Use enum class for Film::Property.

15 files changed, 125 insertions, 109 deletions

diff --git a/src/lib/audio_content.cc b/src/lib/audio_content.cc
index c70afcda4..4f5fd8748 100644
--- a/src/lib/audio_content.cc
+++ b/src/lib/audio_content.cc
@@ -146,7 +146,7 @@ AudioContent::technical_summary () const
 void
 AudioContent::set_mapping (AudioMapping mapping)
 {
-	ChangeSignaller<Content> cc (_parent, AudioContentProperty::STREAMS);
+	ContentChangeSignaller cc (_parent, AudioContentProperty::STREAMS);
 
 	int c = 0;
 	for (auto i: streams()) {
@@ -328,7 +328,7 @@ AudioContent::add_properties (shared_ptr<const Film> film, list<UserProperty>& p
 void
 AudioContent::set_streams (vector<AudioStreamPtr> streams)
 {
-	ChangeSignaller<Content> cc (_parent, AudioContentProperty::STREAMS);
+	ContentChangeSignaller cc (_parent, AudioContentProperty::STREAMS);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -347,7 +347,7 @@ AudioContent::stream () const
 void
 AudioContent::add_stream (AudioStreamPtr stream)
 {
-	ChangeSignaller<Content> cc (_parent, AudioContentProperty::STREAMS);
+	ContentChangeSignaller cc (_parent, AudioContentProperty::STREAMS);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -358,7 +358,7 @@ AudioContent::add_stream (AudioStreamPtr stream)
 void
 AudioContent::set_stream (AudioStreamPtr stream)
 {
-	ChangeSignaller<Content> cc (_parent, AudioContentProperty::STREAMS);
+	ContentChangeSignaller cc (_parent, AudioContentProperty::STREAMS);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
diff --git a/src/lib/butler.h b/src/lib/butler.h
index 49a57a826..8c7f554cb 100644
--- a/src/lib/butler.h
+++ b/src/lib/butler.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2016-2017 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2016-2021 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -18,15 +18,16 @@
 
 */
 
-#include "video_ring_buffers.h"
-#include "audio_ring_buffers.h"
-#include "text_ring_buffers.h"
 #include "audio_mapping.h"
+#include "audio_ring_buffers.h"
+#include "change_signaller.h"
 #include "exception_store.h"
+#include "text_ring_buffers.h"
+#include "video_ring_buffers.h"
+#include <boost/asio.hpp>
+#include <boost/signals2.hpp>
 #include <boost/thread.hpp>
 #include <boost/thread/condition.hpp>
-#include <boost/signals2.hpp>
-#include <boost/asio.hpp>
 
 class Player;
 class PlayerVideo;
diff --git a/src/lib/change_signaller.h b/src/lib/change_signaller.h
index 55a5f2dc5..74965fc3e 100644
--- a/src/lib/change_signaller.h
+++ b/src/lib/change_signaller.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2018 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2018-2021 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -18,16 +18,24 @@
 
 */
 
+
 #ifndef DCPOMATIC_CHANGE_SIGNALLER_H
 #define DCPOMATIC_CHANGE_SIGNALLER_H
 
-#include <boost/noncopyable.hpp>
 
-template <class T>
-class ChangeSignaller : public boost::noncopyable
+enum class ChangeType
+{
+	PENDING,
+	DONE,
+	CANCELLED
+};
+
+
+template <class T, class P>
+class ChangeSignaller
 {
 public:
-	ChangeSignaller (T* t, int p)
+	ChangeSignaller (T* t, P p)
 		: _thing (t)
 		, _property (p)
 		, _done (true)
@@ -44,6 +52,9 @@ public:
 		}
 	}
 
+	ChangeSignaller (ChangeSignaller const&) = delete;
+	ChangeSignaller& operator== (ChangeSignaller const&) = delete;
+
 	void abort ()
 	{
 		_done = false;
@@ -51,8 +62,9 @@ public:
 
 private:
 	T* _thing;
-	int _property;
+	P _property;
 	bool _done;
 };
 
