From 222087a07737d167f1ddada34ed1bf35789eb271 Mon Sep 17 00:00:00 2001
From: Rossen Hristov <rossen.hristov@telerik.com>
Date: Tue, 17 Mar 2015 12:27:37 +0200
Subject: [PATCH] Fixed all DatePicker issues in both platforms and covered
 with tests.

---
 CrossPlatformModules.csproj                   |  10 +-
 apps/pickers-demo/main-page.ts                |  16 ++-
 apps/pickers-demo/main-page.xml               |   2 +-
 apps/pickers-demo/model.ts                    |  30 +++++
 apps/tests/testRunner.ts                      |   1 +
 .../date-picker-tests-native.android.ts       |  25 ++++
 .../date-picker/date-picker-tests-native.d.ts |  10 ++
 .../date-picker-tests-native.ios.ts           |  36 ++++++
 .../tests/ui/date-picker/date-picker-tests.ts | 109 ++++++++++++++++++
 .../tests/ui/list-picker/list-picker-tests.ts |   2 +-
 ui/date-picker/date-picker-common.ts          |   6 +-
 ui/date-picker/date-picker.android.ts         |  30 +++--
 ui/date-picker/date-picker.d.ts               |   4 +-
 ui/date-picker/date-picker.ios.ts             |  40 ++++---
 ui/list-picker/list-picker-common.ts          |   2 +-
 15 files changed, 282 insertions(+), 41 deletions(-)
 create mode 100644 apps/tests/ui/date-picker/date-picker-tests-native.android.ts
 create mode 100644 apps/tests/ui/date-picker/date-picker-tests-native.d.ts
 create mode 100644 apps/tests/ui/date-picker/date-picker-tests-native.ios.ts
 create mode 100644 apps/tests/ui/date-picker/date-picker-tests.ts

diff --git a/CrossPlatformModules.csproj b/CrossPlatformModules.csproj
index 7e4c48402..03ab93a8d 100644
--- a/CrossPlatformModules.csproj
+++ b/CrossPlatformModules.csproj
@@ -131,6 +131,14 @@
       <DependentUpon>segmented-bar-tests-native.d.ts</DependentUpon>
     </TypeScriptCompile>
     <TypeScriptCompile Include="apps\tests\ui\segmented-bar\segmented-bar-tests.ts" />
+    <TypeScriptCompile Include="apps\tests\ui\date-picker\date-picker-tests-native.android.ts">
+      <DependentUpon>date-picker-tests-native.d.ts</DependentUpon>
+    </TypeScriptCompile>
+    <TypeScriptCompile Include="apps\tests\ui\date-picker\date-picker-tests-native.d.ts" />
+    <TypeScriptCompile Include="apps\tests\ui\date-picker\date-picker-tests-native.ios.ts">
+      <DependentUpon>date-picker-tests-native.d.ts</DependentUpon>
+    </TypeScriptCompile>
+    <TypeScriptCompile Include="apps\tests\ui\date-picker\date-picker-tests.ts" />
     <TypeScriptCompile Include="apps\tests\ui\list-picker\list-picker-tests-native.d.ts" />
     <TypeScriptCompile Include="apps\tests\ui\list-picker\list-picker-tests-native.android.ts">
       <DependentUpon>list-picker-tests-native.d.ts</DependentUpon>
@@ -1483,7 +1491,7 @@
           <SaveServerSettingsInUserFile>False</SaveServerSettingsInUserFile>
         </WebProjectProperties>
       </FlavorProperties>
-      <UserProperties ui_2scroll-view_2package_1json__JSONSchema="http://json.schemastore.org/package" apps_2editable-text-demo_2package_1json__JSONSchema="http://json.schemastore.org/package" apps_2absolute-layout-demo_2package_1json__JSONSchema="http://json.schemastore.org/package" apps_2gallery-app_2package_1json__JSONSchema="http://json.schemastore.org/package" ui_2content-view_2package_1json__JSONSchema="http://json.schemastore.org/package" ui_2web-view_2package_1json__JSONSchema="http://json.schemastore.org/package" ui_2layouts_2linear-layout_2package_1json__JSONSchema="http://json.schemastore.org/package" ui_2layouts_2absolute-layout_2package_1json__JSONSchema="http://json.schemastore.org/package" ui_2layouts_2dock-layout_2package_1json__JSONSchema="" ui_2layouts_2grid-layout_2package_1json__JSONSchema="" ui_2layouts_2wrap-layout_2package_1json__JSONSchema="http://json.schemastore.org/package" />
+      <UserProperties ui_2layouts_2wrap-layout_2package_1json__JSONSchema="http://json.schemastore.org/package" ui_2layouts_2grid-layout_2package_1json__JSONSchema="" ui_2layouts_2dock-layout_2package_1json__JSONSchema="" ui_2layouts_2absolute-layout_2package_1json__JSONSchema="http://json.schemastore.org/package" ui_2layouts_2linear-layout_2package_1json__JSONSchema="http://json.schemastore.org/package" ui_2web-view_2package_1json__JSONSchema="http://json.schemastore.org/package" ui_2content-view_2package_1json__JSONSchema="http://json.schemastore.org/package" apps_2gallery-app_2package_1json__JSONSchema="http://json.schemastore.org/package" apps_2absolute-layout-demo_2package_1json__JSONSchema="http://json.schemastore.org/package" apps_2editable-text-demo_2package_1json__JSONSchema="http://json.schemastore.org/package" ui_2scroll-view_2package_1json__JSONSchema="http://json.schemastore.org/package" />
     </VisualStudio>
   </ProjectExtensions>
 </Project>
\ No newline at end of file
diff --git a/apps/pickers-demo/main-page.ts b/apps/pickers-demo/main-page.ts
index 0affea7de..58be20b9a 100644
--- a/apps/pickers-demo/main-page.ts
+++ b/apps/pickers-demo/main-page.ts
@@ -18,16 +18,26 @@ export function onPageLoaded(args: observableModule.EventData) {
     page = <pagesModule.Page>args.object;
     page.bindingContext = viewModel;
 
