Add ReactInstanceHolder

Reviewed By: astreet

Differential Revision: D3328342

fbshipit-source-id: af4e825d0b7c2d3d4490094a939e97cc527dd242

ReactAndroid/src/main/java/com/facebook/react/ReactActivity.java

@@ -40,38 +40,8 @@ public abstract class ReactActivity extends Activity
   private @Nullable PermissionListener mPermissionListener;
   private @Nullable ReactInstanceManager mReactInstanceManager;
   private @Nullable ReactRootView mReactRootView;
-  private LifecycleState mLifecycleState = LifecycleState.BEFORE_RESUME;
   private DoubleTapReloadRecognizer mDoubleTapReloadRecognizer;
-
-  /**
-   * Returns the name of the bundle in assets. If this is null, and no file path is specified for
-   * the bundle, the app will only work with {@code getUseDeveloperSupport} enabled and will
-   * always try to load the JS bundle from the packager server.
-   * e.g. "index.android.bundle"
-   */
-  protected @Nullable String getBundleAssetName() {
-    return "index.android.bundle";
-  };
-
-  /**
-   * Returns a custom path of the bundle file. This is used in cases the bundle should be loaded
-   * from a custom path. By default it is loaded from Android assets, from a path specified
-   * by {@link getBundleAssetName}.
-   * e.g. "file://sdcard/myapp_cache/index.android.bundle"
-   */
-  protected @Nullable String getJSBundleFile() {
-    return null;
-  }
-
-  /**
-   * Returns the name of the main module. Determines the URL used to fetch the JS bundle
-   * from the packager server. It is only used when dev support is enabled.
-   * This is the first file to be executed once the {@link ReactInstanceManager} is created.
-   * e.g. "index.android"
-   */
-  protected String getJSMainModuleName() {
-    return "index.android";
-  }
+  private boolean mDoRefresh = false;
 
   /**
    * Returns the launchOptions which will be passed to the {@link ReactInstanceManager}
@@ -91,44 +61,6 @@ public abstract class ReactActivity extends Activity
    */
   protected abstract String getMainComponentName();
 
-  /**
-   * Returns whether dev mode should be enabled. This enables e.g. the dev menu.
-   */
-  protected abstract boolean getUseDeveloperSupport();
-
-  /**
-   * Returns a list of {@link ReactPackage} used by the app.
-   * You'll most likely want to return at least the {@code MainReactPackage}.
-   * If your app uses additional views or modules besides the default ones,
-   * you'll want to include more packages here.
-   */
-  protected abstract List<ReactPackage> getPackages();
-
-  /**
-   * A subclass may override this method if it needs to use a custom instance.
-   */
-  protected ReactInstanceManager createReactInstanceManager() {
-    ReactInstanceManager.Builder builder = ReactInstanceManager.builder()
-        .setApplication(getApplication())
-        .setJSMainModuleName(getJSMainModuleName())
-        .setUseDeveloperSupport(getUseDeveloperSupport())
-        .setInitialLifecycleState(mLifecycleState);
-
-    for (ReactPackage reactPackage : getPackages()) {
-      builder.addPackage(reactPackage);
-    }
-
-    String jsBundleFile = getJSBundleFile();
-
-    if (jsBundleFile != null) {
-      builder.setJSBundleFile(jsBundleFile);
-    } else {
-      builder.setBundleAssetName(getBundleAssetName());
-    }
-
-    return builder.build();
-  }
-
   /**
    * A subclass may override this method if it needs to use a custom {@link ReactRootView}.
    */
@@ -136,6 +68,27 @@ public abstract class ReactActivity extends Activity
     return new ReactRootView(this);
   }
 
