[RN] Add Picture-in-Picture support

This only works automatically on Android >= 8. On other platforms / versions, it
relies on the SDK user on implementing a "reduced UI" mode and reacting to the
"request PIP" delegate method.

android/README.md

@@ -118,8 +118,8 @@ public class MainActivity extends AppCompatActivity {
     }
 
     @Override
-    protected void onPause() {
+    protected void onStop() {
-        super.onPause();
+        super.onStop();
 
         JitsiMeetView.onHostPause(this);
     }
@@ -142,6 +142,10 @@ which displays a single `JitsiMeetView`.
 
 See JitsiMeetView.getDefaultURL.
 
+#### getPictureInPictureAvailable()
+
+See JitsiMeetView.getPictureInPictureAvailable.
+
 #### getWelcomePageEnabled()
 
 See JitsiMeetView.getWelcomePageEnabled.
@@ -154,6 +158,10 @@ See JitsiMeetView.loadURL.
 
 See JitsiMeetView.setDefaultURL.
 
+#### setPictureInPictureAvailable(Boolean)
+
+See JitsiMeetView.setPictureInPictureAvailable.
+
 #### setWelcomePageEnabled(boolean)
 
 See JitsiMeetView.setWelcomePageEnabled.
@@ -179,6 +187,12 @@ if set to `null`, the default built in JavaScript is used: https://meet.jit.si.
 
 Returns the `JitsiMeetViewListener` instance attached to the view.
 
+#### getPictureInPictureAvailable()
+
+turns true if Picture-in-Picture is available, false otherwise. If the user
+doesn't explicitly set it, it will default to true if the platform supports it,
+false otherwise. See the Picture-in-Picture section.
+
 #### getWelcomePageEnabled()
 
 Returns true if the Welcome page is enabled; otherwise, false. If false, a black
@@ -227,6 +241,13 @@ NOTE: Must be called before `loadURL`/`loadURLString` for it to take effect.
 Sets the given listener (class implementing the `JitsiMeetViewListener`
 interface) on the view.
 
+#### setPictureInPictureAvailable(Boolean)
+
+Sets wether Picture-in-Picture is available. When set to `null` if will be
+detected at runtime based on platform support.
+
+NOTE: Must be called before `loadURL`/`loadURLString` for it to take effect.
+
 #### setWelcomePageEnabled(boolean)
 
 Sets whether the Welcome page is enabled. See `getWelcomePageEnabled` for more
@@ -257,7 +278,8 @@ This is a static method.
 
 #### onHostResume(activity)
 
-Helper method which should be called from the activity's `onResume` method.
+Helper method which should be called from the activity's `onResume` or `onStop`
+method.
 
 This is a static method.
 
@@ -269,6 +291,13 @@ activity's `onNewIntent` method.
 
 This is a static method.
 
+#### onUserLeaveHint()
+
+Helper method for integrating automatic Picture-in-Picture. It should be called
+from the activity's `onUserLeaveHint` method.
+
+This is a static method.
+
 #### JitsiMeetViewListener
 
