BottomNavigation.kt

package com.example.c36b

import android.app.Activity
import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.compose.foundation.Image
import androidx.compose.foundation.background
import androidx.compose.foundation.border
import androidx.compose.foundation.horizontalScroll
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.fillMaxWidth
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.layout.width
import androidx.compose.foundation.lazy.LazyColumn
import androidx.compose.foundation.lazy.LazyRow
import androidx.compose.foundation.lazy.grid.GridCells
import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
import androidx.compose.foundation.rememberScrollState
import androidx.compose.foundation.shape.CircleShape
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.foundation.verticalScroll
import androidx.compose.material.icons.Icons
import androidx.compose.material.icons.filled.ArrowBack
import androidx.compose.material.icons.filled.Home
import androidx.compose.material.icons.filled.Person
import androidx.compose.material.icons.filled.Search
import androidx.compose.material.icons.filled.Settings
import androidx.compose.material3.Button
import androidx.compose.material3.ExperimentalMaterial3Api
import androidx.compose.material3.Icon
import androidx.compose.material3.IconButton
import androidx.compose.material3.NavigationBar
import androidx.compose.material3.NavigationBarItem
import androidx.compose.material3.Scaffold
import androidx.compose.material3.Text
import androidx.compose.material3.TopAppBar
import androidx.compose.material3.TopAppBarDefaults
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.draw.clip
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.layout.ContentScale
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.res.painterResource
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp
import com.example.c36b.ui.theme.C36BTheme

class NaviigationActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContent {
            NavigationBody()
        }
    }
}

@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun NavigationBody() {

    data class BottomNavItem(val label: String, val icon: ImageVector)

    val bottomNavItems = listOf(
        BottomNavItem("Home", Icons.Default.Home),
        BottomNavItem("Search", Icons.Default.Search),
        BottomNavItem("Profile", Icons.Default.Person)
    )

    var selectedIndex by remember { mutableStateOf(0) }


    Scaffold(
        bottomBar = {
            NavigationBar {
                bottomNavItems.forEachIndexed { index, item ->
                    NavigationBarItem(
                        icon = { Icon(item.icon, contentDescription = item.label) },
                        label = { Text(item.label) },
                        selected = selectedIndex == index,
                        onClick = { selectedIndex = index }
                    )
                }
            }
        },
    ) { innerPadding ->
        Box(
            modifier = Modifier
                .padding(innerPadding)
                .fillMaxSize(),
            contentAlignment = Alignment.Center
        ) {
            when (selectedIndex) {
                0 -> Home1()
                1 -> Home2()
                2 -> Home3()
            }
        }
    }
}

@Preview(showBackground = true)
@Composable
fun PrevNavigation() {
    NavigationBody()
}

@Composable
fun Home1() {
    Column(
        modifier = Modifier
            .fillMaxSize()
            .background(color = Color.Gray)
    ) {

    }
}


@Composable
fun Home2() {
    Column(
        modifier = Modifier
            .fillMaxSize()
            .background(color = Color.Yellow)
    ) {

    }
}


@Composable
fun Home3() {
    Column(
        modifier = Modifier
            .fillMaxSize()
            .background(color = Color.Green)
    ) {
    }
}