[pitivi] viewer: Allow using gtksink when gtkglsink is not accessible

[Thibault Saunier <tsaunier src gnome org>]

commit 43d22f14481f9cb16ffed8e852f484c8f8288a44
Author: Thibault Saunier <tsaunier gnome org>
Date:   Sat Sep 19 10:40:51 2015 +0200

    viewer: Allow using gtksink when gtkglsink is not accessible
    
    Fixes T3305

 pitivi/check.py          |   14 ++++++++++++++
 pitivi/utils/pipeline.py |   38 +++++++++++++++++++++++++++++++++++++-
 pitivi/viewer.py         |    8 +++++---
 3 files changed, 56 insertions(+), 4 deletions(-)
---
diff --git a/pitivi/check.py b/pitivi/check.py
index 6548aae..ea6e8e6 100644
--- a/pitivi/check.py
+++ b/pitivi/check.py
@@ -195,6 +195,15 @@ def _check_audiosinks():
     return True
 
 
+def _check_videosink():
+    from gi.repository import Gst
+    # Yes, this can still fail, if PulseAudio is non-responsive for example.
+    if not Gst.ElementFactory.make("gtkglsink", None):
+        if not Gst.ElementFactory.make("gtksink", None):
+            return False
+    return True
+
+
 def _check_gst_python():
     from gi.repository import Gst
     try:
@@ -246,6 +255,11 @@ def check_requirements():
                  "Make sure you have a valid one (pulsesink, alsasink or osssink).")))
         return False
 
+    if not _check_videosink():
+        print((_("Could not create video output sink. "
+                 "Make sure you have a gtksink avalaible.")))
+        return False
+
     return True
 
 
diff --git a/pitivi/utils/pipeline.py b/pitivi/utils/pipeline.py
index c74f4cf..4022d46 100644
--- a/pitivi/utils/pipeline.py
+++ b/pitivi/utils/pipeline.py
@@ -27,6 +27,7 @@ High-level pipelines
 import os
 
 
+from gi.repository import Gdk
 from gi.repository import GLib
 from gi.repository import GObject
 from gi.repository import Gst
@@ -168,6 +169,8 @@ class SimplePipeline(GObject.Object, Loggable):
 
     __gsignals__ = PIPELINE_SIGNALS
 
+    use_glsink = None
+
     class RecoveryState(object):
         NOT_RECOVERING = "not-recovering"
         STARTED_RECOVERING = "started-recovering"
@@ -193,9 +196,42 @@ class SimplePipeline(GObject.Object, Loggable):
         self._timeout_async_id = 0
         self._force_position_listener = False
 
+        self.setSink(self.createSink())
+
+    def __canUseGlSink(self):
+        if SimplePipeline.use_glsink is not None:
+            return SimplePipeline.use_glsink
+
+        try:
+            if GObject.type_is_a(Gdk.Display.get_default().__gtype__,
+                                 GObject.type_from_name("GdkBroadwayDisplay")):
+                SimplePipeline.use_glsink = False
+
+                return SimplePipeline.use_glsink
+        except RuntimeError:
+            # GdkBroadwayDisplay not available
+            pass
+
+        glsink = Gst.ElementFactory.make("gtkglsink", None)
+        if glsink:
+            if glsink.set_state(Gst.State.READY) == Gst.StateChangeReturn.SUCCESS:
+                SimplePipeline.use_glsink = True
+            else:
+                SimplePipeline.use_glsink = False
+            glsink.set_state(Gst.State.NULL)
+        else:
+            SimplePipeline.use_glsink = False
+
+        return SimplePipeline.use_glsink
+
+    def createSink(self):
+        if not self.__canUseGlSink():
+            self.info("Using gtksink")
+            return Gst.ElementFactory.make("gtksink", None)
+
         sink = Gst.ElementFactory.make("glsinkbin", None)
         sink.props.sink = Gst.ElementFactory.make("gtkglsink", None)
-        self.setSink(sink)
+        return sink
 
     def setSink(self, sink):
         self.video_sink = sink
diff --git a/pitivi/viewer.py b/pitivi/viewer.py
index 1c05269..aa816a8 100644
--- a/pitivi/viewer.py
+++ b/pitivi/viewer.py
@@ -135,8 +135,7 @@ class ViewerContainer(Gtk.Box, Loggable):
         self.pipeline.pause()
 
     def __createNewViewer(self):
-        self.sink = Gst.ElementFactory.make("glsinkbin", None)
-        self.sink.props.sink = Gst.ElementFactory.make("gtkglsink", None)
+        self.sink = self.pipeline.createSink()
         self.pipeline.setSink(self.sink)
 
         self.target = ViewerWidget(self.sink, self.app)
@@ -598,7 +597,10 @@ class ViewerWidget(Gtk.AspectFrame, Loggable):
         self.__transformationBox = TransformationBox(app)
 
         # We only work with a gtkglsink inside a glsinkbin
-        self.drawing_area = sink.props.sink.props.widget
+        try:
+            self.drawing_area = sink.props.sink.props.widget
+        except AttributeError:
+            self.drawing_area = sink.props.widget
 
         # We keep the ViewerWidget hidden initially, or the desktop wallpaper
         # would show through the non-double-buffered widget!