Add custom intro page by fetching markdown content from a file (#697)

Signed-off-by: Tilman Vatteroth <tilman.vatteroth@tu-dortmund.de>

.reuse/dep5

@@ -27,6 +27,10 @@ Files: public/index.html
 Copyright: 2021 The HedgeDoc developers (see AUTHORS file)
 License: CC0-1.0
 
+Files: public/intro.md
+Copyright: 2021 The HedgeDoc developers (see AUTHORS file)
+License: CC0-1.0
+
 Files: public/robots.txt
 Copyright: 2021 The HedgeDoc developers (see AUTHORS file)
 License: CC0-1.0

CHANGELOG.md

@@ -69,6 +69,7 @@ SPDX-License-Identifier: CC-BY-SA-4.0
 - Surround selected text with a link via shortcut (ctrl+k or cmd+k).
 - A sidebar for menu options
 - Improved security by wrapping the markdown rendering into an iframe
+- The intro page content can be changed by editing `public/intro.md`
 
 ### Changed
 

cypress/integration/intro.spec.ts

@@ -5,50 +5,58 @@
  */
 
 /* eslint-disable @typescript-eslint/no-unsafe-call */
-describe('Intro', () => {
+describe('Intro page', () => {
   beforeEach(() => {
+    cy.intercept('/intro.md', 'test content')
     cy.visit('/')
   })
 
-  describe('Cover Button are hidden when logged in', () => {
-    it('Sign in Cover Button', () => {
-      cy.get('.cover-button.btn-success')
-        .should('not.exist')
-    })
-
-    it('Features Cover Button', () => {
-      cy.get('.cover-button.btn-primary')
-        .should('not.exist')
+  describe('content', () => {
+    it('fetches and shows the correct intro page content', () => {
+      cy.getMarkdownBody()
+        .contains('test content')
     })
   })
 
-  describe('Cover Button are shown when logged out', () => {
-    beforeEach(() => {
+  describe('features button', () => {
+    it('is hidden when logged in', () => {
+      cy.get('[data-cy="features-button"]')
+        .should('not.exist')
+    })
+
+    it('is visible when logged out', () => {
       cy.logout()
-    })
-
-    it('Sign in Cover Button', () => {
-      cy.get('.cover-button.btn-success')
-        .should('exist')
-    })
-
-    it('Features Cover Button', () => {
-      cy.get('.cover-button.btn-primary')
+      cy.get('[data-cy="features-button"]')
         .should('exist')
     })
   })
 
-  it('Version can be opened and closed', () => {
-    cy.get('#versionModal')
-      .should('not.exist')
-    cy.get('#version')
-      .click()
-    cy.get('#versionModal')
-      .should('be.visible')
-    cy.get('#versionModal .modal-footer .btn')
-      .contains('Close')
-      .click()
-    cy.get('#versionModal')
-      .should('not.exist')
+  describe('sign in button', () => {
+    it('is hidden when logged in', () => {
+      cy.get('[data-cy="sign-in-button"]')
+        .should('not.exist')
+    })
+
+    it('is visible when logged out', () => {
+      cy.logout()
+      cy.get('[data-cy="sign-in-button"]')
+        .should('exist')
+    })
+  })
+
+  describe('version dialog', () => {
+    it('can be opened and closed', () => {
+      cy.get('[data-cy="version-modal"]')
+        .should('not.exist')
+      cy.get('[data-cy="show-version-modal"]')
+        .click()
+      cy.get('[data-cy="version-modal"]')
+        .should('be.visible')
+      cy.get('[data-cy="version-modal"] [data-cy="close-version-modal-button"]')
+        .contains('Close')
+        .click()
+      cy.get('[data-cy="version-modal"]')
+        .should('not.exist')
+    })
   })
 })

cypress/integration/link.spec.ts

@@ -94,21 +94,21 @@ describe('Links Intro', () => {
 
   describe('Feature Links', () => {
     it('Share-Notes', () => {
-      cy.get('i.fa-bolt.fa-3x')
+      cy.get('i.fa-bolt')
         .click()
       cy.url()
         .should('include', '/features#Share-Notes')
     })
 
     it('KaTeX', () => {
-      cy.get('i.fa-bar-chart.fa-3x')
+      cy.get('i.fa-bar-chart')
         .click()
       cy.url()
         .should('include', '/features#MathJax')
     })
 
     it('Slide-Mode', () => {
-      cy.get('i.fa-television.fa-3x')
+      cy.get('i.fa-television')
         .click()
       cy.url()
         .should('include', '/features#Slide-Mode')

cypress/support/getMarkdownRenderer.ts

@@ -14,6 +14,7 @@ declare namespace Cypress {
 
 Cypress.Commands.add('getMarkdownRenderer', () => {
   return cy.get(`iframe[data-cy="documentIframe"]`)
+           .should('be.visible')
            .its('0.contentDocument')
            .should('exist')
            .its('body')

public/intro.md

@@ -0,0 +1,5 @@
+:::warning
+What you see is an UI-Test! It's filled with dummy data, not connected to a backend and no data will be saved.
+:::
+
+![HedgeDoc Screenshot](screenshot.png)

public/locales/en.json

@@ -34,7 +34,8 @@
                 "katex": "Works with charts and KaTeX",
                 "slides": "Supports slide mode"
             },
-            "screenShotAltText": "HedgeDoc Screenshot"
+            "markdownWhileLoading": "Loading...",
+            "markdownLoadingError": "Error while fetching intro content"
         },
         "history": {
             "error": {

