import { Optional } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { SafeResourceUrl, DomSanitizer } from '@angular/platform-browser';
import { Observable } from 'rxjs/Observable';
export declare class GhIconRegistry {
    private _httpClient;
    private _sanitizer;
    private _document;
    /**
     * URLs and cached SVG elements for individual icons.
     * Keys are of the format "[namespace]:[icon]".
     */
    private _svgIconConfigs;
    /** In-progress icon fetches. Used to coalesce multiple requests to the same URL. */
    private _inProgressUrlFetches;
    /** Cache for icons loaded by direct URLs. */
    private _cachedIconsByUrl;
    constructor(_httpClient: HttpClient, _sanitizer: DomSanitizer, _document?: any);
    /**
     * Registers an icon by URL in the default namespace.
     * @param iconName Name under which the icon should be registered.
     * @param url
     */
    addSvgIcon(iconName: string, url: SafeResourceUrl): this;
    /**
     * Registers an icon by URL in the specified namespace.
     * @param namespace Namespace in which the icon should be registered.
     * @param iconName Name under which the icon should be registered.
     * @param url
     */
    addSvgIconInNamespace(namespace: string, iconName: string, url: SafeResourceUrl): this;
    /**
     * Returns an Observable that produces the icon (as an `<svg>` DOM element) with the given name
     * and namespace. The icon must have been previously registered with addIcon or addIconSet;
     * if not, the Observable will throw an error.
     * @param name Name of the icon to be retrieved.
     * @param namespace Namespace in which to look for the icon.
     */
    getNamedSvgIcon(name: string, namespace?: string): Observable<SVGElement>;
    /**
     * Returns an Observable that produces the icon (as an `<svg>` DOM element) from the given URL.
     * The response from the URL may be cached so this will not always cause an HTTP request, but
     * the produced element will always be a new copy of the originally fetched icon. (That is,
     * it will not contain any modifications made to elements previously returned).
     * @param safeUrl URL from which to fetch the SVG icon.
     */
    getSvgIconFromUrl(safeUrl: SafeResourceUrl): Observable<SVGElement>;
    /**
     * Loads the content of the icon URL specified in the SvgIconConfig and creates an SVG element
     * from it.
     */
    private _loadSvgIconFromConfig(config);
    /**
     * Returns the cached icon for a SvgIconConfig if available, or fetches it from its URL if not.
     */
    private _getSvgIconFromConfig(config);
    /** Creates a DOM element from the given SVG string, and adds default attributes. */
    private _createSvgElementForSingleIcon(responseText);
    /** Sets the default attributes for an SVG element to be used as an icon. */
    private _setSvgAttributes(svg);
    /** Creates a DOM element from the given SVG string. */
    private _svgElementFromString(str);
    /**
     * Returns an Observable which produces the string contents of the given URL. Results may be
     * cached, so future calls with the same URL may not cause another HTTP request.
     */
    private _fetchUrl(safeUrl);
}
export declare function ICON_REGISTRY_PROVIDER_FACTORY(parent: GhIconRegistry, httpClient: HttpClient, sanitizer: DomSanitizer, document?: any): GhIconRegistry;
export declare const ICON_REGISTRY_PROVIDER: {
    provide: typeof GhIconRegistry;
    deps: (Optional[] | typeof DomSanitizer)[];
    useFactory: (parent: GhIconRegistry, httpClient: HttpClient, sanitizer: DomSanitizer, document?: any) => GhIconRegistry;
};