Add and remove tips and tip configs with edges

manim/mobject/graph.py

@@ -9,7 +9,7 @@
 
 import itertools as it
 from collections.abc import Hashable, Iterable
-from copy import copy
+from copy import copy, deepcopy
 from typing import TYPE_CHECKING, Any, Literal, Protocol, cast
 
 import networkx as nx
@@ -626,6 +626,7 @@ def __init__(
 
         self.vertices = {v: vertex_type(**self._vertex_config[v]) for v in vertices}
         self.vertices.update(vertex_mobjects)
+        self.add(*self.vertices.values())
 
         self.change_layout(
             layout=layout,
@@ -635,37 +636,16 @@ def __init__(
             root_vertex=root_vertex,
         )
 
-        # build edge_config
         if edge_config is None:
             edge_config = {}
-        default_tip_config = {}
-        default_edge_config = {}
-        if edge_config:
-            default_tip_config = edge_config.pop("tip_config", {})
-            default_edge_config = {
-                k: v
-                for k, v in edge_config.items()
-                if not isinstance(
-                    k, tuple
-                )  # everything that is not an edge is an option
-            }
-        self._edge_config = {}
-        self._tip_config = {}
-        for e in edges:
-            if e in edge_config:
-                self._tip_config[e] = edge_config[e].pop(
-                    "tip_config", copy(default_tip_config)
-                )
-                self._edge_config[e] = edge_config[e]
-            else:
-                self._tip_config[e] = copy(default_tip_config)
-                self._edge_config[e] = copy(default_edge_config)
 
-        self.default_edge_config = default_edge_config
-        self._populate_edge_dict(edges, edge_type)
+        self.edges = {}
+        self._edge_config = {}
+        self.default_edge_config, _ = GenericGraph._split_out_child_configs(
+            edge_config, lambda k: isinstance(k, tuple)
+        )
 
-        self.add(*self.vertices.values())
-        self.add(*self.edges.values())
+        self.add_edges(*edges, edge_type=edge_type, edge_config=edge_config)
 
         self.add_updater(self.update_edges)
 
@@ -674,11 +654,11 @@ def _empty_networkx_graph() -> nx.classes.graph.Graph:
         """Return an empty networkx graph for the given graph type."""
         raise NotImplementedError("To be implemented in concrete subclasses")
 
-    def _populate_edge_dict(
-        self, edges: list[tuple[Hashable, Hashable]], edge_type: type[Mobject]
-    ):
-        """Helper method for populating the edges of the graph."""
-        raise NotImplementedError("To be implemented in concrete subclasses")
+    @staticmethod
+    def _split_out_child_configs(config: dict, is_child_key) -> (dict, dict):
+        parent_config = {k: v for k, v in config.items() if not is_child_key(k)}
+        child_configs = {k: v for k, v in config.items() if is_child_key(k)}
+        return parent_config, child_configs
 
     def __getitem__(self: Graph, v: Hashable) -> Mobject:
         return self.vertices[v]
@@ -1028,28 +1008,20 @@ def _add_edge(
 
         """
         if edge_config is None:
-            edge_config = self.default_edge_config.copy()
-        added_mobjects = []
-        for v in edge:
-            if v not in self.vertices:
-                added_mobjects.append(self._add_vertex(v))
-        u, v = edge
+            edge_config = {}
+
+        added_vertices = [self._add_vertex(v) for v in edge if v not in self.vertices]
 
+        u, v = edge
         self._graph.add_edge(u, v)
 
-        base_edge_config = self.default_edge_config.copy()
-        base_edge_config.update(edge_config)
-        edge_config = base_edge_config
-        self._edge_config[(u, v)] = edge_config
+        self._edge_config[edge] = {**self.default_edge_config, **edge_config}
+        edge_mobject = self._create_edge_mobject(edge, edge_type)
 
-        edge_mobject = edge_type(
-            self[u].get_center(), self[v].get_center(), z_index=-1, **edge_config
-        )
         self.edges[(u, v)] = edge_mobject
-
         self.add(edge_mobject)
-        added_mobjects.append(edge_mobject)
-        return self.get_group_class()(*added_mobjects)
+
+        return self.get_group_class()(*added_vertices, edge_mobject)
 
