Added base template for config ui.

appengine/config_service/ui/bower_components/polymer/lib/utils/gestures.html

+<!--
+@license
+Copyright (c) 2017 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+-->
+<link rel="import" href="boot.html">
+<link rel="import" href="async.html">
+<link rel="import" href="debounce.html">
+
+<script>
+(function() {
+
+  'use strict';
+
+  // detect native touch action support
+  let HAS_NATIVE_TA = typeof document.head.style.touchAction === 'string';
+  let GESTURE_KEY = '__polymerGestures';
+  let HANDLED_OBJ = '__polymerGesturesHandled';
+  let TOUCH_ACTION = '__polymerGesturesTouchAction';
+  // radius for tap and track
+  let TAP_DISTANCE = 25;
+  let TRACK_DISTANCE = 5;
+  // number of last N track positions to keep
+  let TRACK_LENGTH = 2;
+
+  // Disabling "mouse" handlers for 2500ms is enough
+  let MOUSE_TIMEOUT = 2500;
+  let MOUSE_EVENTS = ['mousedown', 'mousemove', 'mouseup', 'click'];
+  // an array of bitmask values for mapping MouseEvent.which to MouseEvent.buttons
+  let MOUSE_WHICH_TO_BUTTONS = [0, 1, 4, 2];
+  let MOUSE_HAS_BUTTONS = (function() {
+    try {
+      return new MouseEvent('test', {buttons: 1}).buttons === 1;
+    } catch (e) {
+      return false;
+    }
+  })();
+
+  /* eslint no-empty: ["error", { "allowEmptyCatch": true }] */
+  // check for passive event listeners
+  let SUPPORTS_PASSIVE = false;
+  (function() {
+    try {
+      let opts = Object.defineProperty({}, 'passive', {get: function() {SUPPORTS_PASSIVE = true;}})
+      window.addEventListener('test', null, opts);
+      window.removeEventListener('test', null, opts);
+    } catch(e) {}
+  })();
+
+  // Check for touch-only devices
+  let IS_TOUCH_ONLY = navigator.userAgent.match(/iP(?:[oa]d|hone)|Android/);
+
+  // touch will make synthetic mouse events
+  // `preventDefault` on touchend will cancel them,
+  // but this breaks `<input>` focus and link clicks
+  // disable mouse handlers for MOUSE_TIMEOUT ms after
+  // a touchend to ignore synthetic mouse events
+  let mouseCanceller = function(mouseEvent) {
+    // Check for sourceCapabilities, used to distinguish synthetic events
+    // if mouseEvent did not come from a device that fires touch events,
+    // it was made by a real mouse and should be counted
+    // http://wicg.github.io/InputDeviceCapabilities/#dom-inputdevicecapabilities-firestouchevents
+    let sc = mouseEvent.sourceCapabilities;
+    if (sc && !sc.firesTouchEvents) {
+      return;
+    }
+    // skip synthetic mouse events
+    mouseEvent[HANDLED_OBJ] = {skip: true};
+    // disable "ghost clicks"
+    if (mouseEvent.type === 'click') {
+      let path = mouseEvent.composedPath && mouseEvent.composedPath();
+      if (path) {
+        for (let i = 0; i < path.length; i++) {
+          if (path[i] === POINTERSTATE.mouse.target) {
+            return;
+          }
+        }
+      }
+      mouseEvent.preventDefault();
+      mouseEvent.stopPropagation();
+    }
+  };
+
+  /**
+   * @param {boolean=} setup True to add, false to remove.
