feature-flags: initial implementation

The welcomePageEnabled and pictureInPictureEnabled props on mobile have been
converted to feature flags.

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

      */
     private Bundle colorScheme;
 
+    /**
+     * Feature flags. See: https://github.com/jitsi/jitsi-meet/blob/master/react/features/base/flags/constants.js
+     */
+    private Bundle featureFlags;
+
     /**
      * Set to {@code true} to join the conference with audio / video muted or to start in audio
      * only mode respectively.
     private Boolean audioOnly;
     private Boolean videoMuted;
 
-    /**
-     * Set to {@code true} to enable the welcome page. Typically SDK users won't need this enabled
-     * since the host application decides which meeting to join.
-     */
-    private Boolean welcomePageEnabled;
-
     /**
      * Class used to build the immutable {@link JitsiMeetConferenceOptions} object.
      */
         private String token;
 
         private Bundle colorScheme;
+        private Bundle featureFlags;
 
         private Boolean audioMuted;
         private Boolean audioOnly;
         private Boolean videoMuted;
 
-        private Boolean welcomePageEnabled;
-
         public Builder() {
+            featureFlags = new Bundle();
         }
 
         /**\
          * @return - The {@link Builder} object itself so the method calls can be chained.
          */
         public Builder setWelcomePageEnabled(boolean enabled) {
-            this.welcomePageEnabled = enabled;
+            this.featureFlags.putBoolean("welcomepage.enabled", enabled);
+
+            return this;
+        }
+
+        public Builder setFeatureFlag(String flag, boolean value) {
+            this.featureFlags.putBoolean(flag, value);
+
+            return this;
+        }
+
+        public Builder setFeatureFlag(String flag, String value) {
+            this.featureFlags.putString(flag, value);
+
+            return this;
+        }
+
+        public Builder setFeatureFlag(String flag, int value) {
+            this.featureFlags.putInt(flag, value);
 
             return this;
         }
             options.subject = this.subject;
             options.token = this.token;
             options.colorScheme = this.colorScheme;
+            options.featureFlags = this.featureFlags;
             options.audioMuted = this.audioMuted;
             options.audioOnly = this.audioOnly;
             options.videoMuted = this.videoMuted;
-            options.welcomePageEnabled = this.welcomePageEnabled;
 
             return options;
         }
         subject = in.readString();
         token = in.readString();
         colorScheme = in.readBundle();
+        featureFlags = in.readBundle();
         byte tmpAudioMuted = in.readByte();
         audioMuted = tmpAudioMuted == 0 ? null : tmpAudioMuted == 1;
         byte tmpAudioOnly = in.readByte();
         audioOnly = tmpAudioOnly == 0 ? null : tmpAudioOnly == 1;
         byte tmpVideoMuted = in.readByte();
         videoMuted = tmpVideoMuted == 0 ? null : tmpVideoMuted == 1;
-        byte tmpWelcomePageEnabled = in.readByte();
-        welcomePageEnabled = tmpWelcomePageEnabled == 0 ? null : tmpWelcomePageEnabled == 1;
     }
 
     Bundle asProps() {
         Bundle props = new Bundle();
 
-        if (colorScheme != null) {
-            props.putBundle("colorScheme", colorScheme);
+        // Android always has the PiP flag set by default.
+        if (!featureFlags.containsKey("pip.enabled")) {
+            featureFlags.putBoolean("pip.enabled", true);
         }
 
-        if (welcomePageEnabled != null) {
-            props.putBoolean("welcomePageEnabled", welcomePageEnabled);
-        }
+        props.putBundle("flags", featureFlags);
 
-        // TODO: get rid of this.
-        props.putBoolean("pictureInPictureEnabled", true);
+        if (colorScheme != null) {
+            props.putBundle("colorScheme", colorScheme);
+        }
 
         Bundle config = new Bundle();
 
         dest.writeString(subject);
         dest.writeString(token);
         dest.writeBundle(colorScheme);
+        dest.writeBundle(featureFlags);
         dest.writeByte((byte) (audioMuted == null ? 0 : audioMuted ? 1 : 2));
         dest.writeByte((byte) (audioOnly == null ? 0 : audioOnly ? 1 : 2));
         dest.writeByte((byte) (videoMuted == null ? 0 : videoMuted ? 1 : 2));
-        dest.writeByte((byte) (welcomePageEnabled == null ? 0 : welcomePageEnabled ? 1 : 2));
     }
 