     def add_edges(
         self,
@@ -1087,13 +1059,12 @@ def add_edges(
         """
         if edge_config is None:
             edge_config = {}
-        non_edge_settings = {k: v for (k, v) in edge_config.items() if k not in edges}
-        base_edge_config = self.default_edge_config.copy()
-        base_edge_config.update(non_edge_settings)
-        base_edge_config = {e: base_edge_config.copy() for e in edges}
-        for e in edges:
-            base_edge_config[e].update(edge_config.get(e, {}))
-        edge_config = base_edge_config
+        else:
+            edge_config = deepcopy(edge_config)
+
+        batch_default_config, custom_configs = GenericGraph._split_out_child_configs(
+            edge_config, lambda k: isinstance(k, tuple)
+        )
 
         edge_vertices = set(it.chain(*edges))
         new_vertices = [v for v in edge_vertices if v not in self.vertices]
@@ -1104,7 +1075,7 @@ def add_edges(
                 self._add_edge(
                     edge,
                     edge_type=edge_type,
-                    edge_config=edge_config[edge],
+                    edge_config={**batch_default_config, **custom_configs.get(edge, {})},
                 ).submobjects
                 for edge in edges
             ),
@@ -1145,7 +1116,7 @@ def _remove_edge(self, edge: tuple[Hashable]):
         edge_mobject = self.edges.pop(edge)
 
         self._graph.remove_edge(*edge)
-        self._edge_config.pop(edge, None)
+        self._edge_config.pop(edge)
 
         self.remove(edge_mobject)
         return edge_mobject
@@ -1544,18 +1515,14 @@ def construct(self):
     def _empty_networkx_graph() -> nx.Graph:
         return nx.Graph()
 
-    def _populate_edge_dict(
-        self, edges: list[tuple[Hashable, Hashable]], edge_type: type[Mobject]
-    ):
-        self.edges = {
-            (u, v): edge_type(
-                self[u].get_center(),
-                self[v].get_center(),
-                z_index=-1,
-                **self._edge_config[(u, v)],
-            )
-            for (u, v) in edges
-        }
+    def _create_edge_mobject(self, edge, edge_type):
+        u, v = edge
+        return edge_type(
+            self[u].get_center(),
+            self[v].get_center(),
+            z_index=-1,
+            **self._edge_config[(u, v)],
+        )
 
     def update_edges(self, graph):
         for (u, v), edge in graph.edges.items():
@@ -1751,21 +1718,24 @@ def construct(self):
     def _empty_networkx_graph() -> nx.DiGraph:
         return nx.DiGraph()
 
-    def _populate_edge_dict(
-        self, edges: list[tuple[Hashable, Hashable]], edge_type: type[Mobject]
-    ):
-        self.edges = {
-            (u, v): edge_type(
-                self[u],
-                self[v],
-                z_index=-1,
-                **self._edge_config[(u, v)],
-            )
-            for (u, v) in edges
-        }
+    @staticmethod
+    def _split_out_tip_configs(config: dict) -> (dict, dict):
+        edge_config, tip_config = GenericGraph._split_out_child_configs(
+            config, lambda k: k == "tip_config"
+        )
+        return edge_config, tip_config.get("tip_config", {})
 
-        for (u, v), edge in self.edges.items():
-            edge.add_tip(**self._tip_config[(u, v)])
+    def _create_edge_mobject(self, edge, edge_type):
+        edge_config, tip_config = DiGraph._split_out_tip_configs(self._edge_config[edge])
+        u, v = edge
+        edge_mobject = edge_type(
+            self[u],
+            self[v],
+            z_index=-1,
+            **edge_config,
+        )
+        edge_mobject.add_tip(**tip_config)
+        return edge_mobject
 
     def update_edges(self, graph):
         """Updates the edges to stick at their corresponding vertices.

tests/test_graphical_units/test_graph.py

@@ -0,0 +1,40 @@
+from __future__ import annotations
+
+from manim import *
+from manim.utils.testing.frames_comparison import frames_comparison
+
+__module_test__ = "graph"
+
+
+@frames_comparison
+def test_digraph_add_edges(scene):
+    vertices = range(5)
+    edges = [
+        (0, 1),
+        (1, 2),
+        (3, 2),
+        (3, 4),
+    ]
+
+    edge_config = {
+        "stroke_width": 2,
+        "tip_config": {
+            "tip_shape": ArrowSquareTip,
+            "tip_length": 0.15,
+        },
+        (3, 4): {
+            "color": RED,
+            "tip_config": {"tip_length": 0.25, "tip_width": 0.25}
+        },
+    }
+
+    g = DiGraph(
+        vertices,
+        [],
+        labels=True,
+        layout="circular",
+    ).scale(1.4)
+
+    g.add_edges(*edges, edge_config=edge_config)
+
+    scene.add(g)