Add generics support to material_dropdown_select and material_select.

PiperOrigin-RevId: 220226649

Author: creisman

angular_components/lib/material_select/material_dropdown_select.dart

@@ -73,19 +73,24 @@ import 'package:angular_components/utils/id_generator/id_generator.dart';
     NgIf,
     PopupSourceDirective,
   ],
+  directiveTypes: [
+    Typed<MaterialSelectDropdownItemComponent<String>>(on: 'deselectItem'),
+    Typed<MaterialSelectDropdownItemComponent<String>>(on: 'emptyGroupLabel'),
+    Typed<MaterialSelectDropdownItemComponent>.of([#T]),
+  ],
   templateUrl: 'material_dropdown_select.html',
   styleUrls: ['material_dropdown_select.scss.css'],
   visibility: Visibility.all, // injected by directives
 )
-class MaterialDropdownSelectComponent extends MaterialSelectBase
+class MaterialDropdownSelectComponent<T> extends MaterialSelectBase<T>
     with
         MaterialDropdownBase,
-        SelectionInputAdapter,
+        SelectionInputAdapter<T>,
         MaterialButtonWrapper,
         TrackLayoutChangesMixin,
         KeyboardHandlerMixin,
         ActivateItemOnKeyPressMixin,
-        ShiftClickSelectionMixin
+        ShiftClickSelectionMixin<T>
     implements PopupSizeProvider, OnChanges, OnDestroy {
   /// Function for use by NgFor for optionGroup.
   ///
@@ -112,10 +117,10 @@ class MaterialDropdownSelectComponent extends MaterialSelectBase
   String buttonAriaLabelledBy;
 
   /// Listener for options changes.
-  StreamSubscription _optionsListener;
+  StreamSubscription<List<OptionGroup<T>>> _optionsListener;
 
   /// Listener for selection changes.
-  StreamSubscription _selectionListener;
+  StreamSubscription<List<SelectionChangeRecord<T>>> _selectionListener;
 
   /// If a parent provides a [PopupSizeProvider], the provider will be used
   /// instead of the implementation of this class.
@@ -223,6 +228,7 @@ class MaterialDropdownSelectComponent extends MaterialSelectBase
 
   /// 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).
@@ -274,7 +280,7 @@ class MaterialDropdownSelectComponent extends MaterialSelectBase
   }
 
   @override
-  set options(SelectionOptions newOptions) {
+  set options(SelectionOptions<T> newOptions) {
     super.options = newOptions;
 
     _updateActiveModel();
@@ -308,7 +314,7 @@ class MaterialDropdownSelectComponent extends MaterialSelectBase
   }
 
   @override
-  set selection(SelectionModel newSelection) {
+  set selection(SelectionModel<T> newSelection) {
     super.selection = newSelection;
     _setInitialActiveItem();
 
@@ -493,7 +499,7 @@ class MaterialDropdownSelectComponent extends MaterialSelectBase
   }
 
   /// If selectionOptions implements Selectable, it is called.
-  bool isOptionDisabled(Object item) {
+  bool isOptionDisabled(T item) {
     // TODO: Verify if this can be simplified to .isDisabledIn.
     //
     // The prior code did a check for `!= SelectableOption.Selected`. It is
@@ -503,7 +509,7 @@ class MaterialDropdownSelectComponent extends MaterialSelectBase
   }
 
   /// Whether to hide [item].
-  bool isOptionHidden(Object item) {
+  bool isOptionHidden(T item) {
     return Selectable.isHiddenIn(options, item, false);
   }
 

angular_components/lib/material_select/material_dropdown_select.html

@@ -62,6 +62,7 @@
     <ng-content></ng-content>
     <div class="options-wrapper" *ngIf="options != null">
       <material-select-dropdown-item
+          #deselectItem
           *ngIf="showDeselectItem"
           keyboardOnlyFocusIndicator
           [class.empty]="options.optionGroups.length == 1"
@@ -103,6 +104,7 @@
             </material-select-dropdown-item>
           </template>
           <material-select-dropdown-item
+              #emptyGroupLabel
               *ngIf="group.isEmpty && group.hasEmptyLabel"
               keyboardOnlyFocusIndicator
               [tabbable]="false"

angular_components/lib/material_select/material_select.dart

@@ -33,15 +33,18 @@ import 'material_select_item.dart';
     Provider(SelectionContainer, useExisting: MaterialSelectComponent)
   ],
   directives: [MaterialListComponent, MaterialSelectItemComponent, NgIf, NgFor],
+  directiveTypes: [
+    Typed<MaterialSelectItemComponent>.of([#T]),
+  ],
   templateUrl: 'material_select.html',
   styleUrls: ['material_select.scss.css'],
 )
-class MaterialSelectComponent extends MaterialSelectBase
+class MaterialSelectComponent<T> extends MaterialSelectBase<T>
     implements HasDisabled {
   @HostBinding('attr.role')
   static const hostRole = 'listbox';
 
-  List<SelectionItem> _selectItems;
+  List<SelectionItem<T>> _selectItems;
 
   /// Function for use by NgFor for optionGroup to avoid recreating the
   /// DOM for the optionGroup.
@@ -56,7 +59,7 @@ class MaterialSelectComponent extends MaterialSelectBase
   /// The [SelectionOptions] instance providing options to render.
   @Input()
   @override
-  set options(SelectionOptions value) {
+  set options(SelectionOptions<T> value) {
     super.options = value;
   }
 
@@ -85,17 +88,17 @@ class MaterialSelectComponent extends MaterialSelectBase
   /// The [SelectionModel] for this container.
   @Input()
   @override
-  set selection(value) {
+  set selection(SelectionModel<T> value) {
     super.selection = value;
     _refreshItems();
   }
 
   @override
-  SelectionModel get selection => super.selection;
+  SelectionModel<T> get selection => super.selection;
 
   /// If selectionOptions implements Selectable, it is called to decided
   /// whether an item is disabled.
-  bool isOptionDisabled(Object item) {
+  bool isOptionDisabled(T item) {
     // TODO: Verify if this can be simplified to .isDisabledIn.
     //
     // The prior code did a check for `!= SelectableOption.Selected`. It is
@@ -118,19 +121,19 @@ class MaterialSelectComponent extends MaterialSelectBase
   String get disabledStr => '$_disabled';
 
   @override
-  ItemRenderer get itemRenderer => _itemRenderer;
-  ItemRenderer _itemRenderer;
+  ItemRenderer<T> get itemRenderer => _itemRenderer;
+  ItemRenderer<T> _itemRenderer;
 
   /// A rendering function to render selection options to a String, if given a
   /// `value`.
   @Input()
-  set itemRenderer(ItemRenderer renderer) {
+  set itemRenderer(ItemRenderer<T> renderer) {
     _itemRenderer = renderer;
     _refreshItems();
   }
 
   @ContentChildren(SelectionItem)
-  set selectItems(List<SelectionItem> value) {
+  set selectItems(List<SelectionItem<T>> value) {
     if (value != null) {
       // ContentChildren call is inside change detection. We can't alter
       // state inside change detector therefore schedule a microtask.
@@ -144,12 +147,12 @@ class MaterialSelectComponent extends MaterialSelectBase
   void _refreshItems() {
     if (_selectItems == null) return;
     if (selection != null) {
-      for (SelectionItem item in _selectItems) {
+      for (SelectionItem<T> item in _selectItems) {
         item.selection = selection;
       }
     }
     if (itemRenderer != null) {
-      for (SelectionItem item in _selectItems) {
+      for (SelectionItem<T> item in _selectItems) {
         item.itemRenderer = itemRenderer;
       }
     }