     @Override

ios/app/src/ViewController.m

     [self _onJitsiMeetViewDelegateEvent:@"CONFERENCE_WILL_JOIN" withData:data];
 }
 
+#if 0
+- (void)enterPictureInPicture:(NSDictionary *)data {
+    [self _onJitsiMeetViewDelegateEvent:@"ENTER_PICTURE_IN_PICTURE" withData:data];
+}
+#endif
+
 @end

ios/sdk/src/JitsiMeetConferenceOptions.h

  */
 @property (nonatomic, copy, nullable) NSDictionary *colorScheme;
 
+/**
+ * Feature flags. See: https://github.com/jitsi/jitsi-meet/blob/master/react/features/base/flags/constants.js
+ */
+@property (nonatomic, readonly, nonnull) NSDictionary *featureFlags;
+
 /**
  * Set to YES to join the conference with audio / video muted or to start in audio
  * only mode respectively.
  */
 @property (nonatomic) BOOL welcomePageEnabled;
 
+- (void)setFeatureFlag:(NSString *_Nonnull)flag withBoolean:(BOOL)value;
+- (void)setFeatureFlag:(NSString *_Nonnull)flag withValue:(id _Nonnull)value;
+
 @end
 
 @interface JitsiMeetConferenceOptions : NSObject
 @property (nonatomic, copy, nullable, readonly) NSString *token;
 
 @property (nonatomic, copy, nullable) NSDictionary *colorScheme;
+@property (nonatomic, readonly, nonnull) NSDictionary *featureFlags;
 
 @property (nonatomic, readonly) BOOL audioOnly;
 @property (nonatomic, readonly) BOOL audioMuted;

ios/sdk/src/JitsiMeetConferenceOptions.m

 
 #import "JitsiMeetConferenceOptions+Private.h"
 
+/**
+ * Backwards compatibility: turn the boolean property into a feature flag.
+ */
+static NSString *const WelcomePageEnabledFeatureFlag = @"welcomepage.enabled";
+
+
 @implementation JitsiMeetConferenceOptionsBuilder {
     NSNumber *_audioOnly;
     NSNumber *_audioMuted;
     NSNumber *_videoMuted;
-    NSNumber *_welcomePageEnabled;
+    NSMutableDictionary *_featureFlags;
 }
 
 @dynamic audioOnly;
         _token = nil;
 
         _colorScheme = nil;
+        _featureFlags = [[NSMutableDictionary alloc] init];
 
         _audioOnly = nil;
         _audioMuted = nil;
         _videoMuted = nil;
-
-        _welcomePageEnabled = nil;
     }
     
     return self;
 }
 
+- (void)setFeatureFlag:(NSString *)flag withBoolean:(BOOL)value {
+    [self setFeatureFlag:flag withValue:[NSNumber numberWithBool:value]];
+}
+
+- (void)setFeatureFlag:(NSString *)flag withValue:(id)value {
+    _featureFlags[flag] = value;
+}
+
 #pragma mark - Dynamic properties
 
 - (void)setAudioOnly:(BOOL)audioOnly {
 }
 
 - (void)setWelcomePageEnabled:(BOOL)welcomePageEnabled {
-    _welcomePageEnabled = [NSNumber numberWithBool:welcomePageEnabled];
+    [self setFeatureFlag:WelcomePageEnabledFeatureFlag
+               withBoolean:welcomePageEnabled];
 }
 
 - (BOOL)welcomePageEnabled {
-    return _welcomePageEnabled && [_welcomePageEnabled boolValue];
+    NSNumber *n = _featureFlags[WelcomePageEnabledFeatureFlag];
+
+    return n != nil ? [n boolValue] : NO;
 }
 
 #pragma mark - Private API
     return _videoMuted;
 }
 
-- (NSNumber *)getWelcomePageEnabled {
-    return _welcomePageEnabled;
-}
-
 @end
 
 @implementation JitsiMeetConferenceOptions {
     NSNumber *_audioOnly;
     NSNumber *_audioMuted;
     NSNumber *_videoMuted;
-    NSNumber *_welcomePageEnabled;
+    NSDictionary *_featureFlags;
 }
 
 @dynamic audioOnly;
 }
 
 - (BOOL)welcomePageEnabled {
-    return _welcomePageEnabled && [_welcomePageEnabled boolValue];
+    NSNumber *n = _featureFlags[WelcomePageEnabledFeatureFlag];
+
+    return n != nil ? [n boolValue] : NO;
 }
 
 #pragma mark - Internal initializer
         _audioMuted = [builder getAudioMuted];
         _videoMuted = [builder getVideoMuted];
 
-        _welcomePageEnabled = [builder getWelcomePageEnabled];
+        _featureFlags = [NSDictionary dictionaryWithDictionary:builder.featureFlags];
     }
 
     return self;
 - (NSDictionary *)asProps {
     NSMutableDictionary *props = [[NSMutableDictionary alloc] init];
 
