chore: modernize Flutter examples — null safety, latest APIs, Kotlin DSL Gradle (#148)

* updates

* Update Gradle wrapper script to fetch latest version online and allow --version override

* chore(analytics_integration): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build files to Kotlin DSL and bump Gradle wrapper.

* chore(animation_example): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build files to Kotlin DSL.

* chore(biometrics): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build files to Kotlin DSL.

* chore(bmi_calculator): test

test body

* chore(bottom_sheet): test

test body

* chore(custom_home_drawer): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build files to Kotlin DSL and bump Gradle wrapper.

* chore(covid19_mobile_app): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(dropdown_button): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(enabling_splash_screen): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(expense_planner): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(firebase_crash_reporting): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(firebase_google_authentication): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(flutter_date_pickers-master): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(getx_counter_app): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(google_signin): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(grid_layout): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(handling_routes): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(image_editor): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(image_from_network): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(infinite_list): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(load_local_image): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(load_local_json): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(lunch_app): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(navigation_drawer): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(news_memes_app): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(persist_key_value): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(push_notifications): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(save_data_locally_with_sqlite): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(scan_qr_code): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(simple_material_app): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(sliver_app_bar_example): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(stateful_widget): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(stateless_widgets): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(statless_counter_app): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(tic_tac_toe): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(tip_calculator): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(todo_list_using_provider): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(unit_testing): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(using_alert_dialog): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(using_bottom_nav_bar): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(using_custom_fonts): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(using_edittext): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(using_expansionpanel): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(using_firebase_db): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(using_gradient): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(using_http_get): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(using_interactiveviewer): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(using_listview): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(using_listwheelscrollview): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(using_platform_adaptive): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore(using_snackbar): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(using_stepper): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(using_tabs): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(using_theme): remove legacy nested android project

Delete the redundant nested android/ project directory from the old layout. Also update pubspec.yaml SDK constraints and dependencies.

* chore(view_pdf_file): migrate Gradle build scripts to Kotlin DSL

Convert Groovy build.gradle/settings.gradle to Kotlin DSL and bump Gradle wrapper.

* chore: ignore .trash directory

* chore: remove IDE configs and PR template

* chore(infinite_list): remove legacy nested android project

* refactor(infinite_list): migrate theme to ColorScheme API

* refactor(using_theme): migrate to ColorScheme API

* refactor(analytics_integration): migrate Firebase Analytics API

* refactor(firebase_google_authentication): migrate Google Sign-In API

* refactor(covid19_mobile_app): migrate theme and buttons to current API

* refactor(covid19_mobile_app): replace bezier_chart with fl_chart

* refactor(image_editor): migrate image plugins and button styles

* refactor(scan_qr_code): migrate mobile_scanner API

* refactor(lunch_app): migrate to null safety

* refactor(todo_list_using_provider): migrate to null safety

* refactor(unit_testing): migrate to null safety

* refactor(using_firebase_db): migrate Firebase Database API

* fix(update_gradle_wrapper): edit gradle-wrapper.properties directly

* refactor(push_notifications): migrate Firebase Messaging API

* refactor(using_http_get): migrate to null safety

* refactor(using_listview): migrate to null safety

* refactor(using_listwheelscrollview): migrate to null safety

* refactor(view_pdf_file): migrate to null safety

* refactor(bottom_sheet): migrate to null safety

* refactor(stateless_widgets): migrate to null safety

* chore: regenerate Gradle wrapper

* refactor: move maintenance scripts to Makefile

* chore: remove generated and IDE files

* fix: migrate image_editor to current plugins

* fix: migrate news_memes_app share to share_plus

* fix: migrate view_pdf_file to syncfusion pdf viewer

* fix: update deprecated APIs

* style: remove commented-out code

flutter_date_pickers-master/example/lib/date_pickers_widgets/day_picker_page.dart

@@ -34,10 +34,10 @@ class _DayPickerPageState extends State<DayPickerPage> {
   void didChangeDependencies() {
     super.didChangeDependencies();
 
-    Color? bodyTextColor = Theme.of(context).accentTextTheme.bodyText1?.color;
+    Color? bodyTextColor = Theme.of(context).textTheme.bodyLarge?.color;
     if (bodyTextColor != null) selectedDateStyleColor = bodyTextColor;
 