+   */
+  function setupTeardownMouseCanceller(setup) {
+    let events = IS_TOUCH_ONLY ? ['click'] : MOUSE_EVENTS;
+    for (let i = 0, en; i < events.length; i++) {
+      en = events[i];
+      if (setup) {
+        document.addEventListener(en, mouseCanceller, true);
+      } else {
+        document.removeEventListener(en, mouseCanceller, true);
+      }
+    }
+  }
+
+  function ignoreMouse(e) {
+    if (!POINTERSTATE.mouse.mouseIgnoreJob) {
+      setupTeardownMouseCanceller(true);
+    }
+    let unset = function() {
+      setupTeardownMouseCanceller();
+      POINTERSTATE.mouse.target = null;
+      POINTERSTATE.mouse.mouseIgnoreJob = null;
+    };
+    POINTERSTATE.mouse.target = e.composedPath()[0];
+    POINTERSTATE.mouse.mouseIgnoreJob = Polymer.Debouncer.debounce(
+          POINTERSTATE.mouse.mouseIgnoreJob
+        , Polymer.Async.timeOut.after(MOUSE_TIMEOUT)
+        , unset);
+  }
+
+  function hasLeftMouseButton(ev) {
+    let type = ev.type;
+    // exit early if the event is not a mouse event
+    if (MOUSE_EVENTS.indexOf(type) === -1) {
+      return false;
+    }
+    // ev.button is not reliable for mousemove (0 is overloaded as both left button and no buttons)
+    // instead we use ev.buttons (bitmask of buttons) or fall back to ev.which (deprecated, 0 for no buttons, 1 for left button)
+    if (type === 'mousemove') {
+      // allow undefined for testing events
+      let buttons = ev.buttons === undefined ? 1 : ev.buttons;
+      if ((ev instanceof window.MouseEvent) && !MOUSE_HAS_BUTTONS) {
+        buttons = MOUSE_WHICH_TO_BUTTONS[ev.which] || 0;
+      }
+      // buttons is a bitmask, check that the left button bit is set (1)
+      return Boolean(buttons & 1);
+    } else {
+      // allow undefined for testing events
+      let button = ev.button === undefined ? 0 : ev.button;
+      // ev.button is 0 in mousedown/mouseup/click for left button activation
+      return button === 0;
+    }
+  }
+
+  function isSyntheticClick(ev) {
+    if (ev.type === 'click') {
+      // ev.detail is 0 for HTMLElement.click in most browsers
+      if (ev.detail === 0) {
+        return true;
+      }
+      // in the worst case, check that the x/y position of the click is within
+      // the bounding box of the target of the event
+      // Thanks IE 10 >:(
+      let t = Gestures._findOriginalTarget(ev);
+      // make sure the target of the event is an element so we can use getBoundingClientRect,
+      // if not, just assume it is a synthetic click
+      if (t.nodeType !== Node.ELEMENT_NODE) {
+        return true;
+      }
+      let bcr = t.getBoundingClientRect();
+      // use page x/y to account for scrolling
+      let x = ev.pageX, y = ev.pageY;
+      // ev is a synthetic click if the position is outside the bounding box of the target
+      return !((x >= bcr.left && x <= bcr.right) && (y >= bcr.top && y <= bcr.bottom));
+    }
+    return false;
+  }
+
+  let POINTERSTATE = {
+    mouse: {
+      target: null,
+      mouseIgnoreJob: null
+    },
+    touch: {
+      x: 0,
+      y: 0,
+      id: -1,
+      scrollDecided: false
+    }
+  };
+
+  function firstTouchAction(ev) {
+    let ta = 'auto';
+    let path = ev.composedPath && ev.composedPath();
+    if (path) {
+      for (let i = 0, n; i < path.length; i++) {
+        n = path[i];
+        if (n[TOUCH_ACTION]) {
+          ta = n[TOUCH_ACTION];
+          break;
+        }
+      }
+    }
+    return ta;
+  }
+
+  function trackDocument(stateObj, movefn, upfn) {
+    stateObj.movefn = movefn;
+    stateObj.upfn = upfn;
+    document.addEventListener('mousemove', movefn);
+    document.addEventListener('mouseup', upfn);
+  }
+
+  function untrackDocument(stateObj) {
+    document.removeEventListener('mousemove', stateObj.movefn);
+    document.removeEventListener('mouseup', stateObj.upfn);
+    stateObj.movefn = null;
+    stateObj.upfn = null;
+  }
+
+  // use a document-wide touchend listener to start the ghost-click prevention mechanism
+  // Use passive event listeners, if supported, to not affect scrolling performance
+  document.addEventListener('touchend', ignoreMouse, SUPPORTS_PASSIVE ? {passive: true} : false);
+
+  /**
+   * Module for adding listeners to a node for the following normalized
+   * cross-platform "gesture" events:
+   * - `down` - mouse or touch went down
+   * - `up` - mouse or touch went up
+   * - `tap` - mouse click or finger tap
+   * - `track` - mouse drag or touch move
+   *
+   * @namespace
+   * @memberof Polymer
+   * @summary Module for adding cross-platform gesture event listeners.
