MainActivity: generate dynamic menu from last two weeks

Make the UI more flexible and
slightly easier to understand.

app/src/main/java/it/danieleverducci/lunatracker/MainActivity.kt

@@ -447,8 +447,8 @@ class MainActivity : AppCompatActivity() {
         val invalidDurationTextColor = ContextCompat.getColor(this, R.color.danger)
 
         // in seconds
-        var sleepStart = event.getStartTime()
-        var sleepEnd = event.getEndTime()
+        var sleepBegin = event.time
+        var sleepEnd = event.time + event.quantity
 
         fun isValidTime(timeUnix: Long): Boolean {
             val now = System.currentTimeMillis() / 1000
@@ -465,31 +465,27 @@ class MainActivity : AppCompatActivity() {
         }
 
         fun updateFields() {
-            datePickerBegin.text = DateUtils.formatDateTime(sleepStart)
+            datePickerBegin.text = DateUtils.formatDateTime(sleepBegin)
             datePickerEnd.text = DateUtils.formatDateTime(sleepEnd)
 
             durationTextView.setTextColor(currentDurationTextColor)
-            val duration = sleepEnd - sleepStart
+            val duration = sleepEnd - sleepBegin
             if (duration == 0L) {
                 // baby is sleeping
                 durationTextView.text = "💤"
-                dateDelimiter.visibility = View.GONE
-                datePickerEnd.visibility = View.GONE
             } else {
                 durationTextView.text = DateUtils.formatTimeDuration(applicationContext, duration)
-                if (!isValidTimeSpan(sleepStart, sleepEnd)) {
+                if (!isValidTimeSpan(sleepBegin, sleepEnd)) {
                     durationTextView.setTextColor(invalidDurationTextColor)
                 }
-                dateDelimiter.visibility = View.VISIBLE
-                datePickerEnd.visibility = View.VISIBLE
             }
 
-            datePickerBegin.setTextColor(if (isValidTime(sleepStart)) { currentDurationTextColor } else { invalidDurationTextColor })
+            datePickerBegin.setTextColor(if (isValidTime(sleepBegin)) { currentDurationTextColor } else { invalidDurationTextColor })
             datePickerEnd.setTextColor(if (isValidTime(sleepEnd)) { currentDurationTextColor } else { invalidDurationTextColor })
         }
 
         val pickedDateTimeBegin = dateTimePicker(event.time, datePickerBegin) { time: Long ->
-            sleepStart = adjustToMinute(time)
+            sleepBegin = adjustToMinute(time)
             updateFields()
         }
 
@@ -498,7 +494,7 @@ class MainActivity : AppCompatActivity() {
             updateFields()
         }
 
-        sleepStart = adjustToMinute(pickedDateTimeBegin.time.time / 1000)
+        sleepBegin = adjustToMinute(pickedDateTimeBegin.time.time / 1000)
         sleepEnd = adjustToMinute(pickedDateTimeEnd.time.time / 1000)
 
         updateFields()
@@ -518,17 +514,17 @@ class MainActivity : AppCompatActivity() {
         }
 
         durationMinus5Button.setOnClickListener {
-            sleepEnd = (sleepEnd - 300).coerceAtLeast(sleepStart)
+            sleepEnd = (sleepEnd - 300).coerceAtLeast(sleepBegin)
             updateFields()
         }
 
         durationPlus5Button.setOnClickListener {
-            sleepEnd = (sleepEnd + 300).coerceAtLeast(sleepStart)
+            sleepEnd = (sleepEnd + 300).coerceAtLeast(sleepBegin)
             updateFields()
         }
 
         durationAsleepButton.setOnClickListener {
-            sleepEnd = sleepStart
+            sleepEnd = sleepBegin
             updateFields()
         }
 
@@ -539,9 +535,9 @@ class MainActivity : AppCompatActivity() {
         }
 
         d.setPositiveButton(android.R.string.ok) { dialogInterface, i ->
-            if (isValidTime(sleepStart) && isValidTime(sleepEnd) && isValidTimeSpan(sleepStart, sleepEnd)) {
-                event.time = sleepStart
-                event.quantity = (sleepEnd - sleepStart).toInt()
+            if (isValidTime(sleepBegin) && isValidTime(sleepEnd) && isValidTimeSpan(sleepBegin, sleepEnd)) {
+                event.time = sleepBegin
+                event.quantity = (sleepEnd - sleepBegin).toInt()
                 onPositive()
             } else {
                 Toast.makeText(this, R.string.toast_date_error, Toast.LENGTH_SHORT).show()