#1 - State hoisting

Jikdroid · Jan 20, 2023 · bce72b6 · bce72b6
1 parent db7c1f0
commit bce72b6
Showing 1 changed file with 68 additions and 23 deletions.
diff --git a/Basics_Codelab/app/src/main/java/jik/compose/basicscodelab/MainActivity.kt b/Basics_Codelab/app/src/main/java/jik/compose/basicscodelab/MainActivity.kt
@@ -3,17 +3,10 @@ package jik.compose.basicscodelab
 import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
-import androidx.compose.foundation.layout.Column
-import androidx.compose.foundation.layout.Row
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.padding
-import androidx.compose.material3.ElevatedButton
-import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.Surface
-import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
+import androidx.compose.foundation.layout.*
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
@@ -31,7 +24,57 @@ class MainActivity : ComponentActivity() {
 }
 
 @Composable
-private fun MyApp(
+private fun MyApp(modifier: Modifier = Modifier) {
+    var shouldShowOnboarding by remember { mutableStateOf(true) }
+
+    Surface(modifier) {
+        if (shouldShowOnboarding) {
+            OnboardingScreen(onContinueClicked = { shouldShowOnboarding = false})
+        } else {
+            Greetings()
+        }
+    }
+}
+
+@Preview
+@Composable
+private fun MyAppPreview() {
+    BasicsCodelabTheme {
+        MyApp(Modifier.fillMaxSize())
+    }
+}
+
+@Composable
+fun OnboardingScreen(
+    onContinueClicked: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+
+    Column(
+        modifier = modifier.fillMaxSize(),
+        verticalArrangement = Arrangement.Center,
+        horizontalAlignment = Alignment.CenterHorizontally
+    ) {
+        Text("Welcome to the Basics Codelab!")
+        Button(
+            modifier = Modifier.padding(vertical = 24.dp),
+            onClick = { onContinueClicked() },
+        ) {
+            Text("Continue")
+        }
+    }
+}
+
+@Preview(showBackground = true, widthDp = 320, heightDp = 320)
+@Composable
+fun OnboardingPreview() {
+    BasicsCodelabTheme {
+        OnboardingScreen(onContinueClicked = {})
+    }
+}
+
+@Composable
+private fun Greetings(
     modifier: Modifier = Modifier,
     names: List<String> = listOf("World", "compose")
 ) {
@@ -42,6 +85,14 @@ private fun MyApp(
     }
 }
 
+@Preview(showBackground = true, widthDp = 320)
+@Composable
+fun GreetingsPreview() {
+    BasicsCodelabTheme {
+        Greetings()
+    }
+}
+
 @Composable
 fun Greeting(name: String) {
     val expanded = remember { mutableStateOf(false) }
@@ -52,9 +103,11 @@ fun Greeting(name: String) {
         modifier = Modifier.padding(vertical = 4.dp, horizontal = 8.dp)
     ) {
         Row(modifier = Modifier.padding(24.dp)) {
-            Column(modifier = Modifier
-                .weight(1f)
-                .padding(bottom = extraPadding)) {
+            Column(
+                modifier = Modifier
+                    .weight(1f)
+                    .padding(bottom = extraPadding)
+            ) {
                 Text(text = "Hello,")
                 Text(text = name)
             }
@@ -64,11 +117,3 @@ fun Greeting(name: String) {
         }
     }
 }
-
-@Preview(showBackground = true, widthDp = 320)
-@Composable
-fun DefaultPreview() {
-    BasicsCodelabTheme {
-        MyApp()
-    }
-}