Updated codebase for the 2019 VM (and improved comments).

.buildozer

+/home/cse/.buildozer_share
\ No newline at end of file

.gitignore

@@ -2,5 +2,4 @@
 *.pyo
 
 .idea
-.buildozer
 bin

buildozer.spec

@@ -36,7 +36,7 @@ version = 1.0
 
 # (list) Application requirements
 # comma separated e.g. requirements = sqlite3,kivy
-requirements = kivy
+requirements = python3,kivy
 
 # (str) Custom source folders for requirements
 # Sets custom source for any requirements with recipes
@@ -88,16 +88,16 @@ fullscreen = 0
 #android.permissions = INTERNET
 
 # (int) Android API to use
-#android.api = 19
+android.api = 21
 
 # (int) Minimum API required
-#android.minapi = 9
+android.minapi = 21
 
 # (int) Android SDK version to use
 #android.sdk = 20
 
 # (str) Android NDK version to use
-#android.ndk = 9c
+android.ndk = 17c
 
 # (bool) Use --private data storage (True) or --dir public storage (False)
 #android.private_storage = True
@@ -146,8 +146,11 @@ fullscreen = 0
 # bootstrap)
 #android.gradle_dependencies =
 
+# (list) Java classes to add as activities to the manifest.
+#android.add_activites = com.example.ExampleActivity
+
 # (str) python-for-android branch to use, defaults to stable
-#p4a.branch = stable
+p4a.branch = master
 
 # (str) OUYA Console category. Should be one of GAME or APP
 # If you leave this blank, OUYA support will not be enabled
@@ -159,6 +162,9 @@ fullscreen = 0
 # (str) XML file to include as an intent filters in <activity> tag
 #android.manifest.intent_filters =
 
+# (str) launchMode to set for the main activity
+#android.manifest.launch_mode = standard
+
 # (list) Android additional libraries to copy into libs/armeabi
 #android.add_libs_armeabi = libs/android/*.so
 #android.add_libs_armeabi_v7a = libs/android-v7/*.so
@@ -201,6 +207,9 @@ android.arch = armeabi-v7a
 # (str) Bootstrap to use for android builds
 # p4a.bootstrap = sdl2
 
+# (int) port number to specify an explicit --port= p4a argument (eg for bootstrap flask)
+#p4a.port =
+
 
 #
 # iOS specific
@@ -220,7 +229,7 @@ android.arch = armeabi-v7a
 [buildozer]
 
 # (int) Log level (0 = error only, 1 = info, 2 = debug (with command output))
-log_level = 2
+log_level = 1
 
 # (int) Display warning if buildozer is run as root (0 = False, 1 = True)
 warn_on_root = 1

demo.kv

@@ -3,7 +3,7 @@ BoxLayout:
     BoxLayout:
         id: fields
         orientation: 'vertical'
-        size_hint: (1, 6)
+        size_hint: (1.0, 6.0)
     BoxLayout:
         orientation: 'horizontal'
         Button:
@@ -17,9 +17,9 @@ BoxLayout:
             on_press: app.print_total()
 
 <Field>:
-    orientation: 'horizontal'  # Field is a kind of BoxLayout
+    orientation: 'horizontal'  # Field is a kind of BoxLayout.
     Label:
-        text: root.label_text  # Refers to a property declared in the Field class
+        text: root.label_text  # In a subwidget's Kv, `root.…` refers to a property of the Field widget.
     TextInput:
         id: input
         multiline: False

main.py

@@ -10,23 +10,22 @@ class Field(BoxLayout):
 class DemoApp(App):
     def add_field(self):
         container = self.root.ids.fields
-        new_label_text = 'Field #{index}: '.format(index=len(container.children))
-        container.add_widget(Field(label_text=new_label_text))
+        container.add_widget(Field(label_text=f'Field #{len(container.children)}: '))
 
     def remove_field(self):
         container = self.root.ids.fields
         if len(container.children) > 0:
-            container.remove_widget(container.children[0])  # children are indexed in reverse display order
+            container.remove_widget(container.children[0])  # Children are indexed in reverse display order.
 
     def print_total(self):
         container = self.root.ids.fields
         total = 0
         for field in container.children:
             try:
-                total += float(field.ids.input.text)  # refer to a subwidget by id
+                total += float(field.ids.input.text)  # `widget.ids.…` can be used to refer to a subwidget by ID.
             except ValueError:
-                pass  # ignore non-numeric values
-        print('Total of fields\' numeric values: {total}'.format(total=total))
+                pass  # Ignore non-numeric values.
+        print(f'Total of fields\' numeric values: {total}')
 
 
 if __name__ == '__main__':