src/components/document-read-only-page/document-read-only-page.tsx

@@ -22,6 +22,7 @@ import { RenderIframe } from '../editor-page/renderer-pane/render-iframe'
 import { DocumentInfobar } from './document-infobar'
 import { ErrorWhileLoadingNoteAlert } from './ErrorWhileLoadingNoteAlert'
 import { LoadingNoteAlert } from './LoadingNoteAlert'
+import { RendererType } from '../render-page/rendering-message'
 
 export const DocumentReadOnlyPage: React.FC = () => {
 
@@ -55,10 +56,11 @@ export const DocumentReadOnlyPage: React.FC = () => {
           noteId={ id }
           viewCount={ noteDetails.viewCount }
         />
-        <RenderIframe extraClasses={ 'flex-fill' }
+        <RenderIframe frameClasses={ 'flex-fill h-100 w-100' }
                       markdownContent={ markdownContent }
                       onFirstHeadingChange={ onFirstHeadingChange }
-                      onFrontmatterChange={ onFrontmatterChange }/>
+                      onFrontmatterChange={ onFrontmatterChange }
+                      rendererType={RendererType.DOCUMENT}/>
       </ShowIf>
     </div>
   )

src/components/editor-page/editor-page.tsx

@@ -32,6 +32,7 @@ import { RenderIframe } from './renderer-pane/render-iframe'
 import { Sidebar } from './sidebar/sidebar'
 import { Splitter } from './splitter/splitter'
 import { DualScrollState, ScrollState } from './synced-scroll/scroll-props'
+import { RendererType } from '../render-page/rendering-message'
 
 export interface EditorPagePathParams {
   id: string
@@ -115,13 +116,15 @@ export const EditorPage: React.FC = () => {
               showRight={ editorMode === EditorMode.PREVIEW || editorMode === EditorMode.BOTH }
               right={
                 <RenderIframe
+                  frameClasses={'h-100 w-100'}
                   markdownContent={ markdownContent }
                   onMakeScrollSource={ setRendererToScrollSource }
                   onFirstHeadingChange={ updateNoteTitleByFirstHeading }
                   onTaskCheckedChange={ SetCheckboxInMarkdownContent }
                   onFrontmatterChange={ setNoteFrontmatter }
                   onScroll={ onMarkdownRendererScroll }
-                  scrollState={ scrollState.rendererScrollState }/>
+                  scrollState={ scrollState.rendererScrollState }
+                  rendererType={ RendererType.DOCUMENT }/>
               }
               containerClassName={ 'overflow-hidden' }/>
             <Sidebar/>

src/components/editor-page/renderer-pane/render-iframe.tsx

@@ -10,13 +10,20 @@ import { useIsDarkModeActivated } from '../../../hooks/common/use-is-dark-mode-a
 import { ApplicationState } from '../../../redux'
 import { isTestMode } from '../../../utils/is-test-mode'
 import { IframeEditorToRendererCommunicator } from '../../render-page/iframe-editor-to-renderer-communicator'
-import { MarkdownDocumentProps } from '../../render-page/markdown-document'
-import { ImageDetails } from '../../render-page/rendering-message'
+import { RendererProps } from '../../render-page/markdown-document'
+import { ImageDetails, RendererType } from '../../render-page/rendering-message'
 import { ScrollState } from '../synced-scroll/scroll-props'
 import { useOnIframeLoad } from './hooks/use-on-iframe-load'
 import { ShowOnPropChangeImageLightbox } from './show-on-prop-change-image-lightbox'
 
-export const RenderIframe: React.FC<MarkdownDocumentProps> = (
+export interface RenderIframeProps extends RendererProps {
+  onRendererReadyChange?: (rendererReady: boolean) => void
+  rendererType: RendererType,
+  forcedDarkMode?: boolean
+  frameClasses?: string
+}
+
+export const RenderIframe: React.FC<RenderIframeProps> = (
   {
     markdownContent,
     onTaskCheckedChange,
@@ -25,9 +32,13 @@ export const RenderIframe: React.FC<MarkdownDocumentProps> = (
     onFirstHeadingChange,
     onScroll,
     onMakeScrollSource,
-    extraClasses
+    frameClasses,
+    onRendererReadyChange,
+    rendererType,
+    forcedDarkMode
   }) => {
-  const darkMode = useIsDarkModeActivated()
+  const savedDarkMode = useIsDarkModeActivated()
+  const darkMode = forcedDarkMode ?? savedDarkMode
   const [rendererReady, setRendererReady] = useState<boolean>(false)
   const [lightboxDetails, setLightboxDetails] = useState<ImageDetails | undefined>(undefined)
 
@@ -37,6 +48,11 @@ export const RenderIframe: React.FC<MarkdownDocumentProps> = (
   const resetRendererReady = useCallback(() => setRendererReady(false), [])
   const iframeCommunicator = useMemo(() => new IframeEditorToRendererCommunicator(), [])
   const onIframeLoad = useOnIframeLoad(frameReference, iframeCommunicator, rendererOrigin, renderPageUrl, resetRendererReady)
+  const [frameHeight, setFrameHeight] = useState<number>(0)
+
+  useEffect(() => {
+    onRendererReadyChange?.(rendererReady)
+  }, [onRendererReadyChange, rendererReady])
 
