Improvements for bokeh GraphPlot

holoviews/plotting/bokeh/graphs.py

@@ -2,7 +2,7 @@
 import numpy as np
 from bokeh.models import HoverTool, ColumnDataSource
 from bokeh.models import (StaticLayoutProvider, NodesAndLinkedEdges,
-                          EdgesAndLinkedNodes, Patches)
+                          EdgesAndLinkedNodes, Patches, Bezier)
 
 from ...core.util import basestring, dimension_sanitizer, unique_array
 from ...core.options import Cycle
@@ -33,7 +33,7 @@ class GraphPlot(CompositeElementPlot, ColorbarPlot, LegendPlot):
         A list of plugin tools to use on the plot.""")
 
     # Map each glyph to a style group
-    _style_groups = {'scatter': 'node', 'multi_line': 'edge', 'patches': 'edge'}
+    _style_groups = {'scatter': 'node', 'multi_line': 'edge', 'patches': 'edge', 'bezier': 'edge'}
 
     style_opts = (['edge_'+p for p in line_properties] +
                   ['node_'+p for p in fill_properties+line_properties] +
@@ -42,6 +42,9 @@ class GraphPlot(CompositeElementPlot, ColorbarPlot, LegendPlot):
     # Filled is only supported for subclasses
     filled = False
 
+    # Bezier paths
+    bezier = False
+
     # Declares which columns in the data refer to node indices
     _node_indices = [0, 1]
 
@@ -114,12 +117,25 @@ def _get_edge_colors(self, element, ranges, edge_data, edge_mapping, style):
         edge_mapping['edge_selection_'+color_type] = transform
 
 
+    def _get_edge_paths(self, element):
+        path_data = {}
+        xidx, yidx = (1, 0) if self.invert_axes else (0, 1)
+        if element._edgepaths:
+            edges = element._split_edgepaths.split(datatype='array', dimensions=element.edgepaths.kdims)
+            if len(edges) == len(element):
+                path_data['xs'] = [path[:, xidx] for path in edges]
+                path_data['ys'] = [path[:, yidx] for path in edges]
+            else:
+                self.warning('Graph edge paths do not match the number of abstract edges '
+                             'and will be skipped')
+        return path_data, {'xs': 'xs', 'ys': 'ys'}
+
+
     def get_data(self, element, ranges, style):
         # Force static source to False
         static = self.static_source
         self.handles['static_source'] = static
         self.static_source = False
-        xidx, yidx = (1, 0) if self.invert_axes else (0, 1)
 
         # Get node data
         nodes = element.nodes.dimension_values(2)
@@ -152,7 +168,6 @@ def get_data(self, element, ranges, style):
                      ['node_fill_color', 'node_nonselection_fill_color']}
             point_mapping['node_nonselection_fill_color'] = point_mapping['node_fill_color']
 
-        # Get edge data
         edge_mapping = {}
         nan_node = index.max()+1
         start, end = (element.dimension_values(i) for i in range(2))
@@ -163,14 +178,10 @@ def get_data(self, element, ranges, style):
             end = np.array([node_indices.get(y, nan_node) for y in end], dtype=np.int32)
         path_data = dict(start=start, end=end)
         self._get_edge_colors(element, ranges, path_data, edge_mapping, style)
-        if element._edgepaths and not static:
-            edges = element._split_edgepaths.split(datatype='array', dimensions=element.edgepaths.kdims)
-            if len(edges) == len(start):
-                path_data['xs'] = [path[:, 0] for path in edges]
-                path_data['ys'] = [path[:, 1] for path in edges]
-            else:
-                self.warning('Graph edge paths do not match the number of abstract edges '
-                             'and will be skipped')
+        if not static:
+            pdata, pmapping = self._get_edge_paths(element)
+            path_data.update(pdata)
+            edge_mapping.update(pmapping)
 
