add diff_viewer into commit tab

diff_viewer.py

@@ -0,0 +1,538 @@
+# --- START OF FILE diff_viewer.py ---
+
+import tkinter as tk
+from tkinter import ttk, scrolledtext, Canvas, messagebox
+import difflib
+import logging
+import os
+import locale # Per fallback encoding
+
+class DiffViewerWindow(tk.Toplevel):
+    """
+    Toplevel window to display a side-by-side diff of a file.
+    Shows differences between the working directory version and the HEAD version.
+    Includes synchronized scrolling via clicking on the overview minimap.
+    Relies solely on minimap clicks for vertical navigation.
+    """
+    def __init__(self, master, logger, git_commands, repo_path, file_status_line):
+        """
+        Initializes the Diff Viewer window.
+
+        Args:
+            master: The parent widget (usually the main Tkinter root).
+            logger: Logger instance for logging messages.
+            git_commands: Instance of GitCommands for interacting with Git.
+            repo_path (str): Absolute path to the Git repository.
+            file_status_line (str): The full status line from 'git status --short'
+                                    for the file to be diffed (e.g., " M path/to/file.py").
+        """
+        super().__init__(master)
+
+        # Setup Logger (con fallback)
+        if not isinstance(logger, (logging.Logger, logging.LoggerAdapter)):
+            print("ERROR: DiffViewerWindow requires a valid logger. Using fallback.")
+            self.logger = logging.getLogger("DiffViewer_Fallback")
+            self.logger.setLevel(logging.WARNING) # Logga solo warning/error
+        else:
+            self.logger = logger
+
+        # Setup GitCommands
+        if git_commands is None:
+             self.logger.critical("GitCommands instance is required.")
+             raise ValueError("DiffViewerWindow requires a valid GitCommands instance.")
+        self.git_commands = git_commands
+
+        self.repo_path = repo_path
+
+        # Pulisci e valida il percorso del file dalla riga di stato
+        self.relative_file_path = self._clean_relative_path(file_status_line)
+        if not self.relative_file_path:
+             self.logger.error(f"Cannot show diff: Invalid path from '{file_status_line}'.")
+             messagebox.showerror("Error", "Invalid file path for diff.", parent=master)
+             self.after_idle(self.destroy) # Chiudi se percorso non valido
+             return # Esce dall'init
+
+        # Configurazione Finestra Toplevel
+        self.title(f"Diff - {os.path.basename(self.relative_file_path)}")
+        self.geometry("920x650") # Dimensioni finestra
+        self.minsize(550, 400) # Dimensioni minime
+        self.grab_set()        # Rendi modale
+        self.transient(master) # Appare sopra il parent
+
+        # Stato interno
+        self.head_content_lines = []
+        self.workdir_content_lines = []
+        self.diff_map = [] # Mappa per minimappa: 0=uguale, 1=rimosso/mod, 2=aggiunto/mod
+        self._scrolling_active = False # Flag per prevenire eventi ricorsivi
+
+        # Costruisci l'interfaccia grafica
+        self._create_widgets()
+
+        # Carica il contenuto dei file e calcola/mostra il diff
+        load_ok = False
+        try:
+            load_ok = self._load_content()
+            if load_ok:
+                self._compute_and_display_diff()
+                self._setup_scrolling() # Configura solo il click sulla minimappa
+            else:
+                 # Se _load_content fallisce, mostra errore nei widget
+                 self.logger.warning("Content loading failed, populating text widgets with error messages.")
+                 self._populate_text(self.text_head, ["<Error loading HEAD content>"])
+                 self._populate_text(self.text_workdir, ["<Error loading Workdir content>"])
+                 # Disegna comunque la minimappa (sarà vuota)
+                 self.minimap_canvas.after(50, self._draw_minimap)
+
+        except Exception as load_err:
+             # Errore imprevisto durante il caricamento/diff
+             self.logger.exception(f"Unexpected error during diff setup for '{self.relative_file_path}': {load_err}")
+             messagebox.showerror("Fatal Error", f"Failed to display diff:\n{load_err}", parent=self)
+             self.after_idle(self.destroy) # Chiudi in caso di errore grave
+             return # Esce dall'init
+
+        # Centra la finestra rispetto al parent
+        self._center_window(master)
+
+
+    def _clean_relative_path(self, file_status_line):
+        """
+        Extracts a clean relative path from a git status line.
+        Handles status codes, spaces, renames, and quotes.
+        """
+        try:
+            # Pulisci caratteri speciali e spazi esterni
+            line = file_status_line.strip('\x00').strip()
+            if not line:
+                self.logger.warning("Received empty status line for cleaning.")
