Initial commit — Copydev Imposing Tool

Outil d'imposition PDF desktop (PyQt6) remplacant Quite Imposing Plus.
9 fonctions : livret, n-up, step & repeat, imposition manuelle,
jointure pages, pages blanches, numerotation, masquage, fonds perdus.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/engine/pdf_utils.py

@@ -0,0 +1,143 @@
+"""Utilitaires PDF communs pour Copydev Imposing Tool."""
+
+from pypdf import PdfReader, PdfWriter, PageObject, Transformation
+from reportlab.pdfgen import canvas
+from reportlab.lib.units import mm, inch
+from reportlab.lib.pagesizes import A4, A3, letter
+import io
+import math
+
+# Tailles de pages predefinies (largeur, hauteur en points)
+PAGE_SIZES = {
+    "A4 Portrait": (595.28, 841.89),
+    "A4 Paysage": (841.89, 595.28),
+    "A3 Portrait": (841.89, 1190.55),
+    "A3 Paysage": (1190.55, 841.89),
+    "Letter Portrait": (612, 792),
+    "Letter Paysage": (792, 612),
+    "Legal Portrait": (612, 1008),
+    "Legal Paysage": (1008, 612),
+}
+
+# Conversion
+PT_TO_MM = 25.4 / 72
+MM_TO_PT = 72 / 25.4
+
+
+def mm_to_pt(val_mm):
+    """Convertir millimetres en points."""
+    return val_mm * MM_TO_PT
+
+
+def pt_to_mm(val_pt):
+    """Convertir points en millimetres."""
+    return val_pt * PT_TO_MM
+
+
+def get_page_size(page):
+    """Obtenir la taille d'une page (largeur, hauteur) en points."""
+    box = page.mediabox
+    w = float(box.width)
+    h = float(box.height)
+    return w, h
+
+
+def create_blank_page(width, height):
+    """Creer une page blanche avec les dimensions donnees (en points)."""
+    packet = io.BytesIO()
+    c = canvas.Canvas(packet, pagesize=(width, height))
+    c.showPage()
+    c.save()
+    packet.seek(0)
+    reader = PdfReader(packet)
+    return reader.pages[0]
+
+
+def merge_page_onto(base_page, overlay_page, x=0, y=0, scale=1.0, rotation=0):
+    """Fusionner une page overlay sur une page de base a une position donnee."""
+    if rotation:
+        overlay_page = overlay_page.rotate(rotation)
+
+    transform = Transformation().scale(scale, scale).translate(x, y)
+    overlay_page.add_transformation(transform)
+    base_page.merge_page(overlay_page)
+    return base_page
+
+
+def create_crop_marks_page(width, height, positions, mark_length=14.17, mark_offset=7.09, line_width=0.25):
+    """Creer une page avec des reperes de coupe aux positions donnees.
+
+    positions: liste de tuples (x, y) ou placer les reperes
+    mark_length: longueur des traits (defaut 5mm = 14.17pt)
+    mark_offset: distance du bord de la page (defaut 2.5mm = 7.09pt)
+    """
+    packet = io.BytesIO()
+    c = canvas.Canvas(packet, pagesize=(width, height))
+    c.setLineWidth(line_width)
+    c.setStrokeColorRGB(0, 0, 0)
+
+    for x, y in positions:
+        # Trait horizontal gauche
+        c.line(x - mark_offset - mark_length, y, x - mark_offset, y)
+        # Trait horizontal droit
+        c.line(x + mark_offset, y, x + mark_offset + mark_length, y)
+        # Trait vertical bas
+        c.line(x, y - mark_offset - mark_length, x, y - mark_offset)
+        # Trait vertical haut
+        c.line(x, y + mark_offset, x, y + mark_offset + mark_length)
+
+    c.showPage()
+    c.save()
+    packet.seek(0)
+    reader = PdfReader(packet)
+    return reader.pages[0]
+
+
+def smart_crop_marks(sheet_width, sheet_height, grid_positions, cell_width, cell_height,
+                     margin_left=0, margin_top=0, mark_length=14.17, mark_offset=7.09):
+    """Generer des reperes de coupe intelligents pour une grille n-up.
+
+    Evite les chevauchements avec le contenu des pages.
+    """
+    positions = set()
+
+    for col, row in grid_positions:
+        x = margin_left + col * cell_width
+        y = sheet_height - margin_top - row * cell_height
+
+        # 4 coins de chaque cellule
+        corners = [
+            (x, y),
+            (x + cell_width, y),
+            (x, y - cell_height),
+            (x + cell_width, y - cell_height),
+        ]
+        for cx, cy in corners:
+            positions.add((cx, cy))
+
+    return create_crop_marks_page(sheet_width, sheet_height, list(positions),
+                                  mark_length, mark_offset)
+
+
+def pad_to_multiple(reader, multiple=4):
+    """Ajouter des pages blanches pour atteindre un multiple donne."""
+    num_pages = len(reader.pages)
+    remainder = num_pages % multiple
+    if remainder == 0:
+        return reader
+
+    pages_to_add = multiple - remainder
+    writer = PdfWriter()
+    for page in reader.pages:
+        writer.add_page(page)
+
+    last_page = reader.pages[-1]
+    w, h = get_page_size(last_page)
+
+    for _ in range(pages_to_add):
+        writer.add_blank_page(w, h)
+
+    output = io.BytesIO()
+    writer.write(output)
+    output.seek(0)
+    return PdfReader(output)