-    viewModel.items = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
-    viewModel.selectedIndex = 5;
-
     label = page.getViewById<labelModule.Label>("label");
     listPicker = page.getViewById<listPickerModule.ListPicker>("listPicker");
     datePicker = page.getViewById<datePickerModule.DatePicker>("datePicker");
     timePicker = page.getViewById<timePickerModule.TimePicker>("timePicker");
+
+    viewModel.items = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
+    viewModel.selectedIndex = 5;
+
+    //viewModel.day = 9;
+    //viewModel.month = 2;
+    //viewModel.year = 1980;
 }
 
 export function onTap(args: observableModule.EventData) {
     console.log("onTap");
+
     viewModel.items = ["Male", "Female"];
+    viewModel.selectedIndex = 1;
+
+    viewModel.day = viewModel.day + 1;
+    viewModel.month = viewModel.month + 1;
+    viewModel.year = viewModel.year + 1;
 }
\ No newline at end of file
diff --git a/apps/pickers-demo/main-page.xml b/apps/pickers-demo/main-page.xml
index 8a8c03ae6..a386bb99c 100644
--- a/apps/pickers-demo/main-page.xml
+++ b/apps/pickers-demo/main-page.xml
@@ -3,7 +3,7 @@
     <Button id="button" text="GO!" height="50" width="100" tap="onTap"/>
     <Label id="label" text="{{ selectedIndex }}" height="50" width="100" />
     <ListPicker id="listPicker" selectedIndex="{{ selectedIndex }}" items="{{ items }}"/>
-    <DatePicker id="datePicker"/>
+    <DatePicker id="datePicker" day="{{ day }}" month="{{ month }}" year="{{ year }}"/>
     <TimePicker id="timePicker"/>
   </StackLayout>
 </Page>
\ No newline at end of file
diff --git a/apps/pickers-demo/model.ts b/apps/pickers-demo/model.ts
index 0b7d457a9..73a9c2761 100644
--- a/apps/pickers-demo/model.ts
+++ b/apps/pickers-demo/model.ts
@@ -24,4 +24,34 @@ export class WebViewModel extends observable.Observable {
         this._items = value;
         this.notify({ object: this, eventName: observable.knownEvents.propertyChange, propertyName: "items", value: value });
     }
+
+    private _day: number;
+    get day(): number {
+        return this._day;
+    }
+    set day(value: number) {
+        console.log("day:" + value);
+        this._day = value;
+        this.notify({ object: this, eventName: observable.knownEvents.propertyChange, propertyName: "day", value: value });
+    }
+
+    private _month: number;
+    get month(): number {
+        return this._month;
+    }
+    set month(value: number) {
+        console.log("month:" + value);
+        this._month = value;
+        this.notify({ object: this, eventName: observable.knownEvents.propertyChange, propertyName: "month", value: value });
+    }
+    
+    private _year: number;
+    get year(): number {
+        return this._year;
+    }
+    set year(value: number) {
+        console.log("year:" + value);
+        this._year = value;
+        this.notify({ object: this, eventName: observable.knownEvents.propertyChange, propertyName: "year", value: value });
+    }
 }
\ No newline at end of file
diff --git a/apps/tests/testRunner.ts b/apps/tests/testRunner.ts
index 997234e35..0c08b188d 100644
--- a/apps/tests/testRunner.ts
+++ b/apps/tests/testRunner.ts
@@ -48,6 +48,7 @@ allTests["FORMATTEDSTRING"] = require("./text/formatted-string-tests");
 allTests["FILE-SYSTEM-ACCESS"] = require("./file-system-access-tests/file-system-access-tests");
 allTests["XML-DECLARATION"] = require("./xml-declaration/xml-declaration-tests");
 allTests["LIST-PICKER"] = require("./ui/list-picker/list-picker-tests");
+allTests["DATE-PICKER"] = require("./ui/date-picker/date-picker-tests");
 
