Convert AsyncWorker to Kotlin

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

ui/src/main/java/com/wireguard/android/util/AsyncWorker.java

@@ -1,66 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-package com.wireguard.android.util;
-
-import android.os.Handler;
-
-import com.wireguard.util.NonNullForAll;
-
-import java.util.concurrent.Executor;
-
-import java9.util.concurrent.CompletableFuture;
-import java9.util.concurrent.CompletionStage;
-
-/**
- * Helper class for running asynchronous tasks and ensuring they are completed on the main thread.
- */
-
-@NonNullForAll
-public class AsyncWorker {
-    private final Executor executor;
-    private final Handler handler;
-
-    public AsyncWorker(final Executor executor, final Handler handler) {
-        this.executor = executor;
-        this.handler = handler;
-    }
-
-    public CompletionStage<Void> runAsync(final AsyncRunnable<?> runnable) {
-        final CompletableFuture<Void> future = new CompletableFuture<>();
-        executor.execute(() -> {
-            try {
-                runnable.run();
-                handler.post(() -> future.complete(null));
-            } catch (final Throwable t) {
-                handler.post(() -> future.completeExceptionally(t));
-            }
-        });
-        return future;
-    }
-
-    public <T> CompletionStage<T> supplyAsync(final AsyncSupplier<T, ?> supplier) {
-        final CompletableFuture<T> future = new CompletableFuture<>();
-        executor.execute(() -> {
-            try {
-                final T result = supplier.get();
-                handler.post(() -> future.complete(result));
-            } catch (final Throwable t) {
-                handler.post(() -> future.completeExceptionally(t));
-            }
-        });
-        return future;
-    }
-
-    @FunctionalInterface
-    public interface AsyncRunnable<E extends Throwable> {
-        void run() throws E;
-    }
-
-    @FunctionalInterface
-    public interface AsyncSupplier<T, E extends Throwable> {
-        T get() throws E;
-    }
-}

ui/src/main/java/com/wireguard/android/util/AsyncWorker.kt

@@ -0,0 +1,43 @@
+/*
+ * Copyright © 2017-2020 WireGuard LLC. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package com.wireguard.android.util
+
+import android.os.Handler
+import java.util.concurrent.Executor
+import java9.util.concurrent.CompletableFuture
+import java9.util.concurrent.CompletionStage
+
+/**
+ * Helper class for running asynchronous tasks and ensuring they are completed on the main thread.
+ */
+
+class AsyncWorker(private val executor: Executor, private val handler: Handler) {
+
+    fun runAsync(run: () -> Unit): CompletionStage<Void> {
+        val future = CompletableFuture<Void>()
+        executor.execute {
+            try {
+                run()
+                handler.post { future.complete(null) }
+            } catch (t: Throwable) {
+                handler.post { future.completeExceptionally(t) }
+            }
+        }
+        return future
+    }
+
+    fun <T> supplyAsync(get: () -> T?): CompletionStage<T> {
+        val future = CompletableFuture<T>()
+        executor.execute {
+            try {
+                val result = get()
+                handler.post { future.complete(result) }
+            } catch (t: Throwable) {
+                handler.post { future.completeExceptionally(t) }
+            }
+        }
+        return future
+    }
+}