Multiple binding sets collapsed to one. Added comment explaining selection modes.

examples/widgets/list_cascade.py

@@ -4,7 +4,8 @@ from kivy.uix.button import Button
 from kivy.uix.listview import ListView, ListAdapter
 from kivy.uix.mixins.selection import SelectionObserver, SelectableItem
 from kivy.properties import ListProperty, StringProperty, ObjectProperty
-
+from kivy.clock import Clock
+from kivy.graphics.instructions import Callback
 
 # This is an expansion on the "master-detail" example to illustrate
 # cascading from the selection of one list view to another.
@@ -25,11 +26,6 @@ class ListItem(SelectableItem, Button):
         self.bind(on_release=self.handle_selection)
 
     def handle_selection(self, button):
-#        if not self.is_selected:
-#            self.select()
-#        else:
-#            self.deselect()
-
         self.list_adapter.handle_selection(self)
 
     def select(self, *args):
@@ -52,10 +48,12 @@ class FruitsListView(SelectionObserver, ListView):
     def __init__(self, **kwargs):
         super(FruitsListView, self).__init__(**kwargs)
 
+    # Observed selection is fruit categories list.
     def observed_selection_changed(self, observed_selection):
         if len(observed_selection.selection) == 0:
             return
 
+        # Clear the previously built views.
         self.item_view_instances = {}
 
         # Single selection is operational for fruit categories list.
@@ -70,8 +68,12 @@ class FruitsListView(SelectionObserver, ListView):
         # to self.adapter.initialize_selection().
         self.adapter.data = fruit_categories[fruit_category]
 
+        #print self.adapter.selection[0], self.adapter.selection[0].background_color
+
         self.populate()
 
+        self.canvas.ask_update()
+
         print 'just added or updated fruit category'
 
 

kivy/uix/mixins/selection.py

@@ -42,6 +42,11 @@ class SelectionObserver(object):
 
 class SelectionSupport(object):
     selection = ListProperty([])
+    # none -- use the list as a simple list (no select action)
+    # single -- multi-touch/click ignored. single item selecting only
+    # multiple -- multi-touch / incremental clicks to select allowed
+    # filter -- idea only now. Could pass in filtering function to
+    #           perform associated items selection
     selection_mode = OptionProperty('multiple',
             options=('none', 'single', 'multiple', 'filter'))
     allow_empty_selection = BooleanProperty(True)
@@ -50,9 +55,9 @@ class SelectionSupport(object):
 
     def __init__(self, **kwargs):
         super(SelectionSupport, self).__init__(**kwargs)
-        self.bind(data=self.update_selection)
-        self.bind(selection_mode=self.update_selection)
-        self.bind(allow_empty_selection=self.update_selection)
+        self.bind(data=self.initialize_selection,
+                  selection_mode=self.initialize_selection,
+                  allow_empty_selection=self.initialize_selection)
 
     def register_selection_observer(self, obs):
         if isinstance(obs, SelectionObserver):