fix: joystick in 'dynamic' mode gets stuck on iOS

fix #94

README.md

@@ -225,11 +225,11 @@ Three modes are possible :
 - new joystick is created at each new touch farther than `options.catchDistance` of any previously created joystick.
 - the joystick is faded-out when released but not destroyed.
 - when touch is made **inside** the `options.catchDistance` a new direction is triggered immediately.
-- when touch is made **oustide** the `options.catchDistance` the previous joystick is destroyed and a new one is created.
+- when touch is made **outside** the `options.catchDistance` the previous joystick is destroyed and a new one is created.
 - **cannot** be multitouch.
 
 #### `'static'`
-- a joystick is positionned immediately at `options.position`.
+- a joystick is positioned immediately at `options.position`.
 - one joystick per zone.
 - each new touch triggers a new direction.
 - **cannot** be multitouch.
@@ -289,7 +289,7 @@ Your manager has the following signature :
 
 #### `manager.on(type, handler)`
 
-If you whish to listen to internal events like :
+If you wish to listen to internal events like :
 
 ```javascript
 manager.on('event#1 event#2', function (evt, data) {

src/collection.js

@@ -228,6 +228,7 @@ Collection.prototype.pressureFn = function (touch, nipple, identifier) {
 Collection.prototype.onstart = function (evt) {
     var self = this;
     var opts = self.options;
+    var origEvt = evt;
     evt = u.prepareEvent(evt);
 
     // Update the box position
@@ -239,6 +240,22 @@ Collection.prototype.onstart = function (evt) {
         if (self.actives.length < opts.maxNumberOfNipples) {
             self.processOnStart(touch);
         }
+        else if(origEvt.type.match(/^touch/)){
+            // zombies occur when end event is not received on Safari
+            // first touch removed before second touch, we need to catch up...
+            // so remove where touches in manager that no longer exist
+            Object.keys(self.manager.ids).forEach(function(k){
+                if(Object.values(origEvt.touches).findIndex(function(t){return t.identifier===k;}) < 0){
+                    // manager has id that doesn't exist in touches
+                    var e = [evt[0]];
+                    e.identifier = k;
+                    self.processOnEnd(e);
+                }
+            });
+            if(self.actives.length < opts.maxNumberOfNipples){
+                self.processOnStart(touch);
+            }
+        }
     };
 
     u.map(evt, process);