[FIX] Back button closing activity when on root stack screen (#2804)

* Make hardware back button to behave as home button on root screens

* Remove unnecessary code

* Remove handleBackPress from OnboardingView

* Fix lint

android/app/src/main/AndroidManifest.xml

@@ -29,7 +29,7 @@
             android:configChanges="keyboard|keyboardHidden|orientation|screenSize|uiMode"
             android:exported="true"
             android:label="@string/app_name"
-            android:launchMode="singleTask"
+            android:launchMode="singleTop"
             android:windowSoftInputMode="adjustResize">
             <intent-filter>
                 <action android:name="android.intent.action.DOWNLOAD_COMPLETE" />

android/app/src/main/java/chat/rocket/reactnative/MainActivity.java

@@ -37,6 +37,11 @@ public class MainActivity extends ReactFragmentActivity {
         RNBootSplash.init(R.drawable.launch_screen, MainActivity.this);
     }
 
+    @Override
+    public void invokeDefaultOnBackPressed() {
+        moveTaskToBack(true);
+    }
+
     /**
     * Returns the name of the main component registered from JavaScript. This is used to schedule
     * rendering of the component.

app/AppContainer.js

@@ -7,7 +7,7 @@ import { connect } from 'react-redux';
 import Navigation from './lib/Navigation';
 import { defaultHeader, getActiveRouteName, navigationTheme } from './utils/navigation';
 import {
-	ROOT_LOADING, ROOT_OUTSIDE, ROOT_NEW_SERVER, ROOT_INSIDE, ROOT_SET_USERNAME, ROOT_BACKGROUND
+	ROOT_LOADING, ROOT_OUTSIDE, ROOT_NEW_SERVER, ROOT_INSIDE, ROOT_SET_USERNAME
 } from './actions/app';
 
 // Stacks
@@ -65,7 +65,7 @@ const App = React.memo(({ root, isMasterDetail }) => {
 		>
 			<Stack.Navigator screenOptions={{ headerShown: false, animationEnabled: false }}>
 				<>
-					{root === ROOT_LOADING || root === ROOT_BACKGROUND ? (
+					{root === ROOT_LOADING ? (
 						<Stack.Screen
 							name='AuthLoading'
 							component={AuthLoadingView}

app/actions/app.js

@@ -5,7 +5,6 @@ export const ROOT_INSIDE = 'inside';
 export const ROOT_LOADING = 'loading';
 export const ROOT_NEW_SERVER = 'newServer';
 export const ROOT_SET_USERNAME = 'setUsername';
-export const ROOT_BACKGROUND = 'background';
 
 export function appStart({ root, ...args }) {
 	return {

app/views/OnboardingView/index.js

 import React from 'react';
 import {
-	View, Text, Image, BackHandler, Linking
+	View, Text, Image, Linking
 } from 'react-native';
 import PropTypes from 'prop-types';
-import { connect } from 'react-redux';
 import Orientation from 'react-native-orientation-locker';
 
-import { appStart as appStartAction, ROOT_BACKGROUND } from '../../actions/app';
 import I18n from '../../i18n';
 import Button from '../../containers/Button';
 import styles from './styles';
@@ -23,7 +21,6 @@ class OnboardingView extends React.Component {
 
 	static propTypes = {
 		navigation: PropTypes.object,
-		appStart: PropTypes.func,
 		theme: PropTypes.string
 	}
 
@@ -34,18 +31,6 @@ class OnboardingView extends React.Component {
 		}
 	}
 
-	componentDidMount() {
-		const { navigation } = this.props;
-		this.unsubscribeFocus = navigation.addListener('focus', () => {
-			this.backHandler = BackHandler.addEventListener('hardwareBackPress', this.handleBackPress);
-		});
-		this.unsubscribeBlur = navigation.addListener('blur', () => {
-			if (this.backHandler && this.backHandler.remove) {
-				this.backHandler.remove();
-			}
-		});
-	}
-
 	shouldComponentUpdate(nextProps) {
 		const { theme } = this.props;
 		if (theme !== nextProps.theme) {
@@ -54,21 +39,6 @@ class OnboardingView extends React.Component {
 		return false;
 	}
 
-	componentWillUnmount() {
-		if (this.unsubscribeFocus) {
-			this.unsubscribeFocus();
-		}
-		if (this.unsubscribeBlur) {
-			this.unsubscribeBlur();
-		}
-	}
-
-	handleBackPress = () => {
-		const { appStart } = this.props;
-		appStart({ root: ROOT_BACKGROUND });
-		return false;
-	}
-
 	connectServer = () => {
 		logEvent(events.ONBOARD_JOIN_A_WORKSPACE);
 		const { navigation } = this.props;
@@ -116,8 +86,4 @@ class OnboardingView extends React.Component {
 	}
 }
 
-const mapDispatchToProps = dispatch => ({
-	appStart: params => dispatch(appStartAction(params))
-});
-
-export default connect(null, mapDispatchToProps)(withTheme(OnboardingView));
+export default withTheme(OnboardingView);

app/views/RoomsListView/index.js

@@ -29,7 +29,6 @@ import {
 	roomsRequest as roomsRequestAction,
 	closeServerDropdown as closeServerDropdownAction
 } from '../../actions/rooms';
-import { appStart as appStartAction, ROOT_BACKGROUND } from '../../actions/app';
 import debounce from '../../utils/debounce';
 import { isIOS, isTablet } from '../../utils/deviceInfo';
 import RoomsListHeaderView from './Header';
@@ -549,12 +548,10 @@ class RoomsListView extends React.Component {
 
 	handleBackPress = () => {
 		const { searching } = this.state;
-		const { appStart } = this.props;
 		if (searching) {
 			this.cancelSearch();
 			return true;
 		}
-		appStart({ root: ROOT_BACKGROUND });
 		return false;
 	};
 
@@ -1044,7 +1041,6 @@ const mapDispatchToProps = dispatch => ({
 	toggleSortDropdown: () => dispatch(toggleSortDropdownAction()),
 	openSearchHeader: () => dispatch(openSearchHeaderAction()),
 	closeSearchHeader: () => dispatch(closeSearchHeaderAction()),
-	appStart: params => dispatch(appStartAction(params)),
 	roomsRequest: params => dispatch(roomsRequestAction(params)),
 	selectServerRequest: server => dispatch(selectServerRequestAction(server)),
 	closeServerDropdown: () => dispatch(closeServerDropdownAction())