+
 #endif
diff --git a/src/lib/content.cc b/src/lib/content.cc
index 40790bdc0..0171563ae 100644
--- a/src/lib/content.cc
+++ b/src/lib/content.cc
@@ -229,7 +229,7 @@ Content::set_position (shared_ptr<const Film> film, DCPTime p, bool force_emit)
 		audio->modify_position (film, p);
 	}
 
-	ChangeSignaller<Content> cc (this, ContentProperty::POSITION);
+	ContentChangeSignaller cc (this, ContentProperty::POSITION);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -256,7 +256,7 @@ Content::set_trim_start (ContentTime t)
 		audio->modify_trim_start (t);
 	}
 
-	ChangeSignaller<Content> cc (this, ContentProperty::TRIM_START);
+	ContentChangeSignaller cc (this, ContentProperty::TRIM_START);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -267,7 +267,7 @@ Content::set_trim_start (ContentTime t)
 void
 Content::set_trim_end (ContentTime t)
 {
-	ChangeSignaller<Content> cc (this, ContentProperty::TRIM_END);
+	ContentChangeSignaller cc (this, ContentProperty::TRIM_END);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -338,7 +338,7 @@ Content::paths_valid () const
 void
 Content::set_paths (vector<boost::filesystem::path> paths)
 {
-	ChangeSignaller<Content> cc (this, ContentProperty::PATH);
+	ContentChangeSignaller cc (this, ContentProperty::PATH);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -389,7 +389,7 @@ Content::reel_split_points (shared_ptr<const Film>) const
 void
 Content::set_video_frame_rate (double r)
 {
-	ChangeSignaller<Content> cc (this, ContentProperty::VIDEO_FRAME_RATE);
+	ContentChangeSignaller cc (this, ContentProperty::VIDEO_FRAME_RATE);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -408,7 +408,7 @@ Content::set_video_frame_rate (double r)
 void
 Content::unset_video_frame_rate ()
 {
-	ChangeSignaller<Content> cc (this, ContentProperty::VIDEO_FRAME_RATE);
+	ContentChangeSignaller cc (this, ContentProperty::VIDEO_FRAME_RATE);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
diff --git a/src/lib/content.h b/src/lib/content.h
index 8a28762d3..eafadd3ec 100644
--- a/src/lib/content.h
+++ b/src/lib/content.h
@@ -212,7 +212,7 @@ private:
 	friend struct best_dcp_frame_rate_test_single;
 	friend struct best_dcp_frame_rate_test_double;
 	friend struct audio_sampling_rate_test;
-	template<class> friend class ChangeSignaller;
+	template<class, class> friend class ChangeSignaller;
 
 	void signal_change (ChangeType, int);
 
@@ -232,4 +232,8 @@ private:
 	bool _change_signals_frequent;
 };
 
+
+typedef ChangeSignaller<Content, int> ContentChangeSignaller;
+
+
 #endif
diff --git a/src/lib/content_part.h b/src/lib/content_part.h
index a81334270..443c356b1 100644
--- a/src/lib/content_part.h
+++ b/src/lib/content_part.h
@@ -41,7 +41,7 @@ protected:
 	void
 	maybe_set (T& member, T new_value, int property) const
 	{
-		ChangeSignaller<Content> cc (_parent, property);
+		ContentChangeSignaller cc (_parent, property);
 		{
 			boost::mutex::scoped_lock lm (_mutex);
 			if (member == new_value) {
@@ -56,7 +56,7 @@ protected:
 	void
 	maybe_set (boost::optional<T>& member, T new_value, int property) const
 	{
-		ChangeSignaller<Content> cc (_parent, property);
+		ContentChangeSignaller cc (_parent, property);
 		{
 			boost::mutex::scoped_lock lm (_mutex);
 			if (member && member.get() == new_value) {
diff --git a/src/lib/dcp_content.cc b/src/lib/dcp_content.cc
index 4bd718e96..156a1a205 100644
--- a/src/lib/dcp_content.cc
+++ b/src/lib/dcp_content.cc
@@ -219,10 +219,10 @@ DCPContent::examine (shared_ptr<const Film> film, shared_ptr<Job> job)
 	bool const needed_kdm = needs_kdm ();
 	string const old_name = name ();
 
