src/cobalt/debug/remote/devtools/front_end/source_frame/PreviewFactory.js

// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

export class PreviewFactory {
  /**
   * @param {!Common.ContentProvider} provider
   * @param {string} mimeType
   * @returns {!Promise<?UI.Widget>}
   */
  static async createPreview(provider, mimeType) {
    let resourceType = Common.ResourceType.fromMimeType(mimeType);
    if (resourceType === Common.resourceTypes.Other) {
      resourceType = provider.contentType();
    }

    switch (resourceType) {
      case Common.resourceTypes.Image:
        return new SourceFrame.ImageView(mimeType, provider);
      case Common.resourceTypes.Font:
        return new SourceFrame.FontView(mimeType, provider);
    }

    const deferredContent = await provider.requestContent();
    if (deferredContent.error) {
      return new UI.EmptyWidget(deferredContent.error);
    } else if (!deferredContent.content) {
      return new UI.EmptyWidget(Common.UIString('Nothing to preview'));
    }

    let content = deferredContent.content;
    if (await provider.contentEncoded()) {
      content = window.atob(content);
    }

    const parsedXML = SourceFrame.XMLView.parseXML(content, mimeType);
    if (parsedXML) {
      return SourceFrame.XMLView.createSearchableView(parsedXML);
    }

    const jsonView = await SourceFrame.JSONView.createView(content);
    if (jsonView) {
      return jsonView;
    }

    if (resourceType.isTextType()) {
      const highlighterType =
          provider.contentType().canonicalMimeType() || mimeType.replace(/;.*/, '');  // remove charset
      return SourceFrame.ResourceSourceFrame.createSearchableView(
          provider, highlighterType, true /* autoPrettyPrint */);
    }

    return null;
  }
}

/* Legacy exported object */
self.SourceFrame = self.SourceFrame || {};

/* Legacy exported object */
SourceFrame = SourceFrame || {};

/** @constructor */
SourceFrame.PreviewFactory = PreviewFactory;