   useEffect(() => () => iframeCommunicator.unregisterEventListener(), [iframeCommunicator])
   useEffect(() => iframeCommunicator.onFirstHeadingChange(onFirstHeadingChange), [iframeCommunicator,
@@ -49,8 +65,15 @@ export const RenderIframe: React.FC<MarkdownDocumentProps> = (
   useEffect(() => iframeCommunicator.onTaskCheckboxChange(onTaskCheckedChange), [iframeCommunicator,
     onTaskCheckedChange])
   useEffect(() => iframeCommunicator.onImageClicked(setLightboxDetails), [iframeCommunicator])
-  useEffect(() => iframeCommunicator.onRendererReady(() => setRendererReady(true)), [darkMode, iframeCommunicator,
-    scrollState])
+  useEffect(() => iframeCommunicator.onRendererReady(() => {
+    iframeCommunicator.sendSetBaseConfiguration({
+      baseUrl: window.location.toString(),
+      rendererType
+    })
+    setRendererReady(true)
+  }), [darkMode, rendererType, iframeCommunicator, rendererReady, scrollState])
+  useEffect(() => iframeCommunicator.onHeightChange(setFrameHeight), [iframeCommunicator])
+
   useEffect(() => {
     if (rendererReady) {
       iframeCommunicator.sendSetDarkmode(darkMode)
@@ -65,12 +88,6 @@ export const RenderIframe: React.FC<MarkdownDocumentProps> = (
     }
   }, [iframeCommunicator, rendererReady, scrollState])
 
-  useEffect(() => {
-    if (rendererReady) {
-      iframeCommunicator.sendSetBaseUrl(window.location.toString())
-    }
-  }, [iframeCommunicator, rendererReady])
-
   useEffect(() => {
     if (rendererReady) {
       iframeCommunicator.sendSetMarkdownContent(markdownContent)
@@ -79,8 +96,9 @@ export const RenderIframe: React.FC<MarkdownDocumentProps> = (
 
   return <Fragment>
     <ShowOnPropChangeImageLightbox details={ lightboxDetails }/>
-    <iframe data-cy={ 'documentIframe' } onLoad={ onIframeLoad } title="render" src={ renderPageUrl }
+    <iframe style={ { height: `${ frameHeight }px` } } data-cy={ 'documentIframe' } onLoad={ onIframeLoad }
+            title="render" src={ renderPageUrl }
             { ...isTestMode() ? {} : { sandbox: 'allow-downloads allow-same-origin allow-scripts allow-popups' } }
-            ref={ frameReference } className={ `h-100 w-100 border-0 ${ extraClasses ?? '' }` }/>
+            ref={ frameReference } className={ `border-0 ${ frameClasses ?? '' }` }/>
   </Fragment>
 }

src/components/intro-page/cover-buttons/cover-buttons.tsx

@@ -1,7 +1,7 @@
 /*
- SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
-
- SPDX-License-Identifier: AGPL-3.0-only
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
  */
 
 import React from 'react'
@@ -38,6 +38,7 @@ export const CoverButtons: React.FC = () => {
       </ShowIf>
       <Link to="/n/features">
         <Button
+          data-cy={ 'features-button' }
           className="cover-button"
           variant="primary"
           size="lg"

src/components/intro-page/feature-links.tsx

@@ -13,29 +13,29 @@ import { ForkAwesomeIcon } from '../common/fork-awesome/fork-awesome-icon'
 export const FeatureLinks: React.FC = () => {
   useTranslation()
   return (
-    <Row className="mb-5">
-      <Col md={ 4 }>
+    <Row className="mb-5 d-flex flex-row justify-content-center">
+      <Col md={ 3 }>
         <Link to={ '/n/features#Share-Notes' } className="text-light">
-          <ForkAwesomeIcon icon="bolt" size="3x"/>
-          <h5>
+          <ForkAwesomeIcon icon="bolt" size="2x"/>
+          <h6>
             <Trans i18nKey="landing.intro.features.collaboration"/>
-          </h5>
+          </h6>
         </Link>
       </Col>
-      <Col md={ 4 }>
+      <Col md={ 3 }>
         <Link to={ '/n/features#MathJax' } className="text-light">
-          <ForkAwesomeIcon icon="bar-chart" size="3x"/>
-          <h5>
+          <ForkAwesomeIcon icon="bar-chart" size="2x"/>
+          <h6>
             <Trans i18nKey="landing.intro.features.katex"/>
-          </h5>
+          </h6>
         </Link>
       </Col>
-      <Col md={ 4 }>
+      <Col md={ 3 }>
         <Link to={ '/n/features#Slide-Mode' } className="text-light">
-          <ForkAwesomeIcon icon="television" size="3x"/>
-          <h5>
+          <ForkAwesomeIcon icon="television" size="2x"/>
+          <h6>
             <Trans i18nKey="landing.intro.features.slides"/>
-          </h5>
+          </h6>
         </Link>
       </Col>
     </Row>

src/components/intro-page/hooks/use-intro-page-content.ts

@@ -0,0 +1,29 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { useEffect, useState } from 'react'
+import { useTranslation } from 'react-i18next'
+import { getFrontPageContent } from '../requests'
+import { useFrontendBaseUrl } from '../../../hooks/common/use-frontend-base-url'
+
+const MARKDOWN_WHILE_LOADING = ':zzz: {message}'
+const MARKDOWN_IF_ERROR = ':::danger\n' +
+  '{message}\n' +
+  ':::'
+
+export const useIntroPageContent = (): string => {
+  const { t } = useTranslation()
+  const [content, setContent] = useState<string>(() => MARKDOWN_WHILE_LOADING.replace('{message}', t('landing.intro.markdownWhileLoading')))
+  const frontendBaseUrl = useFrontendBaseUrl()
+
+  useEffect(() => {
+    getFrontPageContent(frontendBaseUrl)
+      .then((content) => setContent(content))
+      .catch(() => setContent(MARKDOWN_IF_ERROR.replace('{message}', t('landing.intro.markdownLoadingError'))))
+  }, [frontendBaseUrl, t])
+
+  return content
+}

