support permalinks to lines in source code view (#1472)

This features adjusts the syntax checker to render a little link icon next to a hovered line. When clicked,
a permanent link to this line is created and copied to the user's clipboard. When visiting the link,
the focused row is highlighted.

Co-authored-by: Eduard Heimbuch <eduard.heimbuch@cloudogu.com>

scm-ui/ui-components/src/CopyToClipboard.ts

@@ -0,0 +1,45 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+export default async function copyToClipboard(text: string) {
+  if (navigator.clipboard) {
+    return navigator.clipboard.writeText(text);
+  } else {
+    const textArea = document.createElement("textarea");
+    textArea.value = text;
+    textArea.style.position = "fixed"; //avoid scrolling to bottom
+    document.body.appendChild(textArea);
+    textArea.focus();
+    textArea.select();
+
+    try {
+      document.execCommand("copy");
+      return Promise.resolve();
+    } catch (e) {
+      return Promise.reject(e);
+    } finally {
+      document.body.removeChild(textArea);
+    }
+  }
+}

scm-ui/ui-components/src/SyntaxHighlighter.stories.tsx

@@ -21,7 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-import React from "react";
+import React, { ReactNode } from "react";
 import { storiesOf } from "@storybook/react";
 import styled from "styled-components";
 import SyntaxHighlighter from "./SyntaxHighlighter";
@@ -31,12 +31,16 @@ import GoHttpServer from "./__resources__/HttpServer.go";
 import JsHttpServer from "./__resources__/HttpServer.js";
 import PyHttpServer from "./__resources__/HttpServer.py";
 import Markdown from "./__resources__/test-page.md";
+import { MemoryRouter } from "react-router-dom";
 
 const Spacing = styled.div`
   padding: 1em;
 `;
 
+const RoutingDecorator = (story: () => ReactNode) => <MemoryRouter initialEntries={["/"]}>{story()}</MemoryRouter>;
+
 storiesOf("SyntaxHighlighter", module)
+  .addDecorator(RoutingDecorator)
   .add("Java", () => (
     <Spacing>
       <SyntaxHighlighter language="java" value={JavaHttpServer} />

scm-ui/ui-components/src/SyntaxHighlighter.tsx

@@ -21,37 +21,68 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-import React from "react";
+import React, { FC, useEffect, useState } from "react";
 
 import { PrismAsyncLight as ReactSyntaxHighlighter } from "react-syntax-highlighter";
 import { defaultLanguage, determineLanguage } from "./languages";
 // eslint-disable-next-line no-restricted-imports
 import highlightingTheme from "./syntax-highlighting";
+import { useLocation } from "react-router-dom";
+import { withContextPath } from "./urls";
+import createSyntaxHighlighterRenderer from "./SyntaxHighlighterRenderer";
+
+const LINE_NUMBER_URL_HASH_REGEX = /^#line-(.*)$/;
 
 type Props = {
   language?: string;
   value: string;
   showLineNumbers?: boolean;
+  permalink?: string;
 };
 
-class SyntaxHighlighter extends React.Component<Props> {
-  static defaultProps: Partial<Props> = {
-    language: defaultLanguage,
-    showLineNumbers: true
-  };
+const SyntaxHighlighter: FC<Props> = ({
+  language = defaultLanguage,
+  showLineNumbers = true,
+  value,
+  permalink
+}) => {
+  const location = useLocation();
+  const [contentRef, setContentRef] = useState<HTMLElement | null>();
 
-  render() {
-    const { showLineNumbers, language } = this.props;
-    return (
+  useEffect(() => {
+    const match = location.hash.match(LINE_NUMBER_URL_HASH_REGEX);
+    if (contentRef && match) {
+      const lineNumber = match[1];
+      // We defer the content check until after the syntax-highlighter has rendered
+      setTimeout(() => {
+        const element = contentRef.querySelector(`#line-${lineNumber}`);
+        if (element && element.scrollIntoView) {
+          element.scrollIntoView();
+        }
+      });
+    }
+  }, [value, contentRef]);
+
+  const createLinePermaLink = (lineNumber: number) =>
+    window.location.protocol +
+    "//" +
+    window.location.host +
+    withContextPath((permalink || location.pathname) + "#line-" + lineNumber);
+
+  const defaultRenderer = createSyntaxHighlighterRenderer(createLinePermaLink, showLineNumbers);
+
+  return (
+    <div ref={setContentRef}>
       <ReactSyntaxHighlighter
-        showLineNumbers={showLineNumbers}
+        showLineNumbers={false}
         language={determineLanguage(language)}
         style={highlightingTheme}
+        renderer={defaultRenderer}
       >
-        {this.props.value}
+        {value}
       </ReactSyntaxHighlighter>
-    );
-  }
-}
+    </div>
+  );
+};
 
