Fixed bug when adding a trade without fees or sdr (#144)

CHANGELOG.md

@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## []
+### Fixed
+- Bug preventing to add a trade with fee equal to zero
+
 ### Changed
 - Updated Pipfile unifying packages and adding custom scripts
 - Grouped icons in the header bar under one single popover menu

src/UI/gtk/AddTradeWindow.py

@@ -229,9 +229,9 @@ def _check_data_validity(self):
                 not self._price_entry.get_sensitive()
                 or self._is_float_valid(self._price_entry.get_text()),
                 not self._fee_entry.get_sensitive()
-                or self._is_float_valid(self._fee_entry.get_text()),
+                or self._is_float_valid(self._fee_entry.get_text(), zero_ok=True),
                 not self._sdr_entry.get_sensitive()
-                or self._is_float_valid(self._sdr_entry.get_text()),
+                or self._is_float_valid(self._sdr_entry.get_text(), zero_ok=True),
                 not self._notes_entry.get_sensitive()
                 or self._is_string_valid(self._notes_entry.get_text(), empty_ok=True),
             ]
@@ -245,10 +245,12 @@ def _is_string_valid(self, string_value, empty_ok=False):
         except:
             return False
 
-    def _is_float_valid(self, string_value):
+    def _is_float_valid(self, string_value, zero_ok=False):
         try:
             f = float(string_value)
-            return True if f > 0.0 else False
+            if f > 0.0 or (f == 0.0 and zero_ok):
+                return True
+            return False
         except:
             return False