import { ElementRef, ChangeDetectorRef, QueryList, OnInit, OnChanges, DoCheck, OnDestroy, AfterContentInit, NgZone, EventEmitter, SimpleChanges } from '@angular/core';
import { SelectionModel } from '@angular/cdk/collections';
import { ActiveDescendantKeyManager } from '@angular/cdk/a11y';
import { Overlay, RepositionScrollStrategy, CdkConnectedOverlay } from '@angular/cdk/overlay';
import { ControlValueAccessor, FormGroupDirective, NgControl, NgForm } from '@angular/forms';
import { Observable } from 'rxjs/Observable';
import { CanDisable, HasTabIndex, ErrorStateMatcher, CanUpdateErrorState } from '@dynatrace/ngx-groundhog/core';
import { GhFormFieldControl } from '@dynatrace/ngx-groundhog/form-field';
import { GhOption, GhOptionSelectionChange } from './option';
/** The height of the select items. */
export declare const SELECT_ITEM_HEIGHT = 32;
/**
 * The maximum count of items that should be visible in the panel at once.
 * To indicate that the panel can be scrolled, show half of the next item
 */
export declare const SELECT_MAX_ITEMS_VISIBLE = 7.5;
/** Change event object that is emitted when the select value has changed. */
export interface GhSelectChange {
    /** Reference to the select that emitted the change event. */
    source: GhSelect;
    /** Current value of the select that emitted the event. */
    value: any;
}
export declare class GhSelectBase {
    _elementRef: ElementRef;
    _defaultErrorStateMatcher: ErrorStateMatcher;
    _parentForm: NgForm;
    _parentFormGroup: FormGroupDirective;
    ngControl: NgControl;
    constructor(_elementRef: ElementRef, _defaultErrorStateMatcher: ErrorStateMatcher, _parentForm: NgForm, _parentFormGroup: FormGroupDirective, ngControl: NgControl);
}
export declare const _GhSelectMixinBase: (new (...args: any[]) => HasTabIndex) & (new (...args: any[]) => CanDisable) & (new (...args: any[]) => CanUpdateErrorState) & typeof GhSelectBase;
export declare class GhSelect extends _GhSelectMixinBase implements OnInit, OnChanges, OnDestroy, DoCheck, AfterContentInit, CanDisable, HasTabIndex, ControlValueAccessor, CanUpdateErrorState, GhFormFieldControl<any> {
    private _changeDetectorRef;
    private _ngZone;
    ngControl: NgControl;
    private _overlay;
    /** The placeholder displayed in the trigger of the select. */
    private _placeholder;
    /** Whether or not the overlay panel is open. */
    private _panelOpen;
    /** Whether filling out the select is required in the form. */
    private _required;
    /** Unique id for this input. */
    private _uid;
    /** _uid or provided id via input */
    private _id;
    /** Current value of the select */
    private _value;
    /** Emits whenever the component is destroyed. */
    private _destroy;
    /** Comparison function to specify which option is displayed. Defaults to object equality. */
    private _compareWith;
    /** The scroll position of the overlay panel, calculated to center the selected option. */
    private _scrollTop;
    /** Last emitted position of the overlay */
    private _connectionPair;
    /** Deals with the selection logic. */
    _selectionModel: SelectionModel<GhOption>;
    /** The IDs of child options to be passed to the aria-owns attribute. */
    _optionIds: string;
    /** The aria-describedby attribute on the select for improved a11y. */
    _ariaDescribedby: string;
    /** Whether the select is focused. */
    focused: boolean;
    /** Manages keyboard events for options in the panel. */
    _keyManager: ActiveDescendantKeyManager<GhOption>;
    /** `View -> model callback called when value changes` */
    _onChange: (value: any) => void;
    /** `View -> model callback called when select has been touched` */
    _onTouched: () => void;
    /** The last measured value for the trigger's client bounding rect. */
    _triggerRect: ClientRect;
    /** Whether the panel's animation is done. */
    _panelDoneAnimating: boolean;
    /** The max height of the select's overlay panel */
    _maxPanelHeight: number;
    /** Strategy that will be used to handle scrolling while the select panel is open. */
    _scrollStrategy: RepositionScrollStrategy;
    _positions: {
        originX: string;
        originY: string;
        overlayX: string;
        overlayY: string;
    }[];
    /** Classes to be passed to the select panel. Supports the same syntax as `ngClass`. */
    panelClass: string | Set<string> | string[] | {
        [key: string]: any;
    };
    /** Placeholder to be shown if no value has been selected. */
    placeholder: string;
    /** Value of the select. */
    value: any;
    /** Unique id of the element. */
    id: string;
    /** Whether the component is required. */
    required: boolean;
    /**
     * A function to compare the option values with the selected values. The first argument
     * is a value from an option. The second is a value from the selection. A boolean
     * should be returned.
     */
    compareWith: (o1: any, o2: any) => boolean;
    /** Aria label of the select. If not specified, the placeholder will be used as label. */
    ariaLabel: string;
    /** Input that can be used to specify the `aria-labelledby` attribute. */
    ariaLabelledby: string;
    /** An object used to control when error messages are shown. */
    errorStateMatcher: ErrorStateMatcher;
    /** Event emitted when the select has been opened. */
    readonly openedChange: EventEmitter<boolean>;
    /** Event emitted when the selected value has been changed by the user. */
    readonly selectionChange: EventEmitter<GhSelectChange>;
    /**
     * Event that emits whenever the raw value of the select changes. This is here primarily
     * to facilitate the two-way binding for the `value` input.
