Upgrading samples to flutter_lints, part 1 of n (#804)

place_tracker/lib/place_details.dart

@@ -37,7 +37,7 @@ class PlaceDetailsState extends State<PlaceDetails> {
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(
-        title: Text('${_place.name}'),
+        title: Text(_place.name),
         backgroundColor: Colors.green[700],
         actions: [
           Padding(

place_tracker/lib/place_list.dart

@@ -92,7 +92,7 @@ class _CategoryButton extends StatelessWidget {
     }
 
     return Container(
-      margin: EdgeInsets.symmetric(vertical: 12.0),
+      margin: const EdgeInsets.symmetric(vertical: 12.0),
       decoration: BoxDecoration(
         border: Border(
           bottom: BorderSide(
@@ -179,14 +179,14 @@ class _PlaceListTile extends StatelessWidget {
         }),
       ),
       child: Container(
-        padding: EdgeInsets.only(top: 16.0),
+        padding: const EdgeInsets.only(top: 16.0),
         child: Column(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
             Text(
               place.name,
               textAlign: TextAlign.left,
-              style: TextStyle(
+              style: const TextStyle(
                 fontWeight: FontWeight.bold,
                 fontSize: 20.0,
               ),
@@ -209,7 +209,7 @@ class _PlaceListTile extends StatelessWidget {
               maxLines: 4,
               overflow: TextOverflow.ellipsis,
             ),
-            SizedBox(height: 16.0),
+            const SizedBox(height: 16.0),
             Divider(
               height: 2.0,
               color: Colors.grey[700],

place_tracker/lib/place_map.dart

@@ -206,7 +206,7 @@ class PlaceMapState extends State<PlaceMap> {
       // Show a confirmation snackbar that has an action to edit the new place.
       ScaffoldMessenger.of(context).showSnackBar(
         SnackBar(
-          duration: Duration(seconds: 3),
+          duration: const Duration(seconds: 3),
           content:
               const Text('New place added.', style: TextStyle(fontSize: 16.0)),
           action: SnackBarAction(
@@ -293,7 +293,7 @@ class PlaceMapState extends State<PlaceMap> {
       final newMarker = Marker(
         markerId: MarkerId(_lastMapPosition.toString()),
         position: _lastMapPosition,
-        infoWindow: InfoWindow(title: 'New Place'),
+        infoWindow: const InfoWindow(title: 'New Place'),
         draggable: true,
         icon: BitmapDescriptor.defaultMarkerWithHue(BitmapDescriptor.hueGreen),
       );
@@ -433,12 +433,12 @@ class PlaceMapState extends State<PlaceMap> {
     switch (category) {
       case PlaceCategory.favorite:
         return BitmapDescriptor.fromAssetImage(
-            createLocalImageConfiguration(context, size: Size.square(32)),
+            createLocalImageConfiguration(context, size: const Size.square(32)),
             'assets/heart.png');
         break;
       case PlaceCategory.visited:
         return BitmapDescriptor.fromAssetImage(
-            createLocalImageConfiguration(context, size: Size.square(32)),
+            createLocalImageConfiguration(context, size: const Size.square(32)),
             'assets/visited.png');
         break;
       case PlaceCategory.wantToGo:
@@ -598,7 +598,7 @@ class _MapFabs extends StatelessWidget {
               backgroundColor: Colors.green,
               child: const Icon(Icons.add_location, size: 36.0),
             ),
-            SizedBox(height: 12.0),
+            const SizedBox(height: 12.0),
             FloatingActionButton(
               heroTag: 'toggle_map_type_button',
               onPressed: onToggleMapTypePressed,

place_tracker/lib/place_tracker_app.dart

@@ -19,7 +19,7 @@ enum PlaceTrackerViewType {
 class PlaceTrackerApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-    return MaterialApp(
+    return const MaterialApp(
       home: _PlaceTrackerHomePage(),
     );
   }
@@ -46,7 +46,7 @@ class _PlaceTrackerHomePage extends StatelessWidget {
         backgroundColor: Colors.green[700],
         actions: [
           Padding(
-            padding: EdgeInsets.fromLTRB(0.0, 0.0, 16.0, 0.0),
+            padding: const EdgeInsets.fromLTRB(0.0, 0.0, 16.0, 0.0),
             child: IconButton(
               icon: Icon(
                 state.viewType == PlaceTrackerViewType.map
@@ -67,8 +67,8 @@ class _PlaceTrackerHomePage extends StatelessWidget {
       ),
       body: IndexedStack(
         index: state.viewType == PlaceTrackerViewType.map ? 0 : 1,
-        children: [
-          PlaceMap(center: const LatLng(45.521563, -122.677433)),
+        children: const [
+          PlaceMap(center: LatLng(45.521563, -122.677433)),
           PlaceList()
         ],
       ),