+                return ""
+
+            # Trova il primo spazio per separare lo stato dal percorso
+            space_index = -1
+            for i, char in enumerate(line):
+                if char.isspace():
+                    space_index = i
+                    break
+
+            # Se non c'è spazio o è alla fine, il formato è sospetto
+            if space_index == -1 or space_index + 1 >= len(line):
+                # Se la linea non contiene spazi, potremmo assumere che sia solo il nome file?
+                # Questo potrebbe accadere se lo stato viene perso prima. Per sicurezza,
+                # richiediamo uno spazio per separare stato e percorso.
+                self.logger.warning(f"Could not find valid space separator in status line: '{line}'")
+                return "" # Ritorna vuoto se non c'è separatore valido
+
+            # Estrai la parte del percorso dopo il primo spazio
+            relative_path_raw = line[space_index + 1:].strip()
+
+            # Gestisci rinominati nel formato "XY orig -> new"
+            if "->" in relative_path_raw:
+                # Prendi solo il nome del file *nuovo* (dopo ->)
+                relative_path = relative_path_raw.split("->")[-1].strip()
+            else:
+                relative_path = relative_path_raw
+
+            # Gestisci le quote se presenti (tipico se non si usa -z)
+            if len(relative_path) >= 2 and relative_path.startswith('"') and relative_path.endswith('"'):
+                 relative_path = relative_path[1:-1]
+
+            # Controlla se il risultato è vuoto dopo la pulizia
+            if not relative_path:
+                 self.logger.warning(f"Extracted path is empty from status line: '{line}'")
+                 return ""
+
+            self.logger.debug(f"Cleaned path from '{file_status_line}' -> '{relative_path}'")
+            return relative_path
+
+        except Exception as e:
+            self.logger.error(f"Error cleaning path from status line '{file_status_line}': {e}", exc_info=True)
+            return "" # Ritorna vuoto in caso di errore
+
+
+    def _center_window(self, parent):
+        """Centers the Toplevel window relative to its parent."""
+        try:
+            self.update_idletasks() # Assicura dimensioni aggiornate
+            # Calcola le coordinate
+            parent_x = parent.winfo_rootx()
+            parent_y = parent.winfo_rooty()
+            parent_width = parent.winfo_width()
+            parent_height = parent.winfo_height()
+            window_width = self.winfo_width()
+            window_height = self.winfo_height()
+            x = parent_x + (parent_width // 2) - (window_width // 2)
+            y = parent_y + (parent_height // 2) - (window_height // 2)
+            # Assicura visibilità sullo schermo
+            screen_width = self.winfo_screenwidth()
+            screen_height = self.winfo_screenheight()
+            x = max(0, min(x, screen_width - window_width))
+            y = max(0, min(y, screen_height - window_height))
+            # Imposta geometria
+            self.geometry(f"+{int(x)}+{int(y)}")
+        except Exception as e:
+            self.logger.error(f"Could not center DiffViewerWindow: {e}", exc_info=True)
+
+
+    def _create_widgets(self):
+        """Creates the main widgets for the diff view (NO main scrollbar)."""
+        main_frame = ttk.Frame(self, padding=5)
+        main_frame.pack(fill=tk.BOTH, expand=True)
+        main_frame.rowconfigure(1, weight=1) # Riga dei text widget si espande
+        # Colonne: Sinistra (HEAD), Destra (Workdir), Minimap
+        main_frame.columnconfigure(0, weight=1)
+        main_frame.columnconfigure(1, weight=1)
+        main_frame.columnconfigure(2, weight=0, minsize=40) # Minimap larghezza fissa
+
+        # Etichette Titoli
+        ttk.Label(main_frame, text=f"HEAD (Repository Version)").grid(
+            row=0, column=0, sticky='w', padx=(5,2), pady=(0, 2))
+        ttk.Label(main_frame, text=f"Working Directory Version").grid(
+            row=0, column=1, sticky='w', padx=(2,5), pady=(0, 2))
+        ttk.Label(main_frame, text="Overview").grid(
+            row=0, column=2, sticky='w', padx=(5,0), pady=(0, 2))
+
+        # Widget Testo (senza scrollbar individuali o yscrollcommand)
+        text_font = ("Consolas", 10) # Font Monospace
+        common_text_opts = {
+            "wrap": tk.NONE, # No a capo
+            "font": text_font,
+            "padx": 5, "pady": 5,
+            "undo": False, # Non serve undo in visualizzazione
+            "state": tk.DISABLED, # Inizia non modificabile
+            "borderwidth": 1,
+            "relief": tk.SUNKEN
+        }
+        self.text_head = tk.Text(main_frame, **common_text_opts)
+        self.text_workdir = tk.Text(main_frame, **common_text_opts)
+
+        self.text_head.grid(row=1, column=0, sticky='nsew', padx=(5, 2))
+        self.text_workdir.grid(row=1, column=1, sticky='nsew', padx=(2, 5))
+
+        # Minimap Canvas
+        self.minimap_canvas = Canvas(
+            main_frame, width=40, bg='#F0F0F0',
+            relief=tk.SUNKEN, borderwidth=1, highlightthickness=0
+        )
+        self.minimap_canvas.grid(row=1, column=2, sticky='ns', padx=(5, 0))
+        self.minimap_canvas.bind("<Configure>", self._on_minimap_resize)
+
+        # Configurazione Tag per Highlighting
+        self.text_head.tag_config("removed", background="#FFE0E0") # Rosso chiaro
+        self.text_head.tag_config("empty", background="#F5F5F5", foreground="#A0A0A0") # Grigio per filler
+        self.text_workdir.tag_config("added", background="#E0FFE0") # Verde chiaro
+        self.text_workdir.tag_config("empty", background="#F5F5F5", foreground="#A0A0A0") # Grigio per filler
+
+
+    def _load_content(self):
+        """Loads file content from HEAD and working directory."""
