#!/usr/bin/env python
# coding: utf-8

# # Linking and Layout
# 
# > [<i class="fa fa-2x fa-paper-plane text-info fa-fw"> </i> Simple example](./Simple%20example.ipynb)
# >
# > [<i class="fa fa-2x fa-space-shuttle text-info fa-fw"> </i> Advanced examples](./More%20examples.ipynb)
# >
# > <i class="fa fa-2x fa-link text-info fa-fw"> </i> Linking and Layout
# >
# > [<i class="fa fa-2x fa-image text-info fa-fw"> </i> Exporting Images](./Exporting%20Images.ipynb)
# 

# In[1]:


from ipysankeywidget import SankeyWidget


# > <i class="fa fa-info-circle fa-2x fa-fw text-primary"></i> This uses the base [ipywidgets](https://github.com/ipython/ipywidgets) for layout and data, but you can use any widgets!

# In[2]:


from ipywidgets import (
    VBox,
    HBox,
    IntSlider,
)


# In[3]:


links = [
    {'source': 'start', 'target': 'A', 'value': 10},
    {'source': 'A', 'target': 'B', 'value': 10},
    {'source': 'C', 'target': 'A', 'value': 10},
    {'source': 'A', 'target': 'C', 'value': 10},
]


# In[4]:


sankey = SankeyWidget(links=links)
sankey


# > <i class="fa fa-gears fa-2x fa-fw text-info"></i> A convenience factory function

# In[5]:


def slider(link, i, sankey):
    value = IntSlider(description="{source} → {target}".format(**link), min=0, max=10, step=1, value=10)

    def _change(change):
        sankey.links[i]["value"] = value.value
        sankey.send_state()
    
    value.observe(_change)
    
    return value


# Build up a slider per link to control the value:

# In[6]:


sliders = [slider(link, i, sankey) for i, link in enumerate(links)]


# In[7]:


box = HBox(children=[sankey, VBox(children=sliders)])
box


# In[ ]: