/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
import { coerceCssPixelValue } from '@angular/cdk/coercion';
import { supportsScrollBehavior } from '@angular/cdk/platform';
const scrollBehaviorSupported = supportsScrollBehavior();
/**
 * Strategy that will prevent the user from scrolling while the overlay is visible.
 */
export class BlockScrollStrategy {
    constructor(_viewportRuler, document) {
        this._viewportRuler = _viewportRuler;
        this._previousHTMLStyles = { top: '', left: '' };
        this._isEnabled = false;
        this._document = document;
    }
    /** Attaches this scroll strategy to an overlay. */
    attach() { }
    /** Blocks page-level scroll while the attached overlay is open. */
    enable() {
        if (this._canBeEnabled()) {
            const root = this._document.documentElement;
            this._previousScrollPosition = this._viewportRuler.getViewportScrollPosition();
            // Cache the previous inline styles in case the user had set them.
            this._previousHTMLStyles.left = root.style.left || '';
            this._previousHTMLStyles.top = root.style.top || '';
            // Note: we're using the `html` node, instead of the `body`, because the `body` may
            // have the user agent margin, whereas the `html` is guaranteed not to have one.
            root.style.left = coerceCssPixelValue(-this._previousScrollPosition.left);
            root.style.top = coerceCssPixelValue(-this._previousScrollPosition.top);
            root.classList.add('cdk-global-scrollblock');
            this._isEnabled = true;
        }
    }
    /** Unblocks page-level scroll while the attached overlay is open. */
    disable() {
        if (this._isEnabled) {
            const html = this._document.documentElement;
            const body = this._document.body;
            const htmlStyle = html.style;
            const bodyStyle = body.style;
            const previousHtmlScrollBehavior = htmlStyle.scrollBehavior || '';
            const previousBodyScrollBehavior = bodyStyle.scrollBehavior || '';
            this._isEnabled = false;
            htmlStyle.left = this._previousHTMLStyles.left;
            htmlStyle.top = this._previousHTMLStyles.top;
            html.classList.remove('cdk-global-scrollblock');
            // Disable user-defined smooth scrolling temporarily while we restore the scroll position.
            // See https://developer.mozilla.org/en-US/docs/Web/CSS/scroll-behavior
            // Note that we don't mutate the property if the browser doesn't support `scroll-behavior`,
            // because it can throw off feature detections in `supportsScrollBehavior` which
            // checks for `'scrollBehavior' in documentElement.style`.
            if (scrollBehaviorSupported) {
                htmlStyle.scrollBehavior = bodyStyle.scrollBehavior = 'auto';
            }
            window.scroll(this._previousScrollPosition.left, this._previousScrollPosition.top);
            if (scrollBehaviorSupported) {
                htmlStyle.scrollBehavior = previousHtmlScrollBehavior;
                bodyStyle.scrollBehavior = previousBodyScrollBehavior;
            }
        }
    }
    _canBeEnabled() {
        // Since the scroll strategies can't be singletons, we have to use a global CSS class
        // (`cdk-global-scrollblock`) to make sure that we don't try to disable global
        // scrolling multiple times.
        const html = this._document.documentElement;
        if (html.classList.contains('cdk-global-scrollblock') || this._isEnabled) {
            return false;
        }
        const body = this._document.body;
        const viewport = this._viewportRuler.getViewportSize();
        return body.scrollHeight > viewport.height || body.scrollWidth > viewport.width;
    }
}
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left: number};\n  private _isEnabled = false;\n  private _document: Document;\n\n  constructor(private _viewportRuler: ViewportRuler, document: any) {\n    this._document = document;\n  }\n\n  /** Attaches this scroll strategy to an overlay. */\n  attach() {}\n\n  /** Blocks page-level scroll while the attached overlay is open. */\n  enable() {\n    if (this._canBeEnabled()) {\n      const root = this._document.documentElement!;\n\n      this._previousScrollPosition = this._viewportRuler.getViewportScrollPosition();\n\n      // Cache the previous inline styles in case the user had set them.\n      this._previousHTMLStyles.left = root.style.left || '';\n      this._previousHTMLStyles.top = root.style.top || '';\n\n      // Note: we're using the `html` node, instead of the `body`, because the `body` may\n      // have the user agent margin, whereas the `html` is guaranteed not to have one.\n      root.style.left = coerceCssPixelValue(-this._previousScrollPosition.left);\n      root.style.top = coerceCssPixelValue(-this._previousScrollPosition.top);\n      root.classList.add('cdk-global-scrollblock');\n      this._isEnabled = true;\n    }\n  }\n\n  /** Unblocks page-level scroll while the attached overlay is open. */\n  disable() {\n    if (this._isEnabled) {\n      const html = this._document.documentElement!;\n      const body = this._document.body!;\n      const htmlStyle = html.style;\n      const bodyStyle = body.style;\n      const previousHtmlScrollBehavior = htmlStyle.scrollBehavior || '';\n      const previousBodyScrollBehavior = bodyStyle.scrollBehavior || '';\n\n      this._isEnabled = false;\n\n      htmlStyle.left = this._previousHTMLStyles.left;\n      htmlStyle.top = this._previousHTMLStyles.top;\n      html.classList.remove('cdk-global-scrollblock');\n\n      // Disable user-defined smooth scrolling temporarily while we restore the scroll position.\n      // See https://developer.mozilla.org/en-US/docs/Web/CSS/scroll-behavior\n      // Note that we don't mutate the property if the browser doesn't support `scroll-behavior`,\n      // because it can throw off feature detections in `supportsScrollBehavior` which\n      // checks for `'scrollBehavior' in documentElement.style`.\n      if (scrollBehaviorSupported) {\n        htmlStyle.scrollBehavior = bodyStyle.scrollBehavior = 'auto';\n      }\n\n      window.scroll(this._previousScrollPosition.left, this._previousScrollPosition.top);\n\n      if (scrollBehaviorSupported) {\n        htmlStyle.scrollBehavior = previousHtmlScrollBehavior;\n        bodyStyle.scrollBehavior = previousBodyScrollBehavior;\n      }\n    }\n  }\n\n  private _canBeEnabled(): boolean {\n    // Since the scroll strategies can't be singletons, we have to use a global CSS class\n    // (`cdk-global-scrollblock`) to make sure that we don't try to disable global\n    // scrolling multiple times.\n    const html = this._document.documentElement!;\n\n    if (html.classList.contains('cdk-global-scrollblock') || this._isEnabled) {\n      return false;\n    }\n\n    const body = this._document.body;\n    const viewport = this._viewportRuler.getViewportSize();\n    return body.scrollHeight > viewport.height || body.scrollWidth > viewport.width;\n  }\n}\n"]}