 `JitsiMeetViewListener` provides an interface apps can implement to listen to
@@ -385,3 +414,15 @@ rules file:
 -keep class org.jitsi.meet.sdk.** { *; }
 ```
 
+## Picture-in-Picture
+
+The Jitsi Meet app and SDK will enable Android's native Picture-in-Picture mode
+iff the platform is supported: for Android >= Oreo.
+
+If the SDK is integrated in an application which calls
+`enterPictureInPictureMode` for the Jitsi Meet activity, the it will self-adjust
+by removing some UI elements.
+
+Alternatively, this can be explicitly disabled with the
+`setPctureInPictureAvailable` methods in the Jitsi Meet view or activity.
+

android/app/src/main/AndroidManifest.xml

@@ -7,10 +7,12 @@
       android:label="@string/app_name"
       android:theme="@style/AppTheme">
     <activity
-        android:configChanges="keyboard|keyboardHidden|orientation|screenSize"
+        android:configChanges="keyboard|keyboardHidden|orientation|screenSize|smallestScreenSize|screenLayout"
         android:label="@string/app_name"
         android:launchMode="singleTask"
         android:name=".MainActivity"
+        android:resizeableActivity="true"
+        android:supportsPictureInPicture="true"
         android:windowSoftInputMode="adjustResize">
       <intent-filter>
         <action android:name="android.intent.action.MAIN" />

android/app/src/main/java/org/jitsi/meet/MainActivity.java

@@ -95,7 +95,9 @@ public class MainActivity extends JitsiMeetActivity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         // As this is the Jitsi Meet app (i.e. not the Jitsi Meet SDK), we do
-        // want the Welcome page to be enabled. It defaults to disabled in the
+        // want to enable some options.
+
+        // The welcome page defaults to disabled in the
         // SDK at the time of this writing but it is clearer to be explicit
         // about what we want anyway.
         setWelcomePageEnabled(true);

android/sdk/src/main/java/org/jitsi/meet/sdk/JitsiMeetActivity.java

@@ -17,6 +17,7 @@
 package org.jitsi.meet.sdk;
 
 import android.content.Intent;
+import android.content.res.Configuration;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
@@ -41,9 +42,7 @@ import java.net.URL;
  * hooked to the React Native subsystem via proxy calls through the
  * {@code JKConferenceView} static methods.
  */
-public class JitsiMeetActivity
+public class JitsiMeetActivity extends AppCompatActivity {
-    extends AppCompatActivity {
-
     /**
      * The request code identifying requests for the permission to draw on top
      * of other apps. The value must be 16-bit and is arbitrarily chosen here.
@@ -69,6 +68,12 @@ public class JitsiMeetActivity
      */
     private JitsiMeetView view;
 
+    /**
+     * Whether Picture-in-Picture is available. The value is used only while
+     * {@link #view} equals {@code null}.
+     */
+    private Boolean pipAvailable;
+
     /**
      * Whether the Welcome page is enabled. The value is used only while
      * {@link #view} equals {@code null}.
@@ -91,6 +96,15 @@ public class JitsiMeetActivity
         return view == null ? defaultURL : view.getDefaultURL();
     }
 
+    /**
+     *
+     * @see JitsiMeetView#getPictureInPictureAvailable()
+     */
+    public Boolean getPictureInPictureAvailable() {
+        return view == null
+            ? pipAvailable : view.getPictureInPictureAvailable();
+    }
+
     /**
      *
      * @see JitsiMeetView#getWelcomePageEnabled()
@@ -123,6 +137,7 @@ public class JitsiMeetActivity
         // XXX Before calling JitsiMeetView#loadURL, make sure to call whatever
         // is documented to need such an order in order to take effect:
         view.setDefaultURL(defaultURL);
+        view.setPictureInPictureAvailable(pipAvailable);
         view.setWelcomePageEnabled(welcomePageEnabled);
 
         view.loadURL(null);
@@ -224,19 +239,24 @@ public class JitsiMeetActivity
     }
 
     @Override
-    protected void onPause() {
+    protected void onResume() {
-        super.onPause();
+        super.onResume();
+
+        defaultBackButtonImpl = new DefaultHardwareBackBtnHandlerImpl(this);
+        JitsiMeetView.onHostResume(this, defaultBackButtonImpl);
+    }
+
+    @Override
+    public void onStop() {
+        super.onStop();
 
         JitsiMeetView.onHostPause(this);
