katex_flutter

Render scientific equations using the KaTeX library.

  • Mathematics / Maths Equations (Algebra, Calculus, Geometry, Geometry etc...)
  • Physics Equations
  • Signal Processing Equations
  • Chemistry Equations
  • Statistics / Stats Equations

Rendering is done using KaTeX.

katex_flutter is working on Android, iOS, and the web platform. Desktop support is planned.

On mobile platofrom this package mainly depends on webview_flutter plugin.

On web platform this package directly into Flutter's platfrom view's shadow root.

Unlike flutter_tex it does not create a local web server. This increases the performance significantly and allows non-mobile platforms.

API

KaTeX(
  @required laTeX,             // The LaTeX code to be rendered
  delimiter = '\$',            // The delimiter to be used for inline LaTeX
  displayDelimiter = '\$\$',   // The delimiter to be used for Display (centered, "important") LaTeX
  color = Colors.black,        // Background color
  background = Colors.white,   // Text color
  inheritWidth = true);        // Whether to use the parent's width or only the minimum required by the equation

Use this package as a library

Add this to your package's pubspec.yaml file:

dependencies:
  katex_flutter: ^2.3.0+14

You can install packages from the command line with Flutter:

flutter pub get

Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.

Now in your Dart code, you can use:

import 'package:katex_flutter/katex_flutter.dart';

Web-only: update web/index.html

Add the following code into the <head>...</head> section of your web/index.html:

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/katex.min.css"
    integrity="sha384-zB1R0rpPzHqg7Kpt0Aljp8JPLqbXI3bhnPWROx27a9N0Ll6ZP/+DiW/UqRcLbRjq" crossorigin="anonymous">
<script defer src="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/katex.min.js"
    integrity="sha384-y23I5Q6l+B6vatafAwxRu/0oK/79VlbSz7Q9aiSZUvyWYIYsd+qj+o24G5ZU2zJz"
    crossorigin="anonymous"></script>
<script defer src="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/contrib/auto-render.min.js"
    integrity="sha384-kWPLUVMOks5AQFrykwIup5lo0m3iMkkHrD0uJ4H5cjeGihAutqP0yW0J6dpFiVkI"
    crossorigin="anonymous"></script>
<script src="katex_flutter.js"></script>

Alternatively you could add the path to a local KaTeX library as well. Note that this will only work on web platform but not on mobile devices.

Then run:

flutter pub run katex_flutter:main

This will generate the required files in your web folder.

If you want to use different LaTeX delimiters than $ for inline and $$ for display LaTeX in web, you should modify the delimiters section in web/katex_flutter.js. In future releases these manual changes will become unneccesairy. We just didn't have enough of time for coding a dynamic implimentation.

Android-only: update android/app/src/main/AndroidManifest.xml

Due to an issue in the webview_flutter plugin you need to add the following to your android/app/src/main/AndroidManifest.xml:

<uses-permission android:name="android.permission.WAKE_LOCK" />

The issue is tracked at https://github.com/flutter/flutter/issues/49912

Source code

The source code is hosted on GitLab. It's licensed under the terms and conditions of the EUPL-1.2.

This package was initially created for the education project TestApp.

Libraries

katex_flutter
katex_flutter_mobile
katex_flutter_stub
katex_flutter_web