-	ChangeSignaller<Content> cc_texts (this, DCPContentProperty::TEXTS);
-	ChangeSignaller<Content> cc_assets (this, DCPContentProperty::NEEDS_ASSETS);
-	ChangeSignaller<Content> cc_kdm (this, DCPContentProperty::NEEDS_KDM);
-	ChangeSignaller<Content> cc_name (this, DCPContentProperty::NAME);
+	ContentChangeSignaller cc_texts (this, DCPContentProperty::TEXTS);
+	ContentChangeSignaller cc_assets (this, DCPContentProperty::NEEDS_ASSETS);
+	ContentChangeSignaller cc_kdm (this, DCPContentProperty::NEEDS_KDM);
+	ContentChangeSignaller cc_name (this, DCPContentProperty::NAME);
 
 	if (job) {
 		job->set_progress_unknown ();
@@ -509,7 +509,7 @@ DCPContent::set_default_colour_conversion ()
 void
 DCPContent::set_reference_video (bool r)
 {
-	ChangeSignaller<Content> cc (this, DCPContentProperty::REFERENCE_VIDEO);
+	ContentChangeSignaller cc (this, DCPContentProperty::REFERENCE_VIDEO);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -520,7 +520,7 @@ DCPContent::set_reference_video (bool r)
 void
 DCPContent::set_reference_audio (bool r)
 {
-	ChangeSignaller<Content> cc (this, DCPContentProperty::REFERENCE_AUDIO);
+	ContentChangeSignaller cc (this, DCPContentProperty::REFERENCE_AUDIO);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -531,7 +531,7 @@ DCPContent::set_reference_audio (bool r)
 void
 DCPContent::set_reference_text (TextType type, bool r)
 {
-	ChangeSignaller<Content> cc (this, DCPContentProperty::REFERENCE_TEXT);
+	ContentChangeSignaller cc (this, DCPContentProperty::REFERENCE_TEXT);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -788,7 +788,7 @@ DCPContent::take_settings_from (shared_ptr<const Content> c)
 void
 DCPContent::set_cpl (string id)
 {
-	ChangeSignaller<Content> cc (this, DCPContentProperty::CPL);
+	ContentChangeSignaller cc (this, DCPContentProperty::CPL);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
diff --git a/src/lib/ffmpeg_content.cc b/src/lib/ffmpeg_content.cc
index 7f1c75a93..b1bb632b1 100644
--- a/src/lib/ffmpeg_content.cc
+++ b/src/lib/ffmpeg_content.cc
@@ -248,8 +248,8 @@ FFmpegContent::as_xml (xmlpp::Node* node, bool with_paths) const
 void
 FFmpegContent::examine (shared_ptr<const Film> film, shared_ptr<Job> job)
 {
-	ChangeSignaller<Content> cc1 (this, FFmpegContentProperty::SUBTITLE_STREAMS);
-	ChangeSignaller<Content> cc2 (this, FFmpegContentProperty::SUBTITLE_STREAM);
+	ContentChangeSignaller cc1 (this, FFmpegContentProperty::SUBTITLE_STREAMS);
+	ContentChangeSignaller cc2 (this, FFmpegContentProperty::SUBTITLE_STREAM);
 