         defaultBackButtonImpl = null;
     }
 
     @Override
-    protected void onResume() {
+    protected void onUserLeaveHint() {
-        super.onResume();
+        JitsiMeetView.onUserLeaveHint();
-
-        defaultBackButtonImpl = new DefaultHardwareBackBtnHandlerImpl(this);
-        JitsiMeetView.onHostResume(this, defaultBackButtonImpl);
     }
 
     /**
@@ -251,6 +271,18 @@ public class JitsiMeetActivity
         }
     }
 
+    /**
+     *
+     * @see JitsiMeetView#setPictureInPictureAvailable(Boolean)
+     */
+    public void setPictureInPictureAvailable(Boolean pipAvailable) {
+        if (view == null) {
+            this.pipAvailable = pipAvailable;
+        } else {
+            view.setPictureInPictureAvailable(pipAvailable);
+        }
+    }
+
     /**
      *
      * @see JitsiMeetView#setWelcomePageEnabled(boolean)

android/sdk/src/main/java/org/jitsi/meet/sdk/JitsiMeetView.java

@@ -21,6 +21,7 @@ import android.app.Application;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
+import android.os.Build;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
@@ -30,8 +31,11 @@ import com.facebook.react.ReactInstanceManager;
 import com.facebook.react.ReactRootView;
 import com.facebook.react.bridge.NativeModule;
 import com.facebook.react.bridge.ReactApplicationContext;
+import com.facebook.react.bridge.ReactContext;
+import com.facebook.react.bridge.WritableMap;
 import com.facebook.react.common.LifecycleState;
 import com.facebook.react.modules.core.DefaultHardwareBackBtnHandler;
+import com.facebook.react.modules.core.DeviceEventManagerModule;
 import com.rnimmersive.RNImmersiveModule;
 
 import java.net.URL;
@@ -65,6 +69,7 @@ public class JitsiMeetView extends FrameLayout {
             new AppInfoModule(reactContext),
             new AudioModeModule(reactContext),
             new ExternalAPIModule(reactContext),
+            new PictureInPictureModule(reactContext),
             new ProximityModule(reactContext),
             new WiFiStatsModule(reactContext)
         );
@@ -243,6 +248,36 @@ public class JitsiMeetView extends FrameLayout {
         }
     }
 
+    /**
+     * Activity lifecycle method which should be called from
+     * {@code Activity.onUserLeaveHint} so we can do the required internal
+     * processing.
+     *
+     * This is currently not mandatory.
+     */
+    public static void onUserLeaveHint() {
+        sendEvent("onUserLeaveHint", null);
+    }
+
+    /**
+     * Helper function to send an event to JavaScript.
+     *
+     * @param eventName {@code String} containing the event name.
+     * @param params {@code WritableMap} optional ancillary data for the event.
+     */
+    private static void sendEvent(
+            String eventName, @Nullable WritableMap params) {
+        if (reactInstanceManager != null) {
+            ReactContext reactContext
+                = reactInstanceManager.getCurrentReactContext();
+            if (reactContext != null) {
+                reactContext
+                    .getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter.class)
+                    .emit(eventName, params);
+            }
+        }
+    }
+
     /**
      * The default base {@code URL} used to join a conference when a partial URL
      * (e.g. a room name only) is specified to {@link #loadURLString(String)} or
@@ -264,6 +299,12 @@ public class JitsiMeetView extends FrameLayout {
      */
     private JitsiMeetViewListener listener;
 
+    /**
+     * Whether Picture-in-Picture is available. If {@code null}  it will default
+     * to {@code true} iff the platform supports it.
+     */
+    private Boolean pipAvailable;
+
     /**
      * React Native root view.
      */
@@ -328,6 +369,17 @@ public class JitsiMeetView extends FrameLayout {
         return listener;
     }
 
+    /**
+     * Gets whether Picture-in-Picture is currently available. It's only
+     * supported on Android API >= 26 (Oreo), so it should not be enabled on
+     * older platform versions.
+     *
+     * @return {@code true} if PiP is available, {@code false} otherwise.
+     */
+    public Boolean getPictureInPictureAvailable() {
+        return pipAvailable;
+    }
+
     /**
      * Gets whether the Welcome page is enabled. If {@code true}, the Welcome
