fix(material/datepicker): hide date selection model from docs (#22056)

* Hides some symbols related to the date selection model from the public API docs.
* Fixes that `MatDateSelectionModel` was marked as a directive, rather than an injectable.

Fixes #21985.

Author: crisbeto

src/material/datepicker/date-selection-model.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {FactoryProvider, Injectable, Optional, SkipSelf, OnDestroy, Directive} from '@angular/core';
+import {FactoryProvider, Injectable, Optional, SkipSelf, OnDestroy} from '@angular/core';
 import {DateAdapter} from '@angular/material/core';
 import {Observable, Subject} from 'rxjs';
 
@@ -32,7 +32,10 @@ export class DateRange<D> {
  */
 export type ExtractDateTypeFromSelection<T> = T extends DateRange<infer D> ? D : NonNullable<T>;
 
-/** Event emitted by the date selection model when its selection changes. */
+/**
+ * Event emitted by the date selection model when its selection changes.
+ * @docs-private
+ */
 export interface DateSelectionModelChange<S> {
   /** New value for the selection. */
   selection: S;
@@ -41,8 +44,11 @@ export interface DateSelectionModelChange<S> {
   source: unknown;
 }
 
-/** A selection model containing a date selection. */
-@Directive()
+/**
+ * A selection model containing a date selection.
+ * @docs-private
+ */
+@Injectable()
 export abstract class MatDateSelectionModel<S, D = ExtractDateTypeFromSelection<S>>
     implements OnDestroy {
   private _selectionChanged = new Subject<DateSelectionModelChange<S>>();
@@ -88,7 +94,10 @@ export abstract class MatDateSelectionModel<S, D = ExtractDateTypeFromSelection<
   abstract clone(): MatDateSelectionModel<S, D>;
 }
 
-/**  A selection model that contains a single date. */
+/**
+ * A selection model that contains a single date.
+ * @docs-private
+ */
 @Injectable()
 export class MatSingleDateSelectionModel<D> extends MatDateSelectionModel<D | null, D> {
   constructor(adapter: DateAdapter<D>) {
@@ -124,7 +133,10 @@ export class MatSingleDateSelectionModel<D> extends MatDateSelectionModel<D | nu
   }
 }
 
-/**  A selection model that contains a date range. */
+/**
+ * A selection model that contains a date range.
+ * @docs-private
+ */
 @Injectable()
 export class MatRangeDateSelectionModel<D> extends MatDateSelectionModel<DateRange<D>, D> {
   constructor(adapter: DateAdapter<D>) {
@@ -193,7 +205,10 @@ export function MAT_SINGLE_DATE_SELECTION_MODEL_FACTORY(
   return parent || new MatSingleDateSelectionModel(adapter);
 }
 
-/** Used to provide a single selection model to a component. */
+/**
+ * Used to provide a single selection model to a component.
+ * @docs-private
+ */
 export const MAT_SINGLE_DATE_SELECTION_MODEL_PROVIDER: FactoryProvider = {
   provide: MatDateSelectionModel,
   deps: [[new Optional(), new SkipSelf(), MatDateSelectionModel], DateAdapter],
@@ -207,7 +222,10 @@ export function MAT_RANGE_DATE_SELECTION_MODEL_FACTORY(
   return parent || new MatRangeDateSelectionModel(adapter);
 }
 
-/** Used to provide a range selection model to a component. */
+/**
+ * Used to provide a range selection model to a component.
+ * @docs-private
+ */
 export const MAT_RANGE_DATE_SELECTION_MODEL_PROVIDER: FactoryProvider = {
   provide: MatDateSelectionModel,
   deps: [[new Optional(), new SkipSelf(), MatDateSelectionModel], DateAdapter],

tools/public_api_guard/material/datepicker.d.ts

@@ -394,8 +394,8 @@ export declare abstract class MatDateSelectionModel<S, D = ExtractDateTypeFromSe
     abstract isValid(): boolean;
     ngOnDestroy(): void;
     updateSelection(value: S, source: unknown): void;
-    static ɵdir: i0.ɵɵDirectiveDefWithMeta<MatDateSelectionModel<any, any>, never, never, {}, {}, never>;
     static ɵfac: i0.ɵɵFactoryDef<MatDateSelectionModel<any, any>, never>;
+    static ɵprov: i0.ɵɵInjectableDef<MatDateSelectionModel<any, any>>;
 }
 
 export declare class MatEndDate<D> extends _MatDateRangeInputBase<D> implements CanUpdateErrorState, DoCheck, OnInit {