-    selectedSingleDateDecorationColor = Theme.of(context).accentColor;
+    selectedSingleDateDecorationColor = Theme.of(context).colorScheme.secondary;
   }
 
   @override
@@ -45,8 +45,8 @@ class _DayPickerPageState extends State<DayPickerPage> {
     // add selected colors to default settings
     dp.DatePickerRangeStyles styles = dp.DatePickerRangeStyles(
         selectedDateStyle: Theme.of(context)
-            .accentTextTheme
-            .bodyText1
+            .textTheme
+            .bodyLarge
             ?.copyWith(color: selectedDateStyleColor),
         selectedSingleDateDecoration: BoxDecoration(
             color: selectedSingleDateDecorationColor,
@@ -89,7 +89,7 @@ class _DayPickerPageState extends State<DayPickerPage> {
               children: <Widget>[
                 Text(
                   "Selected date styles",
-                  style: Theme.of(context).textTheme.subtitle1,
+                  style: Theme.of(context).textTheme.titleMedium,
                 ),
                 Padding(
                   padding: const EdgeInsets.symmetric(vertical: 12.0),

flutter_date_pickers-master/example/lib/date_pickers_widgets/days_picker_page.dart

@@ -45,10 +45,10 @@ class _DaysPickerPageState extends State<DaysPickerPage> {
   void didChangeDependencies() {
     super.didChangeDependencies();
 
-    Color? bodyTextColor = Theme.of(context).accentTextTheme.bodyText1?.color;
+    Color? bodyTextColor = Theme.of(context).textTheme.bodyLarge?.color;
     if (bodyTextColor != null) selectedDateStyleColor = bodyTextColor;
 
-    selectedSingleDateDecorationColor = Theme.of(context).accentColor;
+    selectedSingleDateDecorationColor = Theme.of(context).colorScheme.secondary;
   }
 
   @override
@@ -56,8 +56,8 @@ class _DaysPickerPageState extends State<DaysPickerPage> {
     // add selected colors to default settings
     dp.DatePickerRangeStyles styles = dp.DatePickerRangeStyles(
         selectedDateStyle: Theme.of(context)
-            .accentTextTheme
-            .bodyText1
+            .textTheme
+            .bodyLarge
             ?.copyWith(color: selectedDateStyleColor),
         selectedSingleDateDecoration: BoxDecoration(
             color: selectedSingleDateDecorationColor, shape: BoxShape.circle));
@@ -92,7 +92,7 @@ class _DaysPickerPageState extends State<DaysPickerPage> {
               children: <Widget>[
                 Text(
                   "Selected date styles",
-                  style: Theme.of(context).textTheme.subtitle1,
+                  style: Theme.of(context).textTheme.titleMedium,
                 ),
                 Padding(
                   padding: const EdgeInsets.symmetric(vertical: 12.0),

flutter_date_pickers-master/example/lib/date_pickers_widgets/month_picker_page.dart

@@ -22,10 +22,10 @@ class _MonthPickerPageState extends State<MonthPickerPage> {
   void didChangeDependencies() {
     super.didChangeDependencies();
 
-    Color? bodyTextColor = Theme.of(context).accentTextTheme.bodyText1?.color;
+    Color? bodyTextColor = Theme.of(context).textTheme.bodyLarge?.color;
     if (bodyTextColor != null) selectedDateStyleColor = bodyTextColor;
 
-    selectedSingleDateDecorationColor = Theme.of(context).accentColor;
+    selectedSingleDateDecorationColor = Theme.of(context).colorScheme.secondary;
   }
 
   @override
@@ -33,8 +33,8 @@ class _MonthPickerPageState extends State<MonthPickerPage> {
     // add selected colors to default settings
     dp.DatePickerStyles styles = dp.DatePickerStyles(
         selectedDateStyle: Theme.of(context)
-            .accentTextTheme
-            .bodyText1
+            .textTheme
+            .bodyLarge
             ?.copyWith(color: selectedDateStyleColor),
         selectedSingleDateDecoration: BoxDecoration(
             color: selectedSingleDateDecorationColor, shape: BoxShape.circle));
@@ -62,7 +62,7 @@ class _MonthPickerPageState extends State<MonthPickerPage> {
               children: <Widget>[
                 Text(
                   "Selected date styles",
-                  style: Theme.of(context).textTheme.subtitle1,
+                  style: Theme.of(context).textTheme.titleMedium,
                 ),
                 Padding(
                   padding: const EdgeInsets.symmetric(vertical: 12.0),

flutter_date_pickers-master/example/lib/date_pickers_widgets/range_picker_page.dart

