Add date picker to widgets library and teach fitness app to use it

Also, add an example for the date picker

examples/fitness/lib/date_utils.dart

@@ -13,6 +13,12 @@ class DateUtils {
   static const MS_IN_WEEK =
         DateTime.DAYS_PER_WEEK * Duration.MILLISECONDS_PER_DAY;
 
+  // TODO(jmesserly): locale specific date format
+  static String _twoDigits(int n) {
+    if (n >= 10) return "${n}";
+    return "0${n}";
+  }
+
   /** Formats a time in H:MM A format */
   static String toHourMinutesString(Duration duration) {
     assert(duration.inDays == 0);
@@ -68,14 +74,16 @@ class DateUtils {
     } else if (delta.inMilliseconds < MS_IN_WEEK) {
       return WEEKDAYS[then.weekday];
     } else {
-      // TODO(jmesserly): locale specific date format
-      String twoDigits(int n) {
-        if (n >= 10) return "${n}";
-        return "0${n}";
-      }
-      String twoDigitMonth = twoDigits(then.month);
-      String twoDigitDay = twoDigits(then.day);
+      String twoDigitMonth = _twoDigits(then.month);
+      String twoDigitDay = _twoDigits(then.day);
       return "${then.year}-${twoDigitMonth}-${twoDigitDay}";
     }
   }
+
+  static String toDateString(DateTime then) {
+    // TODO(jmesserly): locale specific date format
+    String twoDigitMonth = _twoDigits(then.month);
+    String twoDigitDay = _twoDigits(then.day);
+    return "${then.year}-${twoDigitMonth}-${twoDigitDay}";
+  }
 }

examples/fitness/lib/fitness_item.dart

@@ -21,7 +21,7 @@ abstract class FitnessItem {
   Map toJson() => { 'when' : when.toIso8601String() };
 
   // TODO(jackson): Internationalize
-  String get displayDate => DateUtils.toRecentTimeString(when);
+  String get displayDate => DateUtils.toDateString(when);
 
   FitnessItemRow toRow({ FitnessItemHandler onDismissed });
 }

examples/fitness/lib/measurement.dart

@@ -17,6 +17,7 @@ class Measurement extends FitnessItem {
   Map toJson() {
     Map json = super.toJson();
     json['weight'] = weight;
+    json['type'] = runtimeType.toString();
     return json;
   }
 
@@ -53,6 +54,55 @@ class MeasurementRow extends FitnessItemRow {
   }
 }
 
+class MeasurementDateDialog extends StatefulComponent {
+  MeasurementDateDialog({ this.navigator, this.previousDate });
+
+  Navigator navigator;
+  DateTime previousDate;
+
+  @override
+  void initState() {
+    _selectedDate = previousDate;
+  }
+
+  void syncConstructorArguments(MeasurementDateDialog source) {
+    navigator = source.navigator;
+    previousDate = source.previousDate;
+  }
+
+  DateTime _selectedDate;
+
+  void _handleDateChanged(DateTime value) {
+    setState(() {
+      _selectedDate = value;
+    });
+  }
+
+  Widget build() {
+    return new Dialog(
+      content: new DatePicker(
+        selectedDate: _selectedDate,
+        firstDate: new DateTime(2015, 8),
+        lastDate: new DateTime(2101),
+        onChanged: _handleDateChanged
+      ),
+      contentPadding: EdgeDims.zero,
+      actions: [
+        new FlatButton(
+          child: new Text('CANCEL'),
+          onPressed: navigator.pop
+        ),
+        new FlatButton(
+          child: new Text('OK'),
+          onPressed: () {
+            navigator.pop(_selectedDate);
+          }
+        ),
+      ]
+    );
+  }
+}
+
 class MeasurementFragment extends StatefulComponent {
 
   MeasurementFragment({ this.navigator, this.onCreated });
@@ -66,6 +116,7 @@ class MeasurementFragment extends StatefulComponent {
   }
 
   String _weight = "";
+  DateTime _when = new DateTime.now();
   String _errorMessage = null;
 
   EventDisposition _handleSave() {
@@ -79,7 +130,7 @@ class MeasurementFragment extends StatefulComponent {
       });
       return EventDisposition.processed;
     }
-    onCreated(new Measurement(when: new DateTime.now(), weight: parsedWeight));
+    onCreated(new Measurement(when: _when, weight: parsedWeight));
     navigator.pop();
     return EventDisposition.processed;
   }
@@ -107,23 +158,44 @@ class MeasurementFragment extends StatefulComponent {
 
   static final GlobalKey weightKey = new GlobalKey();
 
