kivy/examples/widgets/list_master_detail.py

from kivy.uix.gridlayout import GridLayout
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.properties import ObjectProperty, \
                            NumericProperty, ListProperty, \
                            StringProperty
from kivy.uix.listview import ListView, ListItemButton
from kivy.adapters.mixins.selection import SingleSelectionObserver, \
        SelectableItem
from kivy.adapters.listadapter import ListAdapter

# A "master-detail" view is a good way to experiment with a listview
# (the master) and another view (detail view) that gets updated upon
# selection.

# DetailView is an observer of the selection of the associated list view,
# so SelectionObserver is mixed in, requiring an override of the
# observed_selection_changed() method.

class DetailView(SingleSelectionObserver, GridLayout):
    fruit_name = StringProperty('')

    def __init__(self, **kwargs):
        kwargs['cols'] = 2
        super(DetailView, self).__init__(**kwargs)
        self.bind(fruit_name=self.redraw)

        self.fruit_name = self.observed_list_adapter.selection[0].text

    def redraw(self, *args):
        self.clear_widgets()
        self.add_widget(Label(text="Name:", halign='right'))
        self.add_widget(Label(text=self.fruit_name))
        for category in descriptors:
            self.add_widget(Label(text="{0}:".format(category),
                                  halign='right'))
            self.add_widget(
                    Label(text=str(fruit_data[self.fruit_name][category])))

    def observed_selection_changed(self, list_adapter, selection):
        if len(list_adapter.selection) == 0:
            return

        selected_object = list_adapter.selection[0]

        if type(selected_object) is str:
            self.fruit_name = selected_object
        else:
            self.fruit_name = str(selected_object)
        print 'just added or updated detail label'


class MasterDetailView(GridLayout):
    '''Implementation of an MasterDetailView with a vertical scrollable list
    on the left (the master, or source list) and a detail view on the right.
    '''

    divider = ObjectProperty(None)

    divider_width = NumericProperty(2)

    def __init__(self, items, **kwargs):
        #kwargs['orientation'] = 'horizontal'
        kwargs['cols'] = 2
        kwargs['size_hint'] = (1.0, 1.0)
        super(MasterDetailView, self).__init__(**kwargs)

        list_item_args_converter = lambda x: {'text': x,
                                              'size_hint_y': None,
                                              'height': 25}
        list_adapter = \
                ListAdapter(items,
                            args_converter=list_item_args_converter,
                            selection_mode='single',
                            allow_empty_selection=False,
                            cls=ListItemButton)
        master_list_view = ListView(adapter=list_adapter,
                                    size_hint=(.3, 1.0))
        self.add_widget(master_list_view)

        detail_view = DetailView(
                observed_list_adapter=list_adapter,
                size_hint=(.7, 1.0))
        self.add_widget(detail_view)