 	if (job) {
 		job->set_progress_unknown ();
@@ -375,7 +375,7 @@ FFmpegContent::technical_summary () const
 void
 FFmpegContent::set_subtitle_stream (shared_ptr<FFmpegSubtitleStream> s)
 {
-	ChangeSignaller<Content> cc (this, FFmpegContentProperty::SUBTITLE_STREAM);
+	ContentChangeSignaller cc (this, FFmpegContentProperty::SUBTITLE_STREAM);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -436,7 +436,7 @@ FFmpegContent::approximate_length () const
 void
 FFmpegContent::set_filters (vector<Filter const *> const & filters)
 {
-	ChangeSignaller<Content> cc (this, FFmpegContentProperty::FILTERS);
+	ContentChangeSignaller cc (this, FFmpegContentProperty::FILTERS);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);
@@ -658,7 +658,7 @@ void
 FFmpegContent::signal_subtitle_stream_changed ()
 {
 	/* XXX: this is too late; really it should be before the change */
-	ChangeSignaller<Content> cc (this, FFmpegContentProperty::SUBTITLE_STREAM);
+	ContentChangeSignaller cc (this, FFmpegContentProperty::SUBTITLE_STREAM);
 }
 
 vector<shared_ptr<FFmpegAudioStream> >
diff --git a/src/lib/film.cc b/src/lib/film.cc
index 193dedf4c..772024902 100644
--- a/src/lib/film.cc
+++ b/src/lib/film.cc
@@ -1034,21 +1034,21 @@ Film::set_directory (boost::filesystem::path d)
 void
 Film::set_name (string n)
 {
-	ChangeSignaller<Film> ch (this, NAME);
+	FilmChangeSignaller ch (this, Property::NAME);
 	_name = n;
 }
 
 void
 Film::set_use_isdcf_name (bool u)
 {
-	ChangeSignaller<Film> ch (this, USE_ISDCF_NAME);
+	FilmChangeSignaller ch (this, Property::USE_ISDCF_NAME);
 	_use_isdcf_name = u;
 }
 
 void
 Film::set_dcp_content_type (DCPContentType const * t)
 {
-	ChangeSignaller<Film> ch (this, DCP_CONTENT_TYPE);
+	FilmChangeSignaller ch (this, Property::DCP_CONTENT_TYPE);
 	_dcp_content_type = t;
 }
 
@@ -1060,7 +1060,7 @@ Film::set_dcp_content_type (DCPContentType const * t)
 void
 Film::set_container (Ratio const * c, bool explicit_user)
 {
-	ChangeSignaller<Film> ch (this, CONTAINER);
+	FilmChangeSignaller ch (this, Property::CONTAINER);
 	_container = c;
 
 	if (explicit_user) {
@@ -1076,7 +1076,7 @@ Film::set_container (Ratio const * c, bool explicit_user)
 void
 Film::set_resolution (Resolution r, bool explicit_user)
 {
-	ChangeSignaller<Film> ch (this, RESOLUTION);
+	FilmChangeSignaller ch (this, Property::RESOLUTION);
 	_resolution = r;
 
 	if (explicit_user) {
@@ -1088,14 +1088,14 @@ Film::set_resolution (Resolution r, bool explicit_user)
 void
 Film::set_j2k_bandwidth (int b)
 {
-	ChangeSignaller<Film> ch (this, J2K_BANDWIDTH);
+	FilmChangeSignaller ch (this, Property::J2K_BANDWIDTH);
 	_j2k_bandwidth = b;
 }
 
 void
 Film::set_isdcf_metadata (ISDCFMetadata m)
 {
-	ChangeSignaller<Film> ch (this, ISDCF_METADATA);
+	FilmChangeSignaller ch (this, Property::ISDCF_METADATA);
 	_isdcf_metadata = m;
 }
 