src/components/intro-page/intro-page.tsx

@@ -1,37 +1,54 @@
 /*
- SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
-
- SPDX-License-Identifier: AGPL-3.0-only
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ *SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import React, { Fragment } from 'react'
-import { Trans, useTranslation } from 'react-i18next'
+import React, { Fragment, useState } from 'react'
+import { Trans } from 'react-i18next'
 import { Branding } from '../common/branding/branding'
 import {
   HedgeDocLogoSize,
   HedgeDocLogoType,
   HedgeDocLogoWithText
 } from '../common/hedge-doc-logo/hedge-doc-logo-with-text'
+import { RenderIframe } from '../editor-page/renderer-pane/render-iframe'
 import { CoverButtons } from './cover-buttons/cover-buttons'
 import { FeatureLinks } from './feature-links'
-import screenshot from './img/screenshot.png'
+import { useIntroPageContent } from './hooks/use-intro-page-content'
+import { ShowIf } from '../common/show-if/show-if'
+import { ForkAwesomeIcon } from '../common/fork-awesome/fork-awesome-icon'
+import { RendererType } from '../render-page/rendering-message'
 
 export const IntroPage: React.FC = () => {
-  const { t } = useTranslation()
+  const introPageContent = useIntroPageContent()
+  const [showSpinner, setShowSpinner] = useState<boolean>(true)
 
-  return <Fragment>
-    <h1 dir='auto' className={ 'align-items-center d-flex justify-content-center flex-column' }>
-      <HedgeDocLogoWithText logoType={ HedgeDocLogoType.COLOR_VERTICAL } size={ HedgeDocLogoSize.BIG }/>
-    </h1>
-    <p className="lead">
-      <Trans i18nKey="app.slogan"/>
-    </p>
-    <div className={ 'mb-5' }>
-      <Branding delimiter={ false }/>
-    </div>
-
-    <CoverButtons/>
-    <img alt={ t('landing.intro.screenShotAltText') } src={ screenshot } className="img-fluid mb-5"/>
-    <FeatureLinks/>
-  </Fragment>
+  return (
+    <Fragment>
+      <div className={ 'flex-fill mt-3' }>
+        <h1 dir='auto' className={ 'align-items-center d-flex justify-content-center flex-column' }>
+          <HedgeDocLogoWithText logoType={ HedgeDocLogoType.COLOR_VERTICAL } size={ HedgeDocLogoSize.BIG }/>
+        </h1>
+        <p className="lead">
+          <Trans i18nKey="app.slogan"/>
+        </p>
+        <div className={ 'mb-5' }>
+          <Branding delimiter={ false }/>
+        </div>
+        <CoverButtons/>
+        <ShowIf condition={ showSpinner }>
+          <ForkAwesomeIcon icon={ 'spinner' } className={ 'fa-spin' }/>
+        </ShowIf>
+        <RenderIframe
+          frameClasses={ 'w-100 overflow-y-hidden' }
+          markdownContent={ introPageContent }
+          disableToc={ true }
+          onRendererReadyChange={ (rendererReady => setShowSpinner(!rendererReady)) }
+          rendererType={ RendererType.INTRO }
+          forcedDarkMode={ true }/>
+        <hr className={ 'mb-5' }/>
+      </div>
+      <FeatureLinks/>
+    </Fragment>)
 }

src/components/intro-page/requests.ts

@@ -0,0 +1,17 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { defaultFetchConfig, expectResponseCode } from '../../api/utils'
+
+export const getFrontPageContent = async (baseUrl: string): Promise<string> => {
+  const response = await fetch(baseUrl + '/intro.md', {
+    ...defaultFetchConfig,
+    method: 'GET'
+  })
+  expectResponseCode(response)
+
+  return await response.text()
+}

src/components/landing-layout/footer/version-info.tsx

@@ -1,7 +1,7 @@
 /*
- SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
-
- SPDX-License-Identifier: AGPL-3.0-only
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
  */
 
 import equal from 'fast-deep-equal'
@@ -43,10 +43,10 @@ export const VersionInfo: React.FC = () => {
 
   return (
     <Fragment>
-      <Link id='version' to={ '#' } className={ 'text-light' } onClick={ handleShow }>
+      <Link data-cy={ 'show-version-modal' } to={ '#' } className={ 'text-light' } onClick={ handleShow }>
         <Trans i18nKey={ 'landing.versionInfo.versionInfo' }/>
       </Link>
-      <Modal id='versionModal' show={ show } onHide={ handleClose } animation={ true }>
+      <Modal data-cy={ 'version-modal' } show={ show } onHide={ handleClose } animation={ true }>
         <Modal.Body className="text-dark">
           <h3><Trans i18nKey={ 'landing.versionInfo.title' }/></h3>
           <Row>
@@ -55,7 +55,7 @@ export const VersionInfo: React.FC = () => {
           </Row>
         </Modal.Body>
         <Modal.Footer>
-          <Button variant="secondary" onClick={ handleClose }>
+          <Button variant="secondary" onClick={ handleClose } data-cy={ 'close-version-modal-button' }>
             <Trans i18nKey={ 'common.close' }/>
           </Button>
         </Modal.Footer>

src/components/landing-layout/navigation/sign-in-button.tsx

@@ -1,7 +1,7 @@
 /*
- SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
-
- SPDX-License-Identifier: AGPL-3.0-only
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
  */
 
 import React from 'react'
@@ -13,9 +13,7 @@ import { LinkContainer } from 'react-router-bootstrap'
 import { ApplicationState } from '../../../redux'
 import { ShowIf } from '../../common/show-if/show-if'
 
