Bookmaker: Reduce reportlab dependency to --nup4 usage.

diff --git a/bookmaker.py b/bookmaker.py
index bf9eba838d9c8872c7f551805ebccedde310d6e3..e3e91886add8e1343aae7bc206280ccf6b169f6e 100755 (executable)
--- a/bookmaker.py
+++ b/bookmaker.py
@@ -13,14 +13,12 @@ try:
     import pypdf
 except ImportError:
     fail_with_msg("Can't run without pypdf installed.")
-try:
-    from reportlab.lib.pagesizes import A4
-except ImportError:
-    fail_with_msg("Can't run without reportlab installed.")
 
 # some constants
-A4_WIDTH, A4_HEIGHT = A4
 POINTS_PER_CM = 10 * 72 / 25.4
+A4_WIDTH = 21 * POINTS_PER_CM
+A4_HEIGHT = 29.7 * POINTS_PER_CM
+A4 = (A4_WIDTH, A4_HEIGHT)
 CUT_DEPTH = 1.95 * POINTS_PER_CM
 CUT_WIDTH = 1.05 * POINTS_PER_CM
 MIDDLE_POINT_DEPTH = 0.4 * POINTS_PER_CM
@@ -195,6 +193,11 @@ def parse_args():
 
 def main():
     args = parse_args()
+    if args.nup4:
+        try:
+            import reportlab
+        except ImportError:
+            raise ImportError("-n: need reportlab library installed for --nup4")
 
     # select pages from input files
     pages_to_add = []
@@ -397,11 +400,10 @@ def main():
             print("merged page number %d (of %d)" % (page_count, len(pages_to_add)))
             i += 1
             if i > 3:
-                from reportlab.pdfgen import canvas
                 if args.analyze:
                     # borders
                     packet = io.BytesIO()
-                    c = canvas.Canvas(packet, pagesize=A4)
+                    c = reportlab.pdfgen.canvas.Canvas(packet, pagesize=A4)
                     c.setLineWidth(0.1)
                     c.line(0, A4_HEIGHT, A4_WIDTH, A4_HEIGHT)
                     c.line(0, half_height, A4_WIDTH, half_height)
@@ -420,7 +422,7 @@ def main():
                 x_right_SPINE_LIMIT = A4_WIDTH - x_left_SPINE_LIMIT
                 if args.analyze or front_page:
                     packet = io.BytesIO()
-                    c = canvas.Canvas(packet, pagesize=A4)
+                    c = reportlab.pdfgen.canvas.Canvas(packet, pagesize=A4)
                 if args.analyze:
                     # # spine lines
                     c.setLineWidth(0.1)
@@ -462,5 +464,5 @@ def main():
 if __name__ == "__main__":
     try:
         main()
-    except ValueError as e:
+    except (ImportError, ValueError) as e:
         fail_with_msg(e)