chore: hide internal properties from selection-list api doc

* Recently with the NgModel support for the selection list, the `onTouched` property has been added. This one needs to be prefixed with an underscore to be hidden in the docs.
* Since the initial implementation of the selection-list the `selectionList` variable has been initialized publically in the constructor of the `MatListOption` and therefore shows up in the docs. This property has been made private now.

Author: devversion

src/lib/list/selection-list.ts

@@ -126,7 +126,9 @@ export class MatListOption extends _MatListOptionMixinBase
 
   /** Whether the option is disabled. */
   @Input()
-  get disabled() { return (this.selectionList && this.selectionList.disabled) || this._disabled; }
+  get disabled() {
+    return this._disabled || this._selectionList && this._selectionList.disabled;
+  }
   set disabled(value: any) {
     const newValue = coerceBooleanProperty(value);
 
@@ -138,13 +140,13 @@ export class MatListOption extends _MatListOptionMixinBase
 
   /** Whether the option is selected. */
   @Input()
-  get selected(): boolean { return this.selectionList.selectedOptions.isSelected(this); }
+  get selected(): boolean { return this._selectionList.selectedOptions.isSelected(this); }
   set selected(value: boolean) {
     const isSelected = coerceBooleanProperty(value);
 
     if (isSelected !== this._selected) {
       this._setSelected(isSelected);
-      this.selectionList._reportValueChange();
+      this._selectionList._reportValueChange();
     }
   }
 
@@ -158,7 +160,7 @@ export class MatListOption extends _MatListOptionMixinBase
   constructor(private _element: ElementRef,
               private _changeDetector: ChangeDetectorRef,
               @Optional() @Inject(forwardRef(() => MatSelectionList))
-              public selectionList: MatSelectionList) {
+              private _selectionList: MatSelectionList) {
     super();
   }
 
@@ -169,7 +171,7 @@ export class MatListOption extends _MatListOptionMixinBase
       // available options. Also it can happen that the ControlValueAccessor has an initial value
       // that should be used instead. Deferring the value change report to the next tick ensures
       // that the form control value is not being overwritten.
-      Promise.resolve(() => this.selected && this.selectionList._reportValueChange());
+      Promise.resolve(() => this.selected && this._selectionList._reportValueChange());
     }
   }
 
@@ -178,7 +180,7 @@ export class MatListOption extends _MatListOptionMixinBase
   }
 
   ngOnDestroy(): void {
-    this.selectionList._removeOptionFromList(this);
+    this._selectionList._removeOptionFromList(this);
   }
 
   /** Toggles the selection state of the option. */
@@ -193,15 +195,15 @@ export class MatListOption extends _MatListOptionMixinBase
 
   /** Whether this list item should show a ripple effect when clicked.  */
   _isRippleDisabled() {
-    return this.disabled || this.disableRipple || this.selectionList.disableRipple;
+    return this.disabled || this.disableRipple || this._selectionList.disableRipple;
   }
 
   _handleClick() {
     if (!this.disabled) {
       this.toggle();
 
       // Emit a change event if the selected state of the option changed through user interaction.
-      this.selectionList._emitChangeEvent(this);
+      this._selectionList._emitChangeEvent(this);
 
       // TODO: the `selectionChange` event on the option is deprecated. Remove that in the future.
       this._emitDeprecatedChangeEvent();
@@ -210,12 +212,12 @@ export class MatListOption extends _MatListOptionMixinBase
 
   _handleFocus() {
     this._hasFocus = true;
-    this.selectionList._setFocusedOption(this);
+    this._selectionList._setFocusedOption(this);
   }
 
   _handleBlur() {
     this._hasFocus = false;
-    this.selectionList.onTouched();
+    this._selectionList._onTouched();
   }
 
   /** Retrieves the DOM element of the component host. */
@@ -232,9 +234,9 @@ export class MatListOption extends _MatListOptionMixinBase
     this._selected = selected;
 
     if (selected) {
-      this.selectionList.selectedOptions.select(this);
+      this._selectionList.selectedOptions.select(this);
     } else {
-      this.selectionList.selectedOptions.deselect(this);
+      this._selectionList.selectedOptions.deselect(this);
     }
 
     this._changeDetector.markForCheck();
@@ -261,7 +263,7 @@ export class MatListOption extends _MatListOptionMixinBase
     '[tabIndex]': 'tabIndex',
     'class': 'mat-selection-list',
     '(focus)': 'focus()',
-    '(blur)': 'onTouched()',
+    '(blur)': '_onTouched()',
     '(keydown)': '_keydown($event)',
     '[attr.aria-disabled]': 'disabled.toString()'},
   template: '<ng-content></ng-content>',
@@ -291,7 +293,7 @@ export class MatSelectionList extends _MatSelectionListMixinBase implements Focu
   private _onChange: (value: any) => void = (_: any) => {};
 
   /** View to model callback that should be called if the list or its options lost focus. */
-  onTouched: () => void = () => {};
+  _onTouched: () => void = () => {};
 
   constructor(private _element: ElementRef, @Attribute('tabindex') tabIndex: string) {
     super();
@@ -385,7 +387,7 @@ export class MatSelectionList extends _MatSelectionListMixinBase implements Focu
 
   /** Implemented as part of ControlValueAccessor. */
   registerOnTouched(fn: () => void): void {
-    this.onTouched = fn;
+    this._onTouched = fn;
   }
 
   /** Returns the option with the specified value. */