1 files changed, 135 insertions, 0 deletions
diff --git a/devtools/client/netmonitor/src/components/previews/FontPreview.js b/devtools/client/netmonitor/src/components/previews/FontPreview.js
new file mode 100644
index 0000000000..2692fdefa0
--- /dev/null
+++ b/devtools/client/netmonitor/src/components/previews/FontPreview.js
@@ -0,0 +1,135 @@
+/* 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/. */
+
+"use strict";
+const {
+  gDevTools,
+} = require("resource://devtools/client/framework/devtools.js");
+const {
+  Component,
+} = require("resource://devtools/client/shared/vendor/react.js");
+const PropTypes = require("resource://devtools/client/shared/vendor/react-prop-types.js");
+const {
+  L10N,
+} = require("resource://devtools/client/netmonitor/src/utils/l10n.js");
+
+const {
+  div,
+  img,
+} = require("resource://devtools/client/shared/vendor/react-dom-factories.js");
+
+const { getColor } = require("resource://devtools/client/shared/theme.js");
+
+const FONT_NAME = L10N.getStr("netmonitor.response.name");
+const FONT_MIME_TYPE = L10N.getStr("netmonitor.response.mime");
+const FONT_PREVIEW_FAILED = L10N.getStr(
+  "netmonitor.response.fontPreviewFailed"
+);
+
+const FONT_PREVIEW_TEXT =
+  "ABCDEFGHIJKLM\nNOPQRSTUVWXYZ\nabcdefghijklm\nnopqrstuvwxyz\n0123456789";
+
+class FontPreview extends Component {
+  static get propTypes() {
+    return {
+      connector: PropTypes.object.isRequired,
+      mimeType: PropTypes.string,
+      url: PropTypes.string,
+    };
+  }
+
+  constructor(props) {
+    super(props);
+
+    this.state = {
+      name: "",
+      dataURL: "",
+    };
+
+    this.onThemeChanged = this.onThemeChanged.bind(this);
+  }
+
+  componentDidMount() {
+    this.getPreview();
+
+    // Listen for theme changes as the color of the preview depends on the theme
+    gDevTools.on("theme-switched", this.onThemeChanged);
+  }
+
+  componentDidUpdate(prevProps) {
+    const { url } = this.props;
+    if (prevProps.url !== url) {
+      this.getPreview();
+    }
+  }
+
+  componentWillUnmount() {
+    gDevTools.off("theme-switched", this.onThemeChanged);
+  }
+
+  /**
+   * Handler for the "theme-switched" event.
+   */
+  onThemeChanged(frame) {
+    if (frame === window) {
+      this.getPreview();
+    }
+  }
+
+  /**
+   * Generate the font preview and receives information about the font.
+   */
+  async getPreview() {
+    const { connector } = this.props;
+
+    const toolbox = connector.getToolbox();
+    const inspectorFront = await toolbox.target.getFront("inspector");
+    const { pageStyle } = inspectorFront;
+    const pageFontFaces = await pageStyle.getAllUsedFontFaces({
+      includePreviews: true,
+      includeVariations: false,
+      previewText: FONT_PREVIEW_TEXT,
+      previewFillStyle: getColor("body-color"),
+    });
+
+    const fontFace = pageFontFaces.find(
+      pageFontFace => pageFontFace.URI === this.props.url
+    );
+
+    this.setState({
+      name: fontFace?.name ?? "",
+      dataURL: (await fontFace?.preview.data.string()) ?? "",
+    });
+  }
+
+  render() {
+    const { mimeType } = this.props;
+    const { name, dataURL } = this.state;
+
+    if (dataURL === "") {
+      return div({ className: "empty-notice" }, FONT_PREVIEW_FAILED);
+    }
+
+    return div(
+      { className: "panel-container response-font-box devtools-monospace" },
+      img({
+        className: "response-font",
+        src: dataURL,
+        alt: "",
+      }),
+      div(
+        { className: "response-summary" },
+        div({ className: "tabpanel-summary-label" }, FONT_NAME),
+        div({ className: "tabpanel-summary-value" }, name)
+      ),
+      div(
+        { className: "response-summary" },
+        div({ className: "tabpanel-summary-label" }, FONT_MIME_TYPE),
+        div({ className: "tabpanel-summary-value" }, mimeType)
+      )
+    );
+  }
+}
+
+module.exports = FontPreview;