Task overview now has a RecyclerView adapter and displays dummy data in empty items; added database queries to retrieve tasks

app/src/main/java/com/denizk0461/weserplaner/adapter/TaskOverviewAdapter.kt

@@ -0,0 +1,108 @@
+package com.denizk0461.weserplaner.adapter
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import androidx.recyclerview.widget.DiffUtil
+import androidx.recyclerview.widget.RecyclerView
+import com.denizk0461.weserplaner.BuildConfig
+import com.denizk0461.weserplaner.data.AppDiffUtilCallback
+import com.denizk0461.weserplaner.databinding.ItemTaskBinding
+import com.denizk0461.weserplaner.model.EventTask
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+
+class TaskOverviewAdapter(
+    private val onClickListener: OnClickListener,
+) : RecyclerView.Adapter<TaskOverviewAdapter.TaskViewHolder>() {
+
+    /**
+     * List of all events.
+     */
+    private val tasks: MutableList<EventTask> = mutableListOf()
+
+    /**
+     * View holder class for parent class
+     *
+     * @param binding   view binding object
+     */
+    class TaskViewHolder(val binding: ItemTaskBinding) : RecyclerView.ViewHolder(binding.root)
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): TaskViewHolder {
+        return TaskViewHolder(
+            ItemTaskBinding.inflate(
+                LayoutInflater.from(parent.context),
+                parent,
+                false
+            )
+        )
+    }
+
+    // Set the amount of items to the size of the filtered list, so only events of the current day
+    override fun getItemCount(): Int = tasks.size
+
+    override fun onBindViewHolder(holder: TaskViewHolder, position: Int) {
+
+        // Retrieve item for current position
+        val currentItem = tasks[position]
+
+        // Context for easier reference
+        val context = holder.binding.root.context
+
+        // view set-up
+        SimpleDateFormat("yyyy-MM-dd, HH:mm:ss.SSS", Locale.GERMANY)
+            .format(Date(BuildConfig.BUILD_TIME_MILLIS))
+
+        // Set up single click listener
+        holder.binding.linearLayout.setOnClickListener {
+            onClickListener.onClick(currentItem)
+        }
+
+        // Set up long press listener
+        holder.binding.linearLayout.setOnLongClickListener {
+            onClickListener.onLongClick(currentItem)
+        }
+    }
+
+    /**
+     * Updates the data and calculates the difference between the old dataset and the newly provided
+     * dataset.
+     *
+     * @param newData   new dataset to be displayed
+     */
+    fun setNewData(newData: List<EventTask>) {
+        // Calculate the difference between the old list and the new list
+        val diffResult = DiffUtil.calculateDiff(AppDiffUtilCallback(tasks, newData))
+
+        // Remove all items from the list
+        tasks.clear()
+
+        // Add all items from the new list
+        tasks.addAll(newData)
+
+        // Tell the DiffUtil which items have changed between the two lists
+        diffResult.dispatchUpdatesTo(this)
+    }
+
+    /**
+     * Interface used to evaluate clicks and long presses on a given item.
+     */
+    interface OnClickListener {
+
+        /**
+         * Executed when an item has been clicked.
+         *
+         * @param task  item that has been clicked
+         */
+        fun onClick(task: EventTask)
+
+
+        /**
+         * Executed when an item has been long-pressed.
+         *
+         * @param task  item that has been long-pressed
+         * @return      whether the long press was successful
+         */
+        fun onLongClick(task: EventTask): Boolean
+    }
+}

app/src/main/java/com/denizk0461/weserplaner/data/Extensions.kt

@@ -17,6 +17,9 @@ import com.denizk0461.weserplaner.exception.ParcelNotFoundException
 import com.denizk0461.weserplaner.model.TextSheetContentId
 import com.denizk0461.weserplaner.sheet.TextSheet
 import com.google.android.material.snackbar.Snackbar
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
 import kotlin.jvm.Throws
 
 /*
@@ -148,6 +151,19 @@ fun SwipeRefreshLayout.setRainbowProgressCircle() {
     )
 }
 