-type SignInButtonProps = {
-                           className?: string
-                         } & Omit<ButtonProps, 'href'>
+export type SignInButtonProps = Omit<ButtonProps, 'href'>
 
 export const SignInButton: React.FC<SignInButtonProps> = ({ variant, ...props }) => {
   const { t } = useTranslation()
@@ -25,9 +23,9 @@ export const SignInButton: React.FC<SignInButtonProps> = ({ variant, ...props })
     <ShowIf condition={ anyAuthProviderActive }>
       <LinkContainer to="/login" title={ t('login.signIn') }>
         <Button
+          data-cy={ 'sign-in-button' }
           variant={ variant || 'success' }
-          { ...props }
-        >
+          { ...props }>
           <Trans i18nKey="login.signIn"/>
         </Button>
       </LinkContainer>

src/components/markdown-renderer/full-markdown-renderer.tsx

@@ -71,11 +71,13 @@ export const FullMarkdownRenderer: React.FC<FullMarkdownRendererProps & Addition
       toc => {
         tocAst.current = toc
       },
-      lineMarkers => {
-        currentLineMarkers.current = lineMarkers
-      }
+      onLineMarkerPositionChanged === undefined
+        ? undefined
+        : lineMarkers => {
+          currentLineMarkers.current = lineMarkers
+        }
     )).buildConfiguredMarkdownIt()
-  }, [onFrontmatterChange])
+  }, [onLineMarkerPositionChanged, onFrontmatterChange])
 
   const clearFrontmatter = useCallback(() => {
     hasNewYamlError.current = false

src/components/markdown-renderer/markdown-it-configurator/FullMarkdownItConfigurator.tsx

@@ -29,7 +29,7 @@ export class FullMarkdownItConfigurator extends BasicMarkdownItConfigurator {
     private passYamlErrorState: (error: boolean) => void,
     private onRawMeta: (rawMeta: RawNoteFrontmatter) => void,
     private onToc: (toc: TocAst) => void,
-    private onLineMarkers: (lineMarkers: LineMarkers[]) => void
+    private onLineMarkers?: (lineMarkers: LineMarkers[]) => void
   ) {
     super()
   }
@@ -58,8 +58,12 @@ export class FullMarkdownItConfigurator extends BasicMarkdownItConfigurator {
       AsciinemaReplacer.markdownItPlugin,
       highlightedCode,
       quoteExtra,
-      (markdownIt) => documentToc(markdownIt, this.onToc),
-      (markdownIt) => lineNumberMarker(markdownIt, (lineMarkers) => this.onLineMarkers(lineMarkers))
-    )
+      (markdownIt) => documentToc(markdownIt, this.onToc))
+    if (this.onLineMarkers) {
+      const callback = this.onLineMarkers
+      this.configurations.push(
+        (markdownIt) => lineNumberMarker(markdownIt, (lineMarkers) => callback(lineMarkers))
+      )
+    }
   }
 }

src/components/render-page/hooks/use-image-click-handler.ts

@@ -0,0 +1,23 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import React, { useCallback } from 'react'
+import { ImageClickHandler } from '../../markdown-renderer/replace-components/image/image-replacer'
+import { IframeRendererToEditorCommunicator } from '../iframe-renderer-to-editor-communicator'
+
+export const useImageClickHandler = (iframeCommunicator: IframeRendererToEditorCommunicator): ImageClickHandler => {
+  return useCallback((event: React.MouseEvent<HTMLImageElement, MouseEvent>) => {
+    const image = event.target as HTMLImageElement
+    if (image.src === '') {
+      return
+    }
+    iframeCommunicator.sendClickedImageUrl({
+      src: image.src,
+      alt: image.alt,
+      title: image.title
+    })
+  }, [iframeCommunicator])
+}

src/components/render-page/iframe-editor-to-renderer-communicator.ts

@@ -8,6 +8,7 @@ import { NoteFrontmatter } from '../editor-page/note-frontmatter/note-frontmatte
 import { ScrollState } from '../editor-page/synced-scroll/scroll-props'
 import { IframeCommunicator } from './iframe-communicator'
 import {
+  BaseConfiguration,
   EditorToRendererIframeMessage,
   ImageDetails,
   RendererToEditorIframeMessage,
@@ -22,6 +23,11 @@ export class IframeEditorToRendererCommunicator extends IframeCommunicator<Edito
   private onSetScrollStateHandler?: (scrollState: ScrollState) => void
   private onRendererReadyHandler?: () => void
   private onImageClickedHandler?: (details: ImageDetails) => void
+  private onHeightChangeHandler?: (height: number) => void
+
+  public onHeightChange(handler?: (height: number) => void): void {
+    this.onHeightChangeHandler = handler
+  }
 
   public onFrontmatterChange(handler?: (frontmatter?: NoteFrontmatter) => void): void {
     this.onFrontmatterChangeHandler = handler
@@ -51,10 +57,10 @@ export class IframeEditorToRendererCommunicator extends IframeCommunicator<Edito
     this.onSetScrollStateHandler = handler
   }
 
