flutter_tex

GitHub stars pub package

Contents

About

A Flutter Package to render fully offline so many types of equations and expressions based on LaTeX , TeX and MathML, most commonly used are as followings:

  • Mathematics / Maths Equations and expressions (Algebra, Calculus, Geometry, Geometry etc...)

  • Physics Equations and expressions

  • Signal Processing Equations and expressions

  • Chemistry Equations and expressions

  • Statistics / Stats Equations and expressions

  • It also includes full HTML with JavaScript support.

How it works?

Basically it's a flutter dart wrapper around the most powerful JavaScript libraries MathJax and Katex which render the equations in webview_flutter_plus.

Demo Video

Click to Watch Demo on Youtube

Screenshots

Fonts Sample Quiz Sample TeX Document
TeX Document Image & Video InkWell

How to use?

1: Add flutter_tex latest pub package version under dependencies to your package's pubspec.yaml file.

dependencies:
  flutter_tex: ^4.0.6

2: You can install packages from the command line:

$ flutter packages get

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

3: Now you need to put the following implementations in Android, iOS, and Web respectively.

Android

Make sure to add this line android:usesCleartextTraffic="true" in your <project-directory>/android/app/src/main/AndroidManifest.xml under application like this.

<application
       ...
       ...
       android:usesCleartextTraffic="true">
</application>

It completely works offline, without internet connection, but these are required permissions to work properly:

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

It'll still work in debug mode without permissions, but it won't work in release application without mentioned permissions.

iOS

Add following code in your <project-directory>/ios/Runner/Info.plist

<key>NSAppTransportSecurity</key>
  <dict>
    <key>NSAllowsArbitraryLoads</key> <true/>
  </dict>
<key>io.flutter.embedded_views_preview</key> <true/>

Web

For Web support you need to put <script src="assets/packages/flutter_tex/js/flutter_tex.js"></script> and <script type="text/javascript">window.flutterWebRenderer = "canvaskit";</script> in <head> tag of your <project-directory>/web/index.html like this.

<head>
  
    <meta charset="UTF-8">
    <title>Flutter TeX</title>

    <script src="assets/packages/flutter_tex/js/flutter_tex.js"></script>
    <script type="text/javascript">window.flutterWebRenderer = "canvaskit";</script>
</head>

4: Now in your Dart code, you can use:

import 'package:flutter_tex/flutter_tex.dart';

5: Now you can use TeXView as a widget:

Examples

Quick Example

TeXView(
    child: TeXViewColumn(children: [
      TeXViewInkWell(
        id: "id_0",
        child: TeXViewColumn(children: [
          TeXViewDocument(r"""<h2>Flutter \( \rm\\TeX \)</h2>""",
              style: TeXViewStyle(textAlign: TeXViewTextAlign.Center)),
          TeXViewContainer(
            child: TeXViewImage.network(
                'https://raw.githubusercontent.com/shah-xad/flutter_tex/master/example/assets/flutter_tex_banner.png'),
            style: TeXViewStyle(
              margin: TeXViewMargin.all(10),
              borderRadius: TeXViewBorderRadius.all(20),
            ),
          ),
          TeXViewDocument(r"""<p>                                
                       When \(a \ne 0 \), there are two solutions to \(ax^2 + bx + c = 0\) and they are
                       $$x = {-b \pm \sqrt{b^2-4ac} \over 2a}.$$</p>""",
              style: TeXViewStyle.fromCSS(
                  'padding: 15px; color: white; background: green'))
        ]),
      )
    ]),
    style: TeXViewStyle(
      elevation: 10,
      borderRadius: TeXViewBorderRadius.all(25),
      border: TeXViewBorder.all(TeXViewBorderDecoration(
          borderColor: Colors.blue,
          borderStyle: TeXViewBorderStyle.solid,
          borderWidth: 5)),
      backgroundColor: Colors.white,
    ),
   ),
  )

TeXView Document Example

TeXView Document Example

TeXView Markdown Example

TeXView Markdown Example

TeXView Quiz Example

TeXView Quiz Example

TeXView Custom Fonts Example

TeXView Custom Fonts Example

TeXView Image and Video Example

TeXView Image and Video Example

TeXView InkWell Example

TeXView InkWell Example

Complete Example

Complete Example Code

Application Demo.

Get it on Google Play

Demo Source

Web Demo.

You can find web demo at https://flutter-tex.web.app

Api Changes.

Api Usage.

  • children: A list of TeXViewWidget

  • TeXViewWidget

    • TeXViewDocument Holds TeX data by using a raw string e.g. r"""$$x = {-b \pm \sqrt{b^2-4ac} \over 2a}.$$<br> """ You can also put HTML and Javascript code in it.
    • TeXViewMarkdown Holds markdown data.
    • TeXViewContainer Holds a single TeXViewWidget with styling.
    • TeXViewImage renders image from assets or network.
    • TeXViewColumn holds a list of TeXViewWidget vertically.
    • TeXViewInkWell for listening tap events. Its child and id is mandatory.
    • TeXViewGroup a group of TeXViewGroupItem usually used to create quiz layout.
    • TeXViewDetails like html <details>.

  • TeXViewStyle() You can style each and everything using TeXViewStyle() or by using custom CSS code by TeXViewStyle.fromCSS() where you can pass hard coded String containing CSS code. For more information please check the example.

  • renderingEngine: Render Engine to render TeX (Default is Katex Rendering Engine). Use Katex RenderingEngine for fast render and MathJax RenderingEngine for quality render.

  • loadingWidgetBuilder: Show a loading widget before rendering completes.

  • onRenderFinished: Callback with the rendered page height, when TEX rendering finishes.

  • onTeXViewCreated: Callback when TeXView loading finishes.

For more please see the Example.

To Do:

  • Speed Optimizations as it's a bit slow rendering speed. It takes 1-2 seconds to render after application loaded. (Solved by adding Katex Support)
  • Bug in Web Support on setState everything disappears.

Cautions:

  • Please avoid using too many TeXView in a single page, because this is based on webview_flutter_plus a complete web browser. Which may cause slowing down your app. I am trying to add all necessary widgets within TeXView, So please prefer to use TeXViewWidget. You can check example folder for details. If you find any problem you can report an issue.

Libraries

flutter_tex