add signature setting

For multiple users it helps to
keep track about who did what.

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

@@ -13,6 +13,7 @@ import android.view.ViewGroup
 import android.widget.AdapterView
 import android.widget.ArrayAdapter
 import android.widget.EditText
+import android.widget.LinearLayout
 import android.widget.NumberPicker
 import android.widget.PopupWindow
 import android.widget.Spinner
@@ -57,6 +58,7 @@ class MainActivity : AppCompatActivity() {
     lateinit var buttonsContainer: ViewGroup
     lateinit var recyclerView: RecyclerView
     lateinit var handler: Handler
+    var signature = ""
     var savingEvent = false
     val updateListRunnable: Runnable = Runnable {
         if (logbook != null && !pauseLogbookUpdate)
@@ -168,6 +170,8 @@ class MainActivity : AppCompatActivity() {
             logbookRepo = FileLogbookRepository()
         }
 
+        signature = settingsRepository.loadSignature()
+
         val noBreastfeeding = settingsRepository.loadNoBreastfeeding()
         findViewById<View>(R.id.layout_nipples).visibility = when (noBreastfeeding) {
             true -> View.GONE
@@ -386,6 +390,14 @@ class MainActivity : AppCompatActivity() {
             pauseLogbookUpdate = false
         })
 
+        // show optional signature
+        dialogView.findViewById<TextView>(R.id.dialog_event_detail_type_signature).text = event.signature
+        dialogView.findViewById<LinearLayout>(R.id.dialog_event_signature_layout).visibility = if (event.signature.isNotEmpty()) {
+            View.VISIBLE
+        } else {
+            View.GONE
+        }
+
         // create next/previous links to events of the same type
 
         val previousTextView = dialogView.findViewById<TextView>(R.id.dialog_event_previous)
@@ -635,6 +647,8 @@ class MainActivity : AppCompatActivity() {
     fun logEvent(event: LunaEvent) {
         savingEvent(true)
 
+        event.signature = signature
+
         setLoading(true)
         logbook?.logs?.add(0, event)
         recyclerView.adapter?.notifyItemInserted(0)
@@ -785,7 +799,9 @@ class MainActivity : AppCompatActivity() {
                 dismiss()
             })
             contentView.findViewById<View>(R.id.button_puke).setOnClickListener({
-                askNotes(LunaEvent(LunaEvent.TYPE_PUKE))
+                logEvent(
+                    LunaEvent(LunaEvent.TYPE_PUKE)
+                )
                 dismiss()
             })
             contentView.findViewById<View>(R.id.button_colic).setOnClickListener({