-  public sendSetBaseUrl(baseUrl: string): void {
+  public sendSetBaseConfiguration(baseConfiguration: BaseConfiguration): void {
     this.sendMessageToOtherSide({
-      type: RenderIframeMessageType.SET_BASE_URL,
-      baseUrl
+      type: RenderIframeMessageType.SET_BASE_CONFIGURATION,
+      baseConfiguration
     })
   }
 
@@ -106,6 +112,9 @@ export class IframeEditorToRendererCommunicator extends IframeCommunicator<Edito
       case RenderIframeMessageType.IMAGE_CLICKED:
         this.onImageClickedHandler?.(renderMessage.details)
         return false
+      case RenderIframeMessageType.ON_HEIGHT_CHANGE:
+        this.onHeightChangeHandler?.(renderMessage.height)
+        return false
     }
   }
 }

src/components/render-page/iframe-renderer-to-editor-communicator.ts

@@ -8,6 +8,7 @@ import { NoteFrontmatter } from '../editor-page/note-frontmatter/note-frontmatte
 import { ScrollState } from '../editor-page/synced-scroll/scroll-props'
 import { IframeCommunicator } from './iframe-communicator'
 import {
+  BaseConfiguration,
   EditorToRendererIframeMessage,
   ImageDetails,
   RendererToEditorIframeMessage,
@@ -18,10 +19,10 @@ export class IframeRendererToEditorCommunicator extends IframeCommunicator<Rende
   private onSetMarkdownContentHandler?: ((markdownContent: string) => void)
   private onSetDarkModeHandler?: ((darkModeActivated: boolean) => void)
   private onSetScrollStateHandler?: ((scrollState: ScrollState) => void)
-  private onSetBaseUrlHandler?: ((baseUrl: string) => void)
+  private onSetBaseConfigurationHandler?: ((baseConfiguration: BaseConfiguration) => void)
 
-  public onSetBaseUrl(handler?: (baseUrl: string) => void): void {
-    this.onSetBaseUrlHandler = handler
+  public onSetBaseConfiguration(handler?: (baseConfiguration: BaseConfiguration) => void): void {
+    this.onSetBaseConfigurationHandler = handler
   }
 
   public onSetMarkdownContent(handler?: (markdownContent: string) => void): void {
@@ -84,6 +85,13 @@ export class IframeRendererToEditorCommunicator extends IframeCommunicator<Rende
     })
   }
 
+  public sendHeightChange(height: number): void {
+    this.sendMessageToOtherSide({
+      type: RenderIframeMessageType.ON_HEIGHT_CHANGE,
+      height
+    })
+  }
+
   protected handleEvent(event: MessageEvent<EditorToRendererIframeMessage>): boolean | undefined {
     const renderMessage = event.data
     switch (renderMessage.type) {
@@ -96,8 +104,8 @@ export class IframeRendererToEditorCommunicator extends IframeCommunicator<Rende
       case RenderIframeMessageType.SET_SCROLL_STATE:
         this.onSetScrollStateHandler?.(renderMessage.scrollState)
         return false
-      case RenderIframeMessageType.SET_BASE_URL:
-        this.onSetBaseUrlHandler?.(renderMessage.baseUrl)
+      case RenderIframeMessageType.SET_BASE_CONFIGURATION:
+        this.onSetBaseConfigurationHandler?.(renderMessage.baseConfiguration)
         return false
     }
   }

src/components/render-page/markdown-document.scss

@@ -8,8 +8,7 @@
   width: 100%;
   height: 100%;
   margin: 0;
-  overflow-y: scroll;
-  overflow-x: auto;
+  overflow: auto;
   display: flex;
   flex-direction: row;
 

src/components/render-page/markdown-document.tsx

@@ -5,7 +5,7 @@
  */
 
 import { TocAst } from 'markdown-it-toc-done-right'
-import React, { MutableRefObject, useMemo, useRef, useState } from 'react'
+import React, { MutableRefObject, useEffect, useMemo, useRef, useState } from 'react'
 import { Dropdown } from 'react-bootstrap'
 import useResizeObserver from 'use-resize-observer'
 import { ForkAwesomeIcon } from '../common/fork-awesome/fork-awesome-icon'
@@ -19,8 +19,7 @@ import { FullMarkdownRenderer } from '../markdown-renderer/full-markdown-rendere
 import { ImageClickHandler } from '../markdown-renderer/replace-components/image/image-replacer'
 import './markdown-document.scss'
 
-export interface MarkdownDocumentProps extends ScrollProps {
-  extraClasses?: string
+export interface RendererProps extends ScrollProps {
   onFirstHeadingChange?: (firstHeading: string | undefined) => void
   onFrontmatterChange?: (frontmatter: NoteFrontmatter | undefined) => void
   onTaskCheckedChange?: (lineInMarkdown: number, checked: boolean) => void
@@ -28,11 +27,19 @@ export interface MarkdownDocumentProps extends ScrollProps {
   markdownContent: string,
   baseUrl?: string
   onImageClick?: ImageClickHandler
+  onHeightChange?: (height: number) => void
+  disableToc?: boolean
+}
+
+export interface MarkdownDocumentProps extends RendererProps {
+  additionalOuterContainerClasses?: string
+  additionalRendererClasses?: string
 }
 