 export default SyntaxHighlighter;

scm-ui/ui-components/src/SyntaxHighlighterRenderer.tsx

@@ -0,0 +1,151 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+import React, { FC, useEffect, useState } from "react";
+// eslint-disable-next-line @typescript-eslint/ban-ts-ignore
+// @ts-ignore
+import { createElement } from "react-syntax-highlighter";
+import Icon from "./Icon";
+import Tooltip from "./Tooltip";
+import styled from "styled-components";
+import copyToClipboard from "./CopyToClipboard";
+import { useTranslation } from "react-i18next";
+import { useHistory, useLocation } from "react-router-dom";
+
+const RowContainer = styled.div`
+  .linenumber {
+    display: inline-block;
+    min-width: 3em;
+    padding-right: 1em;
+    text-align: right;
+    user-select: none;
+    color: rgb(154, 154, 154);
+  }
+  span.linenumber:hover {
+    cursor: pointer;
+  }
+  span.linenumber + span > span.linenumber {
+    display: none !important;
+  }
+  &.focused,
+  &.focused > span:last-child {
+    background-color: rgb(229, 245, 252);
+  }
+  i {
+    visibility: hidden;
+  }
+  i:hover {
+    cursor: pointer;
+  }
+  &:hover i {
+    visibility: visible;
+  }
+`;
+
+type CreateLinePermaLinkFn = (lineNumber: number) => string;
+
+type Props = {
+  rows: React.ReactNode[];
+  stylesheet: any;
+  useInlineStyles: boolean;
+  createLinePermaLink: CreateLinePermaLinkFn;
+  showLineNumbers: boolean;
+};
+
+const SyntaxHighlighterRenderer: FC<Props> = ({
+  rows,
+  stylesheet,
+  useInlineStyles,
+  createLinePermaLink,
+  showLineNumbers = true
+}) => {
+  const location = useLocation();
+  const history = useHistory();
+  const [focusedLine, setLineToFocus] = useState<number | undefined>(undefined);
+  const [copying, setCopying] = useState(false);
+  const [t] = useTranslation("repos");
+
+  useEffect(() => {
+    const match = location.hash.match(/^#line-(.*)$/);
+    if (match) {
+      const lineNumber = match[1];
+      setLineToFocus(Number(lineNumber));
+    }
+  }, [location.hash]);
+
+  const lineNumberClick = (lineNumber: number) => {
+    history.push(location.pathname + "#line-" + lineNumber);
+    setCopying(true);
+    copyToClipboard(createLinePermaLink(lineNumber)).finally(() => setCopying(false));
+  };
+
+  return (
+    <>
+      {rows.map((node: React.ReactNode, i: number) => {
+        const lineNumber = i + 1;
+        const line = createElement({
+          node,
+          stylesheet,
+          useInlineStyles,
+          key: `code-segment${i}`
+        });
+        return (
+          <RowContainer
+            id={`line-${lineNumber}`}
+            className={(focusedLine === lineNumber && "focused") || undefined}
+            key={`line-${lineNumber}`}
+          >
+            {showLineNumbers && (
+              <>
+                {copying ? (
+                  <Icon name="spinner" />
+                ) : (
+                  <Tooltip message={t("sources.content.copyPermalink")}>
+                    <Icon name="link" onClick={() => lineNumberClick(lineNumber)} />
+                  </Tooltip>
+                )}
+                <span
+                  onClick={() => history.push(location.pathname + "#line-" + lineNumber)}
+                  className="linenumber react-syntax-highlighter-line-number"
+                >
+                  {lineNumber}
+                </span>
+              </>
+            )}
+            {line}
+          </RowContainer>
+        );
+      })}
+    </>
+  );
+};
+
+//
+export const create = (createLinePermaLink: CreateLinePermaLinkFn, showLineNumbers = false): FC<Props> => {
+  return props => (
+    <SyntaxHighlighterRenderer {...props} createLinePermaLink={createLinePermaLink} showLineNumbers={showLineNumbers} />
+  );
+};
+
+export default create;