gecko-dev/toolkit/actors/ThumbnailsChild.sys.mjs

/* vim: set ts=2 sw=2 sts=2 et tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

const lazy = {};

ChromeUtils.defineESModuleGetters(lazy, {
  PageThumbUtils: "resource://gre/modules/PageThumbUtils.sys.mjs",
});

export class ThumbnailsChild extends JSWindowActorChild {
  receiveMessage(message) {
    switch (message.name) {
      case "Browser:Thumbnail:ContentInfo": {
        let [width, height] = lazy.PageThumbUtils.getContentSize(
          this.contentWindow
        );
        let documentElement = this.document.documentElement;
        let body = this.document.body;
        return {
          width,
          height,
          scrollY: this.contentWindow.scrollY,
          documentHeight: Math.max(
            documentElement.clientHeight,
            documentElement.scrollHeight,
            documentElement.offsetHeight,
            body.clientHeight,
            body.scrollHeight,
            body.offsetHeight
          ),
        };
      }
      case "Browser:Thumbnail:CheckState": {
        /**
         * Remote isSafeForCapture request handler for PageThumbs.
         */
        return new Promise(resolve =>
          Services.tm.idleDispatchToMainThread(() => {
            if (!this.manager) {
              // If we have no manager, our actor has been destroyed, which
              // means we can't respond, and trying to touch
              // `this.contentWindow` or `this.browsingContext` will throw.
              // The `sendQuery` call in the parent will already have been
              // rejected when the actor was destroyed, so there's no need to
              // reject our promise or log an additional error.
              return;
            }

            let result = lazy.PageThumbUtils.shouldStoreContentThumbnail(
              this.contentWindow,
              this.browsingContext.docShell
            );
            resolve(result);
          })
        );
      }
      case "Browser:Thumbnail:GetOriginalURL": {
        /**
         * Remote GetOriginalURL request handler for PageThumbs.
         */
        let channel = this.browsingContext.docShell.currentDocumentChannel;
        let channelError = lazy.PageThumbUtils.isChannelErrorResponse(channel);
        let originalURL;
        try {
          originalURL = channel.originalURI.spec;
        } catch (ex) {}
        return { channelError, originalURL };
      }
    }
    return undefined;
  }
}