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

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import panel as pn
pn.extension()


# The ``Card`` layout allows arranging multiple Panel objects in a collapsible, vertical container with a header bar. It has a list-like API with methods for interactively updating and modifying the layout, including ``append``, ``extend``, ``clear``, ``insert``, ``pop``, ``remove`` and ``__setitem__`` (for replacing the card's contents).
# 
# `Card` components are very helpful for laying out components in a grid in a complex dashboard to make clear visual separations between different sections. The ability to collapse them can also be very useful to save space on a page with a lot of components.
# 
# #### Parameters:
# 
# * **``collapsed``** (bool): Whether the `Card` is collapsed.
# * **``collapsible``** (bool): Whether the `Card` can be expanded and collapsed.
# * **``header``** (Viewable): A Panel component to display in the header bar of the Card.
# * **``objects``** (list): The list of objects to display in the Card, which will be formatted like a `Column`. Should not generally be modified directly except when replaced in its entirety.
# * **``title``** (str): The title to display in the header bar if no explicit `header` is defined.
# 
# Styling related parameters:
# 
# * **``active_header_background``** (str): The background color of the header when the `Card` is expanded.
# * **``background``** (str): The background color of the content area.
# * **``header_color``** (str): The color of the header text.
# * **``button_css_classes``** (list[str]): The list of CSS classes to apply to the collapse button.
# * **``css_classes``** (list[str]): The list of CSS classes to apply to the main area.
# * **``header_background``** (str): The background color of the header.
# * **``header_css_classes``** (list[str]): The list of CSS classes to apply to the header.
# 
# For layout and styling related parameters see the [customization user guide](../../user_guide/Customization.ipynb).
# 
# ___

# A ``Card`` layout can either be instantiated as empty and populated after the fact, or by using a list of objects provided on instantiation as positional arguments. If the objects are not already Panel components they will each be converted to one using the ``pn.panel`` conversion method. Unlike the `Row` and `Column` layouts, a `Card` has an explicit `title` that will be shown in the header bar alongside the collapse button (if the `collapsible` parameter is enabled):

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w1 = pn.widgets.TextInput(name='Text:')
w2 = pn.widgets.FloatSlider(name='Slider')

card = pn.Card(w1, w2, title='Card', background='WhiteSmoke')
card


# The contents of the ``Card.objects`` list should never be modified individually, because Panel cannot detect when items in that list have changed internally, and will thus fail to update any already-rendered views of those objects. Instead, use the provided methods for adding and removing items from the list.  The only change that is safe to make directly to ``Card.objects`` is to replace the list of ``objects`` entirely.  As a simple example of using the methods, we might add an additional widget to the card using the append method:

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w3 = pn.widgets.Select(options=['A', 'B', 'C'])
card.append(w3)


# On a live server or in a notebook the `card` displayed after the previous code cell (above) will dynamically expand in size to accomodate all three widgets and the title. To see the effect in a statically rendered page, we will display the column a second time:

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card


# Whether the `Card` is collapsed or not can be controlled from Python and Javascript:

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print(card.collapsed)
card.collapsed = True


# ### Header
# 
# Instead of using a `title`, a `Card` may also be given an explicit `header` that can contain any component, e.g. in this case the Panel logo:

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logo = 'https://panel.holoviz.org/_static/logo_horizontal.png'

red   = pn.Spacer(background='red', height=50)
green = pn.Spacer(background='green', height=50)
blue  = pn.Spacer(background='blue', height=50)

pn.Card(
    red, green, blue,
    header_background='#2f2f2f',
    header_color='white',
    header=pn.panel(logo, height=40),
    width=300,
)


# ### Layout
# 
# In general a ``Card`` does not have to be given an explicit ``width``, ``height``, or ``sizing_mode``, allowing it to adapt to the size of its contents. However in certain cases it can be useful to declare a fixed-size layout, which its responsively sized contents will then fill, making it possible to achieve equal spacing between multiple objects:

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red   = pn.Spacer(background='red', sizing_mode='stretch_both')
green = pn.Spacer(background='green', sizing_mode='stretch_both')
blue  = pn.Spacer(background='blue', sizing_mode='stretch_both')

pn.Card(red, green, blue, height=300, width=200, title='Fixed size')


# When no fixed size is specified the column will expand to accomodate the sizing behavior of its contents:

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from bokeh.plotting import figure

p1 = figure(height=250, sizing_mode='stretch_width', margin=5)
p2 = figure(height=250, sizing_mode='stretch_width', margin=5)

p1.line([1, 2, 3], [1, 2, 3])
p2.circle([1, 2, 3], [1, 2, 3])

pn.Card(p1, pn.layout.Divider(), p2, title="Responsive", sizing_mode='stretch_width')