[pitivi] factories: add methods to get list of interpolated properties from factories based on stream

[Edward Hervey <edwardrv src gnome org>]

commit 14b3942bb33d557e169cf05eaa7db50e3e53b651
Author: Brandon Lewis <brandon_lewis berkeley edu>
Date:   Wed May 27 16:38:42 2009 -0700

    factories: add methods to get list of interpolated properties from factories based on stream

 pitivi/factories/base.py |    3 +++
 pitivi/factories/file.py |    8 ++++++++
 2 files changed, 11 insertions(+), 0 deletions(-)
---
diff --git a/pitivi/factories/base.py b/pitivi/factories/base.py
index 614816c..bcdc34a 100644
--- a/pitivi/factories/base.py
+++ b/pitivi/factories/base.py
@@ -190,6 +190,9 @@ class ObjectFactory(Signallable, Loggable):
     def __str__(self):
         return "<%s: %s>" % (self.__class__.__name__, self.name)
 
+    def getInterpolatedProperties(self, stream):
+        return {}
+
 class SourceFactory(ObjectFactory):
     """
     Base class for factories that produce output and have no input.
diff --git a/pitivi/factories/file.py b/pitivi/factories/file.py
index 4343452..5f8ed6a 100644
--- a/pitivi/factories/file.py
+++ b/pitivi/factories/file.py
@@ -42,6 +42,14 @@ class FileSourceFactory(RandomAccessSourceFactory):
         # FIXME: backward compatibility
         self.filename = uri
 
+    def getInterpolatedProperties(self, stream):
+        # FIXME: dummy implementation
+        props = RandomAccessSourceFactory.getInterpolatedProperties()
+        if isinstance(stream, AudioStream):
+            return props.update({"volume" : (float, 0.5)})
+        elif isinstance(stream, VideoStream):
+            return props.update({"alpha" : (float, 0.5))
+
 class PictureFileSourceFactory(FileSourceFactory):
     """
     Factory for image sources.