+   */
+  const Gestures = {
+    gestures: {},
+    recognizers: [],
+
+    /**
+     * Finds the element rendered on the screen at the provided coordinates.
+     *
+     * Similar to `document.elementFromPoint`, but pierces through
+     * shadow roots.
+     *
+     * @memberof Polymer.Gestures
+     * @param {number} x Horizontal pixel coordinate
+     * @param {number} y Vertical pixel coordinate
+     * @return {HTMLElement} Returns the deepest shadowRoot inclusive element
+     * found at the screen position given.
+     */
+    deepTargetFind: function(x, y) {
+      let node = document.elementFromPoint(x, y);
+      let next = node;
+      // this code path is only taken when native ShadowDOM is used
+      // if there is a shadowroot, it may have a node at x/y
+      // if there is not a shadowroot, exit the loop
+      while (next && next.shadowRoot && !window.ShadyDOM) {
+        // if there is a node at x/y in the shadowroot, look deeper
+        let oldNext = next;
+        next = next.shadowRoot.elementFromPoint(x, y);
+        // on Safari, elementFromPoint may return the shadowRoot host
+        if (oldNext === next) {
+          break;
+        }
+        if (next) {
+          node = next;
+        }
+      }
+      return node;
+    },
+    /**
+     * a cheaper check than ev.composedPath()[0];
+     *
+     * @private
+     * @param {Event} ev Event.
+     * @return {HTMLElement} Returns the event target.
+     */
+    _findOriginalTarget: function(ev) {
+      // shadowdom
+      if (ev.composedPath) {
+        return ev.composedPath()[0];
+      }
+      // shadydom
+      return ev.target;
+    },
+
+    /**
+     * @private
+     * @param {Event} ev Event.
+     */
+    _handleNative: function(ev) {
+      let handled;
+      let type = ev.type;
+      let node = ev.currentTarget;
+      let gobj = node[GESTURE_KEY];
+      if (!gobj) {
+        return;
+      }
+      let gs = gobj[type];
+      if (!gs) {
+        return;
+      }
+      if (!ev[HANDLED_OBJ]) {
+        ev[HANDLED_OBJ] = {};
+        if (type.slice(0, 5) === 'touch') {
+          let t = ev.changedTouches[0];
+          if (type === 'touchstart') {
+            // only handle the first finger
+            if (ev.touches.length === 1) {
+              POINTERSTATE.touch.id = t.identifier;
+            }
+          }
+          if (POINTERSTATE.touch.id !== t.identifier) {
+            return;
+          }
+          if (!HAS_NATIVE_TA) {
+            if (type === 'touchstart' || type === 'touchmove') {
+              Gestures._handleTouchAction(ev);
+            }
+          }
+        }
+      }
+      handled = ev[HANDLED_OBJ];
+      // used to ignore synthetic mouse events
+      if (handled.skip) {
+        return;
+      }
+      let recognizers = Gestures.recognizers;
+      // reset recognizer state
+      for (let i = 0, r; i < recognizers.length; i++) {
+        r = recognizers[i];
+        if (gs[r.name] && !handled[r.name]) {
+          if (r.flow && r.flow.start.indexOf(ev.type) > -1 && r.reset) {
+            r.reset();
+          }
+        }
+      }
+      // enforce gesture recognizer order
+      for (let i = 0, r; i < recognizers.length; i++) {
+        r = recognizers[i];
+        if (gs[r.name] && !handled[r.name]) {
+          handled[r.name] = true;
+          r[type](ev);
+        }
+      }
+    },
+
+    /**
+     * @private
+     * @param {Event} ev Event.