      * page is rendered when this {@code JitsiMeetView} is not at a URL
@@ -369,12 +421,25 @@ public class JitsiMeetView extends FrameLayout {
         if (defaultURL != null) {
             props.putString("defaultURL", defaultURL.toString());
         }
+
         // externalAPIScope
         props.putString("externalAPIScope", externalAPIScope);
+
+        // pipAvailable
+        boolean pipAvailable_;
+        if (pipAvailable == null) {
+            // set it based on platform availability
+            pipAvailable_ = Build.VERSION.SDK_INT >= Build.VERSION_CODES.O;
+        } else {
+            pipAvailable_ = pipAvailable.booleanValue();
+        }
+        props.putBoolean("pipAvailable", pipAvailable_);
+
         // url
         if (urlObject != null) {
             props.putBundle("url", urlObject);
         }
+
         // welcomePageEnabled
         props.putBoolean("welcomePageEnabled", welcomePageEnabled);
 
@@ -462,6 +527,16 @@ public class JitsiMeetView extends FrameLayout {
         this.listener = listener;
     }
 
+    /**
+     * Sets whether Picture-in-Picture is currently available.
+     *
+     * @param pipAvailable {@code true} if PiP is available, {@code false}
+     * otherwise.
+     */
+    public void setPictureInPictureAvailable(Boolean pipAvailable) {
+        this.pipAvailable = pipAvailable;
+    }
+
     /**
      * Sets whether the Welcome page is enabled. Must be called before
      * {@link #loadURL(URL)} for it to take effect.

android/sdk/src/main/java/org/jitsi/meet/sdk/PictureInPictureModule.java

@@ -0,0 +1,61 @@
+package org.jitsi.meet.sdk;
+
+import android.app.Activity;
+import android.app.PictureInPictureParams;
+import android.os.Build;
+import android.util.Log;
+import android.util.Rational;
+
+import com.facebook.react.bridge.Promise;
+import com.facebook.react.bridge.ReactApplicationContext;
+import com.facebook.react.bridge.ReactContextBaseJavaModule;
+import com.facebook.react.bridge.ReactMethod;
+
+public class PictureInPictureModule extends ReactContextBaseJavaModule {
+    private final static String TAG = "PictureInPicture";
+
+    public PictureInPictureModule(ReactApplicationContext reactContext) {
+        super(reactContext);
+    }
+
+    @Override
+    public String getName() {
+        return TAG;
+    }
+
+    /**
+     * Enters Picture-in-Picture mode for the current activity. This is only
+     * supported in Android API >= 26.
+     *
+     * @param promise a {@code Promise} which will resolve with a {@code null}
+     *                value in case of success, and an error otherwise.
+     */
+    @ReactMethod
+    public void enterPictureInPictureMode(Promise promise) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            final Activity currentActivity = getCurrentActivity();
+
+            if (currentActivity == null) {
+                promise.reject(new Exception("No current Activity!"));
+                return;
+            }
+
+            Log.d(TAG, "Entering PiP mode");
+
+            final PictureInPictureParams.Builder pipParamsBuilder
+                = new PictureInPictureParams.Builder();
+            pipParamsBuilder.setAspectRatio(new Rational(1, 1)).build();
+            final boolean r
+                = currentActivity.enterPictureInPictureMode(pipParamsBuilder.build());
+            if (r) {
+                promise.resolve(null);
+            } else {
+                promise.reject(new Exception("Error entering PiP mode"));
+            }
+
+            return;
+        }
+
+        promise.reject(new Exception("PiP not supported"));
+    }
+}

ios/README.md

@@ -55,6 +55,13 @@ built in JavaScript is used: https://meet.jit.si.
 
 NOTE: Must be set before `loadURL:`/`loadURLString:` for it to take effect.
 
+#### pipAvailable
+
+Property to get / set wether a Picture-in-Picture mode is available. This must
+be implemented by the application at the moment.
+
+NOTE: Must be set before `loadURL:`/`loadURLString:` for it to take effect.
+
 #### welcomePageEnabled
 
 Property to get/set whether the Welcome page is enabled. If `NO`, a black empty
@@ -178,3 +185,24 @@ fails.
 The `data` dictionary contains an "error" key with the error and a "url" key
 with the conference URL which necessitated the loading of the configuration
 file.
+
+#### requestPipMode
