Add unlisten function

Keep generated event handlers, attach with WeakMap to host element
Add tests for events

Support multi-dispatch unlisten (must give event name and handler function
name).

Fixes #1639

src/standard/events.html

@@ -84,20 +84,74 @@
         this._createEventHandler(node, eventName, methodName));
     },
 
+    _boundListenerKey: function(eventName, methodName) {
+      return (eventName + ':' + methodName);
+    },
+
+    _recordEventHandler: function(host, eventName, target, methodName, handler) {
+      var hbl = host.__boundListeners;
+      if (!hbl) {
+        hbl = host.__boundListeners = new WeakMap();
+      }
+      var bl = hbl.get(target);
+      if (!bl) {
+        bl = {};
+        hbl.set(target, bl);
+      }
+      var key = this._boundListenerKey(eventName, methodName);
+      bl[key] = handler;
+    },
+
+    _recallEventHandler: function(host, eventName, target, methodName) {
+      var hbl = host.__boundListeners;
+      if (!hbl) {
+        return;
+      }
+      var bl = hbl.get(target);
+      if (!bl) {
+        return;
+      }
+      var key = this._boundListenerKey(eventName, methodName);
+      return bl[key];
+    },
+
     _createEventHandler: function(node, eventName, methodName) {
       var host = this;
-      return function(e) {
+      var handler = function(e) {
         if (host[methodName]) {
           host[methodName](e, e.detail);
         } else {
           host._warn(host._logf('_createEventHandler', 'listener method `' +
             methodName + '` not defined'));
         }
       };
+      this._recordEventHandler(host, eventName, node, methodName, handler);
+      return handler;
+    },
+
+    /**
+     * Convenience method to remove an event listener from a given element,
+     * late bound to a named method on this element.
+     *
+     * @method unlisten
+     * @param {Element} node Element to remove event listener from.
+     * @param {string} eventName Name of event to stop listening to.
+     * @param {string} methodName Name of handler method on `this` to not call
+     anymore.
+     */
+    unlisten: function(node, eventName, methodName) {
+      var handler = this._recallEventHandler(this, eventName, node, methodName);
+      if (handler) {
+        this._unlisten(node, eventName, handler);
+      }
     },
 
     _listen: function(node, eventName, handler) {
       node.addEventListener(eventName, handler);
+    },
+
+    _unlisten: function(node, eventName, handler) {
+      node.removeEventListener(eventName, handler);
     }
   });
 

src/standard/gestures.html

@@ -224,6 +224,27 @@
       }
     },
 
+    // automate event listener removal for native events
+    remove: function(node, evType, handler) {
+      var recognizer = this.gestures[evType];
+      var deps = recognizer.deps;
+      var name = recognizer.name;
+      var gobj = node[GESTURE_KEY];
+      if (gobj) {
+        for (var i = 0, dep, gd; i < deps.length; i++) {
+          dep = deps[i];
+          gd = gobj[dep];
+          if (gd && gd[name]) {
+            gd[name] = (gd[name] || 1) - 1;
+            if (gd[name] === 0) {
+              node.removeEventListener(dep, this.handleNative);
+            }
+          }
+        }
+      }
+      node.removeEventListener(evType, handler);
+    },
+
     register: function(recog) {
       this.recognizers.push(recog);
       for (var i = 0; i < recog.emits.length; i++) {
@@ -476,6 +497,14 @@
         node.addEventListener(eventName, handler);
       }
     },
+    // override _unlisten to handle gestures
+    _unlisten: function(node, eventName, handler) {
+      if (Gestures.gestures[eventName]) {
+        Gestures.remove(node, eventName, handler);
+      } else {
+        node.removeEventListener(eventName, handler);
+      }
+    },
     /**
      * Override scrolling behavior to all direction, one direction, or none.
      *

test/runner.html

@@ -32,6 +32,7 @@
       'unit/bind.html',
       'unit/bind.html?dom=shadow',
       'unit/notify-path.html',
+      'unit/events.html',
       'unit/gestures.html',
       'unit/utils.html',
       'unit/utils-content.html',

