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

# # Mesh widgets
# 
# In order to control interactive plots, sometimes we need to vary certain parameters which depend on the mesh. Therefore, mesh object has several widgets, which can be used for that purpose.
# 
# The mesh we are going to use as an example is:

# In[1]:


import discretisedfield as df

p1 = (0, 0, 0)
p2 = (100e-9, 50e-9, 20e-9)
n = (20, 10, 4)

region = df.Region(p1=p1, p2=p2)
mesh = df.Mesh(region=region, n=n)


# ## Slider
# 
# Slider widget allows us to navigate through the coordinates of the mesh along the certain axis. For instance, if we want to "slide through" the x-axis, the widget is:

# In[2]:


mesh.slider("x")


# The minimum value of the slider is the x-coordinate of the cell with the minimum coordinates, whereas the maximum value is the x-coordinate of the last cell along the x-direction. The steps on the slider correspond to the distance between cells.
# 
# Widget description is generated by default, and can be changed by passing `description` argument.

# In[3]:


mesh.slider("x", description="my slider")


# Similar to plots, we can change the multiplier:

# In[4]:


mesh.slider("x", multiplier=1e-12)


# We now get the values in picometers and the units are shown in the widget description.
# 
# Slider is based on [ipywidgets.SelectionSlider](https://ipywidgets.readthedocs.io/en/latest/examples/Widget%20List.html#SelectionSlider), so any keyword arguments accepted by it can be passed.

# In[5]:


mesh.slider("x", orientation="vertical")


# ## Axis selector
# 
# A simple widget, which allows us to select the axis we want can be obtained as:

# In[6]:


mesh.axis_selector()


# By default, a dropdown menu is returned where we can select x, y, or z axis. Instead of a dropdown menu, we can ask for radio buttons, by passing `widget='radiobuttons'`.

# In[7]:


mesh.axis_selector(widget="radiobuttons")


# The description of the widget, similar to slider, can be changed using `description` string.

# In[8]:


mesh.axis_selector(description="my selector")