+/**
+ * Formats a date object to a string in the ISO 8601 format. Example:
+ * 2023-05-21, 14:32:59.067
+ *
+ * @receiver                date object to convert to string
+ * @param useHighPrecision  determines whether seconds and milliseconds are shown
+ * @return                  date formatted as ISO 8601 string
+ */
+fun Date.formatToIso8601String(useHighPrecision: Boolean = false): String = SimpleDateFormat(
+    "yyyy-MM-dd, HH:mm${if (useHighPrecision) ":ss.SSS" else ""}",
+    Locale.GERMANY,
+).format(this)
+
 /**
  * Timeslots for which a conversion to an academic quarter is applicable.
  */

app/src/main/java/com/denizk0461/weserplaner/db/AppDAO.kt

@@ -65,6 +65,66 @@ interface AppDAO {
     @Query("DELETE FROM studip_events")
     fun nukeEvents()
 
+    /* --- event tasks --- */
+
+    /**
+     * Retrieve all event tasks ordered by their ID (order: date created).
+     *
+     * @return  tasks ordered by date created
+     */
+    @Query(
+        "SELECT event_tasks.taskId, " +
+                "event_tasks.eventId, " +
+                "event_tasks.dueDate, " +
+                "event_tasks.title AS taskTitle, " +
+                "studip_events.title AS eventTitle, " +
+                "studip_events.lecturer, " +
+                "event_tasks.notes, " +
+                "studip_events.room " +
+                "FROM event_tasks " +
+                "JOIN studip_events ON event_tasks.eventId = studip_events.eventId " +
+                "ORDER BY taskId"
+    )
+    fun getAllTasksOrderDateCreated(): LiveData<List<EventTaskExtended>>
+
+    /**
+     * Retrieve all event tasks ordered alphabetically by their title.
+     *
+     * @return  tasks ordered by title
+     */
+    @Query(
+        "SELECT event_tasks.taskId, " +
+                "event_tasks.eventId, " +
+                "event_tasks.dueDate, " +
+                "event_tasks.title AS taskTitle, " +
+                "studip_events.title AS eventTitle, " +
+                "studip_events.lecturer, " +
+                "event_tasks.notes, " +
+                "studip_events.room " +
+                "FROM event_tasks " +
+                "JOIN studip_events ON event_tasks.eventId = studip_events.eventId " +
+            "ORDER BY taskTitle")
+    fun getAllTasksOrderAlphabetically(): LiveData<List<EventTaskExtended>>
+
+    /**
+     * Retrieve all event tasks ordered by their due date.
+     *
+     * @return  tasks ordered by date due
+     */
+    @Query(
+        "SELECT event_tasks.taskId, " +
+                "event_tasks.eventId, " +
+                "event_tasks.dueDate, " +
+                "event_tasks.title AS taskTitle, " +
+                "studip_events.title AS eventTitle, " +
+                "studip_events.lecturer, " +
+                "event_tasks.notes, " +
+                "studip_events.room " +
+                "FROM event_tasks " +
+                "JOIN studip_events ON event_tasks.eventId = studip_events.eventId " +
+            "ORDER BY dueDate")
+    fun getAllTasksOrderDateDue(): LiveData<List<EventTaskExtended>>
+
     /* --- canteen offers --- */
 
     /**

app/src/main/java/com/denizk0461/weserplaner/db/AppRepository.kt

@@ -80,6 +80,18 @@ class AppRepository(app: Application) {
      */
     fun nukeEvents() { dao.nukeEvents() }
 
+    /**
+     * Retrieves tasks for all events ordered as specified.
+     *
+     * @param order order in which the tasks are returned
+     * @return      tasks wrapped in a LiveData object
+     */
+    fun getTasks(order: TaskOrder): LiveData<List<EventTaskExtended>> = when (order) {
+        TaskOrder.DATE_CREATED -> dao.getAllTasksOrderDateCreated()
+        TaskOrder.ALPHABETICALLY -> dao.getAllTasksOrderAlphabetically()
+        else -> dao.getAllTasksOrderDateDue() // TaskOrder.DATE_DUE
+    }
+
     /**
      * Retrieves the canteen stored in the database. Should always be 0 or 1.
      *

