Resource callbacks

Author: einarf

demosys/effects/effect.py

@@ -76,6 +76,16 @@ class Effect:
     _ctx = None  # type: moderngl.Context
     _sys_camera = None  # type: camera.SystemCamera
 
+    def __init__(self, *args, **kwargs):
+        self.on_resouces_loaded(self.post_load)
+
+    def post_load(self):
+        """
+        Called when all resources are loaded before effects start running.
+        This assumes you have called Effect.__init__()
+        """
+        pass
+
     @property
     def name(self) -> str:
         """Full python path to the effect"""
@@ -205,6 +215,28 @@ def get_data(self, path, local=False, **kwargs) -> Data:
         """
         return resources.data.get(path, create=True, **kwargs)
 
+    # Register callbacks
+
+    def on_resouces_loaded(self, func):
+        """Register callback function when all resources are loaded"""
+        resources.on_loaded(func)
+
+    def on_shaders_loaded(self, func):
+        """Register callback function when shaders are loaded"""
+        resources.shaders.on_loaded(func)
+
+    def on_textures_loaded(self, func):
+        """Register callback function when textures are loaded"""
+        resources.textures.on_loaded(func)
+
+    def on_scenes_loaded(self, func):
+        """Register callback function when scenes are loaded"""
+        resources.scenes.on_loaded(func)
+
+    def on_data_loaded(self, func):
+        """Register callback function when data files are loaded"""
+        resources.data.on_loaded(func)
+
     # Utility methods for matrices
 
     def create_projection(self, fov=75.0, near=1.0, far=100.0, ratio=None):

demosys/resources/__init__.py

@@ -5,6 +5,20 @@
 from .data import data
 from .data import Data  # noqa
 
+ON_LOAD_FUNCS = []
+
+__all__ = [
+    'shaders',
+    'textures',
+    'tracks',
+    'scenes',
+    'data',
+    'Data',
+    'load',
+    'count',
+    'on_loaded',
+]
+
 
 def load():
     scenes.load()
@@ -13,6 +27,13 @@ def load():
     tracks.load()
     data.load()
 
+    for func in ON_LOAD_FUNCS:
+        func()
+
 
 def count():
     return shaders.count + textures.count
+
+
+def on_loaded(func):
+    ON_LOAD_FUNCS.append(func)

demosys/resources/base.py

@@ -0,0 +1,21 @@
+"""
+Base registry class
+"""
+
+
+class BaseRegistry:
+    """
+    Base registry class providing callback functionality
+    for each registry type.
+    """
+
+    def __init__(self):
+        self._on_loaded_funcs = []
+
+    def on_loaded(self, func):
+        """Register functions to call when all data is loaded"""
+        self._on_loaded_funcs.append(func)
+
+    def _on_loaded(self):
+        for func in self._on_loaded_funcs:
+            func()

demosys/resources/data.py

@@ -3,6 +3,7 @@
 """
 from demosys.core.exceptions import ImproperlyConfigured
 from demosys.core.datafiles.finders import get_finders
+from .base import BaseRegistry
 
 
 class Data:
@@ -45,9 +46,10 @@ def _get_load_funcs(self):
                 if attr.startswith("load_")}
 
 
-class DataFiles:
+class DataFiles(BaseRegistry):
     """Registry for requested data files"""
     def __init__(self):
+        super().__init__()
         self.files = []
         self.file_map = {}
 
@@ -89,5 +91,7 @@ def load(self):
             else:
                 raise ImproperlyConfigured("Cannot find data file {}".format(name))
 
+        self._on_loaded()
+
 
 data = DataFiles()

demosys/resources/scenes.py

@@ -5,13 +5,16 @@
 from demosys.scene import Scene
 from demosys.utils.module_loading import import_string
 
+from .base import BaseRegistry
 
-class Scenes:
+
+class Scenes(BaseRegistry):
     """
     A registry for scense requested by effects.
     Once all effects are initialized, we ask this class to load the scenes.
     """
     def __init__(self):
+        super().__init__()
         self.scenes = {}
 
     @property
@@ -54,5 +57,7 @@ def load(self):
             else:
                 raise ImproperlyConfigured("Cannot find scene {}".format(name))
 
+        self._on_loaded()
+
 
 scenes = Scenes()

demosys/resources/shaders.py

@@ -4,13 +4,16 @@
 from demosys.core.shaderfiles.finders import get_finders
 from demosys.opengl import ShaderError, ShaderProgram
 
+from .base import BaseRegistry
 
-class Shaders:
+
+class Shaders(BaseRegistry):
     """
     A registry for shaders requested by effects.
     Once all effects are initialized, we ask this class to load the shaders.
     """
     def __init__(self):
+        super().__init__()
         self.shaders = {}
 
     @property
@@ -46,6 +49,8 @@ def load(self, reload=False):
         for name, shader in self.shaders.items():
             self.load_shader(shader, name=name, reload=reload)
 
+        self._on_loaded()
+
     def load_shader(self, shader, name=None, reload=False):
         """
         Loads a single shader adding it to the shader registry

demosys/resources/textures.py

@@ -6,13 +6,16 @@
 from demosys.core.texturefiles.finders import get_finders
 from demosys.opengl import Texture2D, TextureArray
 
+from .base import BaseRegistry
 
-class Textures:
+
+class Textures(BaseRegistry):
     """
     A registry for textures requested by effects.
     Once all effects are initialized, we ask this class to load the textures.
     """
     def __init__(self):
+        super().__init__()
         self.textures = {}
 
     @property
@@ -56,5 +59,7 @@ def load(self):
             else:
                 raise ImproperlyConfigured("Cannot find texture {}".format(name))
 
+        self._on_loaded()
+
 
 textures = Textures()

docs/source/reference/effect.rst

@@ -21,6 +21,16 @@ Resource Methods
 .. automethod:: Effect.get_scene(path, local=False, **kwargs) -> Scene
 .. automethod:: Effect.get_data(path, local=False, **kwargs) -> Data
 
+Callbacks
+---------
+
+.. automethod:: Effect.post_load()
+.. automethod:: Effect.on_resouces_loaded(func)
+.. automethod:: Effect.on_textures_loaded(func)
+.. automethod:: Effect.on_data_loaded(func)
+.. automethod:: Effect.on_shaders_loaded(func)
+.. automethod:: Effect.on_scenes_loaded(func)
+
 Utility Methods
 ---------------