timeline: Better handle loading inconsistent timelines

Auto transition when having 3 overlapping clips in a same point in the
timeline is not supported as we can't handle it in a nice way. Before we
to avoid creating 2 overlapping transitions (which is plain broken in
NLE) were completely disabling `auto-transition` and removing all
auto-transitions in the timeline but this is pretty weird for the end
user. This commit changes and now makes sure 2 transitions are not
created in the same place.

Also cleanup previous test case.

ges/ges-timeline.c

@@ -959,8 +959,18 @@ _create_auto_transition_from_transitions (GESTimeline * timeline,
       _find_transition_from_auto_transitions (timeline, layer, track, prev,
       next, transition_duration);
 
-  if (auto_transition)
+
+  if (auto_transition) {
+    if (timeline->priv->needs_rollback) {
+      GST_WARNING_OBJECT (timeline,
+          "Created an auto transition where we have 3 overlapping clips"
+          " removing it as this case is NOT allowed nor supported");
+      g_signal_emit_by_name (auto_transition, "destroy-me");
+      timeline->priv->needs_rollback = FALSE;
+      return NULL;
+    }
     return auto_transition;
+  }
 
 
   /* Try to find a transition that perfectly fits with the one that
@@ -2343,28 +2353,6 @@ layer_auto_transition_changed_cb (GESLayer * layer,
     }
   }
   g_list_free_full (clips, gst_object_unref);
-
-  if (timeline->priv->needs_rollback) {
-    GList *tmp, *trans;
-
-    ges_layer_set_auto_transition (layer, FALSE);
-    GST_ERROR_OBJECT (layer, "Has overlapping transition, "
-        " we can't handle that, setting auto_transition"
-        " to FALSE, and removing all transitions");
-    trans = g_list_copy (timeline->priv->auto_transitions);
-    for (tmp = trans; tmp; tmp = tmp->next) {
-      g_signal_emit_by_name (tmp->data, "destroy-me");
-    }
-
-    g_list_free (trans);
-
-    trans = ges_layer_get_clips (layer);
-    for (tmp = trans; tmp; tmp = tmp->next) {
-      if (GES_IS_TRANSITION_CLIP (tmp->data))
-        ges_layer_remove_clip (layer, tmp->data);
-    }
-    g_list_free_full (trans, gst_object_unref);
-  }
 }
 
 static void

tests/check/python/common.py

@@ -26,6 +26,8 @@ gi.require_version("GES", "1.0")
 from gi.repository import Gst  # noqa
 from gi.repository import GES  # noqa
 from gi.repository import GLib  # noqa
+import contextlib  # noqa
+import os  #noqa
 import unittest  # noqa
 import tempfile  # noqa
 
@@ -82,6 +84,23 @@ def create_project(with_group=False, saved=False):
     return timeline
 
 
+@contextlib.contextmanager
+def created_project_file(xges):
+    _, xges_path = tempfile.mkstemp(suffix=".xges")
+    with open(xges_path, "w") as f:
+        f.write(xges)
+
+    yield Gst.filename_to_uri(os.path.abspath(xges_path))
+
+    os.remove(xges_path)
+
+
+def get_asset_uri(name):
+    python_tests_dir = os.path.dirname(os.path.abspath(__file__))
+    assets_dir = os.path.join(python_tests_dir, "..", "assets")
+    return Gst.filename_to_uri(os.path.join(assets_dir, name))
+
+
 class GESTest(unittest.TestCase):
 
     def _log(self, func, format, *args):

tests/check/python/test_timeline.py

@@ -29,9 +29,7 @@ from gi.repository import GES  # noqa
 import unittest  # noqa
 from unittest import mock
 
-from .common import create_main_loop
+from . import common  # noqa
-from .common import create_project
-from .common import GESSimpleTimelineTest  # noqa
 
 Gst.init(None)
 GES.init()
@@ -40,8 +38,8 @@ GES.init()
 class TestTimeline(unittest.TestCase):
 
     def test_signals_not_emitted_when_loading(self):
-        mainloop = create_main_loop()
+        mainloop = common.create_main_loop()
-        timeline = create_project(with_group=True, saved=True)
+        timeline = common.create_project(with_group=True, saved=True)
 