@@ -1106,7 +1106,7 @@ Film::set_isdcf_metadata (ISDCFMetadata m)
 void
 Film::set_video_frame_rate (int f, bool user_explicit)
 {
-	ChangeSignaller<Film> ch (this, VIDEO_FRAME_RATE);
+	FilmChangeSignaller ch (this, Property::VIDEO_FRAME_RATE);
 	_video_frame_rate = f;
 	if (user_explicit) {
 		_user_explicit_video_frame_rate = true;
@@ -1116,18 +1116,18 @@ Film::set_video_frame_rate (int f, bool user_explicit)
 void
 Film::set_audio_channels (int c)
 {
-	ChangeSignaller<Film> ch (this, AUDIO_CHANNELS);
+	FilmChangeSignaller ch (this, Property::AUDIO_CHANNELS);
 	_audio_channels = c;
 }
 
 void
 Film::set_three_d (bool t)
 {
-	ChangeSignaller<Film> ch (this, THREE_D);
+	FilmChangeSignaller ch (this, Property::THREE_D);
 	_three_d = t;
 
 	if (_three_d && _isdcf_metadata.two_d_version_of_three_d) {
-		ChangeSignaller<Film> ch (this, ISDCF_METADATA);
+		FilmChangeSignaller ch (this, Property::ISDCF_METADATA);
 		_isdcf_metadata.two_d_version_of_three_d = false;
 	}
 }
@@ -1135,22 +1135,22 @@ Film::set_three_d (bool t)
 void
 Film::set_interop (bool i)
 {
-	ChangeSignaller<Film> ch (this, INTEROP);
+	FilmChangeSignaller ch (this, Property::INTEROP);
 	_interop = i;
 }
 
 void
 Film::set_audio_processor (AudioProcessor const * processor)
 {
-	ChangeSignaller<Film> ch1 (this, AUDIO_PROCESSOR);
-	ChangeSignaller<Film> ch2 (this, AUDIO_CHANNELS);
+	FilmChangeSignaller ch1 (this, Property::AUDIO_PROCESSOR);
+	FilmChangeSignaller ch2 (this, Property::AUDIO_CHANNELS);
 	_audio_processor = processor;
 }
 
 void
 Film::set_reel_type (ReelType t)
 {
-	ChangeSignaller<Film> ch (this, REEL_TYPE);
+	FilmChangeSignaller ch (this, Property::REEL_TYPE);
 	_reel_type = t;
 }
 
@@ -1158,14 +1158,14 @@ Film::set_reel_type (ReelType t)
 void
 Film::set_reel_length (int64_t r)
 {
-	ChangeSignaller<Film> ch (this, REEL_LENGTH);
+	FilmChangeSignaller ch (this, Property::REEL_LENGTH);
 	_reel_length = r;
 }
 
 void
 Film::set_reencode_j2k (bool r)
 {
-	ChangeSignaller<Film> ch (this, REENCODE_J2K);
+	FilmChangeSignaller ch (this, Property::REENCODE_J2K);
 	_reencode_j2k = r;
 }
 
@@ -1181,7 +1181,7 @@ Film::signal_change (ChangeType type, Property p)
 	if (type == ChangeType::DONE) {
 		_dirty = true;
 
-		if (p == Film::CONTENT) {
+		if (p == Property::CONTENT) {
 			if (!_user_explicit_video_frame_rate) {
 				set_video_frame_rate (best_video_frame_rate());
 			}
@@ -1189,7 +1189,7 @@ Film::signal_change (ChangeType type, Property p)
 
 		emit (boost::bind (boost::ref (Change), type, p));
 
-		if (p == Film::VIDEO_FRAME_RATE || p == Film::SEQUENCE) {
+		if (p == Property::VIDEO_FRAME_RATE || p == Property::SEQUENCE) {
 			/* We want to call Playlist::maybe_sequence but this must happen after the
 			   main signal emission (since the butler will see that emission and un-suspend itself).
 			*/
@@ -1275,7 +1275,7 @@ Film::cpls () const
 void
 Film::set_encrypted (bool e)
 {
-	ChangeSignaller<Film> ch (this, ENCRYPTED);
+	FilmChangeSignaller ch (this, Property::ENCRYPTED);
 	_encrypted = e;
 }
 