# Data from http://www.fda.gov/Food/LabelingNutrition/\
#                FoodLabelingGuidanceRegulatoryInformation/\
#                InformationforRestaurantsRetailEstablishments/\
#                ucm063482.htm
fruit_categories = \
        {'Melons': ['Cantaloupe', 'Honeydew Melon', 'Watermelon'],
         'Tree Fruits': ['Apple', 'Avocado, California', 'Banana', 'Nectarine',
                         'Peach', 'Pear', 'Pineapple', 'Plums',
                         'Sweet Cherries'],
         'Citrus Fruits': ['Grapefruit', 'Lemon', 'Lime', 'Orange',
                           'Tangerine'],
         'Miscellaneous Fruits': ['Grapes', 'Kiwifruit', 'Strawberries']}
descriptors = """(gram weight/ ounce weight)	Calories	Calories from Fa
t	Total Fat	Sodium	Potassium	Total Carbo-hydrate	Dietary Fiber	Suga
rs	Protein	Vitamin A	Vitamin C	Calcium	Iron""".replace('\n', '')
descriptors = [item.strip() for item in descriptors.split('\t')]
units = """(g) 	(%DV)	(mg) 	(%DV)	(mg) 	(%DV)	 (g) 	(%DV)	 (g)
(%DV)	 (g) 	 (g) 	(%DV)	(%DV)	(%DV)	(%DV)""".replace('\n', '')
units = [item.strip() for item in units.split('\t')]
raw_fruit_data = [
{'name':'Apple',
 'Serving Size': '1 large (242 g/8 oz)',
 'data': [130, 0, 0, 0, 0, 0, 260, 7, 34, 11, 5, 20, 25, 1, 2, 8, 2, 2]},
{'name':'Avocado, California',
 'Serving Size': '1/5 medium (30 g/1.1 oz)',
 'data': [50, 35, 4.5, 7, 0, 0, 140, 4, 3, 1, 1, 4, 0, 1, 0, 4, 0, 2]},
{'name':'Banana',
 'Serving Size': '1 medium (126 g/4.5 oz)',
 'data': [110, 0, 0, 0, 0, 0, 450, 13, 30, 10, 3, 12, 19, 1, 2, 15, 0, 2]},
{'name':'Cantaloupe',
 'Serving Size': '1/4 medium (134 g/4.8 oz)',
 'data': [50, 0, 0, 0, 20, 1, 240, 7, 12, 4, 1, 4, 11, 1, 120, 80, 2, 2]},
{'name':'Grapefruit',
 'Serving Size': '1/2 medium (154 g/5.5 oz)',
 'data': [60, 0, 0, 0, 0, 0, 160, 5, 15, 5, 2, 8, 11, 1, 35, 100, 4, 0]},
{'name':'Grapes',
 'Serving Size': '3/4 cup (126 g/4.5 oz)',
 'data': [90, 0, 0, 0, 15, 1, 240, 7, 23, 8, 1, 4, 20, 0, 0, 2, 2, 0]},
{'name':'Honeydew Melon',
 'Serving Size': '1/10 medium melon (134 g/4.8 oz)',
 'data': [50, 0, 0, 0, 30, 1, 210, 6, 12, 4, 1, 4, 11, 1, 2, 45, 2, 2]},
{'name':'Kiwifruit',
 'Serving Size': '2 medium (148 g/5.3 oz)',
 'data': [90, 10, 1, 2, 0, 0, 450, 13, 20, 7, 4, 16, 13, 1, 2, 240, 4, 2]},
{'name':'Lemon',
 'Serving Size': '1 medium (58 g/2.1 oz)',
 'data': [15, 0, 0, 0, 0, 0, 75, 2, 5, 2, 2, 8, 2, 0, 0, 40, 2, 0]},
{'name':'Lime',
 'Serving Size': '1 medium (67 g/2.4 oz)',
 'data': [20, 0, 0, 0, 0, 0, 75, 2, 7, 2, 2, 8, 0, 0, 0, 35, 0, 0]},
{'name':'Nectarine',
 'Serving Size': '1 medium (140 g/5.0 oz)',
 'data': [60, 5, 0.5, 1, 0, 0, 250, 7, 15, 5, 2, 8, 11, 1, 8, 15, 0, 2]},
{'name':'Orange',
 'Serving Size': '1 medium (154 g/5.5 oz)',
 'data': [80, 0, 0, 0, 0, 0, 250, 7, 19, 6, 3, 12, 14, 1, 2, 130, 6, 0]},
{'name':'Peach',
 'Serving Size': '1 medium (147 g/5.3 oz)',
 'data': [60, 0, 0.5, 1, 0, 0, 230, 7, 15, 5, 2, 8, 13, 1, 6, 15, 0, 2]},
{'name':'Pear',
 'Serving Size': '1 medium (166 g/5.9 oz)',
 'data': [100, 0, 0, 0, 0, 0, 190, 5, 26, 9, 6, 24, 16, 1, 0, 10, 2, 0]},
{'name':'Pineapple',
 'Serving Size': '2 slices, 3" diameter, 3/4" thick (112 g/4 oz)',
 'data': [50, 0, 0, 0, 10, 0, 120, 3, 13, 4, 1, 4, 10, 1, 2, 50, 2, 2]},
{'name':'Plums',
 'Serving Size': '2 medium (151 g/5.4 oz)',
 'data': [70, 0, 0, 0, 0, 0, 230, 7, 19, 6, 2, 8, 16, 1, 8, 10, 0, 2]},
{'name':'Strawberries',
 'Serving Size': '8 medium (147 g/5.3 oz)',
 'data': [50, 0, 0, 0, 0, 0, 170, 5, 11, 4, 2, 8, 8, 1, 0, 160, 2, 2]},
{'name':'Sweet Cherries',
 'Serving Size': '21 cherries; 1 cup (140 g/5.0 oz)',
 'data': [100, 0, 0, 0, 0, 0, 350, 10, 26, 9, 1, 4, 16, 1, 2, 15, 2, 2]},
{'name':'Tangerine',
 'Serving Size': '1 medium (109 g/3.9 oz)',
 'data': [50, 0, 0, 0, 0, 0, 160, 5, 13, 4, 2, 8, 9, 1, 6, 45, 4, 0]},
{'name':'Watermelon',
 'Serving Size': '1/18 medium melon; 2 cups diced pieces (280 g/10.0 oz)',
 'data': [80, 0, 0, 0, 0, 0, 270, 8, 21, 7, 1, 4, 20, 1, 30, 25, 2, 4]}]

fruit_data = {}
descriptors_and_units = dict(zip(descriptors, units))
for row in raw_fruit_data:
    fruit_data[row['name']] = {}
    fruit_data[row['name']] = dict({'Serving Size': row['Serving Size']},
            **dict(zip(descriptors_and_units.keys(), row['data'])))

if __name__ == '__main__':

    from kivy.base import runTouchApp

    master_detail = MasterDetailView(sorted(fruit_data.keys()), width=800)

    runTouchApp(master_detail)