+        self.logger.info(f"Loading content for diff: {self.relative_file_path}")
+        load_success = True
+        # Carica HEAD
+        try:
+            head_content_raw = self.git_commands.get_file_content_from_ref(
+                self.repo_path, self.relative_file_path, ref="HEAD"
+            )
+            self.head_content_lines = head_content_raw.splitlines() if head_content_raw is not None else []
+            if head_content_raw is None:
+                 self.logger.warning(f"File '{self.relative_file_path}' not found in HEAD (likely new or deleted in HEAD).")
+        except Exception as e_head:
+             self.logger.error(f"Error loading HEAD content for '{self.relative_file_path}': {e_head}", exc_info=True)
+             self.head_content_lines = [f"<Error loading HEAD: {e_head}>"]
+             load_success = False
+
+        # Carica Working Directory
+        try:
+             workdir_full_path = os.path.join(self.repo_path, self.relative_file_path)
+             if os.path.exists(workdir_full_path) and os.path.isfile(workdir_full_path):
+                  try:
+                      with open(workdir_full_path, 'r', encoding='utf-8') as f:
+                          self.workdir_content_lines = f.read().splitlines()
+                  except UnicodeDecodeError:
+                      self.logger.warning(f"UTF-8 decode failed for WD {workdir_full_path}, trying fallback.")
+                      try:
+                          fallback_encoding = locale.getpreferredencoding(False) or 'latin-1'
+                          with open(workdir_full_path, 'r', encoding=fallback_encoding, errors='replace') as f:
+                              self.workdir_content_lines = f.read().splitlines()
+                      except Exception as fb_e:
+                           self.logger.error(f"WD fallback read failed: {fb_e}")
+                           self.workdir_content_lines = [f"<Error reading WD: {fb_e}>"]
+                           load_success = False
+             else:
+                  self.logger.info(f"Working directory file not found: {workdir_full_path}")
+                  self.workdir_content_lines = [] # File non esiste sul disco
+        except Exception as e_wd:
+            self.logger.error(f"Error loading Workdir content for '{self.relative_file_path}': {e_wd}", exc_info=True)
+            self.workdir_content_lines = [f"<Error loading Workdir: {e_wd}>"]
+            load_success = False
+
+        return load_success
+
+
+    def _compute_and_display_diff(self):
+        """Calculates the diff and populates the text widgets with highlights,
+           ensuring consistent line count for display using SequenceMatcher."""
+        self.logger.debug("Computing and displaying diff...")
+        if not self.head_content_lines and not self.workdir_content_lines:
+             self.logger.warning("Both HEAD and Workdir content are empty or failed.")
+             self._populate_text(self.text_head, ["(No content in HEAD)"])
+             self._populate_text(self.text_workdir, ["(No content in Workdir)"])
+             self.diff_map = []
+             self.minimap_canvas.after(50, self._draw_minimap)
+             return
+
+        matcher = difflib.SequenceMatcher(None, self.head_content_lines, self.workdir_content_lines, autojunk=False)
+        head_lines_display = []
+        workdir_lines_display = []
+        diff_map_for_minimap = []
+
+        self.logger.debug("Generating aligned display lines using SequenceMatcher opcodes...")
+        for tag, i1, i2, j1, j2 in matcher.get_opcodes():
+            head_chunk = self.head_content_lines[i1:i2]
+            workdir_chunk = self.workdir_content_lines[j1:j2]
+
+            if tag == 'equal':
+                for k in range(len(head_chunk)):
+                    head_lines_display.append((' ', head_chunk[k]))
+                    workdir_lines_display.append((' ', workdir_chunk[k]))
+                    diff_map_for_minimap.append(0) # 0 = equal
+            elif tag == 'delete':
+                for k in range(len(head_chunk)):
+                    head_lines_display.append(('-', head_chunk[k]))
+                    workdir_lines_display.append(('empty', ''))
+                    diff_map_for_minimap.append(1) # 1 = deleted/modified head
+            elif tag == 'insert':
+                for k in range(len(workdir_chunk)):
+                    head_lines_display.append(('empty', ''))
+                    workdir_lines_display.append(('+', workdir_chunk[k]))
+                    diff_map_for_minimap.append(2) # 2 = added/modified workdir
+            elif tag == 'replace':
+                len_head = len(head_chunk)
+                len_workdir = len(workdir_chunk)
+                max_len = max(len_head, len_workdir)
+                for k in range(max_len):
+                    head_line = head_chunk[k] if k < len_head else ''
+                    workdir_line = workdir_chunk[k] if k < len_workdir else ''
+                    head_code = '-' if k < len_head else 'empty'
+                    workdir_code = '+' if k < len_workdir else 'empty'
+                    head_lines_display.append((head_code, head_line))
+                    workdir_lines_display.append((workdir_code, workdir_line))
+                    # Segna come modificato (1 per rosso, 2 per verde)
+                    diff_map_for_minimap.append(1 if head_code != 'empty' else 2)
+
+        # Verifica coerenza (opzionale ma utile per debug)
+        if len(head_lines_display) != len(workdir_lines_display) or \
+           len(head_lines_display) != len(diff_map_for_minimap):
+             self.logger.error("Internal Diff Error: Mismatch in aligned line counts!")
+        else:
+             self.logger.debug(f"Aligned display generated with {len(head_lines_display)} lines.")
+
+        self.diff_map = diff_map_for_minimap # Aggiorna mappa per minimappa
+
+        # Popola widget testo
+        self._populate_text(self.text_head, head_lines_display)
+        self._populate_text(self.text_workdir, workdir_lines_display)
+
+        # Disegna minimappa (con ritardo)
+        self.minimap_canvas.after(100, self._draw_minimap)
+
+
+    def _populate_text(self, text_widget, lines_data):
+        """Populates a text widget with lines and applies tags."""
+        widget_name = text_widget.winfo_name()
+        self.logger.debug(f"Populating widget {widget_name} with {len(lines_data)} lines.")
+        text_widget.config(state=tk.NORMAL) # Abilita per modifica
+        text_widget.delete('1.0', tk.END)   # Pulisci contenuto precedente
+
+        if not lines_data:
+            self.logger.debug(f"No lines data for {widget_name}.")
+            text_widget.insert('1.0', "(No content)\n", ("empty",)) # Mostra messaggio vuoto
+        else:
+            content_string = ""
+            tags_to_apply = [] # Lista di (tag_name, start_index, end_index)
+            current_line_num = 1 # Tkinter usa indice 1-based
+            for data_tuple in lines_data:
+                if not isinstance(data_tuple, tuple) or len(data_tuple) != 2:
+                    self.logger.warning(f"Skipping malformed data in {widget_name}: {data_tuple}")
+                    line_content = "<Internal Error: Bad data format>\n"
+                    code = 'error' # Codice fittizio per evitare errori tag
+                else:
+                    code, content = data_tuple
+                    line_content = content + '\n' # Aggiungi newline per Text widget
+
+                # Aggiungi il contenuto della riga alla stringa completa
+                content_string += line_content
+
+                # Calcola indici per i tag
+                start_index = f"{current_line_num}.0"
+                end_index = f"{current_line_num}.end" # .end si riferisce alla fine della linea logica
+
+                # Aggiungi tag alla lista se necessario
+                if code == '-': tags_to_apply.append(("removed", start_index, end_index))
+                elif code == '+': tags_to_apply.append(("added", start_index, end_index))
+                elif code == 'empty': tags_to_apply.append(("empty", start_index, end_index))
+
+                current_line_num += 1 # Incrementa numero linea per la prossima iterazione
+
+            # Inserisci tutto il testo in una volta sola
+            text_widget.insert('1.0', content_string)
+
+            # Applica tutti i tag raccolti
+            for tag, start, end in tags_to_apply:
+                try:
+                     text_widget.tag_add(tag, start, end)
+                except tk.TclError as tag_err:
+                     self.logger.error(f"Error applying tag '{tag}' from {start} to {end}: {tag_err}")
+
+        text_widget.config(state=tk.DISABLED) # Disabilita dopo aver popolato
+        text_widget.yview_moveto(0.0)         # Assicura che sia all'inizio
+
+
+    def _draw_minimap(self):
+        """Draws the minimap overview based on self.diff_map."""
+        canvas = self.minimap_canvas
+        canvas.delete("diff_line")
+        canvas.delete("viewport_indicator")
+
+        num_lines = len(self.diff_map)
+        if num_lines == 0:
+            self.logger.debug("No diff map data for minimap.")
+            return
+
+        canvas.update_idletasks()
+        canvas_width = canvas.winfo_width()
+        canvas_height = canvas.winfo_height()
+
+        if canvas_width <= 1 or canvas_height <= 1:
+            self.logger.debug(f"Skipping minimap draw due to invalid dimensions: {canvas_width}x{canvas_height}")
+            return
+
+        self.logger.debug(f"Drawing minimap ({canvas_width}x{canvas_height}) for {num_lines} lines.")
+
+        # Calcola l'altezza ESATTA per linea, senza max(1.0) inizialmente
+        # per vedere se il problema è l'arrotondamento
+        exact_line_height = float(canvas_height) / num_lines if num_lines > 0 else 1.0
+
+        # --- MODIFICA: Arrotondamento e gestione bordo inferiore ---
+        accumulated_height = 0.0
+        for i, diff_type in enumerate(self.diff_map):
+            y_start = round(accumulated_height) # Arrotonda inizio
+
+            # Calcola l'altezza *teorica* per questa linea
+            current_line_height = exact_line_height
+            accumulated_height += current_line_height
+            y_end = round(accumulated_height) # Arrotonda fine
+
+            # Assicura che y_end sia almeno y_start + 1 per visibilità
+            if y_end <= y_start: y_end = y_start + 1
+
+            # Gestione ultima linea per riempire esattamente il canvas
+            if i == num_lines - 1:
+                 y_end = canvas_height # Forza l'ultima linea ad arrivare al bordo
+
+            # Colore (come modificato prima per avere rosso per tutte le diff)
+            color = '#F0F0F0' # Grigio
+            if diff_type == 1 or diff_type == 2:
+                 color = '#F8D0D0' # Rosso
+
+            canvas.create_rectangle(0, y_start, canvas_width, y_end,
+                                    fill=color, outline="", tags="diff_line")
+        # --- FINE MODIFICA ---
+
+        self._update_minimap_viewport()
+
+
+    # --- Scrolling Logic (Solo Minimap Click) ---
+
+    def _setup_scrolling(self):
+         """ Configure ONLY minimap click for navigation. """
+         self.minimap_canvas.bind("<Button-1>", self._on_minimap_click)
+         # Nessun altro binding necessario (no scrollbar, no yscrollcommand)
+
+    def _reset_scroll_flag(self):
+        """Resets the scrolling flag."""
+        self._scrolling_active = False
+
+    def _update_minimap_viewport(self):
+        """ Updates the indicator rectangle on the minimap. """
+        canvas = self.minimap_canvas
+        canvas.delete("viewport_indicator") # Rimuovi il vecchio
+        try:
+            # Leggi la posizione della vista da uno dei widget testo
+            first, last = self.text_head.yview()
+        except tk.TclError:
+            self.logger.warning("TclError getting text view, cannot update minimap viewport.")
+            return # Esce se il widget è distrutto
+
+        # Assicurati che le dimensioni siano valide
+        canvas.update_idletasks()
+        canvas_height = canvas.winfo_height()
+        canvas_width = canvas.winfo_width()
+        if canvas_height <= 1 or canvas_width <=1 :
+            self.logger.debug("Canvas not ready for viewport update.")
+            return
+
+        # Calcola coordinate y del rettangolo indicatore
+        y_start = first * canvas_height
+        y_end = last * canvas_height
+        # Assicura altezza minima di 1 pixel
+        if y_end <= y_start : y_end = y_start + 1
+
+        # Disegna il nuovo indicatore
+        canvas.create_rectangle(
+            1, y_start, canvas_width - 1, y_end, # Margine laterale 1px
+            outline='black', width=1,
+            tags="viewport_indicator"
+        )
+        # Assicurati che sia sopra le linee colorate
+        canvas.tag_raise("viewport_indicator")
+
+
+    def _on_minimap_click(self, event):
+        """ Handles clicks on the minimap to scroll the text views. """
+        if self._scrolling_active: return # Previene chiamate multiple
+        self._scrolling_active = True
+        try:
+             canvas = self.minimap_canvas
+             canvas_height = canvas.winfo_height()
+             if canvas_height <= 1: return # Canvas non pronto
+
+             # Calcola la frazione verticale del click
+             target_fraction = event.y / canvas_height
+             # Limita la frazione tra 0.0 e poco meno di 1.0 per evitare problemi
+             target_fraction = max(0.0, min(target_fraction, 1.0))
+
+             self.logger.debug(f"Minimap clicked at y={event.y}, fraction={target_fraction:.3f}")
+
+             # Muovi entrambi i widget di testo a quella frazione
+             # yview_moveto imposta la *prima* linea visibile a quella frazione
+             self.text_head.yview_moveto(target_fraction)
+             self.text_workdir.yview_moveto(target_fraction)
+
+             # Aggiorna l'indicatore sulla minimappa per riflettere la nuova vista
+             self._update_minimap_viewport()
+
+        finally:
+             # Resetta il flag dopo un breve ritardo per evitare loop
+             self.after(50, self._reset_scroll_flag) # Ritardo leggermente aumentato
+             
+    # Usiamo un debounce semplice per evitare ridisegni troppo frequenti durante il drag
+    _configure_timer_id = None
+
+    def _on_minimap_resize(self, event):
+        """Called when the minimap canvas is resized (e.g., window resize).
+           Schedules a redraw after a short delay (debounce)."""
+        # Cancella il timer precedente se esiste
+        if self._configure_timer_id:
+            self.after_cancel(self._configure_timer_id)
+
+        # Pianifica il ridisegno dopo un breve ritardo (es. 100ms)
+        # Questo evita di ridisegnare continuamente mentre l'utente trascina il bordo
+        self._configure_timer_id = self.after(100, self._redraw_minimap_on_resize)
+
+    def _redraw_minimap_on_resize(self):
+        """Actually redraws the minimap. Called by the debounced timer."""
+        self.logger.debug("Redrawing minimap due to resize event.")
+        self._configure_timer_id = None # Resetta ID timer
+        # Chiama la funzione di disegno esistente
+        self._draw_minimap()
+
+# --- END OF FILE diff_viewer.py ---

git_commands.py

@@ -1100,4 +1100,81 @@ class GitCommands:
             raise
         except Exception as e:
              self.logger.exception(f"Unexpected error in get_matching_gitignore_rule: {e}")
-             raise GitCommandError(f"Unexpected check-ignore -v error: {e}", command=command) from e
+             raise GitCommandError(f"Unexpected check-ignore -v error: {e}", command=command) from e
+         
+    def get_status_short(self, working_directory):
+        """
+        Gets the repository status in short format (-z for null termination).
+
+        Returns:
+            list: A list of strings, each representing a changed file
+                  and its status (e.g., " M filename", "?? newfile").
+                  Returns empty list on error.
+        """
+        self.logger.debug(f"Getting short status for '{working_directory}'")
+        # -z null terminates filenames, safer for paths with spaces/special chars
+        # --ignored=no : Non mostrare file ignorati (di solito default, ma esplicito)
+        command = ["git", "status", "--short", "-z", "--ignored=no"]
+        try:
+            # L'output di status può essere utile, ma non enorme. Logghiamolo a DEBUG.
+            result = self.log_and_execute(command, working_directory, check=True, log_output_level=logging.DEBUG)
+            # Split by null terminator and filter out empty strings
+            status_lines = [line for line in result.stdout.split('\0') if line]
+            self.logger.info(f"Git status check returned {len(status_lines)} changed/untracked items.")
+            return status_lines
+        except (GitCommandError, ValueError) as e:
+            self.logger.error(f"Failed to get git status: {e}")
+            return [] # Ritorna lista vuota in caso di errore
+        except Exception as e:
+            self.logger.exception(f"Unexpected error getting git status: {e}")
+            return []
+
+    def get_file_content_from_ref(self, working_directory, file_path, ref="HEAD"):
+        """
+        Retrieves the content of a file from a specific Git reference (e.g., HEAD, index).
+
+        Args:
+            working_directory (str): Path to the Git repository.
+            file_path (str): Relative path to the file within the repo.
+            ref (str): The Git reference (e.g., "HEAD", "master", commit hash, or ":" for index).
+
+        Returns:
+            str or None: The file content as a string, or None if the file
+                         doesn't exist in that ref or an error occurs.
+        """
+        # Normalizza i separatori per Git (usa sempre '/')
+        git_style_path = file_path.replace(os.path.sep, '/')
+        ref_prefix = f"{ref}:" if ref else ":" # Usa ":" per l'index se ref è vuoto o None
+
+        # Costruisci l'argomento ref:path
+        ref_path_arg = f"{ref_prefix}{git_style_path}"
+
+        self.logger.debug(f"Getting file content for '{ref_path_arg}' in '{working_directory}'")
+        command = ["git", "show", ref_path_arg]
+
+        try:
+            # check=False perché un file non trovato in HEAD/index non è un errore fatale,
+            # significa solo che è nuovo o cancellato. L'output va a DEBUG.
+            result = self.log_and_execute(command, working_directory, check=False, log_output_level=logging.DEBUG)
+
+            if result.returncode == 0:
+                # Successo, ritorna il contenuto (stdout)
+                return result.stdout
+            elif result.returncode == 128 and ("exists on disk, but not in" in result.stderr or \
+                                                "does not exist in" in result.stderr or \
+                                                "did not match any file" in result.stderr):
+                # Codice 128 con errore specifico -> file non trovato nel ref
+                self.logger.debug(f"File '{git_style_path}' not found in ref '{ref}'.")
+                return None # Ritorna None per indicare file non esistente nel ref
+            else:
+                # Altro errore di git show
+                self.logger.error(f"git show command failed for '{ref_path_arg}' with code {result.returncode}. Stderr: {result.stderr}")
+                return None # Ritorna None per indicare errore generico
+
+        except (GitCommandError, ValueError) as e:
+            # Questo catturerebbe errori nell'esecuzione del comando stesso (raro se check=False)
+            self.logger.error(f"Error executing git show for '{ref_path_arg}': {e}")
+            return None
+        except Exception as e:
+            self.logger.exception(f"Unexpected error in get_file_content_from_ref for '{ref_path_arg}': {e}")
+            return None

gui.py

@@ -381,6 +381,8 @@ class MainFrame(ttk.Frame):
         refresh_branches_cb,
         checkout_branch_cb,
         create_branch_cb,
+        refresh_changed_files_cb, # <-- NUOVO PARAMETRO
+        open_diff_viewer_cb, 
     ):
         """Initializes the MainFrame with tabs."""
         super().__init__(master)
@@ -405,6 +407,8 @@ class MainFrame(ttk.Frame):
         self.refresh_branches_callback = refresh_branches_cb
         self.checkout_branch_callback = checkout_branch_cb
         self.create_branch_callback = create_branch_cb
+        self.open_diff_viewer_callback = open_diff_viewer_cb
+        
 
         # Store instances and initial data
         self.config_manager = config_manager_instance
@@ -793,56 +797,88 @@ class MainFrame(ttk.Frame):
         return frame
 
     def _create_commit_tab(self):
-        """Creates the frame for the 'Commit' tab."""
-        # (No changes needed here for this modification)
+        """Creates the frame for the 'Commit' tab with changed files list."""
         frame = ttk.Frame(self.notebook, padding=(10, 10))
-        frame.rowconfigure(2, weight=1)
-        frame.columnconfigure(0, weight=1)
+        # Riduci peso riga messaggio, aumenta peso riga lista file
+        frame.rowconfigure(2, weight=0) # Riga messaggio commit non si espande molto
+        frame.rowconfigure(4, weight=1) # Riga lista file si espande
+        frame.columnconfigure(0, weight=1) # Colonna principale si espande
+
+        # --- Sezione Autocommit --- (Invariata)
         self.autocommit_checkbox = ttk.Checkbutton(
-            frame,
+            frame,  # <<< DEVE ESSERE 'frame' QUI
             text="Enable Autocommit before 'Create Bundle' action",
             variable=self.autocommit_var,
             state=tk.DISABLED,
         )
-        self.autocommit_checkbox.grid(
-            row=0, column=0, columnspan=2, sticky="w", padx=5, pady=(0, 10)
-        )
-        self.create_tooltip(
-            self.autocommit_checkbox,
-            "If checked, use message below to commit before Create Bundle.",
-        )
-        ttk.Label(frame, text="Commit Message:").grid(
-            row=1, column=0, columnspan=2, sticky="w", padx=5
-        )
+        self.autocommit_checkbox.grid(row=0, column=0, columnspan=3, sticky="w", padx=5, pady=(0, 5))
+        self.create_tooltip(self.autocommit_checkbox, "...")
+
+        # --- Sezione Messaggio Commit --- (Altezza ridotta)
+        ttk.Label(frame, text="Commit Message:").grid(row=1, column=0, columnspan=3, sticky="w", padx=5)
         self.commit_message_text = scrolledtext.ScrolledText(
             frame,
-            height=7,
-            width=60,
-            wrap=tk.WORD,
-            font=("Segoe UI", 9),
-            state=tk.DISABLED,
-            undo=True,
-            padx=5,
-            pady=5,
+            height=3, # <<< Altezza ridotta
+            width=60, wrap=tk.WORD, font=("Segoe UI", 9),
+            state=tk.DISABLED, undo=True, padx=5, pady=5,
         )
-        self.commit_message_text.grid(
-            row=2, column=0, columnspan=2, sticky="nsew", padx=5, pady=(0, 5)
+        self.commit_message_text.grid(row=2, column=0, columnspan=3, sticky="ew", padx=5, pady=(0, 5))
+        self.create_tooltip(self.commit_message_text, "Enter commit message...")
+
+        # --- MODIFICA: Aggiunta Sezione Changed Files ---
+        changes_frame = ttk.LabelFrame(frame, text="Changes to be Committed / Staged", padding=(10, 5))
+        changes_frame.grid(row=3, column=0, columnspan=3, sticky='nsew', padx=5, pady=(5,5))
+        changes_frame.rowconfigure(0, weight=1)    # Lista si espande
+        changes_frame.columnconfigure(0, weight=1) # Lista si espande
+
+        # Lista File Modificati
+        list_sub_frame = ttk.Frame(changes_frame) # Frame per listbox e scrollbar
+        list_sub_frame.grid(row=0, column=0, sticky='nsew', pady=(0, 5))
+        list_sub_frame.rowconfigure(0, weight=1)
+        list_sub_frame.columnconfigure(0, weight=1)
+
+        self.changed_files_listbox = tk.Listbox(
+            list_sub_frame,
+            height=8, # Altezza iniziale, ma si espanderà con la riga 4 di 'frame'
+            exportselection=False,
+            selectmode=tk.SINGLE,
+            font=("Consolas", 9), # Font Monospace utile per status
         )
-        self.create_tooltip(
-            self.commit_message_text, "Enter commit message for manual or autocommit."
+        self.changed_files_listbox.grid(row=0, column=0, sticky="nsew")
+        # Associa doppio click all'apertura del diff viewer (verrà collegato in GitUtility)
+        self.changed_files_listbox.bind("<Double-Button-1>", self._on_changed_file_double_click)
+
+        scrollbar_list = ttk.Scrollbar(
+            list_sub_frame, orient=tk.VERTICAL, command=self.changed_files_listbox.yview
         )
+        scrollbar_list.grid(row=0, column=1, sticky="ns")
+        self.changed_files_listbox.config(yscrollcommand=scrollbar_list.set)
+        self.create_tooltip(self.changed_files_listbox, "Double-click a file to view changes (diff).")
+
+        # Pulsante Refresh Lista File
+        self.refresh_changes_button = ttk.Button(
+            changes_frame,
+            text="Refresh List",
+            # Collegato a callback in GitUtility
+            # command=self.refresh_changed_files_callback
+            state=tk.DISABLED # Abilitato quando repo è pronto
+        )
+        self.refresh_changes_button.grid(row=1, column=0, sticky="w", padx=(0, 5), pady=(5, 0))
+        self.create_tooltip(self.refresh_changes_button, "Refresh the list of changed files.")
+        # --- FINE MODIFICA ---
+
+
+        # --- Pulsante Commit Manuale --- (Spostato sotto)
         self.commit_button = ttk.Button(
-            frame,
+            frame, # Ora nel frame principale
             text="Commit All Changes Manually",
-            command=self.commit_changes_callback,
+            # command=self.commit_changes_callback
             state=tk.DISABLED,
         )
-        self.commit_button.grid(
-            row=3, column=0, columnspan=2, sticky="e", padx=5, pady=5
-        )
-        self.create_tooltip(
-            self.commit_button, "Stage ALL changes and commit with the message above."
-        )
+        # Messo in basso a destra
+        self.commit_button.grid(row=4, column=2, sticky="se", padx=5, pady=5)
+        self.create_tooltip(self.commit_button, "Stage ALL changes and commit with the message above.")
+
         return frame
 
     def _create_tags_tab(self):
@@ -1306,3 +1342,27 @@ class MainFrame(ttk.Frame):
 
     def update_tooltip(self, widget, text):
         self.create_tooltip(widget, text)  # Recreate is simplest
+        
+    def update_changed_files_list(self, files_status_list):
+        """Clears and populates the changed files listbox."""
+        if not hasattr(self, "changed_files_listbox"): return
+        self.changed_files_listbox.config(state=tk.NORMAL)
+        self.changed_files_listbox.delete(0, tk.END)
+        if files_status_list:
+             # Potresti voler formattare meglio lo stato qui
+             for status_line in files_status_list:
+                 self.changed_files_listbox.insert(tk.END, status_line)
+        else:
+             self.changed_files_listbox.insert(tk.END, "(No changes detected)")
+             
+    # Questo chiamerà la funzione vera in GitUtility
+    def _on_changed_file_double_click(self, event):
+        # Recupera l'indice selezionato dalla listbox
+        widget = event.widget
+        selection = widget.curselection()
+        if selection:
+            index = selection[0]
+            file_status_line = widget.get(index)
+            # Chiama il metodo del controller (verrà impostato in __init__ di MainFrame)
+            if hasattr(self, 'open_diff_viewer_callback') and callable(self.open_diff_viewer_callback):
+                 self.open_diff_viewer_callback(file_status_line)