Create event file.

app/src/main/java/com/hyperling/expensetracker/ExpenseEvent.kt

@@ -0,0 +1,12 @@
+package com.hyperling.expensetracker
+
+sealed interface ExpenseEvent {
+    object SaveExpense: ExpenseEvent
+    data class SetName(val name: String): ExpenseEvent
+    data class SetCost(val cost: Double): ExpenseEvent
+    data class SetRate(val rate: Rate): ExpenseEvent
+    object ShowDialog: ExpenseEvent
+    object HideDialog: ExpenseEvent
+    data class SortExpenses(val rate: Rate): ExpenseEvent
+    data class DeleteExpense(val expense: Expense): ExpenseEvent
+}