WIP

lib/commands.py

@@ -5,6 +5,27 @@ from .svg import apply_transforms
 from .svg.tags import SVG_USE_TAG, SVG_SYMBOL_TAG, CONNECTION_START, CONNECTION_END, XLINK_HREF
 
 
+class CommandParseError(Exception):
+    pass
+
+
+def get_node_by_url(svg, url):
+    # url will be #path12345.  Find the object at the other end.
+
+    if url is None:
+        raise CommandParseError("url is None")
+
+    if not url.startswith('#'):
+        raise CommandParseError("invalid connection url: %s" % url)
+
+    id = url[1:]
+
+    try:
+        return svg.xpath(".//*[@id='%s']" % id)[0]
+    except (IndexError, AttributeError):
+        raise CommandParseError("could not find node by url %s" % id)
+
+
 class Command(object):
     def __init__(self, connector):
         self.connector = connector
@@ -12,22 +33,6 @@ class Command(object):
 
         self.parse_command()
 
-    def get_node_by_url(self, url):
-        # url will be #path12345.  Find the object at the other end.
-
-        if url is None:
-            raise ValueError("url is None")
-
-        if not url.startswith('#'):
-            raise ValueError("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)
-
     def parse_connector_path(self):
         path = cubicsuperpath.parsePath(self.connector.get('d'))
         return apply_transforms(path, self.connector)
@@ -36,27 +41,27 @@ class Command(object):
         path = self.parse_connector_path()
 
         neighbors = [
-            (self.get_node_by_url(self.connector.get(CONNECTION_START)), path[0][0][1]),
-            (self.get_node_by_url(self.connector.get(CONNECTION_END)), path[0][-1][1])
+            (get_node_by_url(self.svg, self.connector.get(CONNECTION_START)), path[0][0][1]),
+            (get_node_by_url(self.svg, self.connector.get(CONNECTION_END)), path[0][-1][1])
         ]
 
         if neighbors[0][0].tag != SVG_USE_TAG:
             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))
+        self.symbol = self.get_node_by_url(self.svg, neighbors[0][0].get(XLINK_HREF))
 
         if self.symbol.tag != SVG_SYMBOL_TAG:
-            raise ValueError("use points to non-symbol")
+            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 ValueError("symbol is not an Ink/Stitch command")
+            raise CommandParseError("symbol is not an Ink/Stitch command")
 
         self.target = neighbors[1][0]
         self.target_point = neighbors[1][1]
@@ -64,6 +69,17 @@ class Command(object):
     def __repr__(self):
         return "Command('%s', %s)" % (self.command, self.target_point)
 
+class StandaloneCommand(object):
+    def __init__(self, symbol):
+        self.symbol = symbol
+        self.svg = self.connector.getroottree().getroot()
+
+        self.parse_command()
+
+    def parse_command(self):
+        pass
+
+
 def find_commands(node):
     """Find the symbols this node is connected to and return them as Commands"""
 
@@ -82,5 +98,24 @@ def find_commands(node):
 
     return commands
 
+def layer_commands(layer, command):
+    """Find standalone (unconnected) command symbols in this layer."""
+    pass
+
+def global_commands(svg):
+    """Find all unconnected command symbols in the SVG."""
+
+    xpath = ".//svg:use[starts-with(@xlink:href, '#inkstitch_')]"
+    symbols = svg.xpath(xpath, namespace=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