         # Reload the project, check the group.
         project = GES.Project.new(uri=timeline.get_asset().props.uri)
@@ -66,7 +64,7 @@ class TestTimeline(unittest.TestCase):
         handle.assert_not_called()
 
 
-class TestSplitting(GESSimpleTimelineTest):
+class TestSplitting(common.GESSimpleTimelineTest):
     def setUp(self):
         self.track_types = [GES.TrackType.AUDIO]
         super(TestSplitting, self).setUp()
@@ -118,7 +116,7 @@ class TestSplitting(GESSimpleTimelineTest):
         ])
 
 
-class TestEditing(GESSimpleTimelineTest):
+class TestEditing(common.GESSimpleTimelineTest):
 
     def test_transition_disappears_when_moving_to_another_layer(self):
         self.timeline.props.auto_transition = True
@@ -176,7 +174,7 @@ class TestEditing(GESSimpleTimelineTest):
         self.assertEquals(len(self.layer.get_clips()), 4)
 
 
-class TestSnapping(GESSimpleTimelineTest):
+class TestSnapping(common.GESSimpleTimelineTest):
 
     def test_snapping(self):
         self.timeline.props.auto_transition = True
@@ -216,7 +214,7 @@ class TestSnapping(GESSimpleTimelineTest):
         self.assertEqual(clip1.props.duration, split_position)
         self.assertEqual(clip2.props.start, split_position)
 
-class TestTransitions(GESSimpleTimelineTest):
+class TestTransitions(common.GESSimpleTimelineTest):
 
     def test_emission_order_for_transition_clip_added_signal(self):
         self.timeline.props.auto_transition = True
@@ -245,6 +243,75 @@ class TestTransitions(GESSimpleTimelineTest):
         self.assertEqual(
             signals, ["notify::start", "clip-added", "clip-added"])
 