 export const MarkdownDocument: React.FC<MarkdownDocumentProps> = (
   {
-    extraClasses,
+    additionalOuterContainerClasses,
+    additionalRendererClasses,
     onFirstHeadingChange,
     onFrontmatterChange,
     onMakeScrollSource,
@@ -41,42 +48,53 @@ export const MarkdownDocument: React.FC<MarkdownDocumentProps> = (
     markdownContent,
     onImageClick,
     onScroll,
-    scrollState
+    scrollState,
+    onHeightChange,
+    disableToc
   }) => {
   const rendererRef = useRef<HTMLDivElement | null>(null)
   const internalDocumentRenderPaneRef = useRef<HTMLDivElement>(null)
   const [tocAst, setTocAst] = useState<TocAst>()
-  const width = useResizeObserver({ ref: internalDocumentRenderPaneRef.current }).width ?? 0
+
+  const internalDocumentRenderPaneSize = useResizeObserver({ ref: internalDocumentRenderPaneRef.current })
+  const rendererSize = useResizeObserver({ ref: rendererRef.current })
+
+  const containerWidth = internalDocumentRenderPaneSize.width ?? 0
+
+  useEffect(() => {
+    if (!onHeightChange) {
+      return
+    }
+    onHeightChange(rendererSize.height ? rendererSize.height + 1 : 0)
+  }, [rendererSize.height, onHeightChange])
 
   const contentLineCount = useMemo(() => markdownContent.split('\n').length, [markdownContent])
   const [onLineMarkerPositionChanged, onUserScroll] = useSyncedScrolling(internalDocumentRenderPaneRef, rendererRef, contentLineCount, scrollState, onScroll)
 
   return (
-    <div className={ `markdown-document ${ extraClasses ?? '' }` }
+    <div className={ `markdown-document ${ additionalOuterContainerClasses ?? '' }` }
          ref={ internalDocumentRenderPaneRef } onScroll={ onUserScroll } onMouseEnter={ onMakeScrollSource }>
       <div className={ 'markdown-document-side' }/>
-      <div className={ 'bg-light markdown-document-content' }>
+      <div className={ 'markdown-document-content' }>
         <YamlArrayDeprecationAlert/>
         <FullMarkdownRenderer
           rendererRef={ rendererRef }
-          className={ 'flex-fill pt-4 mb-3' }
+          className={ `flex-fill mb-3 ${ additionalRendererClasses ?? '' }` }
           content={ markdownContent }
           onFirstHeadingChange={ onFirstHeadingChange }
           onLineMarkerPositionChanged={ onLineMarkerPositionChanged }
           onFrontmatterChange={ onFrontmatterChange }
           onTaskCheckedChange={ onTaskCheckedChange }
-          onTocChange={ (tocAst) => setTocAst(tocAst) }
+          onTocChange={ setTocAst }
           baseUrl={ baseUrl }
           onImageClick={ onImageClick }/>
-
       </div>
-
       <div className={ 'markdown-document-side pt-4' }>
-        <ShowIf condition={ !!tocAst }>
-          <ShowIf condition={ width >= 1100 }>
+        <ShowIf condition={ !!tocAst && !disableToc }>
+          <ShowIf condition={ containerWidth >= 1100 }>
             <TableOfContents ast={ tocAst as TocAst } className={ 'sticky' } baseUrl={ baseUrl }/>
           </ShowIf>
-          <ShowIf condition={ width < 1100 }>
+          <ShowIf condition={ containerWidth < 1100 }>
             <div className={ 'markdown-toc-sidebar-button' }>
               <Dropdown drop={ 'up' }>
                 <Dropdown.Toggle id="toc-overlay-button" variant={ 'secondary' } className={ 'no-arrow' }>

src/components/render-page/render-page.tsx

@@ -12,15 +12,17 @@ import { setNoteFrontmatter } from '../../redux/note-details/methods'
 import { NoteFrontmatter } from '../editor-page/note-frontmatter/note-frontmatter'
 import { ScrollState } from '../editor-page/synced-scroll/scroll-props'
 import { ImageClickHandler } from '../markdown-renderer/replace-components/image/image-replacer'
+import { useImageClickHandler } from './hooks/use-image-click-handler'
 import { IframeRendererToEditorCommunicator } from './iframe-renderer-to-editor-communicator'
 import { MarkdownDocument } from './markdown-document'
+import { BaseConfiguration, RendererType } from './rendering-message'
 
 export const RenderPage: React.FC = () => {
   useApplyDarkMode()
 
   const [markdownContent, setMarkdownContent] = useState('')
   const [scrollState, setScrollState] = useState<ScrollState>({ firstLineInView: 1, scrolledPercentage: 0 })
-  const [baseUrl, setBaseUrl] = useState<string>()
+  const [baseConfiguration, setBaseConfiguration] = useState<BaseConfiguration | undefined>(undefined)
 
   const editorOrigin = useSelector((state: ApplicationState) => state.config.iframeCommunication.editorOrigin)
 
@@ -35,7 +37,7 @@ export const RenderPage: React.FC = () => {
     return () => iframeCommunicator.unregisterEventListener()
   }, [iframeCommunicator])
 
-  useEffect(() => iframeCommunicator.onSetBaseUrl(setBaseUrl), [iframeCommunicator])
+  useEffect(() => iframeCommunicator.onSetBaseConfiguration(setBaseConfiguration), [iframeCommunicator])
   useEffect(() => iframeCommunicator.onSetMarkdownContent(setMarkdownContent), [iframeCommunicator])
   useEffect(() => iframeCommunicator.onSetDarkMode(setDarkMode), [iframeCommunicator])
   useEffect(() => iframeCommunicator.onSetScrollState(setScrollState), [iframeCommunicator, scrollState])
@@ -61,37 +63,45 @@ export const RenderPage: React.FC = () => {
     iframeCommunicator.sendSetScrollState(scrollState)
   }, [iframeCommunicator])
 
