import { AfterContentChecked, AfterContentInit, ChangeDetectorRef, EventEmitter, OnChanges, OnDestroy, QueryList, SimpleChanges } from '@angular/core';
import { Subject } from 'rxjs';
import { Bem } from '../utils/bem';
import { TabHeaderAddonDirective } from './tab-directives';
import { TabHeaderComponent } from './tab-header.component';
import { TabComponent } from './tab.component';
import { TabSize, TabType } from './tabs.types';
/** A simple change event emitted on focus or selection changes. */
export declare class TabChangeEvent {
    /** Index of the currently-selected tab. */
    index: number;
    /** Reference to the currently-selected tab. */
    tab: TabComponent;
}
export declare class TabGroupComponent implements OnChanges, AfterContentChecked, AfterContentInit, OnDestroy {
    private _changeDetectorRef;
    bem: Bem;
    _tabs: QueryList<TabComponent>;
    _headerAddon: TabHeaderAddonDirective;
    _tabHeader: TabHeaderComponent;
    /** The tab index that should be selected after the content has been checked. */
    private _indexToSelect;
    /** Subscription to tabs being added/removed. */
    private _tabsSubscription;
    /** Subscription to changes in the tab labels. */
    private _tabLabelSubscription;
    private _type;
    private _size;
    private _previousHeaderAddon;
    /** Emits whenever the type changes */
    readonly _typeChange: Subject<void>;
    /** Emits whenever the size changes */
    readonly _sizeChange: Subject<void>;
    /** Emits whenever the size changes */
    readonly _addonChange: Subject<void>;
    /** The index of the active tab. */
    selectedIndex: number | null;
    private _selectedIndex;
    type: TabType;
    size: TabSize;
    /** Output to enable support for two-way binding on `[(selectedIndex)]` */
    readonly selectedIndexChange: EventEmitter<number>;
    /** Event emitted when the tab selection has changed. */
    readonly selectedTabChange: EventEmitter<TabChangeEvent>;
    /** Event emitted when focus has changed within a tab group. */
    readonly focusChange: EventEmitter<TabChangeEvent>;
    constructor(_changeDetectorRef: ChangeDetectorRef);
    readonly activeTab: TabComponent;
    ngOnChanges(changes: SimpleChanges): void;
    /**
     * After the content is checked, this component knows what tabs have been defined
     * and what the selected index should be. This is where we can know exactly what position
     * each tab should be in according to the new selected index.
     */
    ngAfterContentChecked(): void;
    ngAfterContentInit(): void;
    ngOnDestroy(): void;
    /** Handle click events, setting new selected index if appropriate. */
    _handleClick(tab: TabComponent, idx: number): void;
    _focusChanged(index: number): void;
    /** Re-aligns the ink bar to the selected tab element. */
    realignActiveIndicator(): void;
    /** Clamps the given index to the bounds of 0 and the tabs length. */
    private _clampTabIndex;
    private _createChangeEvent;
    /**
     * Subscribes to changes in the tab labels. This is needed, because the @Input for the label is
     * on the Tab component, whereas the data binding is inside the TabGroup. In order for the
     * binding to be updated, we need to subscribe to changes in it and trigger change detection
     * manually.
     */
    private _subscribeToTabLabels;
    /** Retrieves the tabindex for the tab. */
    _getTabIndex(tab: TabComponent, idx: number): number | null;
}