Unify Todo Data Model and Improve Adapter Architecture

.gitignore

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+# Android Studio
+*.iml
+<<<<<<< HEAD
+.gradle
+/local.properties
+/.idea/
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.cxx
+
+# Gradle files
+gradle/
+gradlew
+gradlew.bat
+
+# Compiled class files
+*.class
+
+# Log files
+*.log
+
+# IntelliJ
+out/
+
+# Kotlin build files
+build/
+*.hprof
+=======
+.gradle/
+build/
+local.properties
+.idea/
+
+# Kotlin and Android specific
+*.class
+*.log
+*.ctxt
+.mtj.tmp/
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+>>>>>>> pr-4-gapcomputer-kotlinTodoApp
+
+# Virtual machine crash logs
+hs_err_pid*
+
+<<<<<<< HEAD
+# Dependency directories
+node_modules/
+/app/build/
+
+# Local configuration file
+local.properties
+
+# Android Profiling
+*.hprof
+
+# Sensitive or local files
+.env
+
+# Temp files
+*.swp
+*~
+.tmp
+
+# Logs
+logs/
+=======
+# OS generated files
+.DS_Store
+.DS_Store?
+._*
+.Spotlight-V100
+.Trashes
+ehthumbs.db
+Thumbs.db
+
+# Dependency directories
+/node_modules
+/captures
+/app/build
+
+# Environment and local configuration
+.env
+*.keystore
+>>>>>>> pr-4-gapcomputer-kotlinTodoApp

app/build.gradle.kts

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+plugins {
+    id("com.android.application")
+    id("kotlin-android")
+    id("kotlin-kapt")
+}
+
+android {
+    compileSdk = 33
+
+    defaultConfig {
+        applicationId = "com.example.todoapp"
+        minSdk = 24
+        targetSdk = 33
+        versionCode = 1
+        versionName = "1.0"
+
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildFeatures {
+        viewBinding = true
+    }
+}
+
+dependencies {
+    // Kotlin standard library
+    implementation("org.jetbrains.kotlin:kotlin-stdlib:1.8.0")
+
+    // AndroidX
+    implementation("androidx.core:core-ktx:1.9.0")
+    implementation("androidx.appcompat:appcompat:1.6.1")
+    implementation("androidx.recyclerview:recyclerview:1.3.0")
+
+    // Testing
+    testImplementation("junit:junit:4.13.2")
+    testImplementation("org.robolectric:robolectric:4.9")
+    testImplementation("org.mockito:mockito-core:4.8.0")
+    testImplementation("androidx.test:core:1.5.0")
+
+    // Android Testing
+    androidTestImplementation("androidx.test.ext:junit:1.1.5")
+    androidTestImplementation("androidx.test.espresso:espresso-core:3.5.1")
+}
+
+tasks.withType<Test> {
+    configure<JacocoTaskExtension> {
+        isEnabled = true
+    }
+}

app/src/main/java/com/example/todoapp/data/dao/TodoDao.kt

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+package com.example.todoapp.data.dao
+
+import androidx.room.Dao
+import androidx.room.Delete
+import androidx.room.Insert
+import androidx.room.Query
+import androidx.room.Update
+import com.example.todoapp.data.entity.TodoItem
+
+@Dao
+interface TodoDao {
+    /**
+     * Inserts a new todo item into the database
+     * 
+     * @param todoItem The todo item to be inserted
+     * @return The ID of the inserted item
+     */
+    @Insert
+    suspend fun insert(todoItem: TodoItem): Long
+
+    /**
+     * Retrieves all todo items from the database
+     * 
+     * @return A list of all todo items
+     */
+    @Query("SELECT * FROM todo_items")
+    suspend fun getAllTodos(): List<TodoItem>
+
+    /**
+     * Deletes a specific todo item from the database by its ID
+     * 
+     * @param id The unique identifier of the todo item to be deleted
+     * @return Number of rows affected (should be 1 if deletion is successful)
+     */
+    @Query("DELETE FROM todo_items WHERE id = :id")
+    suspend fun deleteTodoById(id: Long): Int
+
+    /**
+     * Alternative deletion method using the entire TodoItem object
+     * 
+     * @param todoItem The todo item to be deleted
+     */
+    @Delete
+    suspend fun deleteTodo(todoItem: TodoItem)
+}

app/src/main/java/com/example/todoapp/data/database/TodoDatabase.kt

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+package com.example.todoapp.data.database
+
+import androidx.room.Database
+import androidx.room.RoomDatabase
+import com.example.todoapp.data.dao.TodoDao
+import com.example.todoapp.data.entity.TodoItem
+
+@Database(entities = [TodoItem::class], version = 1, exportSchema = false)
+abstract class TodoDatabase : RoomDatabase() {
+    abstract fun todoDao(): TodoDao
+
+    companion object {
+        // Singleton implementation can be added here in future
+    }
+}

