add Snaps to bottom sheets

Author: vusters

integration_test/local/dialog/Toast.yaml integration_test/local/dialogsAndToast/Toast.yaml

@@ -8,7 +8,7 @@ import '../framework/test_helper.dart';
 void main() {
   late EnsembleConfig config;
   setUpAll(() async {
-    config = await TestHelper.setupApp(appName: 'dialog');
+    config = await TestHelper.setupApp(appName: 'dialogsAndToast');
   });
 
   group('Testing Toast', () {

integration_test/local/dialog_test.dart integration_test/local/dialogsAndToast_test.dart

@@ -1,3 +1,4 @@
+import 'package:collection/collection.dart';
 import 'package:ensemble/framework/action.dart';
 import 'package:ensemble/framework/data_context.dart';
 import 'package:ensemble/framework/error_handling.dart';
@@ -85,6 +86,14 @@ class ShowBottomSheetAction extends EnsembleAction {
       min: 0,
       max: 1);
 
+  bool isSnap(scopeManager) =>
+      Utils.optionalBool(
+          eval(payload["scrollOptions"]?["snap"], scopeManager)) ??
+      false;
+
+  List<double>? additionalSnaps(scopeManager) => Utils.getList<double>(
+      eval(payload["scrollOptions"]?["additionalViewportSnaps"], scopeManager));
+
   @override
   Future<dynamic> execute(BuildContext context, ScopeManager scopeManager) {
     if (body != null) {
@@ -140,6 +149,12 @@ class ShowBottomSheetAction extends EnsembleAction {
         initialViewport = (minViewport + maxViewport) / 2.0;
       }
 
+      bool useSnap = isSnap(scopeManager);
+      List<double>? snaps = additionalSnaps(scopeManager)
+          ?.where((item) => item > minViewport && item < maxViewport)
+          .toList();
+      snaps?.sort();
+
       // On platforms with a mouse (Web/desktop), there is no min/maxViewport due to platform consistency,
       // so the height will be fixed to initialViewport, and content will just scroll within it.
       // https://docs.flutter.dev/release/breaking-changes/default-scroll-behavior-drag
@@ -148,6 +163,8 @@ class ShowBottomSheetAction extends EnsembleAction {
           minChildSize: minViewport,
           maxChildSize: maxViewport,
           initialChildSize: initialViewport,
+          snap: useSnap,
+          snapSizes: useSnap ? snaps : null,
           builder: (context, scrollController) =>
               buildRootContainer(scopeManager, context,
                   child: SingleChildScrollView(

lib/action/bottom_sheet_actions.dart

@@ -261,10 +261,12 @@ class Utils {
   }
 
   static List<T>? getList<T>(dynamic value) {
-    if (value is YamlList) {
+    if (value is List) {
       List<T> results = [];
       for (var item in value) {
-        results.add(item);
+        if (item is T) {
+          results.add(item);
+        }
       }
       return results;
     }

lib/util/utils.dart

@@ -152,7 +152,7 @@ flutter:
     # integration tests (TODO - exclude from build)
     - integration_test/local/defaultApp/
     - integration_test/local/themedApp/
-    - integration_test/local/dialog/
+    - integration_test/local/dialogsAndToast/
 
   fonts:
     # icon fonts