Sequence and movie FMovieSceneSequenceEditor

There are a few editor FMovieSceneSequenceEditor derived classes.

• FMovieSceneSequenceEditor_ActorSequence
• FMovieSceneSequenceEditor_WidgetAnimation
• FMovieSceneSequenceEditor_TemplateSequence
• FMovieSceneSequenceEditor_LevelSequence

They are all registered with ISequencerModule::RegisterSequenceEditor. Engine example:

ISequencerModule& SequencerModule = FModuleManager::LoadModuleChecked<ISequencerModule>("Sequencer");
SequenceEditorHandle = SequencerModule.RegisterSequenceEditor(ULevelSequence::StaticClass(), MakeUnique<FMovieSceneSequenceEditor_LevelSequence>());

The passed pair of editor and class is stored in SequenceEditors which is iterated in ISequencerModule::FindSequenceEditor.

The function was made in a way that allows you to add different custom FMovieSceneSequenceEditor for an sequence asset type.