app/src/main/java/com/example/todoapp/data/entity/TodoItem.kt

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+package com.example.todoapp.data.entity
+
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+
+@Entity(tableName = "todo_items")
+data class TodoItem(
+    @PrimaryKey(autoGenerate = true)
+    val id: Long = 0,
+
+    @ColumnInfo(name = "title")
+    val title: String,
+
+    @ColumnInfo(name = "description")
+    val description: String,
+
+    @ColumnInfo(name = "is_completed")
+    val isCompleted: Boolean = false
+)

app/src/main/java/com/example/todoapp/ui/adapter/TodoListAdapter.kt

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+package com.example.todoapp.ui.adapter
+
+import android.app.AlertDialog
+import android.content.Context
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import androidx.recyclerview.widget.RecyclerView
+import com.example.todoapp.R
+import com.example.todoapp.data.entity.TodoItem
+import com.example.todoapp.databinding.ItemTodoBinding
+import com.example.todoapp.ui.viewmodel.TodoViewModel
+
+/**
+ * RecyclerView adapter for displaying and managing Todo items
+ * 
+ * @property context Android context for showing dialogs
+ * @property viewModel ViewModel for handling Todo item operations
+ * @property todoList List of Todo items to display
+ */
+class TodoListAdapter(
+    private val context: Context,
+    private val viewModel: TodoViewModel,
+    private var todoList: List<TodoItem>
+) : RecyclerView.Adapter<TodoListAdapter.TodoViewHolder>() {
+
+    /**
+     * Shows a confirmation dialog before deleting a Todo item
+     * 
+     * @param todo The Todo item to be deleted
+     */
+    private fun showDeleteConfirmationDialog(todo: TodoItem) {
+        AlertDialog.Builder(context)
+            .setTitle(R.string.delete_todo_title)
+            .setMessage(R.string.delete_todo_message)
+            .setPositiveButton(R.string.delete) { dialog, _ ->
+                // Confirm deletion
+                viewModel.deleteTodo(todo)
+                dialog.dismiss()
+            }
+            .setNegativeButton(R.string.cancel) { dialog, _ ->
+                // Cancel deletion
+                dialog.dismiss()
+            }
+            .create()
+            .show()
+    }
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): TodoViewHolder {
+        val binding = ItemTodoBinding.inflate(
+            LayoutInflater.from(parent.context), 
+            parent, 
+            false
+        )
+        return TodoViewHolder(binding)
+    }
+
+    override fun onBindViewHolder(holder: TodoViewHolder, position: Int) {
+        val todo = todoList[position]
+        holder.bind(todo)
+    }
+
+    override fun getItemCount(): Int = todoList.size
+
+    inner class TodoViewHolder(private val binding: ItemTodoBinding) : 
+        RecyclerView.ViewHolder(binding.root) {
+
+        fun bind(todo: TodoItem) {
+            binding.apply {
+                // Set todo details
+                todoTitle.text = todo.title
+                todoDescription.text = todo.description
+
+                // Delete button click listener with confirmation dialog
+                deleteButton.setOnClickListener {
+                    showDeleteConfirmationDialog(todo)
+                }
+            }
+        }
+    }
+
+    /**
+     * Update the list of Todo items and notify the adapter
+     * 
+     * @param newList New list of Todo items
+     */
+    fun updateList(newList: List<TodoItem>) {
+        todoList = newList
+        notifyDataSetChanged()
+    }
+}

app/src/main/java/com/example/todoapp/ui/viewmodel/TodoViewModel.kt

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+package com.example.todoapp.ui.viewmodel
+
+import androidx.lifecycle.ViewModel
+import com.example.todoapp.data.entity.TodoItem
+import com.example.todoapp.data.dao.TodoDao
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+
+class TodoViewModel(private val todoDao: TodoDao) : ViewModel() {
+    fun deleteTodo(todoItem: TodoItem) {
+        CoroutineScope(Dispatchers.IO).launch {
+            todoDao.deleteTodo(todoItem)
+        }
+    }
+}

app/src/main/res/values/strings.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <!-- General app strings -->
+    <string name="app_name">Todo App</string>
+
+    <!-- Delete Confirmation Dialog Strings -->
+    <string name="delete_todo_title">Delete Todo</string>
+    <string name="delete_todo_message">Are you sure you want to delete this todo item?</string>
+    <string name="delete">Delete</string>
+    <string name="cancel">Cancel</string>
+</resources>