 var testsWithLongDelay = {
     testLocation: 10000,
diff --git a/apps/tests/ui/date-picker/date-picker-tests-native.android.ts b/apps/tests/ui/date-picker/date-picker-tests-native.android.ts
new file mode 100644
index 000000000..6ec9f870a
--- /dev/null
+++ b/apps/tests/ui/date-picker/date-picker-tests-native.android.ts
@@ -0,0 +1,25 @@
+import datePickerModule = require("ui/date-picker");
+
+export function getNativeYear(datePicker: datePickerModule.DatePicker): number {
+    return datePicker.android.getYear();
+}
+
+export function getNativeMonth(datePicker: datePickerModule.DatePicker): number {
+    return datePicker.android.getMonth() + 1;
+}
+
+export function getNativeDay(datePicker: datePickerModule.DatePicker): number {
+    return datePicker.android.getDayOfMonth();
+}
+
+export function setNativeYear(datePicker: datePickerModule.DatePicker, value: number): void {
+    datePicker.android.updateDate(value, datePicker.android.getMonth(), datePicker.android.getDayOfMonth());
+}
+
+export function setNativeMonth(datePicker: datePickerModule.DatePicker, value: number): void {
+    datePicker.android.updateDate(datePicker.android.getYear(), value - 1, datePicker.android.getDayOfMonth());
+}
+
+export function setNativeDay(datePicker: datePickerModule.DatePicker, value: number): void {
+    datePicker.android.updateDate(datePicker.android.getYear(), datePicker.android.getMonth(), value);
+}
diff --git a/apps/tests/ui/date-picker/date-picker-tests-native.d.ts b/apps/tests/ui/date-picker/date-picker-tests-native.d.ts
new file mode 100644
index 000000000..567f2f9bd
--- /dev/null
+++ b/apps/tests/ui/date-picker/date-picker-tests-native.d.ts
@@ -0,0 +1,10 @@
+//@private
+import datePickerModule = require("ui/date-picker");
+
+export declare function getNativeYear(datePicker: datePickerModule.DatePicker): number;
+export declare function getNativeMonth(datePicker: datePickerModule.DatePicker): number;
+export declare function getNativeDay(datePicker: datePickerModule.DatePicker): number;
+
+export declare function setNativeYear(datePicker: datePickerModule.DatePicker, value: number): void;
+export declare function setNativeMonth(datePicker: datePickerModule.DatePicker, value: number): void;
+export declare function setNativeDay(datePicker: datePickerModule.DatePicker, value: number): void;
\ No newline at end of file
diff --git a/apps/tests/ui/date-picker/date-picker-tests-native.ios.ts b/apps/tests/ui/date-picker/date-picker-tests-native.ios.ts
new file mode 100644
index 000000000..34f444e08
--- /dev/null
+++ b/apps/tests/ui/date-picker/date-picker-tests-native.ios.ts
@@ -0,0 +1,36 @@
+import datePickerModule = require("ui/date-picker");
+
+export function getNativeYear(datePicker: datePickerModule.DatePicker): number {
+    return NSCalendar.currentCalendar().componentsFromDate(NSCalendarUnit.NSCalendarUnitYear | NSCalendarUnit.NSCalendarUnitMonth | NSCalendarUnit.NSCalendarUnitDay, datePicker.ios.date).year;
+}
+
+export function getNativeMonth(datePicker: datePickerModule.DatePicker): number {
+    return NSCalendar.currentCalendar().componentsFromDate(NSCalendarUnit.NSCalendarUnitYear | NSCalendarUnit.NSCalendarUnitMonth | NSCalendarUnit.NSCalendarUnitDay, datePicker.ios.date).month;
+}
+
+export function getNativeDay(datePicker: datePickerModule.DatePicker): number {
+    return NSCalendar.currentCalendar().componentsFromDate(NSCalendarUnit.NSCalendarUnitYear | NSCalendarUnit.NSCalendarUnitMonth | NSCalendarUnit.NSCalendarUnitDay, datePicker.ios.date).day;
+}
+
+export function setNativeYear(datePicker: datePickerModule.DatePicker, value: number): void {
