Merge branch 'dev'

README.md

@@ -5,7 +5,7 @@
 A tool to sign PDF files, with Linux support.
 We are here referring to the visible, non-cryptographic squiggles.
 
-![](README-example.gif)
+![](README-example-use.gif)
 
 ## How
 
@@ -16,6 +16,11 @@ The recommended way is:
 * Use an application of your choice to sign it.
   You can for example use Okular's Freehand Line, or transfer it to your smartphone and use Adobe Acrobat Reader.
   Keep in mind that it's the center of this mini-page that will be used for positioning the signature.
+
+  <img src="README-example-signature.gif" width="250"/>
+
+  It's a good idea to write your signature on an imagined line through the center of the mini-page.
+  That way, it can be positioned correctly by clicking on the signature line.
 * Put the signed file in your signature directory.
   The signature directory is `$PDF_SIGNATURE_DIR`, `$XDG_CONFIG_HOME/pdf_signatures`, `$HOME/.config/pdf_signatures` or `$HOME/.pdf_signatures/`; the first one that exists. Use `pdf-sign -h` to confirm which one will be used on your system.
 

pdf-sign

@@ -65,41 +65,44 @@ def main(args):
             return outFile
         pageSize=Cell(lambda: pdfGetSize(pagePDF()))
         # The chosen signature
-        if args.batch:
+        if args.signature:
-            if not args.signature and not args.text:
+            if args.text:
+                die('--signature and --text cannot be specified together.')
+            if not os.path.exists(args.signature):
+                die(f'File not found: {args.signature}')
+            signatures=[('file', args.signature, args.signature)]
+        elif args.batch:
+            assert not args.signature
+            if not args.text:
                 die('In batch mode, --signature or --text must be specified.')
-            if args.text and len(args.text) > 1:
+            if len(args.text) > 1:
                 die('In batch mode, --text must be given only once.')
-        if args.signature and args.text:
+            validateText(args.text[0], True)
-            die('--signature and --text cannot be specified together.')
+            signatures=[('text', textLabel(args.text[0]), args.text[0])]
-        if args.signature and not os.path.exists(args.signature):
+        else:
-            die(f'File not found: {args.signature}')
+            (signatureDir, signatureDirHelp)=getSignatureDirAndHelp()
-        if args.text:
+            signatures=([('file', x, os.path.join(signatureDir, x))
-            assert(len(args.text) > 0)
+                         for x in filter(isPdfFilename, os.listdir(signatureDir))]
-            latin1_chars=set([*range(0x20, 0x7f), *range(0xa0, 0x100)])
+                        if signatureDir else [])
-            for text in args.text:
+            signatures.sort()
-                text_chars=set(map(ord, text))
+            if not signatures and not args.text:
-                if not text_chars.issubset(latin1_chars):
+                die('Could not find any usable signatures. No --signature, no --text, and ' +
-                    die("Error: Only non-control latin-1 characters are supported in --text." +
+                    ('no .pdf files found in {signatureDir}.'
-                        " Unsupported characters: " + ', '.join(map(hex, text_chars - latin1_chars)))
+                    if signatureDir else
-        signatureDir=getSignatureDir()
+                    f'no signature directory. The options considered for signature directory are: {signatureDirHelp}'))
-        signatures=[('file', x) for x in filter(isPdfFilename, os.listdir(signatureDir))] if not args.signature else [None]
+            if args.text:
-        if not signatures and not args.text:
+                assert(len(args.text) > 0)
-            die(f'Could not find anything usable as signature, since no .pdf files found in {signatureDir} and no --text option given.')
+                for text in args.text:
-        signatures.sort()
+                    validateText(text, True)
-        if args.text:
+                signatures=[('text', textLabel(x), x) for x in args.text] + signatures
-            signatures=[('text', x) for x in args.text] + signatures
         signatureIndex=Cell(0)
-        customText=Cell(('text', time.strftime('%Y-%m-%d')))
         @Cell
         def signaturePath():
-            if args.signature:
+            (signType, _, content)=signatures[signatureIndex()]
-                return args.signature
-            (signType, content)=signatures[signatureIndex()]
             if signType=='cell':
-                (signType, content)=content()
+                (signType, _, content)=content()
             if signType=='file':
-                return os.path.join(signatureDir, content)
+                return content
             assert signType=='text'
             cache = signaturePath._cache
             if content in cache:
@@ -110,13 +113,25 @@ def main(args):
             return fileName
         signaturePath._cache={}
         signatureSize=Cell(lambda: pdfGetSize(signaturePath()))
-        signaturePositionX=Cell(args.x_coordinate)
+        try:
-        signaturePositionY=Cell(args.y_coordinate)
+            xm=m("^(L\\+|L-|R\\+|R-|-|)([0-9.]+)%$", args.x_coordinate)
+            default_x=(lambda x:{'L+':x,'L-':-x,'R+':1+x,'R-':1-x,'-':-x,'':x}[xm[1]])(float(xm[2])/100)
+        except:
+            die('Invalid -x option')
+        try:
+            ym=m("^(T\\+|T-|B\\+|B-|-|)([0-9.]+)%$", args.y_coordinate)
+            default_y=(lambda y:{'T+':y,'T-':-y,'B+':1+y,'B-':1-y,'-':-y,'':y}[ym[1]])(float(ym[2])/100)
+        except:
+            die('Invalid -y option')
+        signaturePositionX=Cell(default_x)
+        signaturePositionY=Cell(default_y)
         signatureScale=Cell(0)
         def translatablePDF(path):
             cache = translatablePDF._cache
             if path not in cache:
                 (w, h) = pdfGetSize(path)
+                if not (1 < w and 1 < h):
