Android embedding refactor PR1: JNI Extraction to FlutterJNI.java (fl…

…utter#7098)

Android embedding refactor: JNI Extraction to FlutterJNI.java

ci/licenses_golden/licenses_flutter

@@ -416,6 +416,11 @@ FILE: ../../../flutter/shell/platform/android/io/flutter/app/FlutterActivityEven
 FILE: ../../../flutter/shell/platform/android/io/flutter/app/FlutterApplication.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/app/FlutterFragmentActivity.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/app/FlutterPluginRegistry.java
+FILE: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java
+FILE: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
+FILE: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/dart/PlatformMessageHandler.java
+FILE: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/renderer/FlutterRenderer.java
+FILE: ../../../flutter/shell/platform/android/io/flutter/embedding/engine/renderer/OnFirstFrameRenderedListener.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/ActivityLifecycleListener.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/BasicMessageChannel.java
 FILE: ../../../flutter/shell/platform/android/io/flutter/plugin/common/BinaryCodec.java

shell/platform/android/.gitignore

@@ -1,2 +1,5 @@
 # Generated by Intellij's Android plugin
 gen
+android.iml
+out/
+

shell/platform/android/BUILD.gn

@@ -102,6 +102,11 @@ java_library("flutter_shell_java") {
     "io/flutter/app/FlutterApplication.java",
     "io/flutter/app/FlutterFragmentActivity.java",
     "io/flutter/app/FlutterPluginRegistry.java",
+    "io/flutter/embedding/engine/FlutterEngine.java",
+    "io/flutter/embedding/engine/FlutterJNI.java",
+    "io/flutter/embedding/engine/dart/PlatformMessageHandler.java",
+    "io/flutter/embedding/engine/renderer/FlutterRenderer.java",
+    "io/flutter/embedding/engine/renderer/OnFirstFrameRenderedListener.java",
     "io/flutter/plugin/common/ActivityLifecycleListener.java",
     "io/flutter/plugin/common/BasicMessageChannel.java",
     "io/flutter/plugin/common/BinaryCodec.java",

shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java

@@ -0,0 +1,42 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package io.flutter.embedding.engine;
+
+/**
+ * A single Flutter execution environment.
+ *
+ * WARNING: THIS CLASS IS EXPERIMENTAL. DO NOT SHIP A DEPENDENCY ON THIS CODE.
+ * IF YOU USE IT, WE WILL BREAK YOU.
+ *
+ * A {@code FlutterEngine} can execute in the background, or it can be rendered to the screen by
+ * using the accompanying {@link FlutterRenderer}.  Rendering can be started and stopped, thus
+ * allowing a {@code FlutterEngine} to move from UI interaction to data-only processing and then
+ * back to UI interaction.
+ *
+ * Multiple {@code FlutterEngine}s may exist, execute Dart code, and render UIs within a single
+ * Android app.
+ *
+ * To start running Flutter within this {@code FlutterEngine}, get a reference to this engine's
+ * {@link DartExecutor} and then use {@link DartExecutor#runFromBundle(FlutterRunArguments)}.
+ * The {@link DartExecutor#runFromBundle(FlutterRunArguments)} method must not be invoked twice on the same
+ * {@code FlutterEngine}.
+ *
+ * To start rendering Flutter content to the screen, use {@link #getRenderer()} to obtain a
+ * {@link FlutterRenderer} and then attach a {@link FlutterRenderer.RenderSurface}.  Consider using
+ * a {@link io.flutter.embedding.android.FlutterView} as a {@link FlutterRenderer.RenderSurface}.
+ */
+public class FlutterEngine {
+  // TODO(mattcarroll): bring in FlutterEngine implementation in future PR
+
+  /**
+   * Lifecycle callbacks for Flutter engine lifecycle events.
+   */
+  public interface EngineLifecycleListener {
+    /**
+     * Lifecycle callback invoked before a hot restart of the Flutter engine.
+     */
+    void onPreEngineRestart();
+  }
+}