test/unit/events-elements.html

@@ -0,0 +1,95 @@
+<!--
+@license
+Copyright (c) 2015 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="../../polymer.html">
+
+<script>
+  var EventLoggerImpl = {
+    created: function() {
+      this._handled = {};
+      this._warned = [];
+      this._removed = [];
+    },
+    handle: function(e) {
+      this._handled[e.currentTarget.localName] = e.type;
+    },
+    _warn: function(array) {
+      var hasColor = array[0].indexOf('%c') === 0;
+      var funIdx = hasColor ? 3 : 2;
+      var messageIdx = hasColor ? 4 : 3;
+      if (array[funIdx] === '_createEventHandler') {
+        this._warned.push(array[messageIdx]);
+      } else {
+        Polymer.Base._warn(array);
+      }
+    },
+    _unlisten: function(node, eventName, handler) {
+      this._removed.push({target: node.localName, event: eventName});
+      Polymer.Base._unlisten(node, eventName, handler);
+    }
+  };
+</script>
+
+<dom-module id="x-listeners">
+  <script>
+    Polymer({
+      is: 'x-listeners',
+      behaviors: [EventLoggerImpl],
+      listeners: {
+        foo: 'handle',
+        bar: 'missing'
+      },
+      teardown: function() {
+        this.unlisten(this, 'foo', 'handle');
+        this.unlisten(this, 'bar', 'missing');
+      }
+    });
+  </script>
+</dom-module>
+
+<dom-module id="x-on">
+  <template>
+    <div id="inner" on-foo="handle" on-bar="missing"></div>
+  </template>
+  <script>
+    Polymer({
+      is: 'x-on',
+      behaviors: [EventLoggerImpl],
+      teardown: function() {
+        this.unlisten(this.$.inner, 'foo', 'handle');
+        this.unlisten(this.$.inner, 'bar', 'missing');
+      }
+    });
+  </script>
+</dom-module>
+
+<dom-module id="x-dynamic">
+  <template>
+    <div id="inner"></div>
+  </template>
+  <script>
+    Polymer({
+      is: 'x-dynamic',
+      behaviors: [EventLoggerImpl],
+      setup: function() {
+        this.listen(this, 'foo', 'handle');
+        this.listen(this.$.inner, 'foo', 'handle');
+        this.listen(this, 'bar', 'missing');
+        this.listen(this.$.inner, 'bar', 'missing');
+      },
+      teardown: function() {
+        this.unlisten(this, 'foo', 'handle');
+        this.unlisten(this.$.inner, 'foo', 'handle');
+        this.unlisten(this, 'bar', 'missing');
+        this.unlisten(this.$.inner, 'bar', 'missing');
+      }
+    });
+  </script>
+</dom-module>

