Move from Java to Kotlin

This commit converts all Java code to Kotlin and improves the structure and performance of most rewritten parts.

app/build.gradle

@@ -1,4 +1,6 @@
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
+apply plugin: 'kotlin-android-extensions'
 
 android {
     compileSdkVersion 29
@@ -13,6 +15,9 @@ android {
             abiFilters "arm64-v8a"
         }
     }
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
     buildTypes {
         release {
             debuggable true
@@ -51,4 +56,9 @@ dependencies {
     implementation 'androidx.preference:preference:1.1.0'
     implementation 'com.google.android.material:material:1.0.0'
     implementation 'me.xdrop:fuzzywuzzy:1.2.0'
+    implementation "androidx.core:core-ktx:1.1.0"
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+}
+repositories {
+    mavenCentral()
 }

app/src/main/java/emu/skyline/GameActivity.kt

@@ -0,0 +1,88 @@
+package emu.skyline
+
+import android.net.Uri
+import android.os.Bundle
+import android.os.ParcelFileDescriptor
+import android.util.Log
+import android.view.InputQueue
+import android.view.Surface
+import android.view.SurfaceHolder
+import android.view.WindowManager
+import androidx.appcompat.app.AppCompatActivity
+import kotlinx.android.synthetic.main.game_activity.*
+import java.io.File
+import java.lang.reflect.Method
+
+class GameActivity : AppCompatActivity(), SurfaceHolder.Callback, InputQueue.Callback {
+    init {
+        System.loadLibrary("skyline") // libskyline.so
+    }
+
+    private lateinit var rom: Uri
+    private lateinit var romFd: ParcelFileDescriptor
+    private lateinit var preferenceFd: ParcelFileDescriptor
+    private lateinit var logFd: ParcelFileDescriptor
+    private var surface: Surface? = null
+    private var inputQueue: Long? = null
+    private lateinit var gameThread: Thread
+    private var halt: Boolean = false
+
+    private external fun executeRom(romString: String, romType: Int, romFd: Int, preferenceFd: Int, logFd: Int)
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.game_activity)
+        rom = intent.getParcelableExtra("romUri")!!
+        val romType = intent.getIntExtra("romType", 0)
+        romFd = contentResolver.openFileDescriptor(rom, "r")!!
+        val preference = File("${applicationInfo.dataDir}/shared_prefs/${applicationInfo.packageName}_preferences.xml")
+        preferenceFd = ParcelFileDescriptor.open(preference, ParcelFileDescriptor.MODE_READ_WRITE)
+        val log = File("${applicationInfo.dataDir}/skyline.log")
+        logFd = ParcelFileDescriptor.open(log, ParcelFileDescriptor.MODE_READ_WRITE)
+        window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN)
+        game_view.holder.addCallback(this)
+        //window.takeInputQueue(this)
+        gameThread = Thread {
+            while ((surface == null))
+                Thread.yield()
+            executeRom(Uri.decode(rom.toString()), romType, romFd.fd, preferenceFd.fd, logFd.fd)
+            runOnUiThread { finish() }
+        }
+        gameThread.start()
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        halt = true
+        gameThread.join()
+        romFd.close()
+        preferenceFd.close()
+        logFd.close()
+    }
+
+    override fun surfaceCreated(holder: SurfaceHolder?) {
+        Log.d("surfaceCreated", "Holder: ${holder.toString()}")
+        surface = holder!!.surface
+    }
+
+    override fun surfaceChanged(holder: SurfaceHolder?, format: Int, width: Int, height: Int) {
+        Log.d("surfaceChanged", "Holder: ${holder.toString()}, Format: $format, Width: $width, Height: $height")
+    }
+
+    override fun surfaceDestroyed(holder: SurfaceHolder?) {
+        Log.d("surfaceDestroyed", "Holder: ${holder.toString()}")
+        surface = null
+    }
+
+    override fun onInputQueueCreated(queue: InputQueue?) {
+        Log.i("onInputQueueCreated", "InputQueue: ${queue.toString()}")
+        val clazz = Class.forName("android.view.InputQueue")
+        val method: Method = clazz.getMethod("getNativePtr")
+        inputQueue = method.invoke(queue)!! as Long
+    }
+
+    override fun onInputQueueDestroyed(queue: InputQueue?) {
+        Log.d("onInputQueueDestroyed", "InputQueue: ${queue.toString()}")
+        inputQueue = null
+    }
+}