@@ -1444,9 +1444,9 @@ void
 Film::playlist_content_change (ChangeType type, weak_ptr<Content> c, int p, bool frequent)
 {
 	if (p == ContentProperty::VIDEO_FRAME_RATE) {
-		signal_change (type, Film::CONTENT);
+		signal_change (type, Property::CONTENT);
 	} else if (p == AudioContentProperty::STREAMS) {
-		signal_change (type, Film::NAME);
+		signal_change (type, Property::NAME);
 	}
 
 	if (type == ChangeType::DONE) {
@@ -1470,8 +1470,8 @@ Film::playlist_length_change ()
 void
 Film::playlist_change (ChangeType type)
 {
-	signal_change (type, CONTENT);
-	signal_change (type, NAME);
+	signal_change (type, Property::CONTENT);
+	signal_change (type, Property::NAME);
 
 	if (type == ChangeType::DONE) {
 		check_settings_consistency ();
@@ -1536,7 +1536,7 @@ void
 Film::playlist_order_changed ()
 {
 	/* XXX: missing PENDING */
-	signal_change (ChangeType::DONE, CONTENT_ORDER);
+	signal_change (ChangeType::DONE, Property::CONTENT_ORDER);
 }
 
 int
@@ -1555,7 +1555,7 @@ Film::set_sequence (bool s)
 		return;
 	}
 
-	ChangeSignaller<Film> cc (this, SEQUENCE);
+	FilmChangeSignaller cc (this, Property::SEQUENCE);
 	_sequence = s;
 	_playlist->set_sequence (s);
 }
@@ -1924,14 +1924,14 @@ Film::closed_caption_tracks () const
 void
 Film::set_marker (dcp::Marker type, DCPTime time)
 {
-	ChangeSignaller<Film> ch (this, MARKERS);
+	FilmChangeSignaller ch (this, Property::MARKERS);
 	_markers[type] = time;
 }
 
 void
 Film::unset_marker (dcp::Marker type)
 {
-	ChangeSignaller<Film> ch (this, MARKERS);
+	FilmChangeSignaller ch (this, Property::MARKERS);
 	_markers.erase (type);
 }
 
@@ -1939,7 +1939,7 @@ Film::unset_marker (dcp::Marker type)
 void
 Film::clear_markers ()
 {
-	ChangeSignaller<Film> ch (this, MARKERS);
+	FilmChangeSignaller ch (this, Property::MARKERS);
 	_markers.clear ();
 }
 
@@ -1947,14 +1947,14 @@ Film::clear_markers ()
 void
 Film::set_ratings (vector<dcp::Rating> r)
 {
-	ChangeSignaller<Film> ch (this, RATINGS);
+	FilmChangeSignaller ch (this, Property::RATINGS);
 	_ratings = r;
 }
 
 void
 Film::set_content_versions (vector<string> v)
 {
-	ChangeSignaller<Film> ch (this, CONTENT_VERSIONS);
+	FilmChangeSignaller ch (this, Property::CONTENT_VERSIONS);
 	_content_versions = v;
 }
 
@@ -1962,7 +1962,7 @@ Film::set_content_versions (vector<string> v)
 void
 Film::set_name_language (dcp::LanguageTag lang)
 {
-	ChangeSignaller<Film> ch (this, NAME_LANGUAGE);
+	FilmChangeSignaller ch (this, Property::NAME_LANGUAGE);
 	_name_language = lang;
 }
 
@@ -1970,7 +1970,7 @@ Film::set_name_language (dcp::LanguageTag lang)
 void
 Film::set_audio_language (dcp::LanguageTag lang)
 {
-	ChangeSignaller<Film> ch (this, AUDIO_LANGUAGE);
+	FilmChangeSignaller ch (this, Property::AUDIO_LANGUAGE);
 	_audio_language = lang;
 }
 