test/unit/events.html

@@ -0,0 +1,148 @@
+<!DOCTYPE html>
+<!--
+@license
+Copyright (c) 2015 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
+-->
+<html>
+<head>
+  <meta charset="UTF-8">
+
+  <script src="../../../webcomponentsjs/webcomponents-lite.js"></script>
+  <script src="../../../web-component-tester/browser.js"></script>
+
+  <link rel="import" href="../../polymer.html">
+  <link rel="import" href="events-elements.html">
+</head>
+<body>
+
+  <script>
+    suite('Event Listeners', function() {
+      var el;
+
+      suite('listeners block', function() {
+        suiteSetup(function() {
+          el = document.createElement('x-listeners');
+          document.body.appendChild(el);
+        });
+
+        suiteTeardown(function() {
+          document.body.removeChild(el);
+        });
+
+        test('setup', function() {
+          var boundListeners = el.__boundListeners;
+          assert(boundListeners, 'listeners are bound');
+          var map = boundListeners.get(el);
+          assert(map, 'events have handlers');
+          Object.keys(el.listeners).forEach(function(l) {
+            var key = Polymer.Base._boundListenerKey(l, el.listeners[l]);
+            assert(map[key], 'listener is in event map');
+          });
+        });
+
+        test('fire', function() {
+          el.fire('foo');
+          assert.equal(el._handled[el.localName], 'foo');
+          el.fire('bar');
+          assert.equal(el._warned.length, 1);
+          assert.equal(el._warned[0], 'listener method `missing` not defined');
+        });
+
+        test('teardown', function() {
+          el.teardown();
+          assert.deepEqual(el._removed[0], {target: el.localName, event: 'foo'});
+          assert.deepEqual(el._removed[1], {target: el.localName, event: 'bar'});
+        });
+      });
+
+      suite('on-*', function() {
+
+        suiteSetup(function() {
+          el = document.createElement('x-on');
+          document.body.appendChild(el);
+        });
+
+        suiteTeardown(function() {
+          document.body.removeChild(el);
+        });
+
+        test('setup', function() {
+          var boundListeners = el.__boundListeners;
+          assert(boundListeners, 'listeners are bound');
+          var map = boundListeners.get(el.$.inner);
+          assert(map, 'events have handlers');
+          assert(el._notes[0].events.length, 2);
+          el._notes[0].events.forEach(function(l) {
+            var key = Polymer.Base._boundListenerKey(l.name, l.value);
+            assert(map[key], 'listener is in event map');
+          });
+        });
+
+        test('fire', function() {
+          var options = {node: el.$.inner};
+          el.fire('foo', {}, options);
+          assert.equal(el._handled.div, 'foo');
+          assert(!el._handled[el.localName]);
+          el.fire('bar', {}, options);
+          assert.equal(el._warned.length, 1);
+          assert.equal(el._warned[0], 'listener method `missing` not defined');
+        });
+
+        test('teardown', function() {
+          el.teardown();
+          assert.deepEqual(el._removed[0], {target: 'div', event: 'foo'});
+          assert.deepEqual(el._removed[1], {target: 'div', event: 'bar'});
+        });
+      });
+
+      suite('dynamic', function() {
+
+        suiteSetup(function() {
+          el = document.createElement('x-dynamic');
+          document.body.appendChild(el);
+        });
+
+        suiteTeardown(function() {
+          document.body.removeChild(el);
+        });
+
+        test('setup', function() {
+          assert(!el.__boundListeners, 'listeners are not bound');
+          el.setup();
+          var boundListeners = el.__boundListeners;
+          assert(boundListeners, 'listeners are bound');
+          var outerMap = boundListeners.get(el);
+          assert(outerMap, 'element events have handlers');
+          var innerMap = boundListeners.get(el.$.inner);
+          assert(innerMap, 'inner div events have handlers');
+        });
+
+        test('fire', function() {
+          var options = {node: el.$.inner};
+          el.fire('foo', {}, options);
+          assert.equal(el._handled.div, 'foo', 'inner handler');
+          assert.equal(el._handled[el.localName], 'foo', 'outer handler');
+          el.fire('bar', {}, options);
+          assert.equal(el._warned.length, 2);
+          assert.equal(el._warned[0], 'listener method `missing` not defined');
+          assert.equal(el._warned[1], 'listener method `missing` not defined');
+        });
+
+        test('teardown', function() {
+          el.teardown();
+          assert.deepEqual(el._removed[0], {target: el.localName, event: 'foo'});
+          assert.deepEqual(el._removed[1], {target: 'div', event: 'foo'});
+          assert.deepEqual(el._removed[2], {target: el.localName, event: 'bar'});
+          assert.deepEqual(el._removed[3], {target: 'div', event: 'bar'});
+        });
+      });
+    });
+  </script>
+
+</body>
+</html>

test/unit/gestures-elements.html

@@ -70,3 +70,18 @@
     });
   </script>
 </dom-module>
+
+<dom-module id="x-dynamic">
+  <script>
+    Polymer({
+      is: 'x-dynamic',
+      handler: function(){},
+      setup: function() {
+        this.listen(this, 'tap', 'handler');
+      },
+      teardown: function() {
+        this.unlisten(this, 'tap', 'handler');
+      }
+    });
+  </script>
+</dom-module>