AndroidSyntaxHighlighter

This is a wrapper of the react-syntax-highlighter for Android to display code with syntax highlight.

This is an early build for my app to view source code of websites. If you want to try it out please download Magic Feed from Google play store and see for the view-source feature which is an intent-filter for URL(ACTION_SEND, text/plain).

How to use it

Add dependency from JitPack.io

https://jitpack.io/#ShinChven/AndroidSyntaxHighlighter

Step 1. Add the JitPack repository to your build file

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

Step 2. Add the dependency

dependencies {
    implementation 'com.github.ShinChven:AndroidSyntaxHighlighter:Tag'
}

Add view in your layout

<com.github.shinchven.androidsyntaxhighlighter.SyntaxHighlightView
...
/>

Use it in your Android component

// initialize the SyntaxHighightView
syntaxHighightView.initialize(object : SyntaxHighlightView.Callback {
    // list all syntax highlight theme when initialization completed
    override fun listStyles(styles: ArrayList<HljsStyle>) {
        Log.i("styles", "${styles.size}")
    }

    // list all supported languages when initialization completed
    override fun listSupportedLanguages(supportedLanguages: ArrayList<String>) {
        Log.i("supportedLanguages", "${supportedLanguages.size}")
    }

    //
    override fun componentDidMount() {
        // must be interacted in UI thread.
        GlobalScope.launch(Dispatchers.Main.immediate) {
            try {
                syntaxHighightView.setCodeString(CODE, "html")
                syntaxHighightView.setShowLineNumbers(true)
                syntaxHighightView.setWrapLines(true)
                syntaxHighightView.setStyle(webView.styles[2])
                syntaxHighightView.setStartingLineNumber(1)
            } catch (e: Exception) {
                e.printStackTrace()
                }
            }
        }
    })
}

Bridged features from react-syntax-highlighter

• language
• style
• showLineNumbers
• wrapLines
• startingLineNumber

How it is implemented

SyntaxHighlighterView is based on WebView, loading a local html from assets with a prebuilt react SPA. JavaScriptInterfaces are implemented for android to call JavaScript function and get data within the SPA.

This library literally contains 2 parts, a React lib to display syntax and an Android lib for android projects to implement.

• The React library is in syntax-highlighter directory.
• The Android library is in androidsyntaxhighlighter directory.

Key source code

• Example
• Android implementation
• React implementation