+    def create_xges(self):
+        uri = common.get_asset_uri("png.png")
+        return """<ges version='0.4'>
+  <project properties='properties;' metadatas='metadatas, author=(string)&quot;&quot;, render-scale=(double)100, format-version=(string)0.4;'>
+    <ressources>
+      <asset id='GESTitleClip' extractable-type-name='GESTitleClip' properties='properties;' metadatas='metadatas;' />
+      <asset id='bar-wipe-lr' extractable-type-name='GESTransitionClip' properties='properties;' metadatas='metadatas, description=(string)GES_VIDEO_STANDARD_TRANSITION_TYPE_BAR_WIPE_LR;' />
+      <asset id='%(uri)s' extractable-type-name='GESUriClip' properties='properties, supported-formats=(int)4, duration=(guint64)18446744073709551615;' metadatas='metadatas, video-codec=(string)PNG, file-size=(guint64)73294;' />
+      <asset id='crossfade' extractable-type-name='GESTransitionClip' properties='properties;' metadatas='metadatas, description=(string)GES_VIDEO_STANDARD_TRANSITION_TYPE_CROSSFADE;' />
+    </ressources>
+    <timeline properties='properties, auto-transition=(boolean)true, snapping-distance=(guint64)31710871;' metadatas='metadatas, duration=(guint64)13929667032;'>
+      <track caps='video/x-raw(ANY)' track-type='4' track-id='0' properties='properties, async-handling=(boolean)false, message-forward=(boolean)true, caps=(string)&quot;video/x-raw\(ANY\)&quot;, restriction-caps=(string)&quot;video/x-raw\,\ width\=\(int\)1920\,\ height\=\(int\)1080\,\ framerate\=\(fraction\)30/1&quot;, mixing=(boolean)true;' metadatas='metadatas;'/>
+      <track caps='audio/x-raw(ANY)' track-type='2' track-id='1' properties='properties, async-handling=(boolean)false, message-forward=(boolean)true, caps=(string)&quot;audio/x-raw\(ANY\)&quot;, restriction-caps=(string)&quot;audio/x-raw\,\ format\=\(string\)S32LE\,\ channels\=\(int\)2\,\ rate\=\(int\)44100\,\ layout\=\(string\)interleaved&quot;, mixing=(boolean)true;' metadatas='metadatas;'/>
+      <layer priority='0' properties='properties, auto-transition=(boolean)true;' metadatas='metadatas, volume=(float)1;'>
+        <clip id='0' asset-id='%(uri)s' type-name='GESUriClip' layer-priority='0' track-types='6' start='0' duration='4558919302' inpoint='0' rate='0' properties='properties, name=(string)uriclip25263, mute=(boolean)false, is-image=(boolean)false;' />
+        <clip id='1' asset-id='bar-wipe-lr' type-name='GESTransitionClip' layer-priority='0' track-types='4' start='3225722559' duration='1333196743' inpoint='0' rate='0' properties='properties, name=(string)transitionclip84;'  children-properties='properties, GESVideoTransition::border=(uint)0, GESVideoTransition::invert=(boolean)false;'/>
+        <clip id='2' asset-id='%(uri)s' type-name='GESUriClip' layer-priority='0' track-types='6' start='3225722559' duration='3479110239' inpoint='4558919302' rate='0' properties='properties, name=(string)uriclip25265, mute=(boolean)false, is-image=(boolean)false;' />
+      </layer>
+      <layer priority='1' properties='properties, auto-transition=(boolean)true;' metadatas='metadatas, volume=(float)1;'>
+        <clip id='3' asset-id='%(uri)s' type-name='GESUriClip' layer-priority='1' track-types='4' start='8566459322' duration='1684610449' inpoint='0' rate='0' properties='properties, name=(string)uriclip25266, mute=(boolean)false, is-image=(boolean)true;' />
+        <clip id='4' asset-id='GESTitleClip' type-name='GESTitleClip' layer-priority='1' track-types='6' start='8566459322' duration='4500940746' inpoint='0' rate='0' properties='properties, name=(string)titleclip69;' />
+        <clip id='5' asset-id='%(uri)s' type-name='GESUriClip' layer-priority='1' track-types='4' start='9566459322' duration='4363207710' inpoint='0' rate='0' properties='properties, name=(string)uriclip25275, mute=(boolean)false, is-image=(boolean)true;' />
+      </layer>
+      <groups>
+      </groups>
+    </timeline>
+</project>
+</ges>""" % {"uri": uri}
+
+    def test_auto_transition(self):
+        xges = self.create_xges()
+        with common.created_project_file(xges) as proj_uri:
+            project = GES.Project.new(proj_uri)
+            timeline = project.extract()
+
+            mainloop = common.create_main_loop()
+            mainloop.run(until_empty=True)
+
+            layers = timeline.get_layers()
+            self.assertEqual(len(layers), 2)
+
+            self.assertTrue(layers[0].props.auto_transition)
+            self.assertTrue(layers[1].props.auto_transition)
+
+    def test_transition_type(self):
+        xges = self.create_xges()
+        with common.created_project_file(xges) as proj_uri:
+            project = GES.Project.new(proj_uri)
+            timeline = project.extract()
+
+            mainloop = common.create_main_loop()
+            mainloop.run(until_empty=True)
+
+            layers = timeline.get_layers()
+            self.assertEqual(len(layers), 2)
+
+            clips = layers[0].get_clips()
+            clip1 = clips[0]
+            clip2 = clips[-1]
+            # There should be a transition because clip1 intersects clip2
+            self.assertLess(clip1.props.start, clip2.props.start)
+            self.assertLess(clip2.props.start, clip1.props.start + clip1.props.duration)
+            self.assertLess(clip1.props.start + clip1.props.duration, clip2.props.start + clip2.props.duration)
+            self.assertEqual(len(clips), 3)
+
+            # Even though 3 clips overlap 1 transition will be created
+            clips = layers[1].get_clips()
+            self.assertEqual(len(clips), 4)
+
 
 class TestPriorities(GESSimpleTimelineTest):
 
@@ -257,4 +324,4 @@ class TestPriorities(GESSimpleTimelineTest):
 
         clip.props.start = 101
         self.timeline.commit()
-        self.assertGreater(clip.props.priority, clip1.props.priority)
+        self.assertGreater(clip.props.priority, clip1.props.priority)