From 9e7fbc8a9221769c007a0ba9d41541bcd7e3565d Mon Sep 17 00:00:00 2001
From: Vladimir Enchev <vladimir.enchev@telerik.com>
Date: Wed, 13 May 2015 10:53:08 +0300
Subject: [PATCH] Binding gestures event handlers support added

---
 .../xml-declaration/xml-declaration-tests.ts   | 17 +++++++++++++++++
 ui/builder/component-builder.ts                | 18 ++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/apps/tests/xml-declaration/xml-declaration-tests.ts b/apps/tests/xml-declaration/xml-declaration-tests.ts
index 4fba06865..844a19b6e 100644
--- a/apps/tests/xml-declaration/xml-declaration-tests.ts
+++ b/apps/tests/xml-declaration/xml-declaration-tests.ts
@@ -2,6 +2,7 @@
 import view = require("ui/core/view");
 import builder = require("ui/builder");
 import page = require("ui/page");
+import buttonModule = require("ui/button");
 import switchModule = require("ui/switch");
 import textFieldModule = require("ui/text-field");
 import gridLayoutModule = require("ui/layouts/grid-layout");
@@ -150,6 +151,22 @@ export function test_parse_ShouldParseBindingsWithObservable() {
     TKUnit.assert(sw.checked === false, "Expected result: false; Actual result: " + sw.checked + "; type: " + typeof (sw.checked));
 };
 
+export function test_parse_ShouldParseBindingsToEvents() {
+    var p = <page.Page>builder.parse("<Page><Button tap='{{ myTap }}' /></Page>");
+    p.bindingContext = { myTap: function (args) { } };
+    var btn = <buttonModule.Button>p.content;
+
+    TKUnit.assert(btn.hasListeners("tap"), "Expected result: true.");
+};
+
+export function test_parse_ShouldParseBindingsToGestures() {
+    var p = <page.Page>builder.parse("<Page><Label tap='{{ myTap }}' /></Page>");
+    p.bindingContext = { myTap: function (args) { } };
+    var lbl = <labelModule.Label>p.content;
+
+    TKUnit.assert((<any>lbl)._gesturesObserver !== undefined, "Expected result: true.");
+};
+
 export function test_parse_ShouldParseSubProperties() {
     var p = <page.Page>builder.parse("<Page><Switch style.visibility='collapsed' checked='{{ myProp }}' /></Page>");
     var obj = new observable.Observable();
diff --git a/ui/builder/component-builder.ts b/ui/builder/component-builder.ts
index ee0f9fb07..eb2a22d01 100644
--- a/ui/builder/component-builder.ts
+++ b/ui/builder/component-builder.ts
@@ -109,6 +109,8 @@ export function setPropertyValue(instance: view.View, instanceModule: Object, ex
     if (isBinding(propertyValue) && instance.bind) {
         if (isEvent) {
             attachEventBinding(instance, propertyName, propertyValue);
+        } else if (isGesture(propertyName, instance)) {
+            attachGestureBinding(instance, propertyName, propertyValue);
         } else {
             var bindOptions = bindingBuilder.getBindingOptions(propertyName, getBindingExpressionFromAttribute(propertyValue));
             instance.bind({
@@ -185,6 +187,22 @@ function attachEventBinding(instance: view.View, eventName: string, value: strin
     instance.on(observable.Observable.propertyChangeEvent, propertyChangeHandler);
 }
 
+function attachGestureBinding(instance: view.View, gestureName: string, value: string) {
+    // Get the event handler from instance.bindingContext.
+    var propertyChangeHandler = (args: observable.PropertyChangeData) => {
+        if (args.propertyName === "bindingContext") {
+            var handler = instance.bindingContext && instance.bindingContext[getBindingExpressionFromAttribute(value)];
+            // Check if the handler is function and add it to the instance for specified event name.
+            if (types.isFunction(handler)) {
+                instance.observe(gestures.fromString(gestureName.toLowerCase()), handler);
+            }
+            instance.off(observable.Observable.propertyChangeEvent, propertyChangeHandler);
+        }
+    };
+
+    instance.on(observable.Observable.propertyChangeEvent, propertyChangeHandler);
+}
+
 function isGesture(name: string, instance: any): boolean {
     return gestures.fromString(name.toLowerCase()) !== undefined;
 }