Вступ до розробки Android-застосунків

android {
    compileSdk = 36

    defaultConfig {
        minSdk = 24
        targetSdk = 36
    }
}

dependencies {
    implementation("androidx.activity:activity-compose:...")
    implementation("androidx.compose.material3:material3:...")
}

MyApplication/
├── app/
│   ├── src/
│   │   ├── main/
│   │   │   ├── java/
│   │   │   │   └── com/example/myapplication/
│   │   │   │       └── MainActivity.kt
│   │   │   ├── res/
│   │   │   │   ├── drawable/
│   │   │   │   ├── mipmap/
│   │   │   │   ├── values/
│   │   │   │   └── xml/
│   │   │   └── AndroidManifest.xml
│   │   ├── test/
│   │   └── androidTest/
│   └── build.gradle.kts
├── gradle/
├── build.gradle.kts
├── settings.gradle.kts
└── gradle.properties

<manifest xmlns:android="http://schemas.android.com/apk/res/android">

    <application
        android:theme="@style/Theme.MyApplication">

        <activity
            android:name=".MainActivity"
            android:exported="true">

            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>

        </activity>

    </application>

</manifest>

val studentName: String = "Олена"
val courseNumber: Int = 2
val rating: Double = 91.5
val isActive: Boolean = true

val university = "ДДТУ"
var completedLabs = 2

completedLabs = 3

val name = "Анастасія"
val age = 20
val progress = 0.75

fun greet(name: String): String {
    return "Вітаю, $name!"
}

fun getStatus(score: Int): String {
    return if (score >= 60) {
        "Зараховано"
    } else {
        "Потрібне доопрацювання"
    }
}

fun getGrade(score: Int): String {
    return when {
        score >= 90 -> "Відмінно"
        score >= 75 -> "Добре"
        score >= 60 -> "Задовільно"
        else -> "Потрібне доопрацювання"
    }
}

var userName: String? = null

val length = userName?.length

val displayName = userName ?: "Гість"

val topics = listOf(
    "Kotlin",
    "Compose",
    "Navigation",
    "Room"
)

for (topic in topics) {
    println(topic)
}

data class Student(
    val name: String,
    val group: String,
    val rating: Double
)

val student = Student(
    name = "Олена",
    group = "ПЗ-23",
    rating = 91.5
)

val onClick = {
    println("Кнопку натиснуто")
}

val onNameChanged: (String) -> Unit = { newName ->
    println(newName)
}

package com.example.myapplication

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.material3.Text

class MainActivity : ComponentActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContent {
            Text(
                text = "Привіт, Android!"
            )
        }
    }
}

onCreate()
onStart()
onResume()
onPause()
onStop()
onDestroy()

import android.os.Bundle
import android.util.Log
import androidx.activity.ComponentActivity

class MainActivity : ComponentActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        Log.d("LIFECYCLE", "onCreate")
    }

    override fun onStart() {
        super.onStart()
        Log.d("LIFECYCLE", "onStart")
    }

    override fun onResume() {
        super.onResume()
        Log.d("LIFECYCLE", "onResume")
    }

    override fun onPause() {
        Log.d("LIFECYCLE", "onPause")
        super.onPause()
    }

    override fun onStop() {
        Log.d("LIFECYCLE", "onStop")
        super.onStop()
    }

    override fun onDestroy() {
        Log.d("LIFECYCLE", "onDestroy")
        super.onDestroy()
    }
}

@Composable
fun Greeting(name: String) {
    Text(
        text = "Вітаю, $name!"
    )
}

UI = f(state)

import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.padding
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp

@Composable
fun StudentScreen() {

    Column(
        modifier = Modifier.padding(24.dp)
    ) {
        Text(text = "Програмування мобільних застосунків")
        Text(text = "Перша Android-сторінка")
    }
}

Text(
    text = "Android",
    modifier = Modifier
        .fillMaxWidth()
        .padding(16.dp)
)

@Composable
fun SaveButton() {

    Button(
        onClick = {
            println("Збереження")
        }
    ) {
        Text(text = "Зберегти")
    }
}

var count by remember {
    mutableStateOf(0)
}

import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.padding
import androidx.compose.material3.Button
import androidx.compose.material3.Text
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.Modifier
import androidx.compose.ui.unit.dp