+     */
+    _handleTouchAction: function(ev) {
+      let t = ev.changedTouches[0];
+      let type = ev.type;
+      if (type === 'touchstart') {
+        POINTERSTATE.touch.x = t.clientX;
+        POINTERSTATE.touch.y = t.clientY;
+        POINTERSTATE.touch.scrollDecided = false;
+      } else if (type === 'touchmove') {
+        if (POINTERSTATE.touch.scrollDecided) {
+          return;
+        }
+        POINTERSTATE.touch.scrollDecided = true;
+        let ta = firstTouchAction(ev);
+        let prevent = false;
+        let dx = Math.abs(POINTERSTATE.touch.x - t.clientX);
+        let dy = Math.abs(POINTERSTATE.touch.y - t.clientY);
+        if (!ev.cancelable) {
+          // scrolling is happening
+        } else if (ta === 'none') {
+          prevent = true;
+        } else if (ta === 'pan-x') {
+          prevent = dy > dx;
+        } else if (ta === 'pan-y') {
+          prevent = dx > dy;
+        }
+        if (prevent) {
+          ev.preventDefault();
+        } else {
+          Gestures.prevent('track');
+        }
+      }
+    },
+
+    /**
+     * Adds an event listener to a node for the given gesture type.
+     *
+     * @memberof Polymer.Gestures
+     * @param {Node} node Node to add listener on
+     * @param {string} evType Gesture type: `down`, `up`, `track`, or `tap`
+     * @param {Function} handler Event listener function to call
+     * @return {boolean} Returns true if a gesture event listener was added.
+     */
+    addListener: function(node, evType, handler) {
+      if (this.gestures[evType]) {
+        this._add(node, evType, handler);
+        return true;
+      }
+    },
+
+    /**
+     * Removes an event listener from a node for the given gesture type.
+     *
+     * @memberof Polymer.Gestures
+     * @param {Node} node Node to remove listener from
+     * @param {string} evType Gesture type: `down`, `up`, `track`, or `tap`
+     * @param {Function} handler Event listener function previously passed to
+     *  `addListener`.
+     * @return {boolean} Returns true if a gesture event listener was removed.
+     */
+    removeListener: function(node, evType, handler) {
+      if (this.gestures[evType]) {
+        this._remove(node, evType, handler);
+        return true;
+      }
+    },
+
+    /**
+     * automate the event listeners for the native events
+     *
+     * @private
+     * @param {HTMLElement} node Node on which to add the event.
+     * @param {string} evType Event type to add.
+     * @param {function} handler Event handler function.
+     */
+    _add: function(node, evType, handler) {
+      let recognizer = this.gestures[evType];
+      let deps = recognizer.deps;
+      let name = recognizer.name;
+      let gobj = node[GESTURE_KEY];
+      if (!gobj) {
+        node[GESTURE_KEY] = gobj = {};
+      }
+      for (let i = 0, dep, gd; i < deps.length; i++) {
+        dep = deps[i];
+        // don't add mouse handlers on iOS because they cause gray selection overlays
+        if (IS_TOUCH_ONLY && MOUSE_EVENTS.indexOf(dep) > -1 && dep !== 'click') {
+          continue;
+        }
+        gd = gobj[dep];
+        if (!gd) {
+          gobj[dep] = gd = {_count: 0};
+        }
+        if (gd._count === 0) {
+          node.addEventListener(dep, this._handleNative);
+        }
+        gd[name] = (gd[name] || 0) + 1;
+        gd._count = (gd._count || 0) + 1;
+      }
+      node.addEventListener(evType, handler);
+      if (recognizer.touchAction) {
+        this.setTouchAction(node, recognizer.touchAction);
+      }
+    },
+
+    /**
+     * automate event listener removal for native events
+     *
+     * @private
+     * @param {HTMLElement} node Node on which to remove the event.
+     * @param {string} evType Event type to remove.
+     * @param {function} handler Event handler function.