+  /**
+   * Get the {@link ReactNativeHost} used by this app. By default, assumes {@link #getApplication()}
+   * is an instance of {@link ReactApplication} and calls
+   * {@link ReactApplication#getReactNativeHost()}. Override this method if your application class
+   * does not implement {@code ReactApplication} or you simply have a different mechanism for
+   * storing a {@code ReactNativeHost}, e.g. as a static field somewhere.
+   */
+  protected ReactNativeHost getReactNativeHost() {
+    return ((ReactApplication) getApplication()).getReactNativeHost();
+  }
+
+  /**
+   * Get whether developer support should be enabled or not. By default this delegates to
+   * {@link ReactNativeHost#getUseDeveloperSupport()}. Override this method if your application
+   * class does not implement {@code ReactApplication} or you simply have a different logic for
+   * determining this (default just checks {@code BuildConfig}).
+   */
+  protected boolean getUseDeveloperSupport() {
+    return ((ReactApplication) getApplication()).getReactNativeHost().getUseDeveloperSupport();
+  }
+
   @Override
   protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
@@ -150,9 +103,11 @@ public abstract class ReactActivity extends Activity
       }
     }
 
-    mReactInstanceManager = createReactInstanceManager();
     mReactRootView = createRootView();
-    mReactRootView.startReactApplication(mReactInstanceManager, getMainComponentName(), getLaunchOptions());
+    mReactRootView.startReactApplication(
+      getReactNativeHost().getReactInstanceManager(),
+      getMainComponentName(),
+      getLaunchOptions());
     setContentView(mReactRootView);
     mDoubleTapReloadRecognizer = new DoubleTapReloadRecognizer();
   }
@@ -161,10 +116,8 @@ public abstract class ReactActivity extends Activity
   protected void onPause() {
     super.onPause();
 
-    mLifecycleState = LifecycleState.BEFORE_RESUME;
-
-    if (mReactInstanceManager != null) {
-      mReactInstanceManager.onHostPause();
+    if (getReactNativeHost().hasInstance()) {
+      getReactNativeHost().getReactInstanceManager().onHostPause();
     }
   }
 
@@ -172,10 +125,8 @@ public abstract class ReactActivity extends Activity
   protected void onResume() {
     super.onResume();
 
-    mLifecycleState = LifecycleState.RESUMED;
-
-    if (mReactInstanceManager != null) {
-      mReactInstanceManager.onHostResume(this, this);
+    if (getReactNativeHost().hasInstance()) {
+      getReactNativeHost().getReactInstanceManager().onHostResume(this, this);
     }
   }
 
@@ -183,31 +134,30 @@ public abstract class ReactActivity extends Activity
   protected void onDestroy() {
     super.onDestroy();
 
-    mReactRootView.unmountReactApplication();
-    mReactRootView = null;
-
-    if (mReactInstanceManager != null) {
-      mReactInstanceManager.destroy();
+    if (mReactRootView != null) {
+      mReactRootView.unmountReactApplication();
+      mReactRootView = null;
     }
+    getReactNativeHost().clear();
   }
 
   @Override
   public void onActivityResult(int requestCode, int resultCode, Intent data) {
-    if (mReactInstanceManager != null) {
-      mReactInstanceManager.onActivityResult(requestCode, resultCode, data);
+    if (getReactNativeHost().hasInstance()) {
+      getReactNativeHost().getReactInstanceManager()
+        .onActivityResult(requestCode, resultCode, data);
     }
   }
 
   @Override
   public boolean onKeyUp(int keyCode, KeyEvent event) {
-    if (mReactInstanceManager != null &&
-        mReactInstanceManager.getDevSupportManager().getDevSupportEnabled()) {
+    if (getReactNativeHost().hasInstance() && getUseDeveloperSupport()) {
       if (keyCode == KeyEvent.KEYCODE_MENU) {
-        mReactInstanceManager.showDevOptionsDialog();
+        getReactNativeHost().getReactInstanceManager().showDevOptionsDialog();
         return true;
       }
       if (mDoubleTapReloadRecognizer.didDoubleTapR(keyCode, getCurrentFocus())) {
-        mReactInstanceManager.getDevSupportManager().handleReloadJS();
+        getReactNativeHost().getReactInstanceManager().getDevSupportManager().handleReloadJS();
       }
     }
     return super.onKeyUp(keyCode, event);
@@ -215,8 +165,8 @@ public abstract class ReactActivity extends Activity
 