+    var comps = NSCalendar.currentCalendar().componentsFromDate(NSCalendarUnit.NSCalendarUnitYear | NSCalendarUnit.NSCalendarUnitMonth | NSCalendarUnit.NSCalendarUnitDay, datePicker.ios.date);
+    comps.year = value;
+    datePicker.ios.setDateAnimated(NSCalendar.currentCalendar().dateFromComponents(comps), false);
+    (<any>datePicker)._changeHandler.valueChanged(datePicker.ios);
+}
+
+export function setNativeMonth(datePicker: datePickerModule.DatePicker, value: number): void {
+    var comps = NSCalendar.currentCalendar().componentsFromDate(NSCalendarUnit.NSCalendarUnitYear | NSCalendarUnit.NSCalendarUnitMonth | NSCalendarUnit.NSCalendarUnitDay, datePicker.ios.date);
+    comps.month = value;
+    datePicker.ios.setDateAnimated(NSCalendar.currentCalendar().dateFromComponents(comps), false);
+    (<any>datePicker)._changeHandler.valueChanged(datePicker.ios);
+}
+
+export function setNativeDay(datePicker: datePickerModule.DatePicker, value: number): void {
+    var comps = NSCalendar.currentCalendar().componentsFromDate(NSCalendarUnit.NSCalendarUnitYear | NSCalendarUnit.NSCalendarUnitMonth | NSCalendarUnit.NSCalendarUnitDay, datePicker.ios.date);
+    comps.day = value;
+    datePicker.ios.setDateAnimated(NSCalendar.currentCalendar().dateFromComponents(comps), false);
+    (<any>datePicker)._changeHandler.valueChanged(datePicker.ios);
+}
+
+    
\ No newline at end of file
diff --git a/apps/tests/ui/date-picker/date-picker-tests.ts b/apps/tests/ui/date-picker/date-picker-tests.ts
new file mode 100644
index 000000000..de5ee16a0
--- /dev/null
+++ b/apps/tests/ui/date-picker/date-picker-tests.ts
@@ -0,0 +1,109 @@
+import TKUnit = require("../../TKUnit");
+import helper = require("../helper");
+import viewModule = require("ui/core/view");
+import datePickerTestsNative = require("./date-picker-tests-native");
+
+// <snippet module="ui/date-picker" title="DatePicker">
+// # DatePicker
+
+// Using a DatePicker requires the "ui/date-picker" module.
+// ``` JavaScript
+import datePickerModule = require("ui/date-picker");
+
+function _createDatePicker(): datePickerModule.DatePicker {
+    // <snippet module="ui/date-picker" title="DatePicker">
+    // ## Creating a DatePicker
+    // ``` JavaScript
+    var datePicker = new datePickerModule.DatePicker();
+    // ```
+    // </snippet>
+    datePicker.id = "DatePicker";
+    return datePicker;
+}
+
+export var test_WhenCreated_YearIsUndefined = function () {
+    helper.buildUIAndRunTest(_createDatePicker(), function (views: Array<viewModule.View>) {
+        var datePicker = <datePickerModule.DatePicker>views[0];
+        var actualValue = datePicker.year;
+        var expectedValue = undefined;
+        TKUnit.assert(actualValue === expectedValue, "Actual: " + actualValue + "; Expected: " + expectedValue);
+    });
+}
+
+export var test_WhenCreated_MonthIsUndefined = function () {
+    helper.buildUIAndRunTest(_createDatePicker(), function (views: Array<viewModule.View>) {
+        var datePicker = <datePickerModule.DatePicker>views[0];
+        var actualValue = datePicker.month;
+        var expectedValue = undefined;
+        TKUnit.assert(actualValue === expectedValue, "Actual: " + actualValue + "; Expected: " + expectedValue);
+    });
+}
+
+export var test_WhenCreated_DayIsUndefined = function () {
+    helper.buildUIAndRunTest(_createDatePicker(), function (views: Array<viewModule.View>) {
+        var datePicker = <datePickerModule.DatePicker>views[0];
+        var actualValue = datePicker.day;
+        var expectedValue = undefined;
+        TKUnit.assert(actualValue === expectedValue, "Actual: " + actualValue + "; Expected: " + expectedValue);