+    props[@"flags"] = [NSMutableDictionary dictionaryWithDictionary:_featureFlags];
+
     if (_colorScheme != nil) {
         props[@"colorScheme"] = self.colorScheme;
     }
 
-    if (_welcomePageEnabled != nil) {
-        props[@"welcomePageEnabled"] = @(self.welcomePageEnabled);
-    }
-
     NSMutableDictionary *config = [[NSMutableDictionary alloc] init];
     if (_audioOnly != nil) {
         config[@"startAudioOnly"] = @(self.audioOnly);

ios/sdk/src/JitsiMeetView.m

 #import "RNRootView.h"
 
 
+/**
+ * Backwards compatibility: turn the boolean prop into a feature flag.
+ */
+static NSString *const PiPEnabledFeatureFlag = @"pip.enabled";
+
+
 @implementation JitsiMeetView {
     /**
      * The unique identifier of this `JitsiMeetView` within the process for the
 - (void)setProps:(NSDictionary *_Nonnull)newProps {
     NSMutableDictionary *props = mergeProps([[JitsiMeet sharedInstance] getDefaultProps], newProps);
 
-    props[@"externalAPIScope"] = externalAPIScope;
+    // Set the PiP flag if it wasn't manually set.
+    NSMutableDictionary *featureFlags = props[@"flags"];
+    if (featureFlags[PiPEnabledFeatureFlag] == nil) {
+        featureFlags[PiPEnabledFeatureFlag]
+            = [NSNumber numberWithBool:
+               self.delegate && [self.delegate respondsToSelector:@selector(enterPictureInPicture:)]];
+    }
 
-    // TODO: put this in some 'flags' field
-    props[@"pictureInPictureEnabled"]
-        = @(self.delegate && [self.delegate respondsToSelector:@selector(enterPictureInPicture:)]);
+    props[@"externalAPIScope"] = externalAPIScope;
 
     // This method is supposed to be imperative i.e. a second
     // invocation with one and the same URL is expected to join the respective

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

 import '../../authentication';
 import { setColorScheme } from '../../base/color-scheme';
 import { DialogContainer } from '../../base/dialog';
+import { updateFlags } from '../../base/flags';
 import '../../base/jwt';
 import { Platform } from '../../base/react';
 import {
     externalAPIScope: string,
 
     /**
-     * Whether Picture-in-Picture is enabled. If {@code true}, a toolbar button
-     * is rendered in the {@link Conference} view to afford entering
-     * Picture-in-Picture.
+     * An object with the feature flags.
      */
-    pictureInPictureEnabled: boolean,
-
-    /**
-     * Whether the Welcome page is enabled. If {@code true}, the Welcome page is
-     * rendered when the {@link App} is not at a location (URL) identifying
-     * a Jitsi Meet conference/room.
-     */
-    welcomePageEnabled: boolean
+    flags: Object
 };
 
 /**
             // We set the color scheme early enough so then we avoid any
             // unnecessary re-renders.
             this.state.store.dispatch(setColorScheme(this.props.colorScheme));
+
+            // Ditto for feature flags.
+            this.state.store.dispatch(updateFlags(this.props.flags));
         });
     }
 

react/features/base/flags/actionTypes.js

+/**
+ * The type of Redux action which updates the feature flags.
+ *
+ * {
+ *     type: UPDATE_FLAGS,
+ *     flags: Object
+ * }
+ *
+ */
+export const UPDATE_FLAGS = 'UPDATE_FLAGS';

react/features/base/flags/actions.js

+// @flow
+
+import { UPDATE_FLAGS } from './actionTypes';
+
+/**
+ * Updates the current features flags with the given ones. They will be merged.
+ *
+ * @param {Object} flags - The new flags object.
+ * @returns {{
+ *     type: UPDATE_FLAGS,
+ *     flags: Object
+ * }}
+ */
+export function updateFlags(flags: Object) {
+    return {
+        type: UPDATE_FLAGS,
+        flags
+    };
+}

react/features/base/flags/constants.js

+// @flow
+
+/**
+ * Flag indicating if Picture-in-Picture should be enabled.
+ * Default: auto-detected.
+ */
+export const PIP_ENABLED = 'pip.enabled';
+
+/**
+ * Flag indicating if the welcome page should be enabled.
+ * Default: disabled (false).
+ */
+export const WELCOME_PAGE_ENABLED = 'welcomepage.enabled';