+  EventDisposition _handleDatePressed(_) {
+    showDialog(navigator, (navigator) {
+      return new MeasurementDateDialog(navigator: navigator, previousDate: _when);
+    }).then((DateTime value) {
+      if (value == null)
+        return;
+      setState(() {
+        _when = value;
+      });
+    });
+    return EventDisposition.processed;
+  }
+
   Widget buildBody() {
-    Measurement measurement = new Measurement(when: new DateTime.now());
+    Measurement measurement = new Measurement(when: _when);
+    // TODO(jackson): Revisit the layout of this pane to be more maintainable
     return new Material(
       type: MaterialType.canvas,
-      child: new ScrollableViewport(
       child: new Container(
         padding: const EdgeDims.all(20.0),
-          child: new BlockBody([
-            new Text(measurement.displayDate),
+        child: new Column([
+          new Listener(
+            onGestureTap: _handleDatePressed,
+            child: new Container(
+              height: 50.0,
+              child: new Column([
+                new Text('Measurement Date'),
+                new Text(measurement.displayDate, style: Theme.of(this).text.caption),
+              ], alignItems: FlexAlignItems.start)
+            )
+          ),
           new Input(
             key: weightKey,
             placeholder: 'Enter weight',
             keyboardType: KeyboardType_NUMBER,
             onChanged: _handleWeightChanged
           ),
-          ])
-        )
+        ], alignItems: FlexAlignItems.stretch)
       )
     );
   }

examples/widgets/date_picker.dart

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:sky/widgets.dart';
+import 'package:sky/theme/colors.dart' as colors;
+
+void main() => runApp(new DatePickerDemo());
+
+class DatePickerDemo extends App {
+
+  DateTime _dateTime;
+
+  void initState() {
+    DateTime now = new DateTime.now();
+    _dateTime = new DateTime(now.year, now.month, now.day);
+  }
+
+  void _handleDateChanged(DateTime dateTime) {
+    setState(() {
+      _dateTime = dateTime;
+    });
+  }
+
+  Widget build() {
+    return new Theme(
+      data: new ThemeData(
+        brightness: ThemeBrightness.light,
+        primarySwatch: colors.Teal
+      ),
+      child: new Stack([
+        new Scaffold(
+          toolbar: new ToolBar(center: new Text("Date Picker")),
+          body: new Material(
+            child: new Row(
+              [new Text(_dateTime.toString())],
+              alignItems: FlexAlignItems.end,
+              justifyContent: FlexJustifyContent.center
+            )
+          )
+        ),
+        new Dialog(
+          content: new DatePicker(
+            selectedDate: _dateTime,
+            firstDate: new DateTime(2015, 8),
+            lastDate: new DateTime(2101),
+            onChanged: _handleDateChanged
+          ),
+          contentPadding: EdgeDims.zero,
+          actions: [
+            new FlatButton(
+              child: new Text('CANCEL')
+            ),
+            new FlatButton(
+              child: new Text('OK')
+            ),
+          ]
+        )
+      ])
+    );
+  }
+}

packages/flutter/lib/widgets.dart

@@ -10,6 +10,7 @@ export 'widgets/basic.dart';
 export 'widgets/button_base.dart';
 export 'widgets/card.dart';
 export 'widgets/checkbox.dart';
+export 'widgets/date_picker.dart';
 export 'widgets/default_text_style.dart';
 export 'widgets/dialog.dart';
 export 'widgets/dismissable.dart';

packages/flutter/lib/widgets/dialog.dart

@@ -25,7 +25,9 @@ class Dialog extends Component {
   Dialog({
     Key key,
     this.title,
+    this.titlePadding,
     this.content,
+    this.contentPadding,
     this.actions,
     this.onDismiss
   }): super(key: key);
@@ -34,10 +36,17 @@ class Dialog extends Component {
   /// of the dialog.
   final Widget title;
 
+  // Padding around the title; uses material design default if none is supplied
+  // If there is no title, no padding will be provided
+  final EdgeDims titlePadding;
+
   /// The (optional) content of the dialog is displayed in the center of the
   /// dialog in a lighter font.
   final Widget content;
 
+  // Padding around the content; uses material design default if none is supplied
+  final EdgeDims contentPadding;
+
   /// The (optional) set of actions that are displayed at the bottom of the
   /// dialog.
   final List<Widget> actions;
@@ -59,8 +68,11 @@ class Dialog extends Component {
     List<Widget> dialogBody = new List<Widget>();
 
     if (title != null) {
+      EdgeDims padding = titlePadding;
+      if (padding == null)
+        padding = new EdgeDims(24.0, 24.0, content == null ? 20.0 : 0.0, 24.0);
       dialogBody.add(new Padding(
-        padding: new EdgeDims(24.0, 24.0, content == null ? 20.0 : 0.0, 24.0),
+        padding: padding,
         child: new DefaultTextStyle(
           style: Theme.of(this).text.title,
           child: title
@@ -69,8 +81,11 @@ class Dialog extends Component {
     }
 
     if (content != null) {
+      EdgeDims padding = contentPadding;
+      if (padding == null)
+        padding = const EdgeDims(20.0, 24.0, 24.0, 24.0);
       dialogBody.add(new Padding(
-        padding: const EdgeDims(20.0, 24.0, 24.0, 24.0),
+        padding: padding,
         child: new DefaultTextStyle(
           style: Theme.of(this).text.subhead,
           child: content

packages/flutter/pubspec.yaml

@@ -13,5 +13,6 @@ dependencies:
   sky_services: ^0.0.14
   sky_tools: ^0.0.10
   vector_math: ^1.4.3
+  intl: ^0.12.4+2
 environment:
   sdk: '>=1.8.0 <2.0.0'