From 49f5bab67fd68908006ae5fdeb4c0ce6f23b3969 Mon Sep 17 00:00:00 2001
From: Mathieu Virbel <mathieu@pymt.eu>
Date: Tue, 9 Nov 2010 19:29:01 +0100
Subject: [PATCH 1/3] widget: allow parent to be None (in case of remove_widget
 for eg)

---
 kivy/uix/widget.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kivy/uix/widget.py b/kivy/uix/widget.py
index 76165657e..243f84c1d 100644
--- a/kivy/uix/widget.py
+++ b/kivy/uix/widget.py
@@ -336,7 +336,7 @@ class Widget(EventDispatcher):
     children = ListProperty([])
 
     #: Parent
-    parent = ObjectProperty(None)
+    parent = ObjectProperty(None, allownone=True)
 
     #: Size hint X
     size_hint_x = NumericProperty(1, allownone=True)

From edd69d63ffe16d33dea5ea49d1d92a282e0cdc16 Mon Sep 17 00:00:00 2001
From: Mathieu Virbel <mathieu@pymt.eu>
Date: Tue, 9 Nov 2010 19:29:15 +0100
Subject: [PATCH 2/3] graphics: make canvas recompile when a child is
 added/removed

---
 kivy/c_ext/graphics.pyx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kivy/c_ext/graphics.pyx b/kivy/c_ext/graphics.pyx
index 78eb8f87a..a0ba99be7 100644
--- a/kivy/c_ext/graphics.pyx
+++ b/kivy/c_ext/graphics.pyx
@@ -91,10 +91,12 @@ cdef class Canvas:
     cpdef add_canvas(self, Canvas canvas):
         if not canvas in self._children:
             self._children.append(canvas)
+        self._need_compile = 1
 
     cpdef remove_canvas(self, Canvas canvas):
         if canvas in self._children:
             self._children.remove(canvas)
+        self._need_compile = 1
 
     cdef add(self, GraphicInstruction instruction):
         self.need_compile = 1

From 3e0443a2d3817e106d2b6ef6e9076801d20ccf6d Mon Sep 17 00:00:00 2001
From: Mathieu Virbel <mathieu@pymt.eu>
Date: Tue, 9 Nov 2010 19:29:26 +0100
Subject: [PATCH 3/3] kvrun: press F5 to reload app

---
 examples/kv/kvrun.py | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/examples/kv/kvrun.py b/examples/kv/kvrun.py
index b03b40545..e690151bc 100644
--- a/examples/kv/kvrun.py
+++ b/examples/kv/kvrun.py
@@ -3,13 +3,24 @@
 from kivy.app import App
 from kivy.clock import Clock
 from kivy.lang import Builder
+from kivy.core.window import Window
 
 class KvApp(App):
     def _print_fps(self, *largs):
         print 'FPS: %2.4f (real draw: %d)' % (
             Clock.get_fps(), Clock.get_rfps())
+
+    def _reload_keypress(self, instance, code, *largs):
+        if code != 286:
+            return
+        for child in Window.children[:]:
+            Window.remove_widget(child)
+        root = Builder.load_file(self.options['filename'])
+        Window.add_widget(root)
+
     def build(self):
         Clock.schedule_interval(self._print_fps, 1)
+        Window.bind(on_keyboard=self._reload_keypress)
         return Builder.load_file(self.options['filename'])
 
 if __name__ == '__main__':