+
+Called when the user requested Picture-in-Picture mode to be entered. At this
+point the application should resize the SDK view to a smaller size if it so
+desires.
+
+### Picture-in-Picture
+
+The Jitsi Meet SDK implements a "reduced UI mode" which will automatically
+adjust the UI when presented in a Picture-in-Picture style scenario. Enabling
+a native Picture-in-Picture mode on iOS is not currently implemented on the SDK
+so applications need to do it themselves.
+
+When `pipAvailable` is set to `YES` or the `requestPipMode` delegate method is
+implemented, the in-call toolbar will show a button to enter PiP mode. It's up
+to the application to reduce the size of the SDK view and put it in such mode.
+
+Once PiP mode has been entered, the SDK will automatically adjust its UI
+elements.
+

ios/sdk/src/JitsiMeetView.h

@@ -25,6 +25,8 @@
 
 @property (copy, nonatomic, nullable) NSURL *defaultURL;
 
+@property (nonatomic) BOOL pipAvailable;
+
 @property (nonatomic) BOOL welcomePageEnabled;
 
 +             (BOOL)application:(UIApplication *_Nonnull)application

ios/sdk/src/JitsiMeetView.m

@@ -109,7 +109,11 @@ void registerFatalErrorHandler() {
 
 @end
 
-@implementation JitsiMeetView
+@implementation JitsiMeetView {
+    NSNumber *_pipAvailable;
+}
+
+@dynamic pipAvailable;
 
 static RCTBridgeWrapper *bridgeWrapper;
 
@@ -265,6 +269,7 @@ static NSMapTable<NSString *, JitsiMeetView *> *views;
     }
 
     props[@"externalAPIScope"] = externalAPIScope;
+    props[@"pipAvailable"] = @(self.pipAvailable);
     props[@"welcomePageEnabled"] = @(self.welcomePageEnabled);
 
     // XXX If urlObject is nil, then it must appear as undefined in the
@@ -315,6 +320,21 @@ static NSMapTable<NSString *, JitsiMeetView *> *views;
     [self loadURLObject:urlString ? @{ @"url": urlString } : nil];
 }
 
+#pragma pipAvailable getter / setter
+
+- (void) setPipAvailable:(BOOL)pipAvailable {
+    _pipAvailable = [NSNumber numberWithBool:pipAvailable];
+}
+
+- (BOOL) pipAvailable {
+    if (_pipAvailable == nil) {
+        return self.delegate
+            && [self.delegate respondsToSelector:@selector(requestPipMode:)];
+    }
+
+    return [_pipAvailable boolValue];
+}
+
 #pragma mark Private methods
 
 /**

ios/sdk/src/JitsiMeetViewDelegate.h

@@ -65,4 +65,13 @@
  */
 - (void)loadConfigError:(NSDictionary *)data;
 
+/**
+ * Called when Picture-in-Picture mode is requested. The app should now resize
+ * iself to a PiP style and then use the JitsiMeetView.onPipModeChanged to
+ * notify the JavaScript side about its action.
+ *
+ * The `data` dictionary is currently empty.
+ */
+- (void)requestPipMode:(NSDictionary *)data;
+
 @end

react/features/app/components/App.native.js

@@ -17,6 +17,7 @@ import '../../mobile/callkit';
 import '../../mobile/external-api';
 import '../../mobile/full-screen';
 import '../../mobile/permissions';
+import '../../mobile/picture-in-picture';
 import '../../mobile/proximity';
 import '../../mobile/wake-lock';
 
@@ -36,6 +37,12 @@ export class App extends AbstractApp {
     static propTypes = {
         ...AbstractApp.propTypes,
 
+        /**
+         * Whether Picture-in-Picture is available. If available, a button will
+         * be shown in the {@link Conference} view so the user can enter it.
+         */
+        pipAvailable: PropTypes.bool,
+
         /**
          * Whether the Welcome page is enabled. If {@code true}, the Welcome
          * page is rendered when the {@link App} is not at a location (URL)

react/features/mobile/external-api/middleware.js

@@ -14,6 +14,8 @@ import { LOAD_CONFIG_ERROR } from '../../base/config';
 import { MiddlewareRegistry } from '../../base/redux';
 import { toURLString } from '../../base/util';
 
+import { REQUEST_PIP_MODE } from '../picture-in-picture';
+
 /**
  * Middleware that captures Redux actions and uses the ExternalAPI module to
  * turn them into native events so the application knows about them.
@@ -62,6 +64,10 @@ MiddlewareRegistry.register(store => next => action => {
         });
         break;
     }
+
+    case REQUEST_PIP_MODE:
+        _sendEvent(store, _getSymbolDescription(action.type), /* data */ {});
+
     }
 
     return result;

react/features/mobile/picture-in-picture/actionTypes.js

@@ -0,0 +1,22 @@
+/**
+ * The type of redux action to set the PiP related event listeners.