+    });
+}
+
+export var testYearFromLocalToNative = function () {
+    helper.buildUIAndRunTest(_createDatePicker(), function (views: Array<viewModule.View>) {
+        var datePicker = <datePickerModule.DatePicker>views[0];
+        var expectedValue = 1980;
+        datePicker.year = expectedValue;
+        var actualValue = datePickerTestsNative.getNativeYear(datePicker);
+        TKUnit.assert(actualValue === expectedValue, "Actual: " + actualValue + "; Expected: " + expectedValue);
+    });
+}
+
+export var testMonthFromLocalToNative = function () {
+    helper.buildUIAndRunTest(_createDatePicker(), function (views: Array<viewModule.View>) {
+        var datePicker = <datePickerModule.DatePicker>views[0];
+        var expectedValue = 5;
+        datePicker.month = expectedValue;
+        var actualValue = datePickerTestsNative.getNativeMonth(datePicker);
+        TKUnit.assert(actualValue === expectedValue, "Actual: " + actualValue + "; Expected: " + expectedValue);
+    });
+}
+
+export var testDayFromLocalToNative = function () {
+    helper.buildUIAndRunTest(_createDatePicker(), function (views: Array<viewModule.View>) {
+        var datePicker = <datePickerModule.DatePicker>views[0];
+        var expectedValue = 19;
+        datePicker.day = expectedValue;
+        var actualValue = datePickerTestsNative.getNativeDay(datePicker);
+        TKUnit.assert(actualValue === expectedValue, "Actual: " + actualValue + "; Expected: " + expectedValue);
+    });
+}
+
+export var testYearFromNativeToLocal = function () {
+    helper.buildUIAndRunTest(_createDatePicker(), function (views: Array<viewModule.View>) {
+        var datePicker = <datePickerModule.DatePicker>views[0];
+        var expectedValue = 1981;
+        datePickerTestsNative.setNativeYear(datePicker, expectedValue);
+        var actualValue = datePicker.year;
+        TKUnit.assert(actualValue === expectedValue, "Actual: " + actualValue + "; Expected: " + expectedValue);
+    });
+}
+
+export var testMonthFromNativeToLocal = function () {
+    helper.buildUIAndRunTest(_createDatePicker(), function (views: Array<viewModule.View>) {
+        var datePicker = <datePickerModule.DatePicker>views[0];
+        var expectedValue = 6;
+        datePickerTestsNative.setNativeMonth(datePicker, expectedValue);
+        var actualValue = datePicker.month;
+        TKUnit.assert(actualValue === expectedValue, "Actual: " + actualValue + "; Expected: " + expectedValue);
+    });
+}
+
+export var testDayFromNativeToLocal = function () {
+    helper.buildUIAndRunTest(_createDatePicker(), function (views: Array<viewModule.View>) {
+        var datePicker = <datePickerModule.DatePicker>views[0];
+        var expectedValue = 20;
+        datePickerTestsNative.setNativeDay(datePicker, expectedValue);
+        var actualValue = datePicker.day;
+        TKUnit.assert(actualValue === expectedValue, "Actual: " + actualValue + "; Expected: " + expectedValue);
+    });
+}
\ No newline at end of file
diff --git a/apps/tests/ui/list-picker/list-picker-tests.ts b/apps/tests/ui/list-picker/list-picker-tests.ts
index e16bf8b43..51c51c93c 100644
--- a/apps/tests/ui/list-picker/list-picker-tests.ts
+++ b/apps/tests/ui/list-picker/list-picker-tests.ts
@@ -167,7 +167,7 @@ export var testSettingSelectedIndexLargerThanCountShouldThrow = function () {
         listPicker.items = _createItems(10);
         TKUnit.assertThrows(function () {
             listPicker.selectedIndex = 10;
-        }, "Setting selectedIndex to a negative number should throw.");
+        }, "Setting selectedIndex to a number larger than item count should throw.");
     });
 }
 
