Add `P'revious support to page_splitter.

gemini_for_labels.py

@@ -306,7 +306,7 @@ def process_copy_group(group_key, files):
 
 # Run ThreadPool on GROUPS (Copies), not individual files
 # Each thread handles one student's full exam copy sequentially
-with ThreadPoolExecutor(max_workers=6) as executor:
+with ThreadPoolExecutor(max_workers=8) as executor:
     # Convert dict items to arguments for map
     # executor.map expects a function and an iterable.
     # We use a lambda or separate function to unpack the tuple if needed,

page_splitter.py

@@ -79,6 +79,7 @@ class PDFPreviewer:
         self.master = master
         self.num = 0
         self.global_rotation = 0 # Rotation appliquée à tous les fichiers
+        self.history = []
         self.setup_next_file()
 
         self._resize_job = None  # For debouncing resize events
@@ -93,7 +94,7 @@ class PDFPreviewer:
             "← / → : Move line 1cm left/right\n"
             "'c': Rotate page 180°, 'C' : rotate all pages, ',' : rotate all files\n"
             "t s r n: keep left, next page, keep none, keep right\n"
-            "z: send this page to the end, 'R':restart file\n"
+            "z: send this page to the end, 'R':restart file, 'P':back to previous file\n"
         )
         self.info_label = tk.Label(master, text=instructions, justify=tk.LEFT)
         self.info_label.pack(pady=5, side=tk.TOP)
@@ -120,7 +121,8 @@ class PDFPreviewer:
         self.master.bind("s", self.confirm_and_next_page)
         self.master.bind("r", self.discard_page)
         self.master.bind("z", self.send_page_end)
-        self.master.bind("R", self.restart_current_file)  # New binding
+        self.master.bind("R", self.restart_current_file)
+        self.master.bind("P", self.go_to_previous_file)
 
 
         # Bind the resize event on the canvas
@@ -280,6 +282,7 @@ class PDFPreviewer:
             self.load_page()
         else:
             self.finish_and_process()
+            self.history.append(self.pdf_path)
             if self.setup_next_file():
                 self._initialize_current_page_settings()
                 self.load_page()
@@ -323,6 +326,42 @@ class PDFPreviewer:
 
         self.remove_dirs()
 
+    def _restore_original(self, path):
+        """Restores the original file from the 'Copies Originales' backup."""
+        dir_name = os.path.dirname(os.path.abspath(path))
+        file_name = os.path.basename(path)
+        backup_path = os.path.join(dir_name, "Copies Originales", file_name)
+
+        if os.path.exists(backup_path):
+            try:
+                # Moving overwrites the generated PDF with the original backup
+                shutil.move(backup_path, path)
+                print(f"Restored original file from: {backup_path}")
+            except Exception as e:
+                print(f"Failed to restore original file: {e}")
+
+    def go_to_previous_file(self, event=None):
+        """Goes back to the beginning of the previously completed file."""
+        if not self.history:
+            return  # Nowhere to go back to
+
+        # Close the currently open document to avoid lock issues
+        if hasattr(self, 'doc'):
+            self.doc.close()
+
+        # 1. Push current file back onto the stack so it processes next
+        self.inputs.append(self.pdf_path)
+
+        # 2. Get the previous file, restore its original state, and push to stack
+        prev_file = self.history.pop()
+        self._restore_original(prev_file)
+        self.inputs.append(prev_file)
+
+        # 3. Reload environment (setup_next_file will pop prev_file back off the stack)
+        self.setup_next_file()
+        self._initialize_current_page_settings()
+        self.load_page()
+        
     def split_filename_left(self, i):
         return os.path.join(self.split_dir, f"{self.base_name}_{i+1}l.pdf")
     def split_filename_right(self, i):