events: allow editing of all used values

1. Allow to change the date/time and
other relevant values of an event
on creation and after it was created.

2. Harmonize layout file names and
variable names.

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

@@ -297,11 +297,7 @@ class MainActivity : AppCompatActivity() {
         val range = NumericUtils(this).getValidEventQuantityRange(LunaEvent.TYPE_TEMPERATURE)!!
         tempSlider.valueFrom = range.first.toFloat()
         tempSlider.valueTo = range.second.toFloat()
-        tempSlider.value = if (event.quantity == 0) {
+        tempSlider.value = range.third.toFloat()
-            range.third.toFloat() // default
-        } else {
-            event.quantity.toFloat() / 10
-        }
 
         val dateTV = dialogView.findViewById<TextView>(R.id.dialog_date_picker)
         val pickedTime = datePickHelper(event.time, dateTV)
@@ -310,7 +306,7 @@ class MainActivity : AppCompatActivity() {
         }
 
         val tempTextView = dialogView.findViewById<TextView>(R.id.dialog_temperature_display)
-        tempTextView.text = tempSlider.value.toString()
+        tempTextView.text = range.third.toString()
         tempSlider.addOnChangeListener({ s, v, b -> tempTextView.text = v.toString() })
 
         d.setPositiveButton(android.R.string.ok) { dialogInterface, i ->