diff --git a/ui/date-picker/date-picker-common.ts b/ui/date-picker/date-picker-common.ts
index 3d26c0aa8..fa11c0727 100644
--- a/ui/date-picker/date-picker-common.ts
+++ b/ui/date-picker/date-picker-common.ts
@@ -4,9 +4,9 @@ import proxy = require("ui/core/proxy");
 import view = require("ui/core/view");
 
 export class DatePicker extends view.View implements definition.DatePicker {
-    public static yearProperty = new dependencyObservable.Property("year", "DatePicker", new proxy.PropertyMetadata(0));
-    public static monthProperty = new dependencyObservable.Property("month", "DatePicker", new proxy.PropertyMetadata(0));
-    public static dayProperty = new dependencyObservable.Property("day", "DatePicker", new proxy.PropertyMetadata(0));
+    public static yearProperty = new dependencyObservable.Property("year", "DatePicker", new proxy.PropertyMetadata(undefined));
+    public static monthProperty = new dependencyObservable.Property("month", "DatePicker", new proxy.PropertyMetadata(undefined));
+    public static dayProperty = new dependencyObservable.Property("day", "DatePicker", new proxy.PropertyMetadata(undefined));
 
     constructor() {
         super();
diff --git a/ui/date-picker/date-picker.android.ts b/ui/date-picker/date-picker.android.ts
index 5e6b5307d..3c941e87a 100644
--- a/ui/date-picker/date-picker.android.ts
+++ b/ui/date-picker/date-picker.android.ts
@@ -5,8 +5,8 @@ import proxy = require("ui/core/proxy");
 function onYearPropertyChanged(data: dependencyObservable.PropertyChangeData) {
     var picker = <DatePicker>data.object;
 
-    if (picker.android) {
-        picker.android.init(data.newValue, picker.month, picker.day, picker._listener);
+    if (picker.android && picker.android.getYear() !== data.newValue) {
+        picker.android.updateDate(data.newValue, picker.android.getMonth(), picker.android.getDayOfMonth());
     }
 }
 
@@ -15,8 +15,8 @@ function onYearPropertyChanged(data: dependencyObservable.PropertyChangeData) {
 function onMonthPropertyChanged(data: dependencyObservable.PropertyChangeData) {
     var picker = <DatePicker>data.object;
 
