App.js

// Imports
import "react-native-gesture-handler";
import { StyleSheet, Text, View } from "react-native";
import * as React from "react";
import { NavigationContainer } from "@react-navigation/native";
import LoginScreen from "./screens/LoginScreen";
import { createStackNavigator } from "@react-navigation/stack";
import RegisterScreen from "./screens/RegisterScreen";
import HomeScreen from "./screens/HomeScreen";
import AddChatScreen from "./screens/AddChatScreen";
import ChatScreen from "./screens/ChatScreen";

// Create the stack
const Stack = createStackNavigator();

// Change header style
const globalScreenOptions = {
  headerStyle: { backgroundColor: "#2C6BED" },
  headerTitleStyle: { color: "white" },
  headerTintColor: "white",
  headerTitleAlign: "center", //Was not in video, needed in order to center header
};

// Creates a stack of screens
// Makes the default screen the login screen, calls the LoginScreen component from LoginScreen.js.
// The register screen is hidden underneath the login screen ...it is "stacked"
export default function App() {
  return (
    <NavigationContainer>
      <Stack.Navigator
        // initialRouteName="Home" //Force to home page, for testing
        screenOptions={globalScreenOptions}
      >
        <Stack.Screen name="Login" component={LoginScreen} />
        <Stack.Screen name="Register" component={RegisterScreen} />
        <Stack.Screen name="Home" component={HomeScreen} />
        <Stack.Screen name="AddChat" component={AddChatScreen} />
        <Stack.Screen name="Chat" component={ChatScreen} />
      </Stack.Navigator>
    </NavigationContainer>
  );
}

// Style the landing page,
// however it doesn't do anything because the code directly goes to the login page.
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: "#fff",
    alignItems: "center",
    justifyContent: "center",
  },
});