+ *
+ * {
+ *     type: _SET_PIP_MODE_LISTENER,
+ *     listeners: Array|undefined
+ * }
+ *
+ * @protected
+ */
+export const _SET_PIP_LISTENERS = Symbol('_SET_PIP_LISTENERS');
+
+/**
+ * The type of redux action which signals that the PiP mode is requested.
+ *
+ * {
+ *      type: REQUEST_PIP_MODE
+ * }
+ *
+ * @public
+ */
+export const REQUEST_PIP_MODE = Symbol('REQUEST_PIP_MODE');

react/features/mobile/picture-in-picture/actions.js

@@ -0,0 +1,37 @@
+// @flow
+
+import {
+    _SET_PIP_LISTENERS,
+    REQUEST_PIP_MODE
+} from './actionTypes';
+
+/**
+ * Sets the listeners for the PiP related events.
+ *
+ * @param {Array} listeners - Array of listeners to be set.
+ * @protected
+ * @returns {{
+ *     type: _SET_PIP_LISTENERS,
+ *     listeners: Array
+ * }}
+ */
+export function _setListeners(listeners: ?Array<any>) {
+    return {
+        type: _SET_PIP_LISTENERS,
+        listeners
+    };
+}
+
+/**
+ * Requests Picture-in-Picture mode.
+ *
+ * @public
+ * @returns {{
+ *     type: REQUEST_PIP_MODE
+ * }}
+ */
+export function requestPipMode() {
+    return {
+        type: REQUEST_PIP_MODE
+    };
+}

react/features/mobile/picture-in-picture/functions.js

@@ -0,0 +1,19 @@
+// @flow
+
+import { NativeModules } from 'react-native';
+
+const pip = NativeModules.PictureInPicture;
+
+/**
+ * Tells the application to enter the Picture-in-Picture mode, if supported.
+ *
+ * @returns {Promise} A promise which is fulfilled when PiP mode was entered, or
+ * rejected in case there was a problem or it isn't supported.
+ */
+export function enterPictureInPictureMode(): Promise<void> {
+    if (pip) {
+        return pip.enterPictureInPictureMode();
+    }
+
+    return Promise.reject(new Error('PiP not supported'));
+}

react/features/mobile/picture-in-picture/index.js

@@ -0,0 +1,6 @@
+export * from './actions';
+export * from './actionTypes';
+export * from './functions';
+
+import './middleware';
+import './reducer';

react/features/mobile/picture-in-picture/middleware.js

@@ -0,0 +1,100 @@
+// @flow
+
+import { DeviceEventEmitter } from 'react-native';
+
+import { APP_WILL_MOUNT, APP_WILL_UNMOUNT } from '../../app';
+import { MiddlewareRegistry } from '../../base/redux';
+
+import { _setListeners } from './actions';
+import { _SET_PIP_LISTENERS, REQUEST_PIP_MODE } from './actionTypes';
+import { enterPictureInPictureMode } from './functions';
+
+/**
+ * Middleware that handles Picture-in-Picture requests. Currently it enters
+ * the native PiP mode on Android, when requested.
+ *
+ * @param {Store} store - Redux store.
+ * @returns {Function}
+ */
+MiddlewareRegistry.register(store => next => action => {
+    switch (action.type) {
+    case _SET_PIP_LISTENERS: {
+        // Remove the current/old listeners.
+        const { listeners } = store.getState()['features/pip'];
+
+        if (listeners) {
+            for (const listener of listeners) {
+                listener.remove();
+            }
+        }
+        break;
+    }
+
+    case APP_WILL_MOUNT:
+        _appWillMount(store);
+        break;
+
+    case APP_WILL_UNMOUNT:
+        store.dispatch(_setListeners(undefined));
+        break;
+
+    case REQUEST_PIP_MODE:
+        _enterPictureInPicture(store);
+        break;
+
+    }
+
+    return next(action);
+});
+
+/**
+ * Notifies the feature pip that the action {@link APP_WILL_MOUNT} is being
+ * dispatched within a specific redux {@code store}.
+ *
+ * @param {Store} store - The redux store in which the specified {@code action}
+ * is being dispatched.
+ * @param {Dispatch} next - The redux dispatch function to dispatch the
+ * specified {@code action} to the specified {@code store}.
+ * @param {Action} action - The redux action {@code APP_WILL_MOUNT} which is
+ * being dispatched in the specified {@code store}.
+ * @private
+ * @returns {*}
+ */
+function _appWillMount({ dispatch, getState }) {
+    const context = {
+        dispatch,
+        getState
+    };
+
+    const listeners = [
+
+        // Android's onUserLeaveHint activity lifecycle callback
+        DeviceEventEmitter.addListener('onUserLeaveHint', () => {
+            _enterPictureInPicture(context);
+        })
+    ];
+
+    dispatch(_setListeners(listeners));
+}
+
+/**
+ * Helper function to enter PiP mode. This is triggered by user request