-    if (picker.android) {
-        picker.android.init(picker.year, data.newValue, picker.day, picker._listener);
+    if (picker.android && picker.android.getMonth() !== (data.newValue - 1)) {
+        picker.android.updateDate(picker.android.getYear(), data.newValue - 1, picker.android.getDayOfMonth());
     }
 }
 
@@ -25,8 +25,8 @@ function onMonthPropertyChanged(data: dependencyObservable.PropertyChangeData) {
 function onDayPropertyChanged(data: dependencyObservable.PropertyChangeData) {
     var picker = <DatePicker>data.object;
 
-    if (picker.android) {
-        picker.android.init(picker.year, picker.month, data.newValue, picker._listener);
+    if (picker.android && picker.android.getDayOfMonth !== data.newValue) {
+        picker.android.updateDate(picker.android.getYear(), picker.android.getMonth(), data.newValue);
     }
 }
 
@@ -54,11 +54,20 @@ export class DatePicker extends common.DatePicker {
                 return that.get();
             },
 
-            onDateChanged: function (picker: android.widget.DatePicker, monthOfYear: number, dayOfMonth: number) {
+            onDateChanged: function (picker: android.widget.DatePicker, year: number, month: number, day: number) {
                 if (this.owner) {
-                    this.owner._onPropertyChangedFromNative(common.DatePicker.yearProperty, picker.getYear());
-                    this.owner._onPropertyChangedFromNative(common.DatePicker.monthProperty, monthOfYear);
-                    this.owner._onPropertyChangedFromNative(common.DatePicker.dayProperty, dayOfMonth);
+
+                    if (year !== this.owner.year) {
+                        this.owner._onPropertyChangedFromNative(common.DatePicker.yearProperty, year);
+                    }
+
+                    if ((month + 1) !== this.owner.month) {
+                        this.owner._onPropertyChangedFromNative(common.DatePicker.monthProperty, month + 1);
+                    }
+
+                    if (day !== this.owner.day) {
+                        this.owner._onPropertyChangedFromNative(common.DatePicker.dayProperty, day);
+                    }                    
                 }
             }
         });
@@ -67,5 +76,6 @@ export class DatePicker extends common.DatePicker {
     public _createUI() {
         this._android = new android.widget.DatePicker(this._context);
         this._android.setCalendarViewShown(false);
+        this._android.init(0, 0, 0, this._listener);
     }
 } 
\ No newline at end of file
diff --git a/ui/date-picker/date-picker.d.ts b/ui/date-picker/date-picker.d.ts
index f96e050b8..aa8c3baa9 100644
--- a/ui/date-picker/date-picker.d.ts
+++ b/ui/date-picker/date-picker.d.ts
@@ -31,12 +31,12 @@ declare module "ui/date-picker" {
         year: number;
 
         /**
-         * Gets or sets the month.
+         * Gets or sets the month. The months start from 1.
          */
         month: number;
 
         /**
-         * Gets or sets the day.
+         * Gets or sets the day. The days start from 1.
          */
         day: number;
     }
diff --git a/ui/date-picker/date-picker.ios.ts b/ui/date-picker/date-picker.ios.ts
index 57e6b9324..170ab0d85 100644
--- a/ui/date-picker/date-picker.ios.ts
+++ b/ui/date-picker/date-picker.ios.ts
@@ -6,7 +6,9 @@ function onYearPropertyChanged(data: dependencyObservable.PropertyChangeData) {
     var picker = <DatePicker>data.object;
 
     if (picker.ios) {
-        setYearMonthDay(picker.ios, data.newValue, picker.month, picker.day);
+        var comps = NSCalendar.currentCalendar().componentsFromDate(NSCalendarUnit.NSCalendarUnitYear | NSCalendarUnit.NSCalendarUnitMonth | NSCalendarUnit.NSCalendarUnitDay, picker.ios.date);
+        comps.year = data.newValue;
+        picker.ios.setDateAnimated(NSCalendar.currentCalendar().dateFromComponents(comps), false);
     }
 }
 
