Optional topologically sorted graph.

When enabling this option (e.g., in the graphviewer), the references
are arranged according to the topological ordering from the model
(that is also used for ordering the witnesses in the edition).

Note that this works by introducing additional, invisible edges, so
you shouldn’t use the graph or dot file produced using this method for
anything else than visualization purposes.

src/graphviewer/graphviewer.py

@@ -31,7 +31,6 @@
 class NoNodes(ValueError):
     pass
 
-
 def prepare_agraph():
     node_str = request.values.get('nodes')
     model = request.values.get('model', 'default')
@@ -52,6 +51,7 @@ def prepare_agraph():
     tred = request.values.get('tred', False)
     nohl = request.values.get('nohl', False)
     syn = request.values.get('syn', False)
+    order = request.values.get('order', False)
     if nodes:
         g = info.subgraph(*nodes, context=context, abs_dates=abs_dates, paths=extra, keep_timeline=True,
                           paths_without_timeline=paths_wo_timeline,
@@ -72,8 +72,12 @@ def prepare_agraph():
                 flash('Cannot produce DAG – subgraph is not acyclic!?', 'error')
         g = simplify_timeline(g)
         g.add_nodes_from(nodes)
+        if order:
+            g = info.order_graph(g)
         agraph = write_dot(g, target=None, highlight=None if nohl else nodes, edge_labels=not no_edge_labels)
         agraph.graph_attr['basename'] = ",".join([str(node.filename.stem if hasattr(node, 'filename') else node) for node in nodes])
+        if order:
+            agraph.graph_attr['ranksep'] = '0.2'
         return agraph
     else:
         raise NoNodes('No nodes in graph')

src/graphviewer/templates/form.html

@@ -97,6 +97,7 @@ <h3>Kantenauswahl und -gestaltung:</h3>
     <p><input type="checkbox" name="syn" id="syn" {% if syn %}checked{% endif %}> <label for="syn">Kanten für »ungefähr gleichzeitig«</label> </p>
     <p><input type="checkbox" name="tred" id="tred" {% if tred %}checked{% endif %}> <label for="tred">Transitive Reduktion</label> </p>
     <p><input type="checkbox" name="no_edge_labels" id="no_edge_labels" {% if no_edge_labels %}checked{% endif %}> <label for="no_edge_labels">keine Kantenbeschriftung</label> </p>
+    <p><input type="checkbox" name="order" id="order" {% if order %}checked{% endif %}> <label for="order">Topologische Sortierung</label></p>
 </form>
 
 {% endblock %}

src/macrogen/graph.py

@@ -19,6 +19,7 @@
 from dataclasses import dataclass
 
 from macrogen.graphutils import is_orphan, find_reachable_by_edge
+from more_itertools import windowed
 
 from .graphutils import mark_edges_to_delete, remove_edges, in_path, first
 from .bibliography import BiblSource
@@ -738,6 +739,29 @@ def subgraph(self, *nodes: Node, context: bool = True, path_to: Iterable[Node] =
         return subgraph
 
 
+    def order_graph(self, graph: nx.MultiDiGraph) -> nx.MultiDiGraph:
+        """
+        This returns a version of the given graph that will be ordered left to right by sort order when layed out
+        using dot.
+        """
+        # noinspection PyTypeChecker  -- graph.copy() will return the correct type
+        result: nx.MultiDiGraph = graph.copy()
+        ref_order = [ref for ref in self.order_refs() if ref in result.nodes]
+        for u, v, k, attr in result.edges(keys=True, data=True):
+            attr['weight'] = 0
+
+        for u, v in windowed(ref_order, 2):
+            if result.has_edge(u, v, 0):
+                result[u][v][0]['weight'] = 1
+            else:
+                result.add_edge(u, v, penwidth=0, dir='none', weight=1)
+        return result
+
+
+
+
+
+
 def macrogenesis_graphs() -> MacrogenesisInfo:
     warn("macrogenesis_graphs() is deprecated, instantiate MacrogenesisInfo directly instead", DeprecationWarning)
     return MacrogenesisInfo()
@@ -1030,3 +1054,4 @@ def stat(self):  # TODO better name
                 involved_cycles=len(self.involved_cycles),
                 removed_source_count=len(self.removed_sources)
         )
+