Scanning and parsing QR codes using computer's camera.

lib/qrscanner.py

@@ -0,0 +1,75 @@
+from util import print_error
+
+try:
+    import zbar
+except ImportError:    
+    print_error("Install zbar package to enable QR scans")
+    zbar = None
+
+from urlparse import urlparse, parse_qs
+
+def is_available():
+    if not zbar:
+        return False
+    return True
+
+def scan_qr():
+    proc = zbar.Processor()
+    proc.init()
+    proc.visible = True
+
+    while True:
+        try:
+            proc.process_one()
+        except:
+            # User closed the preview window
+            return {}
+
+        for r in proc.results:
+            if str(r.type) != 'QRCODE':
+                continue
+
+            return parse_uri(r.data)
+        
+def parse_uri(uri):
+    if ':' not in uri:
+        # It's just an address (not BIP21)
+        return {'address': uri}
+
+    if '//' not in uri:
+        # Workaround for urlparse, it don't handle bitcoin: URI properly
+        uri = uri.replace(':', '://')
+        
+    uri = urlparse(uri)
+    result = {'address': uri.netloc} 
+    
+    if uri.path.startswith('?'):
+        params = parse_qs(uri.path[1:])
+    else:
+        params = parse_qs(uri.path)    
+
+    for k,v in params.items():
+        if k in ('amount', 'label', 'message'):
+            result[k] = v[0]
+        
+    return result    
+
+if __name__ == '__main__':
+    # Run some tests
+    
+    assert(parse_uri('1Marek48fwU7mugmSe186do2QpUkBnpzSN') ==
+           {'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
+
+    assert(parse_uri('bitcoin://1Marek48fwU7mugmSe186do2QpUkBnpzSN') ==
+           {'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
+    
+    assert(parse_uri('bitcoin:1Marek48fwU7mugmSe186do2QpUkBnpzSN') ==
+           {'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
+    
+    assert(parse_uri('bitcoin:1Marek48fwU7mugmSe186do2QpUkBnpzSN?amount=10') ==
+           {'amount': '10', 'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
+    
+    assert(parse_uri('bitcoin:1Marek48fwU7mugmSe186do2QpUkBnpzSN?amount=10&label=slush&message=Small%20tip%20to%20slush') ==
+           {'amount': '10', 'label': 'slush', 'message': 'Small tip to slush', 'address': '1Marek48fwU7mugmSe186do2QpUkBnpzSN'})
+    
+