use signals to enable/disable the cancel button

src/plugins/logfile/filterwidget.py

@@ -4,7 +4,7 @@ import tempfile
 import threading
 from typing import Optional, Callable
 
-from PySide6.QtCore import QRunnable, QThreadPool
+from PySide6.QtCore import QRunnable, QThreadPool, Signal
 from PySide6.QtWidgets import QWidget, QVBoxLayout, QHBoxLayout, QLineEdit, QCheckBox, QPushButton
 
 from src.ui.bigtext.bigtext import BigText
@@ -85,6 +85,7 @@ class FilterTask(QRunnable):
 class FilterWidget(QWidget):
     filter_model: LogFileModel
     filter_task: Optional[FilterTask] = None
+    search_is_running = Signal(bool)
 
     def __init__(self, source_model: LogFileModel):
         super(FilterWidget, self).__init__()
@@ -101,6 +102,7 @@ class FilterWidget(QWidget):
         self.btn_cancel_search = QPushButton(_("Cancel"))
         self.btn_cancel_search.setVisible(False)
         self.btn_cancel_search.pressed.connect(self._cancel_search)
+        self.search_is_running.connect(lambda is_running: self.btn_cancel_search.setVisible(is_running))
 
         self.ignore_case = QCheckBox(_("ignore case"))
         self.ignore_case.setChecked(True)
@@ -185,7 +187,7 @@ class FilterWidget(QWidget):
             regex,
             self._lock,
             self.filter_match_found_listeners,
-            lambda: self.btn_cancel_search.setVisible(True),
-            lambda: self.btn_cancel_search.setVisible(False)
+            lambda: self.search_is_running.emit(True),
+            lambda: self.search_is_running.emit(False)
         )
         QThreadPool.globalInstance().start(self.filter_task)