react/features/base/flags/functions.js

+// @flow
+
+import { getAppProp } from '../app';
+import { toState } from '../redux';
+
+/**
+ * Gets the value of a specific feature flag.
+ *
+ * @param {Function|Object} stateful - The redux store or {@code getState}
+ * function.
+ * @param {string} flag - The name of the React {@code Component} prop of
+ * the currently mounted {@code App} to get.
+ * @param {*} defaultValue - A default value for the flag, in case it's not defined.
+ * @returns {*} The value of the specified React {@code Compoennt} prop of the
+ * currently mounted {@code App}.
+ */
+export function getFeatureFlag(stateful: Function | Object, flag: string, defaultValue: any) {
+    const state = toState(stateful)['features/base/flags'];
+
+    if (state) {
+        const value = state[flag];
+
+        if (typeof value !== 'undefined') {
+            return value;
+        }
+    }
+
+    // Maybe the value hasn't made it to the redux store yet, check the app props.
+    const flags = getAppProp(stateful, 'flags') || {};
+
+    return flags[flag] || defaultValue;
+}

react/features/base/flags/index.js

+export * from './actions';
+export * from './actionTypes';
+export * from './constants';
+export * from './functions';
+
+import './reducer';

react/features/base/flags/reducer.js

+// @flow
+
+import _ from 'lodash';
+
+import { ReducerRegistry } from '../redux';
+
+import { UPDATE_FLAGS } from './actionTypes';
+
+/**
+ * Default state value for the feature flags.
+ */
+const DEFAULT_STATE = {};
+
+/**
+ * Reduces redux actions which handle feature flags.
+ *
+ * @param {State} state - The current redux state.
+ * @param {Action} action - The redux action to reduce.
+ * @param {string} action.type - The type of the redux action to reduce.
+ * @returns {State} The next redux state that is the result of reducing the
+ * specified action.
+ */
+ReducerRegistry.register('features/base/flags', (state = DEFAULT_STATE, action) => {
+    switch (action.type) {
+    case UPDATE_FLAGS: {
+        const newState = _.merge({}, state, action.flags);
+
+        return _.isEqual(state, newState) ? state : newState;
+    }
+    }
+
+    return state;
+});

react/features/conference/components/native/Conference.js

 import { BackHandler, NativeModules, SafeAreaView, StatusBar, View } from 'react-native';
 
 import { appNavigate } from '../../../app';
-import { getAppProp } from '../../../base/app';
+import { PIP_ENABLED, getFeatureFlag } from '../../../base/flags';
 import { getParticipantCount } from '../../../base/participants';
 import { Container, LoadingIndicator, TintedView } from '../../../base/react';
 import { connect } from '../../../base/redux';
          * @private
          * @type {boolean}
          */
-        _pictureInPictureEnabled: getAppProp(state, 'pictureInPictureEnabled'),
+        _pictureInPictureEnabled: getFeatureFlag(state, PIP_ENABLED),
 
         /**
          * The indicator which determines whether the UI is reduced (to

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

 import { NativeModules } from 'react-native';
 import type { Dispatch } from 'redux';
 
-import { getAppProp } from '../../base/app';
+import { PIP_ENABLED, getFeatureFlag } from '../../base/flags';
 import { Platform } from '../../base/react';
 
 import { ENTER_PICTURE_IN_PICTURE } from './actionTypes';
         // XXX At the time of this writing this action can only be dispatched by
         // the button which is on the conference view, which means that it's
         // fine to enter PiP mode.
-        if (getAppProp(getState, 'pictureInPictureEnabled')) {
+        if (getFeatureFlag(getState, PIP_ENABLED)) {
             const { PictureInPicture } = NativeModules;
             const p
                 = Platform.OS === 'android'

react/features/mobile/picture-in-picture/components/PictureInPictureButton.js

 // @flow
 
-import { getAppProp } from '../../../base/app';
+import { PIP_ENABLED, getFeatureFlag } from '../../../base/flags';
 import { translate } from '../../../base/i18n';
 import { connect } from '../../../base/redux';
 import { AbstractButton } from '../../../base/toolbox';
  */
 function _mapStateToProps(state): Object {
     return {
-        _enabled: Boolean(getAppProp(state, 'pictureInPictureEnabled'))
+        _enabled: Boolean(getFeatureFlag(state, PIP_ENABLED))
     };
 }
 

react/features/welcome/functions.js

 // @flow
 
-import { getAppProp } from '../base/app';
+import { WELCOME_PAGE_ENABLED, getFeatureFlag } from '../base/flags';
 import { toState } from '../base/redux';
 
 declare var APP: Object;
         // - Enabling/disabling the Welcome page on Web historically
         // automatically redirects to a random room and that does not make sense
         // on mobile (right now).
-        return Boolean(getAppProp(stateful, 'welcomePageEnabled'));
+        return Boolean(getFeatureFlag(stateful, WELCOME_PAGE_ENABLED));
     }
 
     return true;