projectgus
diff --git a/‎can/viewer.py
Lines changed: 12 additions & 2 deletions b/‎can/viewer.py
Lines changed: 12 additions & 2 deletions
diff --git a/‎test/test_viewer.py
Lines changed: 17 additions & 5 deletions b/‎test/test_viewer.py
Lines changed: 17 additions & 5 deletions
@@ -188,6 +188,16 @@ def draw_can_bus_mess
10000
age(self, msg, sorting=False):
             elif msg.dlc != self.ids[key]["msg"].dlc:
                 length_changed = True
 
+                # Clear the old data bytes when the length of the new message is shorter
+                if msg.dlc < self.ids[key]["msg"].dlc:
+                    self.draw_line(
+                        self.ids[key]["row"],
+                        # Start drawing at the last byte that is not in the new message
+                        52 + msg.dlc * 3,
+                        # Draw spaces where the old bytes were drawn
+                        " " * ((self.ids[key]["msg"].dlc - msg.dlc) * 3 - 1),
+                    )
+
             if new_id_added or length_changed:
                 # Increment the index if it was just added, but keep it if the length just changed
                 row = len(self.ids) + 1 if new_id_added else self.ids[key]["row"]
@@ -441,7 +451,7 @@ def parse_args(args):
         choices=sorted(can.VALID_INTERFACES),
     )
 
-    parser.add_argument(
+    optional.add_argument(
         "-v",
         action="count",
         dest="verbosity",
@@ -515,7 +525,7 @@ def main() -> None:
     parsed_args, can_filters, data_structs = parse_args(sys.argv[1:])
 
     additional_config = {"can_filters": can_filters} if can_filters else {}
-    bus = _create_bus(parsed_args.channel, **additional_config)
+    bus = _create_bus(parsed_args, **additional_config)
     # print(f"Connected to {bus.__class__.__name__}: {bus.channel_info}")
 
     curses.wrapper(CanViewer, bus, data_structs)
 
@@ -30,6 +30,7 @@
 import struct
 import time
 import unittest
+from collections import defaultdict
 from typing import Dict, Tuple, Union
 from unittest.mock import patch
 
@@ -53,6 +54,7 @@
 class StdscrDummy:
     def __init__(self):
         self.key_counter = 0
+        self.draw_buffer = defaultdict(dict)
 
     @staticmethod
     def clear():
@@ -65,13 +67,18 @@ def erase():
     @staticmethod
     def getmaxyx():
         # Set y-value, so scrolling gets tested
-        return 1, 1
+        # Set x-value, so the text will fit in the window
+        return 1, 100
 
-    @staticmethod
-    def addstr(row, col, txt, *args):
+    def addstr(self, row, col, txt, *args):
         assert row >= 0
         assert col >= 0
         assert txt is not None
+
+        # Save the text written into the buffer
+        for i, t in enumerate(txt):
+            self.draw_buffer[row][col + i] = t
+
         # Raise an exception 50 % of the time, so we can make sure the code handles it
         if random.random() < 0.5:
             raise curses.error
@@ -114,7 +121,7 @@ def setUpClass(cls):
         random.seed(0)
 
     def setUp(self):
-        stdscr = StdscrDummy()
+        self.stdscr_dummy = StdscrDummy()
         config = {"interface": "virtual", "receive_own_messages": True}
         bus = can.Bus(**config)
         data_structs = None
@@ -145,7 +152,7 @@ def setUp(self):
             patch_resizeterm.start()
             self.addCleanup(patch_resizeterm.stop)
 
-        self.can_viewer = CanViewer(stdscr, bus, data_structs, testing=True)
+        self.can_viewer = CanViewer(self.stdscr_dummy, bus, data_structs, testing=True)
 
     def tearDown(self):
         # Run the viewer after the test, this is done, so we can receive the CAN-Bus messages and make sure that they
@@ -213,6 +220,11 @@ def test_receive(self):
                 if _id["msg"].arbitration_id == 0x101:
                     # Check if the counter is reset when the length has changed
                     self.assertEqual(_id["count"], 1)
+
+                    # Make sure the line has been cleared after the shorted message was send
+                    for col, v in self.stdscr_dummy.draw_buffer[_id["row"]].items():
+                        if col >= 52 + _id["msg"].dlc * 3:
+                            self.assertEqual(v, " ")
                 elif _id["msg"].arbitration_id == 0x123456:
                     # Check if the counter is incremented
                     if _id["dt"] == 0: