import { DoCheck, OnDestroy, ElementRef, IterableDiffers, KeyValueDiffers, Renderer } from 'angular2/core';
/**
 * The `NgClass` directive conditionally adds and removes CSS classes on an HTML element based on
 * an expression's evaluation result.
 *
 * The result of an expression evaluation is interpreted differently depending on type of
 * the expression evaluation result:
 * - `string` - all the CSS classes listed in a string (space delimited) are added
 * - `Array` - all the CSS classes (Array elements) are added
 * - `Object` - each key corresponds to a CSS class name while values are interpreted as expressions
 * evaluating to `Boolean`. If a given expression evaluates to `true` a corresponding CSS class
 * is added - otherwise it is removed.
 *
 * While the `NgClass` directive can interpret expressions evaluating to `string`, `Array`
 * or `Object`, the `Object`-based version is the most often used and has an advantage of keeping
 * all the CSS class names in a template.
 *
 * ### Example ([live demo](http://plnkr.co/edit/a4YdtmWywhJ33uqfpPPn?p=preview)):
 *
 * ```
 * import {Component} from 'angular2/core';
 * import {NgClass} from 'angular2/common';
 *
 * @Component({
 *   selector: 'toggle-button',
 *   inputs: ['isDisabled'],
 *   template: `
 *      <div class="button" [ngClass]="{active: isOn, disabled: isDisabled}"
 *          (click)="toggle(!isOn)">
 *          Click me!
 *      </div>`,
 *   styles: [`
 *     .button {
 *       width: 120px;
 *       border: medium solid black;
 *     }
 *
 *     .active {
 *       background-color: red;
 *    }
 *
 *     .disabled {
 *       color: gray;
 *       border: medium solid gray;
 *     }
 *   `]
 *   directives: [NgClass]
 * })
 * class ToggleButton {
 *   isOn = false;
 *   isDisabled = false;
 *
 *   toggle(newState) {
 *     if (!this.isDisabled) {
 *       this.isOn = newState;
 *     }
 *   }
 * }
 * ```
 */
export declare class NgClass implements DoCheck, OnDestroy {
    private _iterableDiffers;
    private _keyValueDiffers;
    private _ngEl;
    private _renderer;
    private _differ;
    private _mode;
    private _initialClasses;
    private _rawClass;
    constructor(_iterableDiffers: IterableDiffers, _keyValueDiffers: KeyValueDiffers, _ngEl: ElementRef, _renderer: Renderer);
    initialClasses: any;
    rawClass: any;
    ngDoCheck(): void;
    ngOnDestroy(): void;
    private _cleanupClasses(rawClassVal);
    private _applyKeyValueChanges(changes);
    private _applyIterableChanges(changes);
    private _applyInitialClasses(isCleanup);
    private _applyClasses(rawClassVal, isCleanup);
    private _toggleClass(className, enabled);
}