Add UI feedback on invalid firmware update

CURA-6537

cura/PrinterOutput/FirmwareUpdater.py

@@ -75,4 +75,4 @@ class FirmwareUpdateState(IntEnum):
     communication_error = 4
     io_error = 5
     firmware_not_found_error = 6
-
+    invalid_firmware_error = 7

plugins/FirmwareUpdater/FirmwareUpdaterMachineAction.qml

@@ -151,6 +151,8 @@ Cura.MachineAction
                             return catalog.i18nc("@label","Firmware update failed due to an input/output error.");
                         case 6:
                             return catalog.i18nc("@label","Firmware update failed due to missing firmware.");
+                        case 7:
+                            return catalog.i18nc("@label","Firmware update failed due to invalid firmware file.");
                     }
                 }
 

plugins/USBPrinting/AvrFirmwareUpdater.py

@@ -27,6 +27,9 @@ class AvrFirmwareUpdater(FirmwareUpdater):
         except (FileNotFoundError, AssertionError):
             Logger.log("e", "Unable to read provided hex file. Could not update firmware.")
             self._setFirmwareUpdateState(FirmwareUpdateState.firmware_not_found_error)
+        except Exception:
+            Logger.logException("e", "Failed to read hex file '%s'", self._firmware_file)
+            self._setFirmwareUpdateState(FirmwareUpdateState.invalid_firmware_error)
             return
 
         programmer = stk500v2.Stk500v2()

plugins/USBPrinting/avr_isp/intelHex.py

@@ -5,13 +5,16 @@ See: http://en.wikipedia.org/wiki/Intel_HEX
 This is a python 3 conversion of the code created by David Braam for the Cura project.
 """
 import io
+from typing import List
+
 from UM.Logger import Logger
 
-def readHex(filename):
+
+def readHex(filename: str) -> List[int]:
     """
     Read an verify an intel hex file. Return the data as an list of bytes.
     """
-    data = []
+    data = []  # type: List[int]
     extra_addr = 0
     f = io.open(filename, "r", encoding = "utf-8")
     for line in f: