Merge pull request #23759 from crdlc/bug-1062527

Bug 1062527 - [Homescreen] Unable to launch apps after changing the date to a previous one

apps/sharedtest/test/unit/elements/gaia_grid/grid_view_test.js

@@ -0,0 +1,40 @@
+/* global GridView, GridLayout */
+
+'use strict';
+
+require('/shared/elements/gaia_grid/js/grid_layout.js');
+require('/shared/elements/gaia_grid/js/grid_view.js');
+
+suite('GridView', function() {
+
+  var container;
+
+  setup(function() {
+    container = document.createElement('div');
+    document.body.appendChild(container);
+  });
+
+  teardown(function() {
+    document.body.removeChild(container);
+  });
+
+  test(' reset last scroll time after touchend event', function() {
+    this.sinon.stub(window, 'GridLayout');
+
+    var subject = new GridView({
+      features: {},
+      element: container
+    });
+
+    assert.equal(subject.lastScrollTime, 0);
+
+    subject.lastScrollTime = 1000;
+
+    container.dispatchEvent(new CustomEvent('touchend'));
+
+    assert.equal(subject.lastScrollTime, 0);
+
+    GridLayout.restore();
+  });
+
+});

shared/elements/gaia_grid/js/grid_view.js

@@ -4,6 +4,7 @@
 /* global GridLayout */
 /* global GridZoom */
 /* global LazyLoader */
+/* global performance */
 
 (function(exports) {
 
@@ -164,7 +165,7 @@
 
     // bug 1015000
     onScroll: function() {
-      this.lastScrollTime = Date.now();
+      this.lastScrollTime = performance.now();
     },
 
     onTouchStart: function(e) {
@@ -177,7 +178,10 @@
     // Gecko does that automatically but since we want to use touch events for
     // more responsiveness, we also need to replicate that behavior.
     onTouchEnd: function(e) {
-      if (Date.now() - this.lastScrollTime < PREVENT_TAP_TIMEOUT) {
+      var lastScrollTime = this.lastScrollTime;
+      this.lastScrollTime = 0;
+      var diff = performance.now() - lastScrollTime;
+      if (diff > 0 && diff < PREVENT_TAP_TIMEOUT) {
         return;
       }