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

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get_ipython().run_cell_magic('html', '', '<style>\n.example-container { background: #999999; padding: 2px; min-height: 100px; }\n.example-container.sm { min-height: 50px; }\n.example-box { background: #9999FF; width: 50px; height: 50px; text-align: center; vertical-align: middle; color: white; font-weight: bold; margin: 2px;}\n.example-box.med { width: 65px; height: 65px; }   \n.example-box.lrg { width: 80px; height: 80px; }   \n</style>\n')


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import ipywidgets as widgets
from IPython.display import display


# # Widget Styling

# ## Basic styling

# The widgets distributed with IPython can be styled by setting the following traits:
# 
# - width  
# - height  
# - fore_color  
# - back_color  
# - border_color  
# - border_width  
# - border_style  
# - font_style  
# - font_weight  
# - font_size  
# - font_family  
# 
# The example below shows how a `Button` widget can be styled:

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button = widgets.Button(
    description='Hello World!',
    width=100, # Integers are interpreted as pixel measurements.
    height='2em', # em is valid HTML unit of measurement.
    color='lime', # Colors can be set by name,
    background_color='#0022FF', # and also by color code.
    border_color='red')
display(button)


# ## Parent/child relationships

# To display widget A inside widget B, widget A must be a child of widget B.  Widgets that can contain other widgets have a **`children` attribute**.  This attribute can be **set via a keyword argument** in the widget's constructor **or after construction**.  Calling display on an **object with children automatically displays those children**, too.

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from IPython.display import display

float_range = widgets.FloatSlider()
string = widgets.Text(value='hi')
container = widgets.Box(children=[float_range, string])

container.border_color = 'red'
container.border_style = 'dotted'
container.border_width = 3
display(container) # Displays the `container` and all of it's children.


# ### After the parent is displayed

# Children **can be added to parents** after the parent has been displayed.  The **parent is responsible for rendering its children**.

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container = widgets.Box()
container.border_color = 'red'
container.border_style = 'dotted'
container.border_width = 3
display(container)

int_range = widgets.IntSlider()
container.children=[int_range]


# ## Fancy boxes

# If you need to display a more complicated set of widgets, there are **specialized containers** that you can use.  To display **multiple sets of widgets**, you can use an **`Accordion` or a `Tab` in combination with one `Box` per set of widgets** (as seen below).  The "pages" of these widgets are their children.  To set the titles of the pages, one can **call `set_title`**.

# ### Accordion

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name1 = widgets.Text(description='Location:')
zip1 = widgets.BoundedIntText(description='Zip:', min=0, max=99999)
page1 = widgets.Box(children=[name1, zip1])

name2 = widgets.Text(description='Location:')
zip2 = widgets.BoundedIntText(description='Zip:', min=0, max=99999)
page2 = widgets.Box(children=[name2, zip2])

accord = widgets.Accordion(children=[page1, page2])
display(accord)

accord.set_title(0, 'From')
accord.set_title(1, 'To')


# ### TabWidget

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name = widgets.Text(description='Name:')
color = widgets.Dropdown(description='Color:', options=['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'violet'])
page1 = widgets.Box(children=[name, color])

age = widgets.IntSlider(description='Age:', min=0, max=120, value=50)
gender = widgets.RadioButtons(description='Gender:', options=['male', 'female'])
page2 = widgets.Box(children=[age, gender])

tabs = widgets.Tab(children=[page1, page2])
display(tabs)

tabs.set_title(0, 'Name')
tabs.set_title(1, 'Details')


# # Alignment

# Most widgets have a **`description` attribute**, which allows a label for the widget to be defined.
# The label of the widget **has a fixed minimum width**.
# The text of the label is **always right aligned and the widget is left aligned**:

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display(widgets.Text(description="a:"))
display(widgets.Text(description="aa:"))
display(widgets.Text(description="aaa:"))


# If a **label is longer** than the minimum width, the **widget is shifted to the right**:

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display(widgets.Text(description="a:"))
display(widgets.Text(description="aa:"))
display(widgets.Text(description="aaa:"))
display(widgets.Text(description="aaaaaaaaaaaaaaaaaa:"))


# If a `description` is **not set** for the widget, the **label is not displayed**:

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display(widgets.Text(description="a:"))
display(widgets.Text(description="aa:"))
display(widgets.Text(description="aaa:"))
display(widgets.Text())


# ## Flex boxes

# Widgets can be aligned using the `FlexBox`, `HBox`, and `VBox` widgets.

# ### Application to widgets

# Widgets display vertically by default:

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buttons = [widgets.Button(description=str(i)) for i in range(3)]
display(*buttons)


# ### Using hbox

# To make widgets display horizontally, you need to **child them to a `HBox` widget**.

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container = widgets.HBox(children=buttons)
display(container)


# By setting the width of the container to 100% and its `pack` to `center`, you can center the buttons.

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container.width = '100%'
container.pack = 'center'


# ## Visibility

# Sometimes it is necessary to **hide or show widgets** in place, **without having to re-display** the widget.
# The `visible` property of widgets can be used to hide or show **widgets that have already been displayed** (as seen below).  The `visible` property can be:
# * `True` - the widget is displayed
# * `False` - the widget is hidden, and the empty space where the widget would be is collapsed
# * `None` - the widget is hidden, and the empty space where the widget would be is shown

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w1 = widgets.Latex(value="First line")
w2 = widgets.Latex(value="Second line")
w3 = widgets.Latex(value="Third line")
display(w1, w2, w3)


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w2.visible=None


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w2.visible=False


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w2.visible=True


# ### Another example

# In the example below, a form is rendered, which conditionally displays widgets depending on the state of other widgets.  Try toggling the student checkbox.

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form = widgets.VBox()
first = widgets.Text(description="First Name:")
last = widgets.Text(description="Last Name:")

student = widgets.Checkbox(description="Student:", value=False)
school_info = widgets.VBox(visible=False, children=[
    widgets.Text(description="School:"),
    widgets.IntText(description="Grade:", min=0, max=12)
    ])

pet = widgets.Text(description="Pet's Name:")
form.children = [first, last, student, school_info, pet]
display(form)

def on_student_toggle(name, value):
    if value:
        school_info.visible = True
    else:
        school_info.visible = False
student.on_trait_change(on_student_toggle, 'value')


# [Index](Index.ipynb) - [Back](Widget%20Events.ipynb) - [Next](Custom Widget - Hello World.ipynb)