Fix opening overlay with tap issue on touch devices

See Polymer/polymer#4670

Author: Saulis

test/selecting-items.html

@@ -237,7 +237,7 @@
 
       it('should fire on clear', function() {
         combobox.value = 'foo';
-        combobox.$.clearIcon.click();
+        fire('up', combobox.$.clearIcon);
 
         expect(changeSpy.callCount).to.equal(1);
       });
@@ -315,7 +315,7 @@
       it('should clear the selection when tapping on the icon', function() {
         combobox.open();
 
-        fire('tap', clearIcon);
+        fire('up', clearIcon);
 
         expect(combobox.value).to.eql('');
         expect(combobox.$.overlay._selectedItem).to.be.null;
@@ -325,7 +325,7 @@
       it('should close the dropdown after clearing a selection', function() {
         combobox.open();
 
-        fire('tap', clearIcon);
+        fire('up', clearIcon);
 
         expect(combobox.opened).to.eql(false);
       });

test/toggling-dropdown.html

@@ -39,11 +39,15 @@
     }
 
     function tapInput() {
-      fire('tap', combobox.inputElement);
+      // This listener should listen for "tap" again once composedPath() issues with touch devices
+      // have been fixed. See https://github.com/Polymer/polymer/issues/4670
+      fire('up', combobox.inputElement);
     }
 
     function tapToggleIcon() {
-      fire('tap', combobox.$$('paper-input-container #toggleIcon'));
+      // This listener should listen for "tap" again once composedPath() issues with touch devices
+      // have been fixed. See https://github.com/Polymer/polymer/issues/4670
+      fire('up', combobox.$$('paper-input-container #toggleIcon'));
     }
 
     function overlay() {

test/vaadin-combo-box-light.html

@@ -84,10 +84,10 @@
       });
 
       it('should toggle overlay by tapping toggle element', function() {
-        comboBox._toggleElement.dispatchEvent(new CustomEvent('tap', {bubbles: true}));
+        comboBox._toggleElement.dispatchEvent(new CustomEvent('up', {bubbles: true}));
         expect(comboBox.opened).to.be.true;
 
-        comboBox._toggleElement.dispatchEvent(new CustomEvent('tap', {bubbles: true}));
+        comboBox._toggleElement.dispatchEvent(new CustomEvent('up', {bubbles: true}));
         expect(comboBox.opened).to.be.false;
       });
 

vaadin-combo-box-mixin.html

@@ -198,7 +198,10 @@
       this.addEventListener('vaadin-dropdown-closed', this._onClosed.bind(this));
       this.addEventListener('vaadin-dropdown-opened', this._onOpened.bind(this));
       this.addEventListener('keydown', this._onKeyDown.bind(this));
-      this._addEventListenerToNode(this, 'tap', this._onTap.bind(this));
+
+      // This listener should listen for "tap" again once composedPath() issues with touch devices
+      // have been fixed. See https://github.com/Polymer/polymer/issues/4670
+      this._addEventListenerToNode(this, 'up', this._onTap.bind(this));
     }
 
     _onBlur() {
@@ -218,6 +221,8 @@
     }
 
     _onTap(e) {
+      // prevent 'tap' from getting generated and closing the overlay etc.
+      Polymer.Gestures.prevent('tap');
       this._closeOnBlurIsPrevented = true;
 
       var path = e.composedPath();