Fix classes which extend StringSelectionOptions and implement Selectable.

Many classes extend StringSelectionOptions<T>, but implement Selectable<dynamic>. This will result in runtime errors if the MaterialDropdownSelectComponent which uses the class as options is typed with T other than dynamic.

This CL is part of #TheGreatTypedMaterialDropdownSelectComponentMigration, but only a side change which is written to improve safety and improve correctness, but isn't necessary as a prerequisite to typing MaterialDropdownSelectComponent's itemRenderer.

PiperOrigin-RevId: 225211488

Author: srawlins

examples/material_input_example/lib/material_auto_suggest_input_full_demo.dart

@@ -92,9 +92,9 @@ class MaterialAutoSuggestInputFullDemoComponent {
   final multiModel = SelectionModel<List>.multi();
 
   final suggestionOptions =
-      ExampleSelectionOptions<List<int>>.withOptionGroups(_optionGroups);
+      ExampleSelectionOptions.withOptionGroups(_optionGroups);
   final suggestionOptionsWithItemRenderer =
-      ExampleSelectionOptions<List<int>>.withOptionGroups(_optionGroups,
+      ExampleSelectionOptions.withOptionGroups(_optionGroups,
           toFilterableString: _numberNameRenderer);
 
   final emptySuggestionOptions = StringSelectionOptions(const <String>[]);
@@ -206,16 +206,16 @@ class ExampleLabelRendererComponent implements RendersValue {
   }
 }
 
-class ExampleSelectionOptions<T> extends StringSelectionOptions<T>
-    implements Selectable {
-  ExampleSelectionOptions(List<T> options) : super(options);
+class ExampleSelectionOptions extends StringSelectionOptions<List<int>>
+    implements Selectable<List<int>> {
+  ExampleSelectionOptions(List<List<int>> options) : super(options);
   ExampleSelectionOptions.withOptionGroups(List<OptionGroup> optionGroups,
-      {ItemRenderer<T> toFilterableString})
+      {ItemRenderer<List<int>> toFilterableString})
       : super.withOptionGroups(optionGroups,
             toFilterableString: toFilterableString);
   @override
-  SelectableOption getSelectable(item) {
-    if (item is List && item.contains(13)) {
+  SelectableOption getSelectable(List<int> item) {
+    if (item.contains(13)) {
       return SelectableOption.Disabled;
     }
     return SelectableOption.Selectable;

examples/material_select_example/lib/material_dropdown_select_full_demo.dart

@@ -129,11 +129,11 @@ class MaterialDropdownSelectFullDemoComponent {
   String deselectLabel = 'None';
 
   /// Languages to choose from.
-  ExampleSelectionOptions<Language> languageListOptions =
-      ExampleSelectionOptions<Language>(_languagesList);
+  ExampleSelectionOptions languageListOptions =
+      ExampleSelectionOptions(_languagesList);
 
-  ExampleSelectionOptions<Language> languageGroupedOptions =
-      ExampleSelectionOptions<Language>.withOptionGroups(_languagesGroups);
+  ExampleSelectionOptions languageGroupedOptions =
+      ExampleSelectionOptions.withOptionGroups(_languagesGroups);
 
   StringSelectionOptions<Language> get languageOptions =>
       useOptionGroup ? languageGroupedOptions : languageListOptions;
@@ -305,15 +305,16 @@ class ExampleLabelRendererComponent implements RendersValue<OptionGroup> {
 
 /// If the option does not support toString() that shows the label, the
 /// toFilterableString parameter must be passed to StringSelectionOptions.
-class ExampleSelectionOptions<T> extends StringSelectionOptions<T>
-    implements Selectable {
-  ExampleSelectionOptions(List<T> options)
-      : super(options, toFilterableString: (T option) => option.toString());
+class ExampleSelectionOptions extends StringSelectionOptions<Language>
+    implements Selectable<Language> {
+  ExampleSelectionOptions(List<Language> options)
+      : super(options,
+            toFilterableString: (Language option) => option.toString());
   ExampleSelectionOptions.withOptionGroups(List<OptionGroup> optionGroups)
       : super.withOptionGroups(optionGroups,
-            toFilterableString: (T option) => option.toString());
+            toFilterableString: (Language option) => option.toString());
   @override
-  SelectableOption getSelectable(item) =>
+  SelectableOption getSelectable(Language item) =>
       item is Language && item.code.contains('en')
           ? SelectableOption.Disabled
           : SelectableOption.Selectable;