@@ -1978,7 +1978,7 @@ Film::set_audio_language (dcp::LanguageTag lang)
 void
 Film::set_release_territory (dcp::LanguageTag::RegionSubtag region)
 {
-	ChangeSignaller<Film> ch (this, RELEASE_TERRITORY);
+	FilmChangeSignaller ch (this, Property::RELEASE_TERRITORY);
 	_release_territory = region;
 }
 
@@ -1986,7 +1986,7 @@ Film::set_release_territory (dcp::LanguageTag::RegionSubtag region)
 void
 Film::set_status (dcp::Status s)
 {
-	ChangeSignaller<Film> ch (this, STATUS);
+	FilmChangeSignaller ch (this, Property::STATUS);
 	_status = s;
 }
 
@@ -1994,7 +1994,7 @@ Film::set_status (dcp::Status s)
 void
 Film::set_version_number (int v)
 {
-	ChangeSignaller<Film> ch (this, VERSION_NUMBER);
+	FilmChangeSignaller ch (this, Property::VERSION_NUMBER);
 	_version_number = v;
 }
 
@@ -2002,7 +2002,7 @@ Film::set_version_number (int v)
 void
 Film::set_chain (string c)
 {
-	ChangeSignaller<Film> ch (this, CHAIN);
+	FilmChangeSignaller ch (this, Property::CHAIN);
 	_chain = c;
 }
 
@@ -2010,7 +2010,7 @@ Film::set_chain (string c)
 void
 Film::set_distributor (string d)
 {
-	ChangeSignaller<Film> ch (this, DISTRIBUTOR);
+	FilmChangeSignaller ch (this, Property::DISTRIBUTOR);
 	_distributor = d;
 }
 
@@ -2018,7 +2018,7 @@ Film::set_distributor (string d)
 void
 Film::set_luminance (dcp::Luminance l)
 {
-	ChangeSignaller<Film> ch (this, LUMINANCE);
+	FilmChangeSignaller ch (this, Property::LUMINANCE);
 	_luminance = l;
 }
 
@@ -2033,7 +2033,7 @@ Film::set_subtitle_language (dcp::LanguageTag language)
 void
 Film::unset_subtitle_language ()
 {
-	ChangeSignaller<Film> ch (this, SUBTITLE_LANGUAGES);
+	FilmChangeSignaller ch (this, Property::SUBTITLE_LANGUAGES);
 	_subtitle_languages.clear();
 }
 
@@ -2041,7 +2041,7 @@ Film::unset_subtitle_language ()
 void
 Film::set_subtitle_languages (vector<dcp::LanguageTag> languages)
 {
-	ChangeSignaller<Film> ch (this, SUBTITLE_LANGUAGES);
+	FilmChangeSignaller ch (this, Property::SUBTITLE_LANGUAGES);
 	_subtitle_languages = languages;
 }
 
@@ -2049,7 +2049,7 @@ Film::set_subtitle_languages (vector<dcp::LanguageTag> languages)
 void
 Film::set_facility (string f)
 {
-	ChangeSignaller<Film> ch (this, FACILITY);
+	FilmChangeSignaller ch (this, Property::FACILITY);
 	_facility = f;
 }
 
diff --git a/src/lib/film.h b/src/lib/film.h
index 6828df21a..c354b646c 100644
--- a/src/lib/film.h
+++ b/src/lib/film.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012-2020 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2021 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -26,22 +26,23 @@
 #ifndef DCPOMATIC_FILM_H
 #define DCPOMATIC_FILM_H
 
