突出显示悬停时选中的节点和边缘，并淡化Bokeh Holoviews和弦图中的未选中节点和边缘

Question

在定制Holoviews和弦图的过程中，我一直困扰着几天。我使用一些数据集创建了一个Chord图。当我将鼠标悬停在节点上时，该节点及其关联的边缘会以某种默认颜色突出显示。但是我想要的是，当我将鼠标悬停在一个节点上时，该节点及其相关的边缘应突出显示，同时其他未选择的节点和边缘也应消失。

我在单击一个节点时得到了相同的效果。但我希望此功能悬停。我知道可以使用Bokeh HoverTool中的一些JavaScript回调来完成此操作，但是找不到解决方法。

例如，当前和弦图在节点上悬停时看起来像这样： Current hover effect

但是我想要在悬停时不单击以下内容： Hover Requirement

添加代码以供参考：

source_data = [{"from": "Cronje", "to": "Lord Kitchener", "value": 1}, {"from": "Cronje", "to": "Lord Selborne", "value": 1}, {"from": "Cronje", "to": "George Godfrey", "value": 1}, {"from": "Cronje", "to": "Lord Milner", "value": 1}, {"from": "Cronje", "to": "Booker T. Washington", "value": 1}, {"from": "Cronje", "to": "Dada Abdulla", "value": 1}, {"from": "Cronje", "to": "Lord Lansdowne", "value": 1}, {"from": "Cronje", "to": "Escombe", "value": 1}, {"from": "Cronje", "to": "Messrs", "value": 1}, {"from": "Cronje", "to": "Lawley", "value": 1}, {"from": "Cronje", "to": "Sheth Haji Adam", "value": 1}, {"from": "Cronje", "to": "Lord Ripon", "value": 1}, {"from": "Cronje", "to": "Lord Elgin", "value": 1}, {"from": "Sheth Haji Adam", "to": "Lord Kitchener", "value": 1}, {"from": "Sheth Haji Adam", "to": "Lord Selborne", "value": 1}, {"from": "Sheth Haji Adam", "to": "George Godfrey", "value": 1}, {"from": "Sheth Haji Adam", "to": "Dada Abdulla", "value": 1}, {"from": "Sheth Haji Adam", "to": "Booker T. Washington", "value": 1}, {"from": "Sheth Haji Adam", "to": "Lord Milner", "value": 1}, {"from": "Sheth Haji Adam", "to": "Lord Lansdowne", "value": 1}, {"from": "Sheth Haji Adam", "to": "Escombe", "value": 1}, {"from": "Sheth Haji Adam", "to": "Messrs", "value": 1}, {"from": "Sheth Haji Adam", "to": "Lawley", "value": 1}, {"from": "Sheth Haji Adam", "to": "Lord Elgin", "value": 1}, {"from": "Sheth Haji Adam", "to": "Lord Ripon", "value": 1}, {"from": "Lord Selborne", "to": "Lord Elgin", "value": 1}, {"from": "Lord Selborne", "to": "George Godfrey", "value": 1}, {"from": "Lord Selborne", "to": "Merriman", "value": 1}, {"from": "Lord Selborne", "to": "Olive Schreiner", "value": 1}, {"from": "Lord Selborne", "to": "Dada Abdulla", "value": 1}, {"from": "Lord Selborne", "to": "Booker T. Washington", "value": 1}, {"from": "Lord Selborne", "to": "Lord Milner", "value": 1}, {"from": "Lord Selborne", "to": "Lord Kitchener", "value": 1}, {"from": "Lord Selborne", "to": "Lord Lansdowne", "value": 1}, {"from": "Lord Selborne", "to": "Escombe", "value": 1}, {"from": "Lord Selborne", "to": "Messrs", "value": 1}, {"from": "Lord Selborne", "to": "Lawley", "value": 1}, {"from": "Lord Selborne", "to": "John Molteno", "value": 1}, {"from": "Lord Selborne", "to": "Lord Ripon", "value": 1}, {"from": "George Godfrey", "to": "Dada Abdulla", "value": 1}, {"from": "George Godfrey", "to": "Booker T. Washington", "value": 1}, {"from": "George Godfrey", "to": "Lord Milner", "value": 1}, {"from": "George Godfrey", "to": "Lord Kitchener", "value": 1}, {"from": "George Godfrey", "to": "Lord Lansdowne", "value": 1}, {"from": "George Godfrey", "to": "Escombe", "value": 1}, {"from": "George Godfrey", "to": "Messrs", "value": 1}, {"from": "George Godfrey", "to": "Lawley", "value": 1}, {"from": "George Godfrey", "to": "Lord Elgin", "value": 1}, {"from": "George Godfrey", "to": "Lord Ripon", "value": 1}, {"from": "Merriman", "to": "Lord Lansdowne", "value": 1}, {"from": "Merriman", "to": "John Molteno", "value": 1}, {"from": "Merriman", "to": "Olive Schreiner", "value": 1}, {"from": "Olive Schreiner", "to": "Lord Lansdowne", "value": 1}, {"from": "Olive Schreiner", "to": "John Molteno", "value": 1}, {"from": "Dada Abdulla", "to": "Lord Kitchener", "value": 1}, {"from": "Dada Abdulla", "to": "Booker T. Washington", "value": 1}, {"from": "Dada Abdulla", "to": "Lord Milner", "value": 1}, {"from": "Dada Abdulla", "to": "Lord Lansdowne", "value": 1}, {"from": "Dada Abdulla", "to": "Escombe", "value": 1}, {"from": "Dada Abdulla", "to": "Messrs", "value": 1}, {"from": "Dada Abdulla", "to": "Lawley", "value": 1}, {"from": "Dada Abdulla", "to": "Lord Elgin", "value": 1}, {"from": "Dada Abdulla", "to": "Lord Ripon", "value": 1}, {"from": "Booker T. Washington", "to": "Lord Milner", "value": 1}, {"from": "Booker T. Washington", "to": "Lord Kitchener", "value": 1}, {"from": "Booker T. Washington", "to": "Lord Lansdowne", "value": 1}, {"from": "Booker T. Washington", "to": "Escombe", "value": 1}, {"from": "Booker T. Washington", "to": "Messrs", "value": 1}, {"from": "Booker T. Washington", "to": "Lawley", "value": 1}, {"from": "Booker T. Washington", "to": "Lord Elgin", "value": 1}, {"from": "Booker T. Washington", "to": "Lord Ripon", "value": 1}, {"from": "Lord Milner", "to": "Lord Kitchener", "value": 1}, {"from": "Lord Milner", "to": "Lord Lansdowne", "value": 1}, {"from": "Lord Milner", "to": "Escombe", "value": 1}, {"from": "Lord Milner", "to": "Messrs", "value": 1}, {"from": "Lord Milner", "to": "Lawley", "value": 1}, {"from": "Lord Milner", "to": "Lord Elgin", "value": 1}, {"from": "Lord Milner", "to": "Lord Ripon", "value": 1}, {"from": "Lord Kitchener", "to": "Lord Lansdowne", "value": 1}, {"from": "Lord Kitchener", "to": "Escombe", "value": 1}, {"from": "Lord Kitchener", "to": "Messrs", "value": 1}, {"from": "Lord Kitchener", "to": "Lawley", "value": 1}, {"from": "Lord Kitchener", "to": "Lord Elgin", "value": 1}, {"from": "Lord Kitchener", "to": "Lord Ripon", "value": 1}, {"from": "Lord Lansdowne", "to": "Escombe", "value": 1}, {"from": "Lord Lansdowne", "to": "Messrs", "value": 1}, {"from": "Lord Lansdowne", "to": "Lawley", "value": 1}, {"from": "Lord Lansdowne", "to": "John Molteno", "value": 1}, {"from": "Lord Lansdowne", "to": "Lord Elgin", "value": 1}, {"from": "Lord Lansdowne", "to": "Lord Ripon", "value": 1}, {"from": "Escombe", "to": "Messrs", "value": 1}, {"from": "Escombe", "to": "Lawley", "value": 1}, {"from": "Escombe", "to": "Lord Elgin", "value": 1}, {"from": "Escombe", "to": "Lord Ripon", "value": 1}, {"from": "Messrs", "to": "Lawley", "value": 1}, {"from": "Messrs", "to": "Lord Elgin", "value": 1}, {"from": "Messrs", "to": "Lord Ripon", "value": 1}, {"from": "Lawley", "to": "Lord Elgin", "value": 1}, {"from": "Lawley", "to": "Lord Ripon", "value": 1}, {"from": "Lord Elgin", "to": "Lord Ripon", "value": 1}]
        