@@ -16,7 +18,9 @@ function onMonthPropertyChanged(data: dependencyObservable.PropertyChangeData) {
     var picker = <DatePicker>data.object;
 
     if (picker.ios) {
-        setYearMonthDay(picker.ios, picker.year, data.newValue, picker.day);
+        var comps = NSCalendar.currentCalendar().componentsFromDate(NSCalendarUnit.NSCalendarUnitYear | NSCalendarUnit.NSCalendarUnitMonth | NSCalendarUnit.NSCalendarUnitDay, picker.ios.date);
+        comps.month = data.newValue;
+        picker.ios.setDateAnimated(NSCalendar.currentCalendar().dateFromComponents(comps), false);
     }
 }
 
@@ -26,7 +30,9 @@ function onDayPropertyChanged(data: dependencyObservable.PropertyChangeData) {
     var picker = <DatePicker>data.object;
 
     if (picker.ios) {
-        setYearMonthDay(picker.ios, picker.year, picker.month, data.newValue);
+        var comps = NSCalendar.currentCalendar().componentsFromDate(NSCalendarUnit.NSCalendarUnitYear | NSCalendarUnit.NSCalendarUnitMonth | NSCalendarUnit.NSCalendarUnitDay, picker.ios.date);
+        comps.day = data.newValue;
+        picker.ios.setDateAnimated(NSCalendar.currentCalendar().dateFromComponents(comps), false);
     }
 }
 
@@ -68,26 +74,22 @@ class UIDatePickerChangeHandlerImpl extends NSObject {
     }
 
     public valueChanged(sender: UIDatePicker) {
-        var calendar = NSCalendar.currentCalendar();
-        var comp = calendar.componentsFromDate(NSCalendarUnit.NSHourCalendarUnit | NSCalendarUnit.NSMinuteCalendarUnit, sender.date);
+        var comps = NSCalendar.currentCalendar().componentsFromDate(NSCalendarUnit.NSCalendarUnitYear | NSCalendarUnit.NSCalendarUnitMonth | NSCalendarUnit.NSCalendarUnitDay, sender.date);
+        
+        if (comps.year !== this._owner.year) {
+            this._owner._onPropertyChangedFromNative(common.DatePicker.yearProperty, comps.year);
+        }
 
-        this._owner._onPropertyChangedFromNative(common.DatePicker.yearProperty, comp.year);
-        this._owner._onPropertyChangedFromNative(common.DatePicker.monthProperty, comp.month);
-        this._owner._onPropertyChangedFromNative(common.DatePicker.dayProperty, comp.day);
+        if (comps.month !== this._owner.month) {
+            this._owner._onPropertyChangedFromNative(common.DatePicker.monthProperty, comps.month);
+        }
+
+        if (comps.day !== this._owner.day) {
+            this._owner._onPropertyChangedFromNative(common.DatePicker.dayProperty, comps.day);
+        }
     }
 
     public static ObjCExposedMethods = {
         'valueChanged': { returns: interop.types.void, params: [UIDatePicker] }
     };
-}
-
-function setYearMonthDay(picker: UIDatePicker, year: number, month: number, day: number) {
-    var calendar = NSCalendar.currentCalendar();
-    var comps = new NSDateComponents();
-
-    comps.year = year;
-    comps.month = month;
-    comps.day = day;
-
-    picker.setDateAnimated(calendar.dateFromComponents(comps), false);
 }
\ No newline at end of file
diff --git a/ui/list-picker/list-picker-common.ts b/ui/list-picker/list-picker-common.ts
index ea39484c3..988885e93 100644
--- a/ui/list-picker/list-picker-common.ts
+++ b/ui/list-picker/list-picker-common.ts
@@ -53,7 +53,7 @@ export class ListPicker extends view.View implements definition.ListPicker {
         if (types.isDefined(this.items)) {
             if (index < 0 || index >= this.items.length) {
                 this.selectedIndex = undefined;
-                throw new Error("SelectedIndex should be between [0, items.length)");
+                throw new Error("selectedIndex should be between [0, items.length - 1]");
             }
         }
     }