         # Get hover data
         if any(isinstance(t, HoverTool) for t in self.state.tools):
@@ -182,11 +193,19 @@ def get_data(self, element, ranges, style):
             elif self.inspection_policy == 'edges':
                 for d in element.dimensions():
                     path_data[dimension_sanitizer(d.name)] = element.dimension_values(d)
-        edge_glyph = 'patches_1' if self.filled else 'multi_line_1'
-        data = {'scatter_1': point_data, edge_glyph: path_data, 'layout': layout}
-        mapping = {'scatter_1': point_mapping, edge_glyph: edge_mapping}
+        data = {'scatter_1': point_data, self.edge_glyph: path_data, 'layout': layout}
+        mapping = {'scatter_1': point_mapping, self.edge_glyph: edge_mapping}
         return data, mapping, style
 
+    @property
+    def edge_glyph(self):
+        if self.filled:
+            edge_glyph = 'patches_1'
+        elif self.bezier:
+            edge_glyph = 'bezier_1'
+        else:
+            edge_glyph = 'multi_line_1'
+        return edge_glyph
 
     def _update_datasource(self, source, data):
         """
@@ -205,13 +224,14 @@ def _init_glyphs(self, plot, element, ranges, source):
         # Get data and initialize data source
         style = self.style[self.cyclic_index]
         data, mapping, style = self.get_data(element, ranges, style)
+        edge_mapping = {k: v for k, v in mapping[self.edge_glyph].items()
+                        if 'color' not in k}
         self.handles['previous_id'] = element._plot_id
-        edge_glyph = 'patches_1' if self.filled else 'multi_line_1'
 
         properties = {}
         mappings = {}
         for key in list(mapping):
-            if not any(glyph in key for glyph in ('scatter_1', edge_glyph)):
+            if not any(glyph in key for glyph in ('scatter_1', self.edge_glyph)):
                 continue
             source = self._init_datasource(data.pop(key, {}))
             self.handles[key+'_source'] = source
@@ -229,7 +249,7 @@ def _init_glyphs(self, plot, element, ranges, source):
         # Define static layout
         layout = StaticLayoutProvider(graph_layout=layout)
         node_source = self.handles['scatter_1_source']
-        edge_source = self.handles[edge_glyph+'_source']
+        edge_source = self.handles[self.edge_glyph+'_source']
         renderer = plot.graph(node_source, edge_source, layout, **properties)
 
         # Initialize GraphRenderer
@@ -250,19 +270,20 @@ def _init_glyphs(self, plot, element, ranges, source):
         self.handles['layout_source'] = layout
         self.handles['glyph_renderer'] = renderer
         self.handles['scatter_1_glyph_renderer'] = renderer.node_renderer
-        self.handles[edge_glyph+'_glyph_renderer'] = renderer.edge_renderer
+        self.handles[self.edge_glyph+'_glyph_renderer'] = renderer.edge_renderer
         self.handles['scatter_1_glyph'] = renderer.node_renderer.glyph
-        if self.filled:
-            allowed_properties = Patches.properties()
+        if self.filled or self.bezier:
+            glyph_model = Patches if self.filled else Bezier
+            allowed_properties = glyph_model.properties()
             for glyph_type in ('', 'selection_', 'nonselection_', 'hover_', 'muted_'):
                 glyph = getattr(renderer.edge_renderer, glyph_type+'glyph', None)
                 if glyph is None:
                     continue
-                props = self._process_properties(edge_glyph, properties, mappings)
+                props = self._process_properties(self.edge_glyph, properties, mappings)
                 filtered = self._filter_properties(props, glyph_type, allowed_properties)
-                patches = Patches(**dict(filtered, xs='xs', ys='ys'))
-                glyph = setattr(renderer.edge_renderer, glyph_type+'glyph', patches)
-        self.handles[edge_glyph+'_glyph'] = renderer.edge_renderer.glyph
+                new_glyph = glyph_model(**dict(filtered, **edge_mapping))
+                setattr(renderer.edge_renderer, glyph_type+'glyph', new_glyph)
+        self.handles[self.edge_glyph+'_glyph'] = renderer.edge_renderer.glyph
         if 'hover' in self.handles:
             self.handles['hover'].renderers.append(renderer)
 
@@ -294,3 +315,4 @@ def get_data(self, element, ranges, style):
         # Ensure the edgepaths for the triangles are generated
         element.edgepaths
         return super(TriMeshPlot, self).get_data(element, ranges, style)
+