        
import pandas as pd
import holoviews as hv
from holoviews import opts, dim
import numpy as np
hv.extension('bokeh')
hv.output(size=300)
        
        
df_json = pd.DataFrame(source_data)
        
df_links = pd.DataFrame(columns = ['source', 'target', 'value'])
        
df_links['source'] = df_json['from'].values.tolist()
df_links['target'] = df_json['to'].values.tolist()
df_links['value'] = df_json['value'].values.tolist()
        
unique_names = set(df_json['from'].unique().tolist() + df_json['to'].unique().tolist())
        
df_nodes = pd.DataFrame(columns=['name', 'group'])
df_nodes['name'] = list(unique_names)
        
## Grouping the nodes
df_nodes['group'][0:5] = 0
df_nodes['group'][5:10] = 1
df_nodes['group'][10:] = 2
        
## mapping to numerical value for the source and target node
mapper = {key: i for i, key in enumerate(list(unique_names))}
df_links['source'] = df_links['source'].map(mapper)
df_links['target'] = df_links['target'].map(mapper)
        
links = df_links
nodes = hv.Dataset(df_nodes, 'index')
        
chord = hv.Chord((links, nodes)).select(value=(1, None))
chord.opts(
      opts.Chord(cmap='Category10', edge_cmap='Category10', edge_color=dim('source').str(), 
                       labels='name', node_color=dim('group').str()))