Module, provides

app/build.gradle

@@ -1,6 +1,7 @@
 plugins {
     id 'com.android.application'
     id 'kotlin-android'
+    id 'kotlin-kapt'
 }
 
 android {
@@ -34,9 +35,13 @@ android {
 dependencies {
 
     implementation 'androidx.core:core-ktx:1.7.0'
-    implementation 'androidx.appcompat:appcompat:1.3.1'
-    implementation 'com.google.android.material:material:1.4.0'
-    implementation 'androidx.constraintlayout:constraintlayout:2.1.1'
+    implementation 'androidx.appcompat:appcompat:1.4.1'
+    implementation 'com.google.android.material:material:1.5.0'
+    implementation 'androidx.constraintlayout:constraintlayout:2.1.3'
+
+    implementation 'com.google.dagger:dagger:2.39.1'
+    kapt 'com.google.dagger:dagger-compiler:2.39.1'
+
     testImplementation 'junit:junit:4.+'
     androidTestImplementation 'androidx.test.ext:junit:1.1.3'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'

app/src/main/java/com/example/dependencyinjectionstart/example1/Activity.kt

@@ -1,14 +1,13 @@
 package com.example.dependencyinjectionstart.example1
 
+import javax.inject.Inject
+
 class Activity {
 
-    val monitor = Monitor()
-    val keyboard = Keyboard()
-    val mouse = Mouse()
-    val computerTower = ComputerTower(
-        Storage(),
-        Memory(),
-        Processor()
-    )
-    val computer = Computer(monitor, computerTower, keyboard, mouse)
+    @Inject
+    lateinit var computer: Computer
+
+    init {
+        DaggerMyComponent.create().inject(this)
+    }
 }

app/src/main/java/com/example/dependencyinjectionstart/example1/Component.kt

@@ -0,0 +1,20 @@
+package com.example.dependencyinjectionstart.example1
+
+class Component {
+
+    private fun getComputer() : Computer {
+        val monitor = Monitor()
+        val keyboard = Keyboard()
+        val mouse = Mouse()
+        val computerTower = ComputerTower(
+            Storage(),
+            Memory(),
+            Processor()
+        )
+        return Computer(monitor, computerTower, keyboard, mouse)
+    }
+
+    fun inject(activity: Activity) {
+//        activity.keyboard = Keyboard()
+    }
+}

app/src/main/java/com/example/dependencyinjectionstart/example1/Computer.kt

@@ -1,6 +1,6 @@
 package com.example.dependencyinjectionstart.example1
 
-class Computer(
+class Computer (
     val monitor: Monitor,
     val computerTower: ComputerTower,
     val keyboard: Keyboard,

app/src/main/java/com/example/dependencyinjectionstart/example1/ComputerModule.kt

@@ -0,0 +1,60 @@
+package com.example.dependencyinjectionstart.example1
+
+import dagger.Module
+import dagger.Provides
+
+
+// Если у нас нет доступа к классу (например, библиотеку), то с помощью модуля мы можем создать
+// экземпляр класса с помощью Модуля и его провайдера
+@Module
+class ComputerModule {
+
+    @Provides
+    fun provideMonitor(): Monitor {
+        return Monitor()
+    }
+
+    @Provides
+    fun provideProcessor(): Processor {
+        return Processor()
+    }
+
+    @Provides
+    fun provideMemory(): Memory {
+        return Memory()
+    }
+
+    @Provides
+    fun provideStorage(): Storage {
+        return Storage()
+    }
+
+    @Provides
+    fun provideMouse(): Mouse {
+        return Mouse()
+    }
+
+    @Provides
+    fun provideKeyboard(): Keyboard {
+        return Keyboard()
+    }
+
+    @Provides
+    fun provideComputerTower(
+        storage: Storage,
+        memory: Memory,
+        processor: Processor
+    ): ComputerTower {
+        return ComputerTower(storage, memory, processor)
+    }
+
+    @Provides
+    fun provideComputer(
+        monitor: Monitor,
+        computerTower: ComputerTower,
+        keyboard: Keyboard,
+        mouse: Mouse
+    ): Computer {
+        return Computer(monitor, computerTower, keyboard, mouse)
+    }
+}

app/src/main/java/com/example/dependencyinjectionstart/example1/ComputerTower.kt

@@ -1,6 +1,6 @@
 package com.example.dependencyinjectionstart.example1
 
-class ComputerTower(
+class ComputerTower (
     val storage: Storage,
     val memory: Memory,
     val processor: Processor

app/src/main/java/com/example/dependencyinjectionstart/example1/MyComponent.kt

@@ -0,0 +1,9 @@
+package com.example.dependencyinjectionstart.example1
+
+import dagger.Component
+
+@Component(modules = [ComputerModule::class])
+interface MyComponent {
+
+    fun inject(activity: Activity)
+}

app/src/main/java/com/example/dependencyinjectionstart/example2/presentation/MainActivity.kt

@@ -3,10 +3,13 @@ package com.example.dependencyinjectionstart.example2.presentation
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
 import com.example.dependencyinjectionstart.R
+import com.example.dependencyinjectionstart.example1.Activity
 
 class MainActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
+        val activity = Activity()
+        activity.computer.toString()
     }
 }