     */
    readonly valueChange: EventEmitter<any>;
    /** The currently selected option. */
    readonly selected: GhOption;
    /** Whether the select has a value. */
    readonly empty: boolean;
    /** The value displayed in the trigger. */
    readonly triggerValue: string;
    /** Whether or not the overlay panel is open. */
    readonly panelOpen: boolean;
    /** Returns the aria-label of the select component. */
    readonly _ariaLabel: string | null;
    /** Determines the `aria-activedescendant` to be set on the host. */
    _getAriaActiveDescendant(): string | null;
    /** Panel containing the select options. */
    panel: ElementRef;
    /** Overlay pane containing the options. */
    overlayDir: CdkConnectedOverlay;
    /** Trigger that opens the select. */
    trigger: ElementRef;
    /** All of the defined select options. */
    options: QueryList<GhOption>;
    /** Combined stream of all of the child options' change events. */
    optionSelectionChanges: Observable<GhOptionSelectionChange>;
    constructor(_changeDetectorRef: ChangeDetectorRef, _ngZone: NgZone, _elementRef: ElementRef, _defaultErrorStateMatcher: ErrorStateMatcher, _parentForm: NgForm, _parentFormGroup: FormGroupDirective, ngControl: NgControl, tabIndex: string, _overlay: Overlay);
    /**
     * Hook that triggers after the component has been initialized
     * and the first change detection has run.
     */
    ngOnInit(): void;
    /** Hook that triggers when ng-content and all sub components (the options) are initialized. */
    ngAfterContentInit(): void;
    ngDoCheck(): void;
    ngOnChanges(changes: SimpleChanges): void;
    /** Hook that trigger right before the component will be destroyed. */
    ngOnDestroy(): void;
    /** Opens the panel */
    open(): void;
    /** Closes the panel */
    close(): void;
    /** Toggles the panel */
    toggle(): void;
    /** Focuses the select element. */
    focus(): void;
    /**
     * Sets the select's value. Part of the ControlValueAccessor interface
     * required to integrate with Angular's core forms API.
     */
    writeValue(value: any): void;
    /**
     * Saves a callback function to be invoked when the select's value
     * changes from user input. Part of the ControlValueAccessor interface
     * required to integrate with Angular's core forms API.
     * @param fn Callback to be triggered when the value changes.
     */
    registerOnChange(fn: (value: any) => void): void;
    /**
     * Saves a callback function to be invoked when the select is blurred
     * by the user. Part of the ControlValueAccessor interface required
     * to integrate with Angular's core forms API.
     * @param fn Callback to be triggered when the component has been touched.
     */
    registerOnTouched(fn: () => {}): void;
    /**
     * Disables the select. Part of the ControlValueAccessor interface required
     * to integrate with Angular's core forms API.
     * @param isDisabled Sets whether the component is disabled.
     */
    setDisabledState(isDisabled: boolean): void;
    /** Implemented as part of GhFormFieldControl. */
    setDescribedByIds(ids: string[]): void;
    /** Implemented as part of GhFormFieldControl. */
    onContainerClick(): void;
    /** Drops current option subscriptions and resets from scratch. */
    _resetOptions(): void;
    /** Handles all keydown events on the select. */
    _handleKeydown(event: KeyboardEvent): void;
    /** Handles keyboard events while the select is closed. */
    private _handleClosedKeydown(event);
    /** Handles keyboard events when the selected is open. */
    private _handleOpenKeydown(event);
    /** Invoked when the control gains focus. */
    _onFocus(): void;
    /** Invoked when the control looses focus. */
    _onBlur(): void;
    /** Callback that is invoked when the overlay panel has been attached. */
    _onAttached(): void;
    /**
     * When the panel element is finished transforming in (though not fading in), it
     * emits an event and focuses an option if the panel is open.
     */
    _onPanelDone(): void;
    /**
     * When the panel content is done fading in, the _panelDoneAnimating property is
     * set so the proper class can be added to the panel.
     */
    _onFadeInDone(): void;
    private _initializeSelection();
    /**
     * Highlights the selected item. If no option is selected, it will highlight
     * the first item instead.
     */
    private _highlightCorrectOption();
    /** Gets the index of the provided option in the option list. */
    private _getOptionIndex(option);
    /**
     * Calculates the scroll position of the select's overlay panel.
     * Attempts to center the selected option in the panel. If the option is
     * too high or too low in the panel to be scrolled to the center, it clamps the
     * scroll position to the min or max scroll positions respectively.
     */
    private _calculateOverlayScroll();
    /** Scrolls the active option into view. */
    private _scrollActiveOptionIntoView();
    /** Invoked when an option is clicked. */
    private _onSelect(option);
    /** Clears the select trigger and deselects every option in the list. */
    private _clearSelection(skip?);
    /**
     * Sets the selected option based on a value. If no option can be
     * found with the designated value, the select trigger is cleared.
     */
    private _setSelectionByValue(value, isUserInput?);
    /**
     * Finds and selects and option based on its value.
     * @returns Option that has the corresponding value.
     */
    private _selectValue(value, isUserInput?);
    /** Sets up a key manager to listen to keyboard events on the overlay panel. */
    private _initKeyManager();
    /** Emits change event to set the model value. */
    private _propagateChanges(fallbackValue?);
    /** Records option IDs to pass to the aria-owns property. */
    private _setOptionIds();
    private _updatePanelMaxHeight();
}