Category: Android

MainActivity.kt は「アプリの起動エントリポイント（＝最初に表示される画面）」を定義する場所
UI（画面の中身）はComposable関数として別ファイルに分けて定義 するのが一般的

package com.example.zeus

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.animation.core.animateDpAsState
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.*
import androidx.compose.material3.Button
import androidx.compose.material3.Text
import androidx.compose.runtime.*
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp

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

@Composable
fun AnimatedBoxDemo() {
    var expanded by remember { mutableStateOf(false) }

    val boxSize by animateDpAsState(
        targetValue = if (expanded) 200.dp else 100.dp,
        label = "box animation"
    )

    Column(
        modifier = Modifier
            .fillMaxSize()
            .padding(16.dp),
        horizontalAlignment = Alignment.CenterHorizontally,
        verticalArrangement = Arrangement.Center
    ) {
        Box(
            modifier = Modifier
                .size(boxSize)
                .background(Color(0xFF4CAF50))
        )

        Spacer(modifier = Modifier.height(24.dp))

        Button(onClick = { expanded = !expanded }) {
            Text(if (expanded) "縮小" else "拡大")
        }
    }
}

byはプロパティデリゲーション（Property Delegation）というkotlin独特の記法で任せるという書き方。

/data/api/ApiService.kt

interface ApiService {
    @GET("user/profile")
    suspend fun getUserProfile(): Response<UserProfile>
}

data/api/AuthInterceptor.kt

class AuthInterceptor(private val tokenProvider: ()-> String?):Interceptor {
    override fun intercept(chain: Interceptor.Chain): Response {
        val token = tokenProvider()
        val request = chain.request().newBuilder().apply {
            token?.let {
                addHeader("Authorization", "Bearer $it")
            }
        }.build()
        return chain.proceed(request)
    }
}

data/api/ApiClient.kt

object ApiClient {
    fun create(tokenProvider: () -> String?): ApiService {
        val client = OkHttpClient.Builder()
            .addInterceptor(AuthInterceptor(tokenProvider))
            .build()

        return Retrofit.Builder()
            .baseUrl("https://your-api.com/") // 実際のURLに変更
            .client(client)
            .addConverterFactory(GsonConverterFactory.create())
            .build()
            .create(ApiService::class.java)
    }
}

presentation/viewmodel/MyViewModel.kt

class MyViewModel : ViewModel() {
    private val token = ""

    private val apiService = ApiClient.create {token}

    var userProfile by mutableStateOf<UserProfile?>(null)
        private set

    fun loadUserProfile() {
        viewModelScope.launch {
            try {
                val response = apiService.getUserProfile()
                if (response.isSuccessful) {
                    userProfile = response.body()
                } else {
                    // エラー処理
                }
            } catch (e: Exception) {
                // 通信エラーなど
            }
        }
    }

}

presentation/screen/ProfileScreen.kt

@Composable
fun ProfileScreen(viewModel: MyViewModel = viewModel()) {
    val profile = viewModel.userProfile

    LaunchedEffect(Unit) {
        viewModel.loadUserProfile()
    }

    profile?.let {
        Text("ユーザー名: ${it.name}")
    } ?: Text("読み込み中...")
}

domain/model/UserProfile.kt

data class UserProfile(
    val id: Int,
    val name: String,
    val email: String
)

class MainActivity : ComponentActivity() {

    overrider fun onCreate(savedInstanceState: Bundle?){
        super.onCreate(saveInstanceState)
        setContent {
            MaterialTheme {
                AnimatedBoxExample()
            }
        }
    }

    @Composable
    fun AnimatedBoxExample() {
        var expaned by remember {mutableStateOf(false)}

        val boxSize by animateDpAsState(
            targetValue = if(expanded) 200.dp else 100.dp,
            label ="BoxSizeAnimation"
        )

        Column(
            modifier = Modifier
                .fillMaxSize()
                .padding(32.dp),
            verticalArrangement = Arrangement.Center,
            horizontalAlignment = Alignment.CenterHorizontally
        ) {
            Box(
                modifier = Modifier
                    .size(boxSize)
                    .padding(8.dp),
                contentAlignment = Alignment.Center
            ) {
                color = MaterialTheme.colorScheme.primary,
                modifier = Modifier.fillMaxSize()
            } {}
        }
        Spacer(modifier = Modifier.height(16.dp))

        Button(onClick= {expanded = !expanded}) {
            Text(text =if (expanded) "縮小する" else "拡大する")
        }
    }
}

animateDpAsState：Dp 値を滑らかにアニメーションさせます。
targetValue：アニメーションで変化させたい目標値。
expanded を切り替えることで、Boxのサイズが 100.dp ↔ 200.dp にアニメーション付きで変化。

Open storage area
– Delete unnecessary files that waste space and free up space for what you need.

– Delete unnecessary file such as cache, temporary files, residual data from your Android device or app
– See which apps occupy the most space
– Identify and delete apps you no longer use

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="#ffaa88"
    tools:context=".MainActivity">

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/word"/>
        <EditText
            android:id="@+id/uriname"
            android:inputType="text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />
    </LinearLayout>

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal" >
        <Button
            adnroid:id="@+id/post"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:text="@string/post" />
        <Button
            android:id="@+id/browser"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:text="@string/browser" />
    </LinearLayout>

    <TextView
        android:id="@+id/text_view"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>

file -> project structure を押す

dependency -> libraries dependency を選択する

dependenciesが追加される。

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:26.1.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'org.jdom:jdom2:2.0.6'
}