+                    die(f"The PDF at {path} is unusable as a signature due to too small dimensions.")
                 (double_w, double_h) = (2*w, 2*h)
                 testFile = intmp('translateTest.pdf')
                 subprocess.run([
@@ -128,7 +143,7 @@ def main(args):
                     '-f', path,
                 ], check=True)
                 (test_w, test_h) = pdfGetSize(testFile)
-                if (test_w, test_h) == (double_w, double_h):
+                if abs(test_w - double_w) < 0.01 and abs(test_h - double_h) < 0.01:
                     # The pdf file at path can be translated correctly
                     cache[path] = path
                 elif (test_w, test_h) == (w, h):
@@ -159,11 +174,28 @@ def main(args):
                     die(f"The PDF at {path} is unusable as a signature. Reason unknown.")
             return cache[path]
         translatablePDF._cache={}
+        @Cell
+        def defaultResizeFactor():
+            (pageWidth, pageHeight)=pageSize()
+            try:
+                wm=m("^([0-9.]+)(pts|pt|in|cm|mm|%)$", args.width)
+                maxSignatureWidth=int(float(wm[1])*({'pts':1,'pt':1,'in':72,'cm':28.3,'mm':2.83,'%':pageWidth/100}[wm[2]]))
+            except:
+                die('Invalid -W option')
+            try:
+                hm=m("^([0-9.]+)(pts|pt|in|cm|mm|%)$", args.height)
+                maxSignatureHeight=int(float(hm[1])*({'pts':1,'pt':1,'in':72,'cm':28.3,'mm':2.83,'%':pageHeight/100}[hm[2]]))
+            except:
+                die('Invalid -H option')
+            (signatureWidth, signatureHeight)=signatureSize()
+            return min(args.resize_factor,
+                       maxSignatureWidth / signatureWidth,
+                       maxSignatureHeight / signatureHeight)
         @VolatileCell
         def signaturePositionedPDF():
             (w, h)=pageSize()
             (sw, sh)=signatureSize()
-            resize=1.1**signatureScale()*min(args.width*w/sw, args.height*h/sh)
+            resize=1.1**signatureScale()*defaultResizeFactor()
             dx=w*signaturePositionX()/resize - sw/2
             dy=h*(1-signaturePositionY())/resize - sh/2
             outFile=intmp('signature-positioned.pdf')
@@ -220,6 +252,7 @@ def main(args):
             except ModuleNotFoundError:
                 die('Cannot find Python module `tkinter`, which is needed for interactive use.')
             doSign=False
+            customText=Cell(('text', None, time.strftime('%Y-%m-%d')))
             customTextIndex = len(signatures)
             # Commands
             def uf(fun):
@@ -260,32 +293,25 @@ def main(args):
                 text = simpledialog.askstring(
                     "Custom Text",
                     "Input the text you want to stamp this PDF file with",
-                    initialvalue=customText()[1])
+                    initialvalue=customText()[2])
                 if text == None:
                     return
                 # Validate text
-                text_chars=set(map(ord, text))
+                validateMsg = validateText(text, False)
-                latin1_chars=set([*range(0x20, 0x7f), *range(0xa0, 0x100)])
+                if validateMsg:
-                if not text_chars.issubset(latin1_chars):
                     simpledialog.messagebox.showerror(
                         parent=root,
                         title="Invalid text",
-                        message=f"Only non-control latin-1 characters are supported. Unsupported characters: {', '.join(map(hex, text_chars - latin1_chars))}"
+                        message=validateMsg
-                    )
-                    return
-                if not (1 <= len(text) and len(text) <= 100):
-                    simpledialog.messagebox.showerror(
-                        parent=root,
-                        title="Invalid text",
-                        message="Text must be between 1 and 100 characters long."
                     )
                     return
                 # Set text
-                customText(('text', text))
+                customText(('text', None, text))
                 signatureIndex(customTextIndex)
-                label='Custom text: ' + (text if len(text) <= 20 else (text[:17] + '...'))
+                label='Custom text: ' + textLabel(text)
                 placemenu.entryconfig(len(signatures) + 2, label=label)
                 update()
+            def textLabel(text): return f'"{text}"' if len(text) <= 20 else f'Custom text: "{text[:17]}"...'
             def cmd_abort():
                 root.destroy()
             def cmd_sign():
@@ -323,18 +349,18 @@ def main(args):
                     if root.signatureControlVar.get() != signatureIndex():
                         signatureIndex(root.signatureControlVar.get())
                         update()
-                for index, (_, signature) in enumerate(signatures):
+                for index, (_, signatureText, _) in enumerate(signatures):
                     placemenu.add_radiobutton(
                         value=index,
-                        label=f'{index+1}: {signature}',
+                        label=f'{index+1}: {signatureText}',
                         underline=0 if index<9 else None,
                         variable=root.signatureControlVar,
                         accelerator=(str(index+1) if index<9 else None),
                         command=updateFromSignatureRadio)
-                signatures.append(('cell', customText))
+                signatures.append(('cell', None, customText))
                 placemenu.add_radiobutton(
                     value=customTextIndex,
-                    label='Custom text: ' + customText()[1],
+                    label='Custom text: ' + textLabel(customText()[2]),
                     underline=7,
                     variable=root.signatureControlVar,
                     accelerator='T',
@@ -487,11 +513,21 @@ def qpdfOrPdftk(qpdfCmd, pdftkCmd):
     subprocess.run(cmd, check=True)
     return True # Some lambdas above rely on this
 
