Proper style leaves and key-based style rotation

Author: iosonofabio

iplotx/network.py

@@ -200,7 +200,7 @@ def _add_vertices(self):
                     vertex_labels[vid], **vertex_style.get("label", {})
                 )
 
-            vertex_stylei = rotate_style(vertex_style, i)
+            vertex_stylei = rotate_style(vertex_style, index=i, id=vid)
 
             # Shape of the vertex (Patch)
             art = make_vertex_patch(**vertex_stylei)
@@ -278,7 +278,7 @@ def _add_directed_edges(self, labels=None):
             vpath1 = vertex_paths[vertex_indices[vid1]]
             vpath2 = vertex_paths[vertex_indices[vid2]]
 
-            edge_stylei = rotate_style(edge_style, i)
+            edge_stylei = rotate_style(edge_style, index=i, id=(vid1, vid2))
 
             # These are not the actual edges drawn, only stubs to establish
             # the styles which are then fed into the dynamic, optimised
@@ -343,7 +343,7 @@ def _add_undirected_edges(self, labels=None):
             vpath1 = vertex_paths[vertex_indices[vid1]]
             vpath2 = vertex_paths[vertex_indices[vid2]]
 
-            edge_stylei = rotate_style(edge_style, i)
+            edge_stylei = rotate_style(edge_style, index=i, id=(vid1, vid2))
 
             # These are not the actual edges drawn, only stubs to establish
             # the styles which are then fed into the dynamic, optimised

iplotx/plotting.py

@@ -10,6 +10,7 @@
 )
 from .network import NetworkArtist
 from .groups import GroupingArtist
+from .styles import stylecontext
 
 
 def plot(
@@ -19,6 +20,7 @@ def plot(
     vertex_labels: Union[None, list, dict, pd.Series] = None,
     edge_labels: Union[None, Sequence] = None,
     ax: Union[None, object] = None,
+    styles: Sequence[Union[str, dict]] = (),
 ):
     """Plot this network using the specified layout.
 
@@ -28,11 +30,22 @@ def plot(
         vertex_labels (list, dict, or pandas.Series): The labels for the vertices. If None, no vertex labels
             will be drawn. If a list, the labels are taken from the list. If a dict, the keys
             should be the vertex IDs and the values should be the labels.
+        edge_labels (Union[None, Sequence], optional): The labels for the edges. If None, no edge labels will be drawn. Defaults to None.
         ax (Union[None, object], optional): The axis to plot on. If None, a new figure and axis will be created. Defaults to None.
+        **style: Additional keyword arguments are treated as style for the objects to plot.
 
     Returns:
         A NetworkArtist object.
     """
+    if len(styles):
+        with stylecontext(styles):
+            return plot(
+                network=network,
+                layout=layout,
+                grouping=grouping,
+                edge_labels=edge_labels,
+            )
+
     if (network is None) and (grouping is None):
         raise ValueError("At least one of network or grouping must be provided.")
 

iplotx/styles.py

@@ -1,10 +1,20 @@
-from typing import Union, Sequence
+from typing import Union, Sequence, Hashable
 from copy import deepcopy
 from contextlib import contextmanager
 import numpy as np
 import pandas as pd
 
 
+style_leaves = (
+    "edgecolor",
+    "facecolor",
+    "linewidth",
+    "linestyle",
+    "alpha",
+    "zorder",
+)
+
+
 default = {
     "vertex": {
         "size": 20,
@@ -107,7 +117,8 @@ def _update(style: dict, current: dict):
                 current[key] = value
                 continue
 
-            if isinstance(value, dict):
+            # Style leaves are by definition not to be recurred into
+            if isinstance(value, dict) and (key not in style_leaves):
                 _update(value, current[key])
             elif value is None:
                 del current[key]
@@ -147,16 +158,29 @@ def stylecontext(style: Union[str, dict, Sequence]):
 
 def rotate_style(
     style,
-    i,
-    props=("edgecolor", "facecolor", "linewidth", "linestyle", "alpha", "zorder"),
+    index: Union[int, None] = None,
+    id: Union[Hashable, None] = None,
+    props=style_leaves,
 ):
+    if (index is None) and (id is None):
+        raise ValueError(
+            "At least one of 'index' or 'id' must be provided to rotate_style."
+        )
+
     style = deepcopy(style)
 
     for prop in props:
         val = style.get(prop, None)
         if val is None:
             continue
-        if isinstance(val, (tuple, list, np.ndarray, pd.Index, pd.Series)):
-            style[prop] = val[i % len(val)]
+        # NOTE: this assumes that these properties are leaves of the style tree
+        # Btw: dict includes defaultdict, Couter, etc.
+        if (id is not None) and isinstance(val, (dict, pd.Series)):
+            # This works on both dict-like and Series
+            style[prop] = val[id]
+        elif (index is not None) and isinstance(
+            val, (tuple, list, np.ndarray, pd.Index, pd.Series)
+        ):
+            style[prop] = np.asarray(val)[index % len(val)]
 
     return style

iplotx/tools/matplotlib.py

@@ -101,3 +101,35 @@ def _compute_mid_coord(path):
     raise ValueError(
         "Curve type not straight and not squared/cubic Bezier, cannot compute mid point."
     )
+
+
+def _compute_group_path_with_vertex_padding(
+    points,
+    transform,
+    vertexpadding=10,
+):
+    """Offset path for a group based on vertex padding.
+
+    At the input, the structure is [v1, v1, v1, v2, v2, v2, ...]
+    """
+
+    # Transform into figure coordinates
+    trans = transform.transform
+    trans_inv = transform.inverted().transform
+    points = trans(points)
+
+    npoints = len(points) // 3
+    vprev = points[-1]
+    mprev = atan2(points[0, 1] - vprev[1], points[0, 0] - vprev[0])
+    for i, vcur in enumerate(points[::3]):
+        vnext = points[(i + 1) * 3]
+        mnext = atan2(vnext[1] - vcur[1], vnext[0] - vcur[0])
+
+        mprev_orth = -1 / mprev
+        points[i * 3] = vcur + vertexpadding * mprev_orth
+
+        vprev = vcur
+        mprev = mnext
+
+    points = trans_inv(points)
+    return points