   @Override
   public void onBackPressed() {
-    if (mReactInstanceManager != null) {
-      mReactInstanceManager.onBackPressed();
+    if (getReactNativeHost().hasInstance()) {
+      getReactNativeHost().getReactInstanceManager().onBackPressed();
     } else {
       super.onBackPressed();
     }
@@ -229,8 +179,8 @@ public abstract class ReactActivity extends Activity
 
   @Override
   public void onNewIntent(Intent intent) {
-    if (mReactInstanceManager != null) {
-      mReactInstanceManager.onNewIntent(intent);
+    if (getReactNativeHost().hasInstance()) {
+      getReactNativeHost().getReactInstanceManager().onNewIntent(intent);
     } else {
       super.onNewIntent(intent);
     }

ReactAndroid/src/main/java/com/facebook/react/ReactApplication.java

@@ -0,0 +1,18 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.react;
+
+public interface ReactApplication {
+
+  /**
+   * Get the default {@link ReactNativeHost} for this app.
+   */
+  ReactNativeHost getReactNativeHost();
+}

ReactAndroid/src/main/java/com/facebook/react/ReactNativeHost.java

@@ -0,0 +1,125 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.react;
+
+import javax.annotation.Nullable;
+
+import java.util.List;
+
+import android.app.Application;
+
+import com.facebook.infer.annotation.Assertions;
+
+/**
+ * Simple class that holds an instance of {@link ReactInstanceManager}. This can be used in your
+ * {@link Application class} (see {@link ReactApplication}), or as a static field.
+ */
+public abstract class ReactNativeHost {
+
+  private final Application mApplication;
+  private @Nullable ReactInstanceManager mReactInstanceManager;
+
+  protected ReactNativeHost(Application application) {
+    mApplication = application;
+  }
+
+  /**
+   * Get the current {@link ReactInstanceManager} instance, or create one.
+   */
+  public ReactInstanceManager getReactInstanceManager() {
+    if (mReactInstanceManager == null) {
+      mReactInstanceManager = createReactInstanceManager();
+    }
+    return mReactInstanceManager;
+  }
+
+  /**
+   * Get whether this holder contains a {@link ReactInstanceManager} instance, or not. I.e. if
+   * {@link #getReactInstanceManager()} has been called at least once since this object was created
+   * or {@link #clear()} was called.
+   */
+  public boolean hasInstance() {
+    return mReactInstanceManager != null;
+  }
+
+  /**
+   * Destroy the current instance and release the internal reference to it, allowing it to be GCed.
+   */
+  public void clear() {
+    if (mReactInstanceManager != null) {
+      mReactInstanceManager.destroy();
+      mReactInstanceManager = null;
+    }
+  }
+
+  protected ReactInstanceManager createReactInstanceManager() {
+    ReactInstanceManager.Builder builder = ReactInstanceManager.builder()
+      .setApplication(mApplication)
+      .setJSMainModuleName(getJSMainModuleName())
+      .setUseDeveloperSupport(getUseDeveloperSupport())
+      .setInitialLifecycleState(LifecycleState.BEFORE_CREATE);
+
+    for (ReactPackage reactPackage : getPackages()) {
+      builder.addPackage(reactPackage);
+    }
+
+    String jsBundleFile = getJSBundleFile();
+    if (jsBundleFile != null) {
+      builder.setJSBundleFile(jsBundleFile);
+    } else {
+      builder.setBundleAssetName(Assertions.assertNotNull(getBundleAssetName()));
+    }
+
+    return builder.build();
+  }
+
+  /**
+   * Returns the name of the main module. Determines the URL used to fetch the JS bundle
+   * from the packager server. It is only used when dev support is enabled.
+   * This is the first file to be executed once the {@link ReactInstanceManager} is created.
+   * e.g. "index.android"
+   */
+  protected String getJSMainModuleName() {
+    return "index.android";
+  }
+
+  /**
+   * Returns a custom path of the bundle file. This is used in cases the bundle should be loaded
+   * from a custom path. By default it is loaded from Android assets, from a path specified
+   * by {@link getBundleAssetName}.
+   * e.g. "file://sdcard/myapp_cache/index.android.bundle"
+   */
+  protected @Nullable String getJSBundleFile() {
+    return null;
+  }
+
+  /**
+   * Returns the name of the bundle in assets. If this is null, and no file path is specified for
+   * the bundle, the app will only work with {@code getUseDeveloperSupport} enabled and will
+   * always try to load the JS bundle from the packager server.
+   * e.g. "index.android.bundle"
+   */
+  protected @Nullable String getBundleAssetName() {
+    return "index.android.bundle";
+  }
+
+  /**
+   * Returns whether dev mode should be enabled. This enables e.g. the dev menu.
+   */
+  protected abstract boolean getUseDeveloperSupport();
+
+  /**
+   * Returns a list of {@link ReactPackage} used by the app.
+   * You'll most likely want to return at least the {@code MainReactPackage}.
+   * If your app uses additional views or modules besides the default ones,
+   * you'll want to include more packages here.
+   */
+  protected abstract List<ReactPackage> getPackages();
+}