-def getSignatureDir():
+def validateText(text, do_die):
-    (path, helptxt) = getSignatureDirAndHelp()
+    latin1_chars=set([*range(0x20, 0x7f), *range(0xa0, 0x100)])
-    if not path:
+    text_chars=set(map(ord, text))
-        die(f"Could not find a valid signature directory. The options considered are: {helptxt}")
+    msg = ""
-    return path
+    if not text_chars.issubset(latin1_chars):
+        msg = ("Error: Only non-control latin-1 characters are supported" +
+               (" in --text" if do_die else "") +
+               ". Unsupported characters: " + ', '.join(map(hex, text_chars - latin1_chars)))
+    elif not (1 <= len(text) and len(text) <= 100):
+        msg = "Text must be between 1 and 100 characters long."
+    if not msg:
+        return None
+    if do_die:
+        die(msg)
+    return msg
 
 def getSignatureDirAndHelp():
     def candidate(prevpath, prevhelptxt, nr, lbl, envvar, path):
@@ -742,10 +778,11 @@ parser = argparse.ArgumentParser(description='Sign a PDF file, with a non-crypto
 parser.add_argument('input', metavar='input.pdf', type=str, help='Input PDF file.')
 parser.add_argument('-p', '--page', type=int, default=-1, help='The page to sign, negative for counting from the end. (default: -1)')
 parser.add_argument('-s', '--signature', type=str, help=getSignatureHelp())
-parser.add_argument('-x', '--x-coordinate', type=float, default=0.5, help='Horizontal coordinate of signature center, in page width units. (default: 0.5)')
+parser.add_argument('-x', '--x-coordinate', type=str, default="50%", help='Horizontal coordinate of signature center. Requires unit %% (meaning percent of page width). May be preceded by L+ (default), L-, R+ or R- to give coordinate relative left of right edge of the page. For example, 25%% means a quarter page width from left edge, R-3%% means 3%% of page width from right edge. (default: 50%%)')
-parser.add_argument('-y', '--y-coordinate', type=float, default=0.75, help='Vertical coordinate of signature center, in page height units. (default: 0.75)')
+parser.add_argument('-y', '--y-coordinate', type=str, default="B-25%", help='Vertical coordinate of signature center. Requires unit %% (meaning percent of page height). May be preceded by T+ (default), T-, B+ or B- to give coordinate relative top or bottom edge of the page. For example, 3%% means 3%% of page height from top edge, B-10%% means 10%% of page height from bottom edge. (default: B-25%%)')
-parser.add_argument('-W', '--width', type=float, default=0.28, help='Width of box to fit signature to, in page width units. (default: 0.28)')
+parser.add_argument('-r', '--resize-factor', type=float, default=1.0, help='Resize signature by this factor. If this would make the signature larger than allowed by -W or -H, then instead use the maximum allowed size.')
-parser.add_argument('-H', '--height', type=float, default=0.11, help='Height of box to fit signature to, in page height units. (default: 0.11)')
+parser.add_argument('-W', '--width', type=str, default="50%", help='Maximum width of signature. Supports units pts, in, cm, mm and %% (meaning percent of page width). (default: 50%%)')
+parser.add_argument('-H', '--height', type=str, default="50%", help='Maximum height of signature. Supports units pts, in, cm, mm and %% (meaning percent of page height). (default: 50%%)')
 parser.add_argument('-o', '--output', type=str, help='Output file. (default: Add ".signed" before the extension)')
 parser.add_argument('-b', '--batch', action=argparse.BooleanOptionalAction, default=False, help='Batch mode: do not show GUI. (default: False)')
 parser.add_argument('-f', '--flatten', action=argparse.BooleanOptionalAction, default=True, help='Flatten before signing, preventing subsequent changes in PDF forms. (default: True)')