app/src/main/java/com/denizk0461/weserplaner/fragment/SettingsFragment.kt

@@ -16,6 +16,7 @@ import com.denizk0461.weserplaner.BuildConfig
 import com.denizk0461.weserplaner.R
 import com.denizk0461.weserplaner.activity.FetcherActivity
 import com.denizk0461.weserplaner.activity.ImageActivity
+import com.denizk0461.weserplaner.data.formatToIso8601String
 import com.denizk0461.weserplaner.data.getTextSheet
 import com.denizk0461.weserplaner.data.showSnackBar
 import com.denizk0461.weserplaner.data.showToast
@@ -23,7 +24,6 @@ import com.denizk0461.weserplaner.databinding.FragmentSettingsBinding
 import com.denizk0461.weserplaner.sheet.AllergenConfigSheet
 import com.denizk0461.weserplaner.viewmodel.SettingsViewModel
 import java.nio.charset.StandardCharsets
-import java.text.SimpleDateFormat
 import java.util.*
 
 /**
@@ -318,8 +318,7 @@ class SettingsFragment : AppFragment<FragmentSettingsBinding>() {
         // Set build version code and time text
         @SuppressLint("SetTextI18n")
         binding.buildTimeText.text = "v${BuildConfig.VERSION_CODE} | ${
-            SimpleDateFormat("yyyy-MM-dd, HH:mm:ss.SSS", Locale.GERMANY)
+            Date(BuildConfig.BUILD_TIME_MILLIS).formatToIso8601String(useHighPrecision = true)
-                .format(Date(BuildConfig.BUILD_TIME_MILLIS))
         }"
 
         // Set up switch for showing beta screens

app/src/main/java/com/denizk0461/weserplaner/fragment/TaskOverviewFragment.kt

@@ -6,19 +6,27 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.appcompat.widget.PopupMenu
 import androidx.fragment.app.viewModels
+import androidx.recyclerview.widget.LinearLayoutManager
 import com.denizk0461.weserplaner.R
+import com.denizk0461.weserplaner.adapter.TaskOverviewAdapter
 import com.denizk0461.weserplaner.data.showSnackBar
 import com.denizk0461.weserplaner.databinding.FragmentTaskOverviewBinding
+import com.denizk0461.weserplaner.model.EventTask
+import com.denizk0461.weserplaner.model.TaskOrder
 import com.denizk0461.weserplaner.viewmodel.TaskOverviewViewModel
 
 /**
  * Fragment that shows the user an overview of their tasks and exams.
  */
-class TaskOverviewFragment : AppFragment<FragmentTaskOverviewBinding>() {
+class TaskOverviewFragment : AppFragment<FragmentTaskOverviewBinding>(),
+    TaskOverviewAdapter.OnClickListener {
 
     // View model reference for providing access to the database
     private val viewModel: TaskOverviewViewModel by viewModels()
 
+    // Task adapter for the recycler view
+    private val taskAdapter: TaskOverviewAdapter = TaskOverviewAdapter(this)
+
     // Instantiate the view binding
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
         _binding = FragmentTaskOverviewBinding.inflate(inflater, container, false)
@@ -38,8 +46,6 @@ class TaskOverviewFragment : AppFragment<FragmentTaskOverviewBinding>() {
         )
 
         binding.buttonOrder.setOnClickListener {
-
-
             // Create menu for selecting a new canteen
             PopupMenu(binding.root.context, binding.buttonOrder).apply {
                 setOnMenuItemClickListener { item ->
@@ -60,6 +66,17 @@ class TaskOverviewFragment : AppFragment<FragmentTaskOverviewBinding>() {
             }
         }
 
+        binding.recyclerViewLayout.recyclerView.apply {
+            // Set page to scroll vertically
+            layoutManager = LinearLayoutManager(context, LinearLayoutManager.VERTICAL, false)
+
+            // Assign adapter to this recycler view
+            adapter = taskAdapter
+        }
+
+        // insert sample data TODO change to db
+        taskAdapter.setNewData(viewModel.getTasks(TaskOrder.DATE_DUE))
+
         // Set up scroll change listener to shrink and extend FAB accordingly
         binding.recyclerViewLayout.recyclerView.setOnScrollChangeListener { _, _, scrollY, _, oldScrollY ->
             // Calculate the vertical scroll difference
@@ -73,4 +90,13 @@ class TaskOverviewFragment : AppFragment<FragmentTaskOverviewBinding>() {
             }
         }
     }
+
+    override fun onClick(task: EventTask) {
+        // TODO
+    }
+
+    override fun onLongClick(task: EventTask): Boolean {
+        // TODO
+        return false
+    }
 }

app/src/main/java/com/denizk0461/weserplaner/model/EventTask.kt

@@ -4,6 +4,16 @@ import androidx.room.Entity
 import androidx.room.ForeignKey
 import androidx.room.PrimaryKey
 
