Added an example to work with new fruit images.

examples/widgets/lists/image_detail_view.py

@@ -0,0 +1,44 @@
+from kivy.uix.boxlayout import BoxLayout
+from kivy.uix.gridlayout import GridLayout
+from kivy.uix.label import Label
+from kivy.properties import StringProperty
+from kivy.uix.image import Image
+
+from fruit_data import descriptors
+from fruit_data import fruit_data
+
+
+class ImageDetailView(BoxLayout):
+    fruit_name = StringProperty('')
+
+    def __init__(self, **kwargs):
+        kwargs['orientation'] = 'vertical'
+        super(ImageDetailView, self).__init__(**kwargs)
+
+    def redraw(self, *args):
+        self.clear_widgets()
+
+        self.add_widget(Image(source=filename, size=(256, 256)))
+
+        container = GridLayout(cols=2)
+        container.add_widget(Label(text="Name:", halign='right'))
+        container.add_widget(Label(text=self.fruit_name))
+        for category in descriptors:
+            container.add_widget(Label(text="{0}:".format(category),
+                                  halign='right'))
+            container.add_widget(
+                    Label(text=str(fruit_data[self.fruit_name][category])))
+        self.add_widget(container)
+
+    def on_selection_change(self, list_adapter, *args):
+        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)
+
+        self.redraw()

examples/widgets/lists/list_cascade_images.py

@@ -0,0 +1,94 @@
+from kivy.adapters.listadapter import ListAdapter, ListsAdapter
+from kivy.adapters.mixins.selection import SelectableItem
+from kivy.uix.boxlayout import BoxLayout
+from kivy.uix.gridlayout import GridLayout
+from kivy.uix.listview import ListView, ListItemButton
+from kivy.lang import Builder
+
+from fruit_data import fruit_categories
+
+from image_detail_view import ImageDetailView
+
+# This is a copy of list_cascade.py with image thumbnails added to the list
+# item views and a larger image shown in the detail view for the selected
+# image. It uses the kv template method for the listview that shows list
+# items with thumbnail images of the fruits.
+
+Builder.load_string('''
+[ThumbnailedListItem@SelectableItem,BoxLayout]:
+    size_hint_y: ctx.size_hint_y
+    height: ctx.height
+    Image
+        source: "fruit_images/{0}.32.jpg".format(ctx.text)
+    Label:
+        text: ctx.text
+''')
+
+
+class CascadingView(GridLayout):
+    '''Implementation of a master-detail style view, with a scrollable list
+    of fruit categories on the left (source list), a list of fruits for the
+    selected category in the middle, and a detail view on the right.
+    '''
+
+    def __init__(self, **kwargs):
+        kwargs['cols'] = 3
+        kwargs['size_hint'] = (1.0, 1.0)
+        super(CascadingView, self).__init__(**kwargs)
+
+        list_item_args_converter = lambda x: {'text': x,
+                                              'size_hint_y': None,
+                                              'height': 32}
+
+        # Fruit categories list on the left:
+        #
+        categories = sorted(fruit_categories.keys())
+        fruit_categories_list_adapter = \
+            ListAdapter(data=categories,
+                        args_converter=list_item_args_converter,
+                        selection_mode='single',
+                        allow_empty_selection=False,
+                        cls=ListItemButton)
+        fruit_categories_list_view = \
+                ListView(adapter=fruit_categories_list_adapter,
+                        size_hint=(.2, 1.0))
+        self.add_widget(fruit_categories_list_view)
+
+        # Fruits, for a given category, in the middle:
+        #
+        fruits_list_adapter = \
+                ListsAdapter(
+                    observed_list_adapter=fruit_categories_list_adapter,
+                    lists_dict=fruit_categories,
+                    data=fruit_categories[categories[0]],
+                    args_converter=list_item_args_converter,
+                    selection_mode='single',
+                    allow_empty_selection=False,
+                    template='ThumbnailedListItem')
+        fruits_list_view = \
+                ListView(adapter=fruits_list_adapter,
+                    size_hint=(.2, 1.0))
+        fruit_categories_list_adapter.bind(
+                on_selection_change=fruits_list_adapter.on_selection_change)
+        self.add_widget(fruits_list_view)
+
+        # Detail view, for a given fruit, on the right:
+        #
+        detail_view = ImageDetailView(size_hint=(.6, 1.0))
+        fruits_list_adapter.bind(
+                on_selection_change=detail_view.on_selection_change)
+        self.add_widget(detail_view)
+
+        # Force triggering of on_selection_change() for the DetailView, for
+        # correct initial display.
+        fruits_list_adapter.touch_selection()
+
+
+if __name__ == '__main__':
+
+    from kivy.base import runTouchApp
+
+    # All fruit categories will be shown in the left left (first argument),
+    # and the first category will be auto-selected -- Melons. So, set the
+    # second list to show the melon fruits (second argument).
+    runTouchApp(CascadingView(width=800))