fix: narrow window title exception handling (#141)

* fix: narrow window title exception handling

* test: cover window title errors without a GUI

---------

Co-authored-by: Peter Corke <peter.i.corke@gmail.com>

Author: RoboX2020

src/machinevisiontoolbox/base/imageio.py

@@ -1030,7 +1030,8 @@ def _idisp_opencv(
 def set_window_title(title: str) -> None:
     try:
         _plt().gcf().canvas.manager.set_window_title(title)  # for 3.4 onward
-    except:
+    except (AttributeError, RuntimeError):
+        # Some noninteractive backends do not have a usable window manager.
         pass
 
 

tests/test_window_title_errors.py

@@ -0,0 +1,31 @@
+from types import SimpleNamespace
+from unittest.mock import Mock, patch
+
+import pytest
+
+from machinevisiontoolbox.base import imageio
+
+
+def test_window_title_is_forwarded():
+    """Forward the title to a supported window manager."""
+    manager = Mock()
+    figure = SimpleNamespace(canvas=SimpleNamespace(manager=manager))
+    with patch.object(imageio, "_plt") as pyplot:
+        pyplot.return_value.gcf.return_value = figure
+        imageio.set_window_title("camera")
+    manager.set_window_title.assert_called_once_with("camera")
+
+
+@pytest.mark.parametrize("error", [AttributeError, RuntimeError])
+def test_unsupported_window_title_is_ignored(error):
+    """Tolerate window managers that cannot set a title."""
+    with patch.object(imageio, "_plt", side_effect=error("unsupported")):
+        imageio.set_window_title("camera")
+
+
+@pytest.mark.parametrize("error", [ValueError, KeyboardInterrupt])
+def test_unexpected_window_title_errors_propagate(error):
+    """Do not hide unrelated failures or user interrupts."""
+    with patch.object(imageio, "_plt", side_effect=error()):
+        with pytest.raises(error):
+            imageio.set_window_title("camera")