flutter_tex

About
Demo Video
Screenshots
How to use?
- Android
- iOS
- Web
Examples
Demo Application
Demo Web
Api Changes
Api Usage
Todo
Cautions

About

A Flutter Package to render fully offline so many types of equations and expressions based on LaTeX and TeX, 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.

Rendering of equations depends on mini-mathjax a simplified version of MathJax and Katex JavaScript libraries.

This package mainly depends on webview_flutter.

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 version under dependencies to your package’s pubspec.yaml file.

dependencies:
  flutter_tex: ^3.6.7+5

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>Example
<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> 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>
</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(
    showLoadingWidget: false,
    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,
    ),
    loadingWidget: Center(
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.center,
        mainAxisSize: MainAxisSize.min,
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          CircularProgressIndicator(),
          Text("Rendering...")
        ],
      ),
    ))

TeXView Document Example

TeXView Markdown Example

TeXView Quiz Example

TeXView Custom Fonts Example

TeXView Image and Video Example

TeXView InkWell Example

Complete Example

Complete Example Code

Application Demo.

Demo Source

Web Demo.

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

Api Changes.

Please see CHANGELOG.md.

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.
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 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.

Source Code

Please Visit Flutter Render Latex Source Code at GitHub