-  const onImageClick: ImageClickHandler = useCallback((event) => {
-    const image = event.target as HTMLImageElement
-    if (image.src === '') {
-      return
-    }
-    iframeCommunicator.sendClickedImageUrl({
-      src: image.src,
-      alt: image.alt,
-      title: image.title
-    })
+  const onImageClick: ImageClickHandler = useImageClickHandler(iframeCommunicator)
+
+  const onHeightChange = useCallback((height: number) => {
+    iframeCommunicator.sendHeightChange(height)
   }, [iframeCommunicator])
 
-  if (!baseUrl) {
+  if (!baseConfiguration) {
     return null
   }
 
-  return (
-    <div className={ 'vh-100 w-100' }>
-      <MarkdownDocument
-        extraClasses={ 'bg-light' }
-        markdownContent={ markdownContent }
-        onTaskCheckedChange={ onTaskCheckedChange }
-        onFirstHeadingChange={ onFirstHeadingChange }
-        onMakeScrollSource={ onMakeScrollSource }
-        onFrontmatterChange={ onFrontmatterChange }
-        scrollState={ scrollState }
-        onScroll={ onScroll }
-        baseUrl={ baseUrl }
-        onImageClick={ onImageClick }/>
-    </div>
-  )
+  switch (baseConfiguration.rendererType) {
+    case RendererType.DOCUMENT:
+      return (
+        <MarkdownDocument
+          additionalOuterContainerClasses={ 'vh-100 bg-light' }
+          additionalRendererClasses={ 'mb-3' }
+          markdownContent={ markdownContent }
+          onTaskCheckedChange={ onTaskCheckedChange }
+          onFirstHeadingChange={ onFirstHeadingChange }
+          onMakeScrollSource={ onMakeScrollSource }
+          onFrontmatterChange={ onFrontmatterChange }
+          scrollState={ scrollState }
+          onScroll={ onScroll }
+          baseUrl={ baseConfiguration.baseUrl }
+          onImageClick={ onImageClick }/>
+      )
+    case RendererType.INTRO:
+      return (
+        <MarkdownDocument
+          additionalOuterContainerClasses={ 'vh-100 bg-light overflow-y-hidden' }
+          markdownContent={ markdownContent }
+          baseUrl={ baseConfiguration.baseUrl }
+          onImageClick={ onImageClick }
+          disableToc={ true }
+          onHeightChange={ onHeightChange }/>
+      )
+    default:
+      return null
+  }
 }
 
 export default RenderPage

src/components/render-page/rendering-message.ts

@@ -16,7 +16,8 @@ export enum RenderIframeMessageType {
   SET_SCROLL_STATE = 'SET_SCROLL_STATE',
   ON_SET_FRONTMATTER = 'ON_SET_FRONTMATTER',
   IMAGE_CLICKED = 'IMAGE_CLICKED',
-  SET_BASE_URL = 'SET_BASE_URL'
+  ON_HEIGHT_CHANGE = 'ON_HEIGHT_CHANGE',
+  SET_BASE_CONFIGURATION = 'SET_BASE_CONFIGURATION'
 }
 
 export interface RendererToEditorSimpleMessage {
@@ -35,8 +36,8 @@ export interface ImageDetails {
 }
 
 export interface SetBaseUrlMessage {
-  type: RenderIframeMessageType.SET_BASE_URL,
-  baseUrl: string
+  type: RenderIframeMessageType.SET_BASE_CONFIGURATION,
+  baseConfiguration: BaseConfiguration
 }
 
 export interface ImageClickedMessage {
@@ -70,6 +71,11 @@ export interface OnFrontmatterChangeMessage {
   frontmatter: NoteFrontmatter | undefined
 }
 
+export interface OnHeightChangeMessage {
+  type: RenderIframeMessageType.ON_HEIGHT_CHANGE,
+  height: number
+}
+
 export type EditorToRendererIframeMessage =
   SetMarkdownContentMessage |
   SetDarkModeMessage |
@@ -82,4 +88,15 @@ export type RendererToEditorIframeMessage =
   OnTaskCheckboxChangeMessage |
   OnFrontmatterChangeMessage |
   SetScrollStateMessage |
-  ImageClickedMessage
+  ImageClickedMessage |
+  OnHeightChangeMessage
+
+export enum RendererType {
+  DOCUMENT,
+  INTRO
+}
+
+export interface BaseConfiguration {
+  baseUrl: string
+  rendererType: RendererType
+}

src/style/index.scss

@@ -21,7 +21,7 @@
 }
 
 body {
-  background-color: darken($dark, 8%);
+  background-color: $dark;
 }
 
 html {
@@ -87,3 +87,7 @@ body {
 .overflow-x-auto {
   overflow-x: auto !important;
 }
+
+.overflow-y-hidden {
+  overflow-y: hidden !important;
+}

src/style/variables.light.scss

@@ -6,6 +6,7 @@
 
 $blue: #337ab7 !default;
 $cyan: #5EB7E0 !default;
+$dark: #222222 !default;
 
 @import "../../node_modules/bootstrap/scss/functions";
 @import "../../node_modules/bootstrap/scss/mixins";