Debounce navigation buttons in review mode to prevent GUI freeze

When analysis is running and the user presses navigation buttons rapidly,
stop the analysis immediately but defer restarting it until 300ms after
the last button press. This avoids repeated blocking engine stop/start
cycles that make the GUI unresponsive.

Agent-Logs-Url: https://github.com/fsmosca/Python-Easy-Chess-GUI/sessions/71d680e7-f5da-483b-86f3-c7daf8a96f24

Co-authored-by: fsmosca <22366935+fsmosca@users.noreply.github.com>

Author: Copilot

python_easy_chess_gui.py

@@ -69,7 +69,8 @@
 BOX_TITLE = f'{APP_NAME} {APP_VERSION}'
 REVIEW_MAX_DISPLAY_GAMES = 10000
 REVIEW_ANALYSIS_MULTIPV_LINES = 3
-REVIEW_ANALYSIS_PV_MOVES = 7
+REVIEW_ANALYSIS_PV_MOVES = 7
+REVIEW_NAV_DEBOUNCE_SEC = 0.3
 REVIEW_MOVE_LIST_HEIGHT = 11
 REVIEW_ANALYSIS_BOX_HEIGHT = 4
 
@@ -829,8 +830,9 @@ def reset_review_state(self):
         self.review_analysis_lines = [''] * REVIEW_ANALYSIS_MULTIPV_LINES
         self.review_analysis_enabled = False
         self.review_analysis_status = 'Analysis stopped'
-        self.review_analysis_search = None
-        self.review_analysis_engine = None
+        self.review_analysis_search = None
+        self.review_analysis_engine = None
+        self.review_nav_last_time = 0
 
     def update_game(self, mc: int, user_move: str, time_left: int, user_comment: str):
         """Saves moves in the game.
@@ -3107,9 +3109,17 @@ def start_review_mode(self, window):
             button, value = review_window.Read(timeout=50)
             self.poll_review_analysis(review_window)
 
-            # Skip timeout events as analysis updates are processed by
-            # poll_review_analysis() called earlier in the loop.
-            if button == sg.TIMEOUT_KEY:
+            # Skip timeout events as analysis updates are processed by
+            # poll_review_analysis() called earlier in the loop.
+            if button == sg.TIMEOUT_KEY:
+                # Restart analysis after debounce delay following navigation.
+                if (self.review_nav_last_time
+                        and self.review_analysis_enabled
+                        and self.review_analysis_search is None
+                        and time.time() - self.review_nav_last_time
+                            >= REVIEW_NAV_DEBOUNCE_SEC):
+                    self.review_nav_last_time = 0
+                    self.start_review_analysis(review_window)
                 continue
 
             if button is None:
@@ -3200,9 +3210,16 @@ def start_review_mode(self, window):
                     self.update_review_window(review_window)
                     continue
 
-            if position_changed:
-                self.update_review_window(review_window)
-                self.refresh_review_analysis(review_window)
+            if position_changed:
+                self.update_review_window(review_window)
+                if self.review_analysis_enabled:
+                    self.stop_review_analysis()
+                    self.review_nav_last_time = time.time()
+                    self.review_analysis_lines = [''] * REVIEW_ANALYSIS_MULTIPV_LINES
+                    self.review_analysis_status = 'Waiting...'
+                    self.update_review_analysis_panel(review_window)
+                else:
+                    self.refresh_review_analysis(review_window)
 
         self.close_review_analysis()
         review_window.Close()