+     */
+    _remove: function(node, evType, handler) {
+      let recognizer = this.gestures[evType];
+      let deps = recognizer.deps;
+      let name = recognizer.name;
+      let gobj = node[GESTURE_KEY];
+      if (gobj) {
+        for (let i = 0, dep, gd; i < deps.length; i++) {
+          dep = deps[i];
+          gd = gobj[dep];
+          if (gd && gd[name]) {
+            gd[name] = (gd[name] || 1) - 1;
+            gd._count = (gd._count || 1) - 1;
+            if (gd._count === 0) {
+              node.removeEventListener(dep, this._handleNative);
+            }
+          }
+        }
+      }
+      node.removeEventListener(evType, handler);
+    },
+
+    /**
+     * Registers a new gesture event recognizer for adding new custom
+     * gesture event types.
+     *
+     * @memberof Polymer.Gestures
+     * @param {Object} recog Gesture recognizer descriptor
+     */
+    register: function(recog) {
+      this.recognizers.push(recog);
+      for (let i = 0; i < recog.emits.length; i++) {
+        this.gestures[recog.emits[i]] = recog;
+      }
+    },
+
+    /**
+     * @private
+     * @param {string} evName Event name.
+     * @return {Object} Returns the gesture for the given event name.
+     */
+    _findRecognizerByEvent: function(evName) {
+      for (let i = 0, r; i < this.recognizers.length; i++) {
+        r = this.recognizers[i];
+        for (let j = 0, n; j < r.emits.length; j++) {
+          n = r.emits[j];
+          if (n === evName) {
+            return r;
+          }
+        }
+      }
+      return null;
+    },
+
+    /**
+     * Sets scrolling direction on node.
+     *
+     * This value is checked on first move, thus it should be called prior to
+     * adding event listeners.
+     *
+     * @memberof Polymer.Gestures
+     * @param {Node} node Node to set touch action setting on
+     * @param {string} value Touch action value
+     */
+    setTouchAction: function(node, value) {
+      if (HAS_NATIVE_TA) {
+        node.style.touchAction = value;
+      }
+      node[TOUCH_ACTION] = value;
+    },
+
+    /**
+     * Dispatches an event on the `target` element of `type` with the given
+     * `detail`.
+     * @private
+     * @param {HTMLElement} target The element on which to fire an event.
+     * @param {string} type The type of event to fire.
+     * @param {Object=} detail The detail object to populate on the event.
+     */
+    _fire: function(target, type, detail) {
+      let ev = new Event(type, { bubbles: true, cancelable: true, composed: true });
+      ev.detail = detail;
+      target.dispatchEvent(ev);
+      // forward `preventDefault` in a clean way
+      if (ev.defaultPrevented) {
+        let preventer = detail.preventer || detail.sourceEvent;
+        if (preventer && preventer.preventDefault) {
+          preventer.preventDefault();
+        }
+      }
+    },
+
+    /**
+     * Prevents the dispatch and default action of the given event name.
+     *
+     * @memberof Polymer.Gestures
+     * @param {string} evName Event name.
+     */
+    prevent: function(evName) {
+      let recognizer = this._findRecognizerByEvent(evName);
+      if (recognizer.info) {
+        recognizer.info.prevent = true;
+      }
+    },
+
+    /**
+     * Reset the 2500ms timeout on processing mouse input after detecting touch input.
+     *
+     * Touch inputs create synthesized mouse inputs anywhere from 0 to 2000ms after the touch.
+     * This method should only be called during testing with simulated touch inputs.
+     * Calling this method in production may cause duplicate taps or other Gestures.