+/**
+ * Database entity used to store tasks assigned to specific [StudIPEvent] elements.
+ *
+ * @param taskId    primary key for the entity
+ * @param eventId   foreign key referencing the event this task is assigned to
+ * @param dueDate   time and date at which the task is due
+ * @param title     title of the task
+ * @param notes     user-added notes for the task
+ * @param room      room the task may take place in
+ */
 @Entity(
     tableName = "event_tasks",
     foreignKeys = [

app/src/main/java/com/denizk0461/weserplaner/model/EventTaskExtended.kt

@@ -0,0 +1,25 @@
+package com.denizk0461.weserplaner.model
+
+/**
+ * Extended representation of [com.denizk0461.weserplaner.model.EventTask] that includes important
+ * attributes from a given task's associated [com.denizk0461.weserplaner.model.StudIPEvent].
+ *
+ * @param taskId        primary key for the entity
+ * @param eventId       foreign key referencing the event this task is assigned to
+ * @param dueDate       time and date at which the task is due
+ * @param eventTitle    title of the event
+ * @param taskTitle     title of the task
+ * @param lecturer      lecturer(s) organising the event
+ * @param notes         user-added notes for the task
+ * @param room          room the task may take place in
+ */
+data class EventTaskExtended(
+    val taskId: Int,
+    val eventId: Int,
+    val dueDate: Int,
+    val eventTitle: String,
+    val taskTitle: String,
+    val lecturer: String,
+    val notes: String,
+    val room: String,
+)

app/src/main/java/com/denizk0461/weserplaner/model/TaskOrder.kt

@@ -0,0 +1,25 @@
+package com.denizk0461.weserplaner.model
+
+/**
+ * Used to determine the order in which tasks should be shown.
+ *
+ * @param key   index by which to tell which order method to use
+ */
+enum class TaskOrder(key: Int) {
+
+    /**
+     * Order tasks by date due.
+     */
+    DATE_DUE(0),
+
+    /**
+     * Order tasks by date created.
+     */
+    DATE_CREATED(1),
+
+    /**
+     * Order tasks alphabetically.
+     */
+    ALPHABETICALLY(2),
+    ;
+}

app/src/main/java/com/denizk0461/weserplaner/viewmodel/TaskOverviewViewModel.kt

@@ -1,11 +1,26 @@
 package com.denizk0461.weserplaner.viewmodel
 
 import android.app.Application
+import androidx.lifecycle.LiveData
+import com.denizk0461.weserplaner.model.EventTask
+import com.denizk0461.weserplaner.model.TaskOrder
 
 /**
  * View model class for [com.denizk0461.weserplaner.fragment.TaskOverviewFragment].
  */
 class TaskOverviewViewModel(application: Application) : AppViewModel(application) {
 
+    /**
+     * Retrieves tasks for all events ordered as specified.
+     *
+     * @param order order in which the tasks are returned
+     * @return      tasks wrapped in a LiveData object
+     */
+//    fun getTasks(order: TaskOrder): LiveData<List<EventTask>> = repo.getTasks(order)
 
+    fun getTasks(order: TaskOrder) = listOf( // dummy data
+        EventTask(0, 0, 1684758756, "title1", "user notes", "GW2 B-idk"),
+        EventTask(1, 0, 1684798756, "title2", "user notes", "GW3 C-idk"),
+        EventTask(2, 0, 1689758756, "title3", "user notes", "GW4 D-idk"),
+    )
 }

app/src/main/res/layout/fragment_task_overview.xml

@@ -64,7 +64,8 @@
     <include layout="@layout/recycler_view"
         android:id="@+id/recycler_view_layout"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"/>
+        android:layout_height="match_parent"
+        app:layout_behavior="@string/appbar_scrolling_view_behavior"/>
 
     <com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
         android:id="@+id/fab_add_task"

app/src/main/res/layout/recycler_view.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.recyclerview.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
+<androidx.recyclerview.widget.RecyclerView
+    xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/recycler_view"
     android:layout_width="match_parent"
     android:layout_height="match_parent"