+ * (either pressing the button in the toolbox or the home button on Android)
+ * ans this triggers the PiP mode, iff it's available and we are in a
+ * conference.
+ *
+ * @param {Object} store - Redux store.
+ * @private
+ * @returns {void}
+ */
+function _enterPictureInPicture({ getState }) {
+    const state = getState();
+    const { app } = state['features/app'];
+    const { conference, joining } = state['features/base/conference'];
+
+    if (app.props.pipAvailable && (conference || joining)) {
+        enterPictureInPictureMode().catch(e => {
+            console.warn(`Error entering PiP mode: ${e}`);
+        });
+    }
+}

react/features/mobile/picture-in-picture/reducer.js

@@ -0,0 +1,15 @@
+import { ReducerRegistry } from '../../base/redux';
+
+import { _SET_PIP_LISTENERS } from './actionTypes';
+
+ReducerRegistry.register('features/pip', (state = {}, action) => {
+    switch (action.type) {
+    case _SET_PIP_LISTENERS:
+        return {
+            ...state,
+            listeners: action.listeners
+        };
+    }
+
+    return state;
+});

react/features/toolbox/components/Toolbox.native.js

@@ -23,6 +23,7 @@ import {
     makeAspectRatioAware
 } from '../../base/responsive-ui';
 import { ColorPalette } from '../../base/styles';
+import { requestPipMode } from '../../mobile/picture-in-picture';
 import { beginRoomLockRequest } from '../../room-lock';
 import { beginShareRoom } from '../../share-room';
 
@@ -80,6 +81,11 @@ class Toolbox extends Component {
          */
         _onHangup: PropTypes.func,
 
+        /**
+         * Requests Picture-in-Picture mode.
+         */
+        _onPipRequest: PropTypes.func,
+
         /**
          * Sets the lock i.e. password protection of the conference/room.
          */
@@ -101,6 +107,11 @@ class Toolbox extends Component {
          */
         _onToggleCameraFacingMode: PropTypes.func,
 
+        /**
+         * Flag showing whether Picture-in-Picture is available.
+         */
+        _pipAvailable: PropTypes.bool,
+
         /**
          * Flag showing whether video is muted.
          */
@@ -296,6 +307,7 @@ class Toolbox extends Component {
         const underlayColor = 'transparent';
         const {
             _audioOnly: audioOnly,
+            _pipAvailable: pipAvailable,
             _videoMuted: videoMuted
         } = this.props;
 
@@ -305,6 +317,15 @@ class Toolbox extends Component {
             <View
                 key = 'secondaryToolbar'
                 style = { styles.secondaryToolbar }>
+                {
+                    pipAvailable
+                        && <ToolbarButton
+                            iconName = { 'menu-down' }
+                            iconStyle = { iconStyle }
+                            onClick = { this.props._onPipRequest }
+                            style = { style }
+                            underlayColor = { underlayColor } />
+                }
                 {
                     AudioRouteButton
                         && <AudioRouteButton
@@ -391,6 +412,17 @@ function _mapDispatchToProps(dispatch) {
     return {
         ...abstractMapDispatchToProps(dispatch),
 
+        /**
+         * Requests Picture-in-Picture mode.
+         *
+         * @private
+         * @returns {void}
+         * @type {Function}
+         */
+        _onPipRequest() {
+            dispatch(requestPipMode());
+        },
+
         /**
          * Sets the lock i.e. password protection of the conference/room.
          *
@@ -451,6 +483,7 @@ function _mapDispatchToProps(dispatch) {
 function _mapStateToProps(state) {
     const conference = state['features/base/conference'];
     const { enabled } = state['features/toolbox'];
+    const { app } = state['features/app'];
 
     return {
         ...abstractMapStateToProps(state),
@@ -479,7 +512,15 @@ function _mapStateToProps(state) {
          * @protected
          * @type {boolean}
          */
-        _locked: Boolean(conference.locked)
+        _locked: Boolean(conference.locked),
+
+        /**
+         * The indicator which determines if Picture-in-Picture is available.
+         *
+         * @protected
+         * @type {boolean}
+         */
+        _pipAvailable: Boolean(app && app.props.pipAvailable)
     };
 }