HI All,

I am trying to implement an interactive plot where the user can add points to a

multi-segments line.

So far I managed to do this:

```
from bokeh.plotting import figure, output_notebook, show
from bokeh.models import ColumnDataSource, PointDrawTool
from bokeh.events import Tap
import numpy as np
output_notebook()
def bkapp(doc):
p = figure(x_range=(0, 10), y_range=(0, 10), width=400, height=400)
source = ColumnDataSource({'x': [1, 5, 9], 'y': [1, 5, 9]})
def add_point(event):
x = np.array(source.data["x"])
y = np.array(source.data["y"])
indices = np.argsort(x)
x = np.sort(x)
y = y[indices]
data = {"x": list(x), "y": list(y)}
source.data = data
renderer = p.scatter(x="x", y="y", source=source, size=10)
draw_tool = PointDrawTool(renderers=[renderer], empty_value='black')
p.line(x="x", y="y", source=source)
p.on_event(Tap, add_point)
p.add_tools(draw_tool)
p.toolbar.active_tap = draw_tool
doc.add_root(p)
show(bkapp)
```

That seems to work just fine… My issue is that I would like the the python callback to be called when a point is deleted or moved.

Any ideas?

R