import type { IWebXRFeature } from "../webXRFeaturesManager";
import type { EventState } from "../../Misc/observable";
import { Observable } from "../../Misc/observable";
import type { WebXRSessionManager } from "../webXRSessionManager";
/**
 * This is the base class for all WebXR features.
 * Since most features require almost the same resources and callbacks, this class can be used to simplify the development
 * Note that since the features manager is using the `IWebXRFeature` you are in no way obligated to use this class
 */
export declare abstract class WebXRAbstractFeature implements IWebXRFeature {
    protected _xrSessionManager: WebXRSessionManager;
    private _attached;
    private _removeOnDetach;
    /**
     * Is this feature disposed?
     */
    isDisposed: boolean;
    /**
     * Should auto-attach be disabled?
     */
    disableAutoAttach: boolean;
    protected _xrNativeFeatureName: string;
    /**
     * The name of the native xr feature name (like anchor, hit-test, or hand-tracking)
     */
    get xrNativeFeatureName(): string;
    set xrNativeFeatureName(name: string);
    /**
     * Observers registered here will be executed when the feature is attached
     */
    onFeatureAttachObservable: Observable<IWebXRFeature>;
    /**
     * Observers registered here will be executed when the feature is detached
     */
    onFeatureDetachObservable: Observable<IWebXRFeature>;
    /**
     * The dependencies of this feature, if any
     */
    dependsOn?: string[];
    /**
     * Construct a new (abstract) WebXR feature
     * @param _xrSessionManager the xr session manager for this feature
     */
    constructor(_xrSessionManager: WebXRSessionManager);
    /**
     * Is this feature attached
     */
    get attached(): boolean;
    /**
     * attach this feature
     *
     * @param force should attachment be forced (even when already attached)
     * @returns true if successful, false is failed or already attached
     */
    attach(force?: boolean): boolean;
    /**
     * detach this feature.
     *
     * @returns true if successful, false if failed or already detached
     */
    detach(): boolean;
    /**
     * Dispose this feature and all of the resources attached
     */
    dispose(): void;
    /**
     * This function will be executed during before enabling the feature and can be used to not-allow enabling it.
     * Note that at this point the session has NOT started, so this is purely checking if the browser supports it
     *
     * @returns whether or not the feature is compatible in this environment
     */
    isCompatible(): boolean;
    /**
     * This is used to register callbacks that will automatically be removed when detach is called.
     * @param observable the observable to which the observer will be attached
     * @param callback the callback to register
     * @param insertFirst should the callback be executed as soon as it is registered
     */
    protected _addNewAttachObserver<T>(observable: Observable<T>, callback: (eventData: T, eventState: EventState) => void, insertFirst?: boolean): void;
    /**
     * Code in this function will be executed on each xrFrame received from the browser.
     * This function will not execute after the feature is detached.
     * @param _xrFrame the current frame
     */
    protected abstract _onXRFrame(_xrFrame: XRFrame): void;
}