@Composable
fun CounterScreen() {

    // Стан лічильника.
    var count by remember {
        mutableStateOf(0)
    }

    Column(
        modifier = Modifier.padding(24.dp)
    ) {

        // Текст залежить від count.
        Text(
            text = "Натиснуто: $count"
        )

        Button(
            onClick = {
                // Зміна state.
                count++
            }
        ) {
            Text(text = "Натиснути")
        }
    }
}

@Composable
fun StudentForm() {

    var name by remember {
        mutableStateOf("")
    }

    Column(
        modifier = Modifier.padding(24.dp)
    ) {
        OutlinedTextField(
            value = name,
            onValueChange = { newValue ->
                name = newValue
            },
            label = {
                Text("Ім’я студента")
            }
        )

        Text(
            text = "Введено: $name"
        )
    }
}

@Composable
fun StudentScreen() {

    var name by remember {
        mutableStateOf("")
    }

    StudentNameInput(
        name = name,
        onNameChange = { newName ->
            name = newName
        }
    )
}

@Composable
fun StudentNameInput(
    name: String,
    onNameChange: (String) -> Unit
) {
    OutlinedTextField(
        value = name,
        onValueChange = onNameChange,
        label = {
            Text("Ім’я")
        }
    )
}

var count by rememberSaveable {
    mutableStateOf(0)
}

import androidx.compose.runtime.Composable
import androidx.compose.ui.tooling.preview.Preview

@Preview(showBackground = true)
@Composable
fun StudentScreenPreview() {
    StudentScreen()
}

MyApplicationTheme {
    CourseScreen()
}

Text(
    text = "Заголовок",
    style = MaterialTheme.typography.headlineMedium,
    color = MaterialTheme.colorScheme.primary
)

<resources>
    <string name="app_name">Mobile Course</string>
    <string name="welcome_message">Вітаємо у застосунку</string>
</resources>

Text(
    text = stringResource(R.string.welcome_message)
)

R.string.app_name
R.drawable.logo
R.color.primary

res/values/strings.xml
res/values-uk/strings.xml
res/values-en/strings.xml

<uses-permission
    android:name="android.permission.CAMERA" />

adb devices

List of devices attached
emulator-5554    device

Log.d(
    "COURSE",
    "MainActivity створено"
)

V — verbose
D — debug
I — info
W — warning
E — error

val count: Int = "п'ять"

FATAL EXCEPTION: main
java.lang.IllegalStateException: ...
    at com.example.mobilecourse.StudentScreen(...)
    at com.example.mobilecourse.MainActivity(...)

package com.example.mobilecourse

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.foundation.layout.Arrangement
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.padding
import androidx.compose.material3.Button
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Surface
import androidx.compose.material3.Text
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.Modifier
import androidx.compose.ui.unit.dp

class MainActivity : ComponentActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContent {
            MaterialTheme {
                Surface {
                    CourseScreen()
                }
            }
        }
    }
}

@Composable
fun CourseScreen() {

    var completedTopics by remember {
        mutableStateOf(0)
    }

    Column(
        modifier = Modifier
            .fillMaxSize()
            .padding(24.dp),
        verticalArrangement = Arrangement.spacedBy(16.dp)
    ) {

        Text(
            text = "Програмування мобільних застосунків",
            style = MaterialTheme.typography.headlineMedium
        )

        Text(
            text = "Вивчено тем: $completedTopics",
            style = MaterialTheme.typography.bodyLarge
        )

        Button(
            onClick = {
                completedTopics++
            }
        ) {
            Text(text = "Позначити тему")
        }
    }
}

ViewModel
Navigation
Repository
REST API
Room
Coroutines
Flow
Dependency Injection
Testing

@Composable
fun LearningScreen() {

    var lessonNumber by remember {
        mutableStateOf(1)
    }

    Column(
        modifier = Modifier.padding(24.dp),
        verticalArrangement = Arrangement.spacedBy(12.dp)
    ) {

        Text(text = "Мобільна розробка")

        Text(
            text = "Поточна тема: $lessonNumber"
        )

        Button(
            onClick = {
                lessonNumber++
            }
        ) {
            Text(text = "Наступна тема")
        }
    }
}