev.type === 'touchmove') ev.preventDefault();
 
         if (!this.state.dragPointer) {
           if (this.state.options.horizontal) {
@@ -277,7 +290,7 @@ function MdGesture($$MdGestureHandler, $$rAF, $timeout) {
           this.dispatchDragMove(ev);
         }
       },
-      // Only dispatch dragmove events every frame; any more is unnecessray
+      // Only dispatch dragmove events every frame; any more is unnecessary
       dispatchDragMove: $$rAF.throttle(function (ev) {
         // Make sure the drag didn't stop while waiting for the next frame
         if (this.state.isRunning) {
@@ -318,6 +331,19 @@ function MdGesture($$MdGestureHandler, $$rAF, $timeout) {
       }
     });
 
+  function getTouchAction() {
+    var testEl = document.createElement('div');
+    var vendorPrefixes = ['', 'webkit', 'Moz', 'MS', 'ms', 'o'];
+
+    for (var i = 0; i < vendorPrefixes.length; i++) {
+      var prefix = vendorPrefixes[i];
+      var property = prefix ? prefix + 'TouchAction' : 'touchAction';
+      if (angular.isDefined(testEl.style[property])) {
+        return property;
+      }
+    }
+  }
+
 }
 
 /**
@@ -346,6 +372,8 @@ function MdGestureHandler() {
     dispatchEvent: hasJQuery ?  jQueryDispatchEvent : nativeDispatchEvent,
 
     // These are overridden by the registered handler
+    onSetup: angular.noop,
+    onCleanup: angular.noop,
     onStart: angular.noop,
     onMove: angular.noop,
     onEnd: angular.noop,
@@ -395,7 +423,7 @@ function MdGestureHandler() {
       return null;
     },
 
-    // Called from $mdGesture.register when an element reigsters itself with a handler.
+    // Called from $mdGesture.register when an element registers itself with a handler.
     // Store the options the user gave on the DOMElement itself. These options will
     // be retrieved with getNearestParent when the handler starts.
     registerElement: function (element, options) {
@@ -404,11 +432,15 @@ function MdGestureHandler() {
       element[0].$mdGesture[this.name] = options || {};
       element.on('$destroy', onDestroy);
 
+      self.onSetup(element, options || {});
+
       return onDestroy;
 
       function onDestroy() {
         delete element[0].$mdGesture[self.name];
         element.off('$destroy', onDestroy);
+
+        self.onCleanup(element, options || {});
       }
     }
   };