From aef7256e69d5924da1747af2994fef9231cc81b0 Mon Sep 17 00:00:00 2001
From: Nedyalko Nikolov <nedyalko.nikolov@telerik.com>
Date: Wed, 21 Oct 2015 16:42:37 +0300
Subject: [PATCH] Enabled bindings to events and gestures for Bindable instead
 of View.

---
 .../ui/action-bar/action-bar-tests-common.ts  | 34 +++++++++++++++++++
 ui/core/bindable.ts                           |  4 ++-
 ui/core/view-common.ts                        |  6 ++--
 3 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/apps/tests/ui/action-bar/action-bar-tests-common.ts b/apps/tests/ui/action-bar/action-bar-tests-common.ts
index 5dbf44889..ef1a27e66 100644
--- a/apps/tests/ui/action-bar/action-bar-tests-common.ts
+++ b/apps/tests/ui/action-bar/action-bar-tests-common.ts
@@ -4,7 +4,9 @@ import helper = require("../helper");
 import builder = require("ui/builder");
 import button = require("ui/button");
 import PageModule = require("ui/page");
+import viewModule = require("ui/core/view");
 import fs = require("file-system");
+import { Observable } from "data/observable";
 
 // <snippet module="ui/action-bar" title="ActionBar">
 // # ActionBar
@@ -172,6 +174,38 @@ export function test_titleView_inXML_short_definition() {
     TKUnit.assert(centerBtn instanceof button.Button, "cneterView not loaded correctly");
 };
 
+export function test_ActionBarItemBindingToEvent() {
+    var p = <PageModule.Page>builder.parse('<Page><Page.actionBar><ActionBar><ActionBar.actionItems><ActionItem tap="{{ test }}"/></ActionBar.actionItems></ActionBar></Page.actionBar></Page>');
+
+    var testAction = function (views: Array<viewModule.View>) {
+        var page = <PageModule.Page>views[0];
+        var firstHandlerCallCounter = 0;
+        var secondHandlerCallCounter = 0;
+        var firstHandler = function () { firstHandlerCallCounter++; };
+        var secondHandler = function () { secondHandlerCallCounter++; };
+
+        page.bindingContext = new Observable({ "test": firstHandler });
+
+        var actionBarItem = page.actionBar.actionItems.getItemAt(0);
+
+        TKUnit.assertEqual((<any>actionBarItem)._observers["tap"].length, 1, "There should be only one listener");
+        TKUnit.assertEqual((<any>actionBarItem)._observers["tap"][0].callback + "", "function () { firstHandlerCallCounter++; }", "First handler is not equal");
+
+        p.bindingContext.set("test", secondHandler);
+
+        TKUnit.assertEqual((<any>actionBarItem)._observers["tap"].length, 1, "There should be only one listener");
+        TKUnit.assertEqual((<any>actionBarItem)._observers["tap"][0].callback + "", "function () { secondHandlerCallCounter++; }", "Second handler is not equal");
+    }
+
+    helper.navigate(function () { return p; });
+    try {
+        testAction([p]);
+    }
+    finally {
+        helper.goBack();
+    }
+}
+
 export function test_Setting_ActionItems_doesnt_thrown() {
 
     var page: PageModule.Page;
diff --git a/ui/core/bindable.ts b/ui/core/bindable.ts
index 5c7cd524f..cc595e70d 100644
--- a/ui/core/bindable.ts
+++ b/ui/core/bindable.ts
@@ -584,9 +584,11 @@ export class Binding {
         this.updating = true;
 
         try {
-            if (optionsInstance instanceof viewModule.View &&
+            if (optionsInstance instanceof Bindable &&
                 viewModule.isEventOrGesture(options.property, optionsInstance) &&
                 types.isFunction(value)) {
+                // calling off method with null as handler will remove all handlers for options.property event
+                optionsInstance.off(options.property, null, optionsInstance.bindingContext);
                 optionsInstance.on(options.property, value, optionsInstance.bindingContext);
             } else {
                 if (optionsInstance instanceof observable.Observable) {
diff --git a/ui/core/view-common.ts b/ui/core/view-common.ts
index 0fd7f6ac3..3acccd42c 100644
--- a/ui/core/view-common.ts
+++ b/ui/core/view-common.ts
@@ -295,8 +295,10 @@ export class View extends proxy.ProxyObject implements definition.View {
 
     private _disconnectGestureObservers(type: gestures.GestureTypes): void {
         var observers = this.getGestureObservers(type);
-        for (let i = 0; i < observers.length; i++) {
-            observers[i].disconnect();
+        if (observers) {
+            for (let i = 0; i < observers.length; i++) {
+                observers[i].disconnect();
+            }
         }
     }