local-cli/generator-android/templates/package/MainActivity.java

@@ -1,11 +1,6 @@
 package <%= package %>;
 
 import com.facebook.react.ReactActivity;
-import com.facebook.react.ReactPackage;
-import com.facebook.react.shell.MainReactPackage;
-
-import java.util.Arrays;
-import java.util.List;
 
 public class MainActivity extends ReactActivity {
 
@@ -17,24 +12,4 @@ public class MainActivity extends ReactActivity {
     protected String getMainComponentName() {
         return "<%= name %>";
     }
-
-    /**
-     * Returns whether dev mode should be enabled.
-     * This enables e.g. the dev menu.
-     */
-    @Override
-    protected boolean getUseDeveloperSupport() {
-        return BuildConfig.DEBUG;
-    }
-
-    /**
-     * A list of packages used by the app. If the app uses additional views
-     * or modules besides the default ones, add more packages here.
-     */
-    @Override
-    protected List<ReactPackage> getPackages() {
-        return Arrays.<ReactPackage>asList(
-            new MainReactPackage()
-        );
-    }
 }

local-cli/generator-android/templates/package/MainApplication.java

@@ -0,0 +1,35 @@
+package <%= package %>;
+
+import android.app.Application;
+import android.util.Log;
+
+import com.facebook.react.ReactApplication;
+import com.facebook.react.ReactInstanceManager;
+import com.facebook.react.ReactNativeHost;
+import com.facebook.react.ReactPackage;
+import com.facebook.react.shell.MainReactPackage;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class MainApplication extends Application implements ReactApplication {
+
+  private final ReactNativeHost mReactNativeHost = new ReactNativeHost(this) {
+    @Override
+    protected boolean getUseDeveloperSupport() {
+      return BuildConfig.DEBUG;
+    }
+
+    @Override
+    protected List<ReactPackage> getPackages() {
+      return Arrays.<ReactPackage>asList(
+          new MainReactPackage()
+      );
+    }
+  };
+
+  @Override
+  public ReactNativeHost getReactNativeHost() {
+      return mReactNativeHost;
+  }
+}

local-cli/generator-android/templates/src/app/src/main/AndroidManifest.xml

@@ -11,6 +11,7 @@
         android:targetSdkVersion="22" />
 
     <application
+      android:name=".MainApplication"
       android:allowBackup="true"
       android:label="@string/app_name"
       android:icon="@mipmap/ic_launcher"