feat(events): add support for global events

Fixes #1098
Closes #1255

modules/angular2/src/dom/browser_adapter.dart

@@ -119,6 +119,12 @@ class BrowserDomAdapter extends GenericBrowserDomAdapter {
     // addEventListener misses zones so we use element.on.
     element.on[event].listen(callback);
   }
+  Function onAndCancel(EventTarget element, String event, callback(arg)) {
+    // due to https://code.google.com/p/dart/issues/detail?id=17406
+    // addEventListener misses zones so we use element.on.
+    var subscription = element.on[event].listen(callback);
+    return subscription.cancel;
+  }
   void dispatchEvent(EventTarget el, Event evt) {
     el.dispatchEvent(evt);
   }
@@ -288,4 +294,13 @@ class BrowserDomAdapter extends GenericBrowserDomAdapter {
     int keyCode = event.keyCode;
     return _keyCodeToKeyMap.containsKey(keyCode) ? _keyCodeToKeyMap[keyCode] : 'Unidentified';
   }
+  getGlobalEventTarget(String target) {
+    if (target == "window") {
+      return window;
+    } else if (target == "document") {
+      return document;
+    } else if (target == "body") {
+      return document.body;
+    }
+  }
 }

modules/angular2/src/dom/browser_adapter.es6

@@ -73,6 +73,12 @@ export class BrowserDomAdapter extends GenericBrowserDomAdapter {
   on(el, evt, listener) {
     el.addEventListener(evt, listener, false);
   }
+  onAndCancel(el, evt, listener): Function {
+    el.addEventListener(evt, listener, false);
+    //Needed to follow Dart's subscription semantic, until fix of
+    //https://code.google.com/p/dart/issues/detail?id=17406
+    return () => {el.removeEventListener(evt, listener, false);};
+  }
   dispatchEvent(el, evt) {
     el.dispatchEvent(evt);
   }
@@ -353,4 +359,13 @@ export class BrowserDomAdapter extends GenericBrowserDomAdapter {
     }
     return key;
   }
+  getGlobalEventTarget(target:string) {
+    if (target == "window") {
+      return window;
+    } else if (target == "document") {
+      return document;
+    } else if (target == "body") {
+      return document.body;
+    }
+  }
 }

modules/angular2/src/dom/dom_adapter.js

@@ -39,6 +39,9 @@ export class DomAdapter {
   on(el, evt, listener) {
     throw _abstract();
   }
+  onAndCancel(el, evt, listener): Function {
+    throw _abstract();
+  }
   dispatchEvent(el, evt) {
     throw _abstract();
   }
@@ -273,4 +276,7 @@ export class DomAdapter {
   supportsNativeShadowDOM(): boolean {
     throw _abstract();
   }
+  getGlobalEventTarget(target:string) {
+    throw _abstract();
+  }
 }

modules/angular2/src/dom/html_adapter.dart

@@ -29,6 +29,9 @@ class Html5LibDomAdapter implements DomAdapter {
   on(el, evt, listener) {
     throw 'not implemented';
   }
+  Function onAndCancel(el, evt, listener) {
+    throw 'not implemented';
+  }
   dispatchEvent(el, evt) {
     throw 'not implemented';
   }

modules/angular2/src/dom/parse5_adapter.cjs

@@ -86,6 +86,9 @@ export class Parse5DomAdapter extends DomAdapter {
   on(el, evt, listener) {
     //Do nothing, in order to not break forms integration tests
   }
+  onAndCancel(el, evt, listener): Function {
+    //Do nothing, in order to not break forms integration tests
+  }
   dispatchEvent(el, evt) {
     throw _notImplemented('dispatchEvent');
   }