add a button for marking tasks complete

app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/TaskActivity.kt

@@ -3,6 +3,7 @@ package com.simplemobiletools.calendar.pro.activities
 import android.app.DatePickerDialog
 import android.app.TimePickerDialog
 import android.content.Intent
+import android.graphics.Color
 import android.os.Bundle
 import android.view.Menu
 import android.view.MenuItem
@@ -156,6 +157,17 @@ class TaskActivity : SimpleActivity() {
         mEventTypeId = mTask.eventType
         task_title.setText(mTask.title)
         task_description.setText(mTask.description)
+
+        mark_complete.setOnClickListener { toggleCompletion() }
+        mark_complete.beVisible()
+
+        val markCompleteBgColor = if (isWhiteTheme()) {
+            Color.WHITE
+        } else {
+            getAdjustedPrimaryColor()
+        }
+
+        mark_complete.setTextColor(markCompleteBgColor.getContrastColor())
     }
 
     private fun setupNewTask() {
@@ -270,6 +282,20 @@ class TaskActivity : SimpleActivity() {
         task_time.beGoneIf(isChecked)
     }
 
+    private fun toggleCompletion() {
+        if (mTask.isTaskCompleted()) {
+            mTask.flags = mTask.flags.removeBit(FLAG_TASK_COMPLETED)
+        } else {
+            mTask.flags = mTask.flags or FLAG_TASK_COMPLETED
+        }
+
+        ensureBackgroundThread {
+            eventsDB.updateTaskCompletion(mTask.id!!, mTask.flags)
+            hideKeyboard()
+            finish()
+        }
+    }
+
     private fun showEventTypeDialog() {
         hideKeyboard()
         SelectEventTypeDialog(this, mEventTypeId, false, true, false, true) {

app/src/main/kotlin/com/simplemobiletools/calendar/pro/helpers/Constants.kt

@@ -122,7 +122,7 @@ const val REPEAT_ORDER_WEEKDAY = 4                      // i.e. every 4th sunday
 const val FLAG_ALL_DAY = 1
 const val FLAG_IS_IN_PAST = 2
 const val FLAG_MISSING_YEAR = 4
-const val FLAG_TASK_COMPLETE = 8
+const val FLAG_TASK_COMPLETED = 8
 
 // constants related to ICS file exporting / importing
 const val BEGIN_CALENDAR = "BEGIN:VCALENDAR"

app/src/main/kotlin/com/simplemobiletools/calendar/pro/interfaces/EventsDao.kt

@@ -109,6 +109,9 @@ interface EventsDao {
     @Query("UPDATE events SET repetition_exceptions = :repetitionExceptions WHERE id = :id AND type = $TYPE_EVENT")
     fun updateEventRepetitionExceptions(repetitionExceptions: String, id: Long)
 
+    @Query("UPDATE events SET flags = :newFlags WHERE id = :id")
+    fun updateTaskCompletion(id: Long, newFlags: Int)
+
     @Insert(onConflict = OnConflictStrategy.REPLACE)
     fun insertOrUpdate(event: Event): Long
 

app/src/main/kotlin/com/simplemobiletools/calendar/pro/models/Event.kt

@@ -142,6 +142,7 @@ data class Event(
     fun getIsAllDay() = flags and FLAG_ALL_DAY != 0
     fun hasMissingYear() = flags and FLAG_MISSING_YEAR != 0
     fun isTask() = type == TYPE_TASK
+    fun isTaskCompleted() = flags and FLAG_TASK_COMPLETED != 0
 
     fun getReminders() = listOf(
         Reminder(reminder1Minutes, reminder1Type),

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

@@ -170,5 +170,17 @@
             android:layout_below="@+id/event_type_holder"
             android:background="@color/divider_grey"
             android:importantForAccessibility="no" />
+
+        <android.widget.TextView
+            android:id="@+id/mark_complete"
+            style="@style/ColoredButtonStyle"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_below="@+id/event_type_divider"
+            android:layout_centerHorizontal="true"
+            android:layout_marginTop="@dimen/activity_margin"
+            android:text="@string/mark_completed"
+            android:visibility="gone" />
+
     </RelativeLayout>
 </ScrollView>