docs: add information how to add component in a React Native application

Closes #84

docs/react-native.md

@@ -0,0 +1,232 @@
+# React Native Guide Use
+
+## Minimal Requirements
+
+- Kotlin: 1.8.22
+- Gradle: 7.6.1
+
+**Warning: This guide uses the older architecture of React Native, Android UI Components.**
+
+## Setup
+
+### Setting `android/build.gradle`
+
+```
+buildscript {
+    ext {
+        buildToolsVersion = "33.0.0"
+        minSdkVersion = 26
+        compileSdkVersion = 33
+        targetSdkVersion = 33
+        kotlinVersion = "1.8.22"
+        mediaVersion = "1.0.2"
+    }
+    repositories {
+        google()
+        mavenCentral()
+        maven {
+            url 'https://maven.google.com'
+            name 'Google'
+        }
+        maven { url 'https://plugins.gradle.org/m2/' }
+        maven { url 'https://jitpack.io' }
+    }
+    dependencies {
+        classpath('com.android.tools.build:gradle:7.4.2')
+    }
+}
+```
+
+### Setting `android/app/build.gradle`
+
+In `android/app/build.gradle`, add the following lines in `android` and `dependencies`:
+
+```
+android {
+    compileOptions {
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
+    composeOptions {
+        kotlinCompilerExtensionVersion = "1.4.8"
+    }
+
+    buildFeatures {
+        compose true
+    }
+}
+
+dependencies {
+    implementation "com.github.profusion:android-enhanced-video-player:0.2.0"
+    implementation "androidx.media3:media3-exoplayer:$mediaVersion"
+    implementation "androidx.media3:media3-exoplayer-dash:$mediaVersion"
+    implementation "androidx.media3:media3-ui:$mediaVersion"
+
+    def composeBom = platform('androidx.compose:compose-bom:2023.05.01')
+    implementation composeBom
+    androidTestImplementation composeBom
+    implementation 'androidx.compose.ui:ui'
+    implementation 'androidx.compose.ui:ui-tooling-preview'
+    debugImplementation 'androidx.compose.ui:ui-tooling'
+}
+```
+
+# How to setup the component in Android React Native
+
+1. Add the ComposeView in the xml file in `android/app/src/main/res/layout`
+2. Create your component
+3. Create the component's manager
+4. Create the component's package
+5. Import the component's package in `getPackages()` in `android/app/src/main/java/com/rngql/MainApplication.java`
+
+### 1. Add ComposeView in xml file at `android/app/src/main/res/layout`
+
+Consider the file is called `my-xml-file.xml`
+
+```
+<?xml version="1.0" encoding="utf-8"?>
+<merge xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+    <FrameLayout
+        android:id="@+id/player_container"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+        <androidx.compose.ui.platform.ComposeView
+            android:id="@+id/compose_view"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent" />
+    </FrameLayout>
+</merge>
+```
+
+### 2. Create component's view
+
+```
+class NativeVideoView(context: ThemedReactContext) : RelativeLayout(context) {
+    private val composeView: ComposeView
+    private val player: ExoPlayer
+    var uri: String? = null
+        set(value) {
+            field = value
+            updateUri()
+        }
+
+    // Connects the view with the xml file
+    init {
+        inflate(context, R.layout.my-xml-file, this)
+        player = ExoPlayer.Builder(context).build()
+        composeView = findViewById(R.id.compose_view)
+        initContent()
+    }
+
+    // Set the Exoplayer to play a certain uri with a mp4 file
+    private fun updateUri() {
+        player.setMediaItem(MediaItem.fromUri(Uri.parse(uri)))
+        player.prepare()
+    }
+
+    // Responsible to stop media functions if the player is not visible
+    fun onDropViewInstance() {
+        player.release()
+    }
+
+    // Create an instance of EnhancedVideoPlayer which is linked with Exoplayer
+    private fun initContent() {
+        composeView.setContent {
+            EnhancedVideoPlayer(
+                exoPlayer = player,
+            )
+        }
+    }
+}
+
+```
+
+### 3. Create component's manager
+
+```
+class NativeVideoViewManager : SimpleViewManager<NativeVideoView>() {
+    // Defines the name of component used in React Native
+    override fun getName() = "VideoView"
+
+    override fun createViewInstance(reactContext: ThemedReactContext): NativeVideoView {
+        return NativeVideoView(reactContext)
+    }
+
+    // Defines the prop to be used in React Native
+    @ReactProp(name = "uri")
+    fun setUri(view: NativeVideoView, uri: String?) {
+        view.uri = uri
+    }
+
+    // If the view is not available, it'll release the player
+    override fun onDropViewInstance(view: NativeVideoView) {
+        view.onDropViewInstance()
+    }
+}
+
+```
+
+### 4. Create component's package
+
+```
+class NativeVideoViewPackage : ReactPackage {
+    override fun createViewManagers(reactContext: ReactApplicationContext): List<NativeVideoViewManager> {
+        return listOf(NativeVideoViewManager())
+    }
+
+    override fun createNativeModules(p0: ReactApplicationContext): MutableList<NativeModule> {
+        return mutableListOf()
+    }
+}
+```
+
+### 5. Import package in MainApplication
+
+```
+public class MainApplication extends Application implements ReactApplication {
+
+  private final ReactNativeHost mReactNativeHost =
+    new DefaultReactNativeHost(this) {
+      @Override
+          protected List<ReactPackage> getPackages() {
+            List<ReactPackage> packages = new PackageList(this).getPackages();
+            packages.add(new NativeVideoViewPackage());
+            return packages;
+          }
+```
+
+# Usage in React Native
+
+First of all, make sure to clean the cache and build the Android application.
+
+In order to import the components we need to use `requireNativeComponent`.
+
+```
+import { requireNativeComponent } from 'react-native';
+
+interface NativeMediaPlayerProps {
+  style?: StyleProp<ViewStyle>;
+  uri?: string | null;
+}
+
+const NativeVideoView =
+  requireNativeComponent<NativeMediaPlayerProps>('VideoView');
+
+const NativeMediaPlayer = ({
+  style,
+  uri,
+}: NativeMediaPlayerProps): JSX.Element => {
+  return (
+    <NativeVideoView style={style} uri={uri} />
+  );
+};
+
+export default NativeMediaPlayer;
+```
+
+## References
+
+- [Compose in Views](https://developer.android.com/jetpack/compose/migrate/interoperability-apis/compose-in-views)\
+- [Android Native UI Components](https://reactnative.dev/docs/native-components-android)
+- [Stackoverflow: Android: Jetpack Compose and XML in Activity](https://stackoverflow.com/questions/65648904/android-jetpack-compose-and-xml-in-activity)