import type { ManifestBase } from '../types/index.js';
import type { UmbExtensionRegistry } from '../registry/extension.registry.js';
import type { SpecificManifestTypeOrManifestBase } from '../types/map.types.js';
import { UmbControllerBase } from '../../class-api/index.js';
import type { UmbElement } from '../../element-api/index.js';
import { type Observable } from '../../../external/rxjs/index.js';
/**
 * Base class for extension initializers, which are responsible for loading and unloading extensions.
 */
export declare abstract class UmbExtensionInitializerBase<Key extends string, T extends ManifestBase = SpecificManifestTypeOrManifestBase<UmbExtensionManifest, Key>> extends UmbControllerBase {
    #private;
    protected host: UmbElement;
    protected extensionRegistry: UmbExtensionRegistry<T>;
    loaded: Observable<boolean | undefined>;
    /**
     * @param {UmbElement} host The host element to attach the initializer to.
     * @param {UmbExtensionRegistry<T>} extensionRegistry The extension registry to observe.
     * @param {Key} manifestType The manifest type to initialize extensions for.
     * @param {Observable<boolean>} [activeGate] An optional observable that gates instantiation. While it emits `false` the
     * observed set is treated as empty, so all extensions of the type unload; when it emits `true`
     * they instantiate. Lets a subclass defer extensions until some external state is ready (e.g. an
     * authorized user) and tear them down again when it is lost. Omit for the default always-on behaviour.
     */
    constructor(host: UmbElement, extensionRegistry: UmbExtensionRegistry<T>, manifestType: Key, activeGate?: Observable<boolean>);
    /**
     * Perform any logic required to instantiate the extension.
     */
    abstract instantiateExtension(manifest: T): Promise<void> | void;
    /**
     * Perform any logic required to unload the extension.
     */
    abstract unloadExtension(manifest: T): Promise<void> | void;
}