Fix the type of MaterialDropdownSelectComponent's itemRenderer.

PiperOrigin-RevId: 225276100

Author: srawlins

angular_components/lib/material_datepicker/material_time_picker.dart

@@ -27,6 +27,9 @@ import 'package:angular_components/utils/disposer/disposer.dart';
     materialInputDirectives,
     NgStyle,
   ],
+  directiveTypes: [
+    Typed<MaterialDropdownSelectComponent<DateTime>>(),
+  ],
   providers: [
     Provider(HasDisabled, useExisting: MaterialTimePickerComponent),
   ],
@@ -353,7 +356,7 @@ class MaterialTimePickerComponent extends KeyboardHandlerMixin
 ///
 /// Only options between [minTime] and [maxTime] are selectable.
 class TimeSelectionOptions extends StringSelectionOptions<DateTime>
-    implements Selectable {
+    implements Selectable<DateTime> {
   DateTime _minTime;
   DateTime _maxTime;
 
@@ -363,7 +366,7 @@ class TimeSelectionOptions extends StringSelectionOptions<DateTime>
   set maxTime(DateTime time) => _maxTime = time;
 
   @override
-  SelectableOption getSelectable(item) {
+  SelectableOption getSelectable(DateTime item) {
     return item is DateTime &&
             ((_minTime != null && item.isBefore(_minTime)) ||
                 (_maxTime != null && item.isAfter(_maxTime)))

angular_components/lib/material_select/material_dropdown_select.dart

@@ -232,22 +232,10 @@ class MaterialDropdownSelectComponent<T> extends MaterialSelectBase<T>
   }
 
   /// Function to convert an option object to string.
-  ///
-  // TODO(google): Fix this now that generics are supported.
-  // Ideally, [value] would be a [ItemRenderer<T>], where T is also the type
-  // parameter of the SelectionOptions and the SelectionModel, as parent
-  // components typically use a function that accepts a specific type (T).
-  //
-  // However, we don't have a T. Angular doesn't support injecting a
-  // type-annotated component yet, and setters, like [itemRenderer], cannot
-  // be type-annotated. This forces us to accept a plain old [Function] as
-  // [value], in order to avoid uses_dynamic_as_bottom errors. (Basically, a
-  // function like [MaterialTimePicker]'s `String renderTime(DateTime time)`
-  // cannot work as a [ItemRenderer], since it expects DateTime, not dynamic.)
   @Input()
   @override
-  set itemRenderer(Function value) {
-    super.itemRenderer = (item) => value(item);
+  set itemRenderer(ItemRenderer<T> value) {
+    super.itemRenderer = value;
   }
 
   /// Width of the dropdown/list, default none, valid values are 0-5.