Initial commit

app/src/main/java/com/aryan/reader/MainScreen.kt

@@ -0,0 +1,94 @@
+// MainScreen.kt
+package com.aryan.reader
+
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.pager.HorizontalPager
+import androidx.compose.foundation.pager.rememberPagerState
+import androidx.compose.material3.Icon
+import androidx.compose.material3.NavigationBar
+import androidx.compose.material3.NavigationBarItem
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.windowsizeclass.WindowSizeClass
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.painterResource
+import kotlinx.coroutines.launch
+import androidx.compose.runtime.getValue
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.navigation.NavHostController
+
+sealed class BottomBarScreen(val route: String, val label: String, val iconResId: Int) {
+    object Home : BottomBarScreen("home", "Home", R.drawable.home)
+    object Library : BottomBarScreen("library", "Library", R.drawable.library_books)
+}
+
+private val bottomBarItems = listOf(
+    BottomBarScreen.Home,
+    BottomBarScreen.Library,
+)
+
+@Composable
+fun MainScreen(
+    viewModel: MainViewModel,
+    windowSizeClass: WindowSizeClass,
+    navController: NavHostController
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    val viewingShelfName = uiState.viewingShelfName
+
+    if (viewingShelfName != null) {
+        ShelfScreen(viewModel = viewModel)
+    } else {
+        val pagerState = rememberPagerState(
+            initialPage = uiState.mainScreenStartPage,
+            pageCount = { bottomBarItems.size }
+        )
+        val scope = rememberCoroutineScope()
+
+        LaunchedEffect(pagerState.currentPage) {
+            viewModel.setMainScreenPage(pagerState.currentPage)
+        }
+
+        Scaffold(
+            bottomBar = {
+                NavigationBar {
+                    bottomBarItems.forEachIndexed { index, screen ->
+                        NavigationBarItem(
+                            icon = { Icon(painterResource(id = screen.iconResId), contentDescription = screen.label) },
+                            label = { Text(screen.label) },
+                            selected = pagerState.currentPage == index,
+                            onClick = {
+                                scope.launch {
+                                    pagerState.animateScrollToPage(index)
+                                }
+                            }
+                        )
+                    }
+                }
+            }
+        ) { innerPadding ->
+            HorizontalPager(
+                state = pagerState,
+                modifier = Modifier
+                    .fillMaxSize()
+                    .padding(innerPadding),
+                key = { bottomBarItems[it].route },
+                beyondViewportPageCount = 1,
+                userScrollEnabled = false
+            ) { page ->
+                when (page) {
+                    0 -> HomeScreen(
+                        viewModel = viewModel,
+                        windowSizeClass = windowSizeClass,
+                        navController = navController
+                    )
+                    1 -> LibraryScreen(viewModel = viewModel)
+                }
+            }
+        }
+    }
+}