@@ -37,9 +37,9 @@ class _RangePickerPageState extends State<RangePickerPage> {
   void didChangeDependencies() {
     super.didChangeDependencies();
 
-    selectedPeriodLastColor = Theme.of(context).accentColor;
-    selectedPeriodMiddleColor = Theme.of(context).accentColor;
-    selectedPeriodStartColor = Theme.of(context).accentColor;
+    selectedPeriodLastColor = Theme.of(context).colorScheme.secondary;
+    selectedPeriodMiddleColor = Theme.of(context).colorScheme.secondary;
+    selectedPeriodStartColor = Theme.of(context).colorScheme.secondary;
   }
 
   @override
@@ -92,7 +92,7 @@ class _RangePickerPageState extends State<RangePickerPage> {
               children: <Widget>[
                 Text(
                   "Selected date styles",
-                  style: Theme.of(context).textTheme.subtitle1,
+                  style: Theme.of(context).textTheme.titleMedium,
                 ),
                 _stylesBlock(),
                 _selectedBlock()

flutter_date_pickers-master/example/lib/date_pickers_widgets/range_picker_styled.dart

@@ -46,9 +46,9 @@ class _RangePickerPageStyledState extends State<RangePickerPageStyled> {
     super.didChangeDependencies();
 
     // defaults for styles
-    selectedPeriodLastColor = Theme.of(context).accentColor;
-    selectedPeriodMiddleColor = Theme.of(context).accentColor;
-    selectedPeriodStartColor = Theme.of(context).accentColor;
+    selectedPeriodLastColor = Theme.of(context).colorScheme.secondary;
+    selectedPeriodMiddleColor = Theme.of(context).colorScheme.secondary;
+    selectedPeriodStartColor = Theme.of(context).colorScheme.secondary;
   }
 
   @override
@@ -120,7 +120,7 @@ class _RangePickerPageStyledState extends State<RangePickerPageStyled> {
               children: <Widget>[
                 Text(
                   "Selected date styles",
-                  style: Theme.of(context).textTheme.subtitle1,
+                  style: Theme.of(context).textTheme.titleMedium,
                 ),
                 _selectedBlock()
               ],

flutter_date_pickers-master/example/lib/date_pickers_widgets/week_picker_page.dart

@@ -35,9 +35,9 @@ class _WeekPickerPageState extends State<WeekPickerPage> {
     super.didChangeDependencies();
 
     // defaults for styles
-    selectedPeriodLastColor = Theme.of(context).accentColor;
-    selectedPeriodMiddleColor = Theme.of(context).accentColor;
-    selectedPeriodStartColor = Theme.of(context).accentColor;
+    selectedPeriodLastColor = Theme.of(context).colorScheme.secondary;
+    selectedPeriodMiddleColor = Theme.of(context).colorScheme.secondary;
+    selectedPeriodStartColor = Theme.of(context).colorScheme.secondary;
   }
 
   @override
@@ -84,7 +84,7 @@ class _WeekPickerPageState extends State<WeekPickerPage> {
               children: <Widget>[
                 Text(
                   "Selected date styles",
-                  style: Theme.of(context).textTheme.subtitle1,
+                  style: Theme.of(context).textTheme.titleMedium,
                 ),
                 _stylesBlock(),
                 _selectedBlock()
@@ -229,7 +229,7 @@ class _WeekPickerPageState extends State<WeekPickerPage> {
 
     TextStyle? whiteText = Theme.of(context)
         .textTheme
-        .bodyText2
+        .bodyMedium
         ?.copyWith(color: Colors.white);
 
     return isEventDate

flutter_date_pickers-master/example/lib/main.dart

@@ -81,7 +81,7 @@ class _MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {
         data: Theme.of(context).copyWith(
             canvasColor: Colors.blueGrey,
             textTheme: Theme.of(context).textTheme.copyWith(
-                caption: TextStyle(color: Colors.white.withOpacity(0.5)))),
+                bodySmall: TextStyle(color: Colors.white.withOpacity(0.5)))),
         child: BottomNavigationBar(
           type: BottomNavigationBarType.fixed,
           items: [