Make screen a permanent object

pgzero/builtins.py

@@ -7,14 +7,16 @@
 from .keyboard import keyboard
 from .animation import animate
 from .rect import Rect, ZRect
-
 from .loaders import images, sounds
-
 from .constants import mouse, keys, keymods
-
 from .game import exit
 
+# The actual screen will be installed here
+from .screen import screen_instance as screen
+
+
 __all__ = [
+    'screen',  # graphics output
     'Actor', 'images',  # graphics
     'sounds', 'music', 'tone',  # sound
     'clock', 'animate',  # timing

pgzero/game.py

@@ -9,6 +9,7 @@
 import pgzero.keyboard
 import pgzero.screen
 import pgzero.loaders
+import pgzero.screen
 
 from . import constants
 
@@ -69,11 +70,7 @@ def reinit_screen(self):
         h = getattr(mod, 'HEIGHT', 600)
         if w != self.width or h != self.height:
             self.screen = pygame.display.set_mode((w, h), DISPLAY_FLAGS)
-            if hasattr(self.mod, 'screen'):
-                self.mod.screen.surface = self.screen
-            else:
-                screen = pgzero.screen.Screen(self.screen)
-                self.mod.screen = builtins.screen = screen
+            pgzero.screen.screen_instance._set_surface(self.screen)
             self.width = w
             self.height = h
 

pgzero/screen.py

@@ -94,8 +94,7 @@ def textbox(self, *args, **kwargs):
 
 class Screen:
     """Interface to the screen."""
-
-    def __init__(self, surface):
+    def _set_surface(self, surface):
         self.surface = surface
         self.width, self.height = surface.get_size()
 
@@ -148,3 +147,6 @@ def draw(self):
 
     def __repr__(self):
         return "<Screen width={} height={}>".format(self.width, self.height)
+
+
+screen_instance = Screen()