+     *
+     * @memberof Polymer.Gestures
+     */
+    resetMouseCanceller: function() {
+      if (POINTERSTATE.mouse.mouseIgnoreJob) {
+        POINTERSTATE.mouse.mouseIgnoreJob.flush();
+      }
+    }
+  };
+
+  Gestures.register({
+    name: 'downup',
+    deps: ['mousedown', 'touchstart', 'touchend'],
+    flow: {
+      start: ['mousedown', 'touchstart'],
+      end: ['mouseup', 'touchend']
+    },
+    emits: ['down', 'up'],
+
+    info: {
+      movefn: null,
+      upfn: null
+    },
+
+    reset: function() {
+      untrackDocument(this.info);
+    },
+
+    mousedown: function(e) {
+      if (!hasLeftMouseButton(e)) {
+        return;
+      }
+      let t = Gestures._findOriginalTarget(e);
+      let self = this;
+      let movefn = function movefn(e) {
+        if (!hasLeftMouseButton(e)) {
+          self._fire('up', t, e);
+          untrackDocument(self.info);
+        }
+      };
+      let upfn = function upfn(e) {
+        if (hasLeftMouseButton(e)) {
+          self._fire('up', t, e);
+        }
+        untrackDocument(self.info);
+      };
+      trackDocument(this.info, movefn, upfn);
+      this._fire('down', t, e);
+    },
+    touchstart: function(e) {
+      this._fire('down', Gestures._findOriginalTarget(e), e.changedTouches[0], e);
+    },
+    touchend: function(e) {
+      this._fire('up', Gestures._findOriginalTarget(e), e.changedTouches[0], e);
+    },
+    _fire: function(type, target, event, preventer) {
+      Gestures._fire(target, type, {
+        x: event.clientX,
+        y: event.clientY,
+        sourceEvent: event,
+        preventer: preventer,
+        prevent: function(e) {
+          return Gestures.prevent(e);
+        }
+      });
+    }
+  });
+
+  Gestures.register({
+    name: 'track',
+    touchAction: 'none',
+    deps: ['mousedown', 'touchstart', 'touchmove', 'touchend'],
+    flow: {
+      start: ['mousedown', 'touchstart'],
+      end: ['mouseup', 'touchend']
+    },
+    emits: ['track'],
+
+    info: {
+      x: 0,
+      y: 0,
+      state: 'start',
+      started: false,
+      moves: [],
+      addMove: function(move) {
+        if (this.moves.length > TRACK_LENGTH) {
+          this.moves.shift();
+        }
+        this.moves.push(move);
+      },
+      movefn: null,
+      upfn: null,
+      prevent: false
+    },
+
+    reset: function() {
+      this.info.state = 'start';
+      this.info.started = false;
+      this.info.moves = [];
+      this.info.x = 0;
+      this.info.y = 0;
+      this.info.prevent = false;
+      untrackDocument(this.info);
+    },
+
+    hasMovedEnough: function(x, y) {
+      if (this.info.prevent) {
+        return false;
+      }
+      if (this.info.started) {
+        return true;
+      }
+      let dx = Math.abs(this.info.x - x);
+      let dy = Math.abs(this.info.y - y);
+      return (dx >= TRACK_DISTANCE || dy >= TRACK_DISTANCE);
+    },
+
+    mousedown: function(e) {
+      if (!hasLeftMouseButton(e)) {
+        return;
+      }
+      let t = Gestures._findOriginalTarget(e);
+      let self = this;
+      let movefn = function movefn(e) {
+        let x = e.clientX, y = e.clientY;
+        if (self.hasMovedEnough(x, y)) {
+          // first move is 'start', subsequent moves are 'move', mouseup is 'end'
+          self.info.state = self.info.started ? (e.type === 'mouseup' ? 'end' : 'track') : 'start';
+          if (self.info.state === 'start') {
+            // if and only if tracking, always prevent tap
+            Gestures.prevent('tap');
+          }
+          self.info.addMove({x: x, y: y});
+          if (!hasLeftMouseButton(e)) {
+            // always _fire "end"
+            self.info.state = 'end';
+            untrackDocument(self.info);
+          }
+          self._fire(t, e);
+          self.info.started = true;
+        }
+      };
+      let upfn = function upfn(e) {
+        if (self.info.started) {
+          movefn(e);
+        }
+
