1 files changed, 73 insertions, 22 deletions

diff --git a/lib/commands.py b/lib/commands.py
index 02c13b25..cadfa080 100644
--- a/lib/commands.py
+++ b/lib/commands.py
@@ -5,28 +5,44 @@ from .svg import apply_transforms
 from .svg.tags import SVG_USE_TAG, SVG_SYMBOL_TAG, CONNECTION_START, CONNECTION_END, XLINK_HREF
 
 
-class Command(object):
-    def __init__(self, connector):
-        self.connector = connector
-        self.svg = self.connector.getroottree().getroot()
+class CommandParseError(Exception):
+    pass
 
-        self.parse_command()
 
-    def get_node_by_url(self, url):
-        # url will be #path12345.  Find the object at the other end.
+class BaseCommand(object):
+    def parse_symbol(self):
+        if self.symbol.tag != SVG_SYMBOL_TAG:
+            raise CommandParseError("use points to non-symbol")
+
+        self.command = self.symbol.get('id')
 
+        if self.command.startswith('inkstitch_'):
+            self.command = self.command[10:]
+        else:
+            raise CommandParseError("symbol is not an Ink/Stitch command")
+
+    def get_node_by_url(self,url):
+        # url will be #path12345.  Find the corresponding object.
         if url is None:
-            raise ValueError("url is None")
+            raise CommandParseError("url is None")
 
         if not url.startswith('#'):
-            raise ValueError("invalid connection url: %s" % url)
+            raise CommandParseError("invalid connection url: %s" % url)
 
         id = url[1:]
 
         try:
             return self.svg.xpath(".//*[@id='%s']" % id)[0]
         except (IndexError, AttributeError):
-            raise ValueError("could not find node by url %s" % id)
+            raise CommandParseError("could not find node by url %s" % id)
+
+
+class Command(BaseCommand):
+    def __init__(self, connector):
+        self.connector = connector
+        self.svg = self.connector.getroottree().getroot()
+
+        self.parse_command()
 
     def parse_connector_path(self):
         path = cubicsuperpath.parsePath(self.connector.get('d'))
@@ -44,19 +60,10 @@ class Command(object):
             neighbors.reverse()
 
         if neighbors[0][0].tag != SVG_USE_TAG:
-            raise ValueError("connector does not point to a use tag")
+            raise CommandParseError("connector does not point to a use tag")
 
         self.symbol = self.get_node_by_url(neighbors[0][0].get(XLINK_HREF))
-
-        if self.symbol.tag != SVG_SYMBOL_TAG:
-            raise ValueError("use points to non-symbol")
-
-        self.command = self.symbol.get('id')
-
-        if self.command.startswith('inkstitch_'):
-            self.command = self.command[10:]
-        else:
-            raise ValueError("symbol is not an Ink/Stitch command")
+        self.parse_symbol()
 
         self.target = neighbors[1][0]
         self.target_point = neighbors[1][1]
@@ -64,6 +71,23 @@ class Command(object):
     def __repr__(self):
         return "Command('%s', %s)" % (self.command, self.target_point)
 
+
+class StandaloneCommand(BaseCommand):
+    def __init__(self, use):
+        self.node = use
+        self.svg = self.node.getroottree().getroot()
+
+        self.parse_command()
+
+    def parse_command(self):
+        self.symbol = self.get_node_by_url(self.node.get(XLINK_HREF))
+
+        if self.symbol.tag != SVG_SYMBOL_TAG:
+            raise CommandParseError("use points to non-symbol")
+
+        self.parse_symbol()
+
+
 def find_commands(node):
     """Find the symbols this node is connected to and return them as Commands"""
 
@@ -76,11 +100,38 @@ def find_commands(node):
     for connector in connectors:
         try:
             commands.append(Command(connector))
-        except ValueError:
+        except CommandParseError:
             # Parsing the connector failed, meaning it's not actually an Ink/Stitch command.
             pass
 
     return commands
 
+def layer_commands(layer, command):
+    """Find standalone (unconnected) command symbols in this layer."""
+
+    commands = []
+
+    for standalone_command in standalone_commands(layer.getroottree().getroot()):
+        if standalone_command.command == command:
+            if layer in standalone_command.node.iterancestors():
+                commands.append(command)
+
+    return commands
+
+def standalone_commands(svg):
+    """Find all unconnected command symbols in the SVG."""
+
+    xpath = ".//svg:use[starts-with(@xlink:href, '#inkstitch_')]"
+    symbols = svg.xpath(xpath, namespaces=inkex.NSS)
+
+    commands = []
+    for symbol in symbols:
+        try:
+            commands.append(StandaloneCommand(symbol))
+        except CommandParseError:
+            pass
+
+    return commands
+
 def is_command(node):
     return CONNECTION_START in node.attrib or CONNECTION_END in node.attrib