import { FormControl , FormGroupDirective , NgControl , NgForm } from '@angular/forms' ; import { Subject } from 'rxjs' ; import { SbbErrorStateMatcher } from '../error/error-options' ; import { AbstractConstructor , Constructor } from './constructor' ; docs-private export interface CanUpdateErrorState { readonly stateChanges : Subject < void > ; errorState : boolean ; errorStateMatcher : SbbErrorStateMatcher ; updateErrorState ( ) : void ; } docs-private export interface HasErrorState { _parentFormGroup : FormGroupDirective ; _parentForm : NgForm ; _defaultErrorStateMatcher : SbbErrorStateMatcher ; ngControl : NgControl ; } /**
 * Mixin to augment a directive with updateErrorState method.
 * For component with `errorState` and need to update `errorState`.
 */ export function mixinErrorState < T extends AbstractConstructor < HasErrorState > > ( base ) ; export function mixinErrorState < T extends Constructor < HasErrorState > > ( base ) { return class extends base { /** Whether the component is in an error state. */ errorState : boolean = false ; /**
         * Stream that emits whenever the state of the input changes such that the wrapping
         * `SbbField` needs to run change detection.
         */ readonly stateChanges = new Subject < void > ( ) ; errorStateMatcher : SbbErrorStateMatcher ; updateErrorState ( ) { const oldState = this . errorState ; const parent = this . _parentFormGroup || this . _parentForm ; const matcher = this . errorStateMatcher || this . _defaultErrorStateMatcher ; const control = this . ngControl ? ( this . ngControl . control as FormControl ) : null ; const newState = matcher . isErrorState ( control , parent ) ; if ( newState !== oldState ) { this . errorState = newState ; this . stateChanges . next ( ) ; } } constructor ( ... args ) { super ( ... args ) ; } } ; }