+        // remove the temporary listeners
+        untrackDocument(self.info);
+      };
+      // add temporary document listeners as mouse retargets
+      trackDocument(this.info, movefn, upfn);
+      this.info.x = e.clientX;
+      this.info.y = e.clientY;
+    },
+
+    touchstart: function(e) {
+      let ct = e.changedTouches[0];
+      this.info.x = ct.clientX;
+      this.info.y = ct.clientY;
+    },
+
+    touchmove: function(e) {
+      let t = Gestures._findOriginalTarget(e);
+      let ct = e.changedTouches[0];
+      let x = ct.clientX, y = ct.clientY;
+      if (this.hasMovedEnough(x, y)) {
+        if (this.info.state === 'start') {
+          // if and only if tracking, always prevent tap
+          Gestures.prevent('tap');
+        }
+        this.info.addMove({x: x, y: y});
+        this._fire(t, ct);
+        this.info.state = 'track';
+        this.info.started = true;
+      }
+    },
+
+    touchend: function(e) {
+      let t = Gestures._findOriginalTarget(e);
+      let ct = e.changedTouches[0];
+      // only trackend if track was started and not aborted
+      if (this.info.started) {
+        // reset started state on up
+        this.info.state = 'end';
+        this.info.addMove({x: ct.clientX, y: ct.clientY});
+        this._fire(t, ct, e);
+      }
+    },
+
+    _fire: function(target, touch) {
+      let secondlast = this.info.moves[this.info.moves.length - 2];
+      let lastmove = this.info.moves[this.info.moves.length - 1];
+      let dx = lastmove.x - this.info.x;
+      let dy = lastmove.y - this.info.y;
+      let ddx, ddy = 0;
+      if (secondlast) {
+        ddx = lastmove.x - secondlast.x;
+        ddy = lastmove.y - secondlast.y;
+      }
+      return Gestures._fire(target, 'track', {
+        state: this.info.state,
+        x: touch.clientX,
+        y: touch.clientY,
+        dx: dx,
+        dy: dy,
+        ddx: ddx,
+        ddy: ddy,
+        sourceEvent: touch,
+        hover: function() {
+          return Gestures.deepTargetFind(touch.clientX, touch.clientY);
+        }
+      });
+    }
+
+  });
+
+  Gestures.register({
+    name: 'tap',
+    deps: ['mousedown', 'click', 'touchstart', 'touchend'],
+    flow: {
+      start: ['mousedown', 'touchstart'],
+      end: ['click', 'touchend']
+    },
+    emits: ['tap'],
+    info: {
+      x: NaN,
+      y: NaN,
+      prevent: false
+    },
+    reset: function() {
+      this.info.x = NaN;
+      this.info.y = NaN;
+      this.info.prevent = false;
+    },
+    save: function(e) {
+      this.info.x = e.clientX;
+      this.info.y = e.clientY;
+    },
+
+    mousedown: function(e) {
+      if (hasLeftMouseButton(e)) {
+        this.save(e);
+      }
+    },
+    click: function(e) {
+      if (hasLeftMouseButton(e)) {
+        this.forward(e);
+      }
+    },
+
+    touchstart: function(e) {
+      this.save(e.changedTouches[0], e);
+    },
+    touchend: function(e) {
+      this.forward(e.changedTouches[0], e);
+    },
+
+    forward: function(e, preventer) {
+      let dx = Math.abs(e.clientX - this.info.x);
+      let dy = Math.abs(e.clientY - this.info.y);
+      let t = Gestures._findOriginalTarget(e);
+      // dx,dy can be NaN if `click` has been simulated and there was no `down` for `start`
+      if (isNaN(dx) || isNaN(dy) || (dx <= TAP_DISTANCE && dy <= TAP_DISTANCE) || isSyntheticClick(e)) {
+        // prevent taps from being generated if an event has canceled them
+        if (!this.info.prevent) {
+          Gestures._fire(t, 'tap', {
+            x: e.clientX,
+            y: e.clientY,
+            sourceEvent: e,
+            preventer: preventer
+          });
+        }
+      }
+    }
+  });
+
+  /** @deprecated */
+  Gestures.findOriginalTarget = Gestures._findOriginalTarget;
+
+  /** @deprecated */
+  Gestures.add = Gestures.addListener;
+
+  /** @deprecated */
+  Gestures.remove = Gestures.removeListener;
+
+  Polymer.Gestures = Gestures;
+
+})();
+</script>