test: relax log widget test for robustness, and update example (#439)

* fix: fix log widget example and tests

* catch exception

* cleanup

* fix log

* try fix coverage

Author: tlambert03

examples/core_log_widget.py

@@ -1,8 +1,14 @@
+from pymmcore_plus import CMMCorePlus
 from qtpy.QtWidgets import QApplication
 
 from pymmcore_widgets import CoreLogWidget
 
 app = QApplication([])
-wdg = CoreLogWidget()
+core = CMMCorePlus()
+
+wdg = CoreLogWidget(mmcore=core)
+wdg.clear()
 wdg.show()
+
+core.loadSystemConfiguration()
 app.exec()

pyproject.toml

@@ -53,7 +53,7 @@ dependencies = [
     'superqt[quantity,cmap,iconify] >=0.7.1',
     'useq-schema >=0.7.2',
     'vispy >=0.15.0',
-    "pyopengl >=3.1.9; platform_system == 'Darwin'"
+    "pyopengl >=3.1.9; platform_system == 'Darwin'",
 ]
 
 [project.optional-dependencies]
@@ -75,7 +75,7 @@ test = [
     "pyyaml>=6.0.2",
     "zarr >=2.15,<3",
     "numcodecs >0.14.0,<0.16; python_version >= '3.13'",
-    "numcodecs >0.12.0,<0.16"
+    "numcodecs >0.12.0,<0.16",
 ]
 dev = [
     { include-group = "docs" },
@@ -144,7 +144,7 @@ filterwarnings = [
     "error",
     "ignore:distutils Version classes are deprecated",
     "ignore:Failed to disconnect:RuntimeWarning:",
-    "ignore:'count' is passed as positional argument::vispy"
+    "ignore:'count' is passed as positional argument::vispy",
 ]
 
 # https://mypy.readthedocs.io/en/stable/config_file.html
@@ -173,6 +173,10 @@ exclude_lines = [
     "raise NotImplementedError",
 ]
 show_missing = true
+
+[tool.coverage.paths]
+source = ["src/", "*/pymmcore-widgets/pymmcore-widgets/src", "*/site-packages/"]
+
 [tool.coverage.run]
 source = ['pymmcore_widgets']
 

src/pymmcore_widgets/_log.py

@@ -2,10 +2,19 @@
 
 import os
 from collections import deque
+from contextlib import suppress
 from typing import TYPE_CHECKING
 
 from pymmcore_plus import CMMCorePlus
-from qtpy.QtCore import QFileSystemWatcher, QObject, QTimer, QUrl, Signal
+from qtpy.QtCore import (
+    QFileSystemWatcher,
+    QObject,
+    QSize,
+    QTimer,
+    QTimerEvent,
+    QUrl,
+    Signal,
+)
 from qtpy.QtGui import QCloseEvent, QDesktopServices, QFontDatabase, QPalette
 from qtpy.QtWidgets import (
     QApplication,
@@ -43,26 +52,38 @@ def __init__(
         # unless the file is flushed from cache to disk. This does NOT happen
         # when CMMCorePlus.logMessage() is called. So we need to poll the file for
         # Windows' sake.
-        self._timer = QTimer(self)
-        self._timer.setInterval(self._interval)
-        self._timer.timeout.connect(self._read_new)
+        self._timer_id: int | None = None
 
         # Watcher for rotation/truncate events
         self._watcher = QFileSystemWatcher(self)
         self._watcher.addPath(self._path)
         self._watcher.fileChanged.connect(self._on_file_changed)
 
+    def __del__(self) -> None:
+        """Ensure file is closed when object is deleted."""
+        with suppress(RuntimeError):
+            self._stop()
+
+    def timerEvent(self, event: QTimerEvent | None) -> None:
+        if event and event.timerId() == self._timer_id:
+            self._read_new()
+
     def start(self) -> None:
         """Open the file and start polling."""
-        self._file = open(self._path, encoding="utf-8", errors="replace")
-        self._file.seek(0, os.SEEK_END)
-        self._timer.start()
+        if self._timer_id is None:
+            self._file = open(self._path, encoding="utf-8", errors="replace")
+            self._file.seek(0, os.SEEK_END)
+            self._timer_id = self.startTimer(self._interval)
 
     def _stop(self) -> None:
         """Stop polling and close the file."""
-        self._timer.stop()
-        if self._file:
-            self._file.close()
+        if self._timer_id is not None:
+            self.killTimer(self._timer_id)
+            self._timer_id = None
+        if self._file is not None:
+            with suppress(Exception):
+                self._file.close()
+            self._file = None
         self.finished.emit()
 
     def _on_file_changed(self, path: str) -> None:
@@ -151,17 +172,27 @@ def __init__(
         layout.setContentsMargins(0, 0, 0, 0)
         layout.addLayout(file_layout)
         layout.addWidget(self._log_view)
-        self.setLayout(layout)
 
         # --- Connections ---
         self._reader.new_lines.connect(self._append_line)
-        self._clear_btn.clicked.connect(self._log_view.clear)
+        self._clear_btn.clicked.connect(self.clear)
         self._log_btn.clicked.connect(self._open_native)
         self._reader.start()
 
-    def __del__(self) -> None:
-        """Stop reader before deletion."""
-        self._reader._stop()
+        # scroll left to begin
+        def _scroll_left() -> None:
+            if sb := self._log_view.horizontalScrollBar():
+                sb.setValue(0)
+
+        QTimer.singleShot(0, _scroll_left)
+
+    def clear(self) -> None:
+        """Clear the log view."""
+        self._log_view.clear()
+
+    def sizeHint(self) -> QSize:
+        hint = super().sizeHint()
+        return hint.expandedTo(QSize(1000, 800))
 
     def _append_line(self, line: str) -> None:
         """Append a line, respecting pause/follow settings."""
@@ -170,8 +201,6 @@ def _append_line(self, line: str) -> None:
     def closeEvent(self, event: QCloseEvent | None) -> None:
         """Clean up thread on close."""
         self._reader._stop()
-        # self._thread.quit()
-        # self._thread.wait()
         super().closeEvent(event)
 
     def _open_native(self) -> None:

tests/test_core_log_widget.py

@@ -20,19 +20,15 @@ def test_core_log_widget_init(qtbot: QtBot, global_mmcore: CMMCorePlus) -> None:
     log_path = global_mmcore.getPrimaryLogFile()
     assert log_path == wdg._log_path.text()
 
-    # Assert log content is in the widget TextEdit
-    # This is a bit tricky because more can be appended to the log file.
-    with open(log_path) as f:
-        log_content = [s.strip() for s in f.readlines()]
-        # Trim down to the final 5000 lines if necessary
-        # (this is all that will fit in the Log Widget)
-        max_lines = wdg._log_view.maximumBlockCount()
-        if len(log_content) > max_lines:
-            log_content = log_content[-max_lines:]
-    edit_content = [s.strip() for s in wdg._log_view.toPlainText().splitlines()]
-    min_length = min(len(log_content), len(edit_content))
-    for i in range(min_length):
-        assert log_content[i] == edit_content[i]
+    wdg.clear()
+    with qtbot.waitSignal(global_mmcore.events.systemConfigurationLoaded):
+        global_mmcore.loadSystemConfiguration()
+
+    def _check_log() -> None:
+        if "Finished initializing" not in wdg._log_view.toPlainText():
+            raise AssertionError("CoreLogWidget did not finish initializing.")
+
+    qtbot.waitUntil(_check_log, timeout=1000)
 
 
 def test_core_log_widget_update(qtbot: QtBot, global_mmcore: CMMCorePlus) -> None: