Fixes crash when clearing custom field values

app/src/main/java/net/pokeranalytics/android/ui/modules/filter/FilterDetailsFragment.kt

@@ -176,17 +176,29 @@ open class FilterDetailsFragment : RealmFragment(), RowRepresentableDelegate {
 				}
 			}
 			is DoubleValueListFilterItemRow -> {
+				if (value == null) {
+					row.clear()
+				} else {
 					val string = value as String
 					row.add(string.toDouble())
 				}
+			}
 			is IntValueListFilterItemRow -> {
+				if (value == null) {
+					row.clear()
+				} else {
 					val string = value as String
 					row.add(string.toInt())
 				}
+			}
 			is StringValueListFilterItemRow -> {
+				if (value == null) {
+					row.clear()
+				} else {
 					row.add(value as String)
 				}
 			}
+		}
 
 		// Remove the row before updating the selected rows list
 		this.model.selectedRows.remove(row as FilterItemRow)

app/src/main/java/net/pokeranalytics/android/ui/view/rowrepresentable/FilterItemRow.kt

@@ -159,6 +159,10 @@ abstract class ValueListFilterItemRow<T: Comparable<T>>(queryCondition: QueryCon
         this.list.add(value)
     }
 
+    fun clear() {
+        this.list.clear()
+    }
+
     override val queryCondition: QueryCondition?
         get() {
             return if (list.isNotEmpty()) {