-#include "util.h"
-#include "types.h"
-#include "isdcf_metadata.h"
+#include "change_signaller.h"
+#include "dcp_text_track.h"
 #include "frame_rate_change.h"
+#include "isdcf_metadata.h"
 #include "signaller.h"
-#include "dcp_text_track.h"
-#include <dcp/language_tag.h>
-#include <dcp/key.h>
+#include "types.h"
+#include "util.h"
 #include <dcp/encrypted_kdm.h>
+#include <dcp/key.h>
+#include <dcp/language_tag.h>
+#include <boost/filesystem.hpp>
 #include <boost/signals2.hpp>
 #include <boost/thread.hpp>
-#include <boost/filesystem.hpp>
 #include <boost/thread/mutex.hpp>
+#include <inttypes.h>
 #include <string>
 #include <vector>
-#include <inttypes.h>
 
 namespace xmlpp {
 	class Document;
@@ -201,7 +202,7 @@ public:
 	/** Identifiers for the parts of our state;
 	    used for signalling changes.
 	*/
-	enum Property {
+	enum class Property {
 		NONE,
 		NAME,
 		USE_ISDCF_NAME,
@@ -448,7 +449,7 @@ private:
 	friend struct ::isdcf_name_test;
 	friend struct ::recover_test_2d_encrypted;
 	friend struct ::atmos_encrypted_passthrough_test;
-	template <typename> friend class ChangeSignaller;
+	template <class, class> friend class ChangeSignaller;
 
 	boost::filesystem::path info_file (dcpomatic::DCPTimePeriod p) const;
 
@@ -555,4 +556,8 @@ private:
 	friend struct film_metadata_test;
 };
 
+
+typedef ChangeSignaller<Film, Film::Property> FilmChangeSignaller;
+
+
 #endif
diff --git a/src/lib/player.cc b/src/lib/player.cc
index 74e7480f5..b696f04c1 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -120,7 +120,7 @@ Player::construct ()
 	_playlist_content_change_connection = playlist()->ContentChange.connect (bind(&Player::playlist_content_change, this, _1, _3, _4));
 	set_video_container_size (_film->frame_size ());
 
-	film_change (ChangeType::DONE, Film::AUDIO_PROCESSOR);
+	film_change (ChangeType::DONE, Film::Property::AUDIO_PROCESSOR);
 
 	setup_pieces ();
 	seek (DCPTime (), true);
@@ -333,9 +333,9 @@ Player::film_change (ChangeType type, Film::Property p)
 	   last time we were run.
 	*/
 
-	if (p == Film::CONTAINER) {
+	if (p == Film::Property::CONTAINER) {
 		Change (type, PlayerProperty::FILM_CONTAINER, false);
-	} else if (p == Film::VIDEO_FRAME_RATE) {
+	} else if (p == Film::Property::VIDEO_FRAME_RATE) {
 		/* Pieces contain a FrameRateChange which contains the DCP frame rate,
 		   so we need new pieces here.
 		*/
@@ -343,12 +343,12 @@ Player::film_change (ChangeType type, Film::Property p)
 			setup_pieces ();
 		}
 		Change (type, PlayerProperty::FILM_VIDEO_FRAME_RATE, false);
-	} else if (p == Film::AUDIO_PROCESSOR) {
+	} else if (p == Film::Property::AUDIO_PROCESSOR) {
 		if (type == ChangeType::DONE && _film->audio_processor ()) {
 			boost::mutex::scoped_lock lm (_mutex);
 			_audio_processor = _film->audio_processor()->clone (_film->audio_frame_rate ());
 		}
-	} else if (p == Film::AUDIO_CHANNELS) {
+	} else if (p == Film::Property::AUDIO_CHANNELS) {
 		if (type == ChangeType::DONE) {
 			boost::mutex::scoped_lock lm (_mutex);
 			_audio_merger.clear ();
diff --git a/src/lib/playlist.h b/src/lib/playlist.h
index b49baa430..91f39bf6b 100644
--- a/src/lib/playlist.h
+++ b/src/lib/playlist.h
@@ -21,8 +21,9 @@
 #ifndef DCPOMATIC_PLAYLIST_H
 #define DCPOMATIC_PLAYLIST_H
 
-#include "util.h"
+#include "change_signaller.h"
 #include "frame_rate_change.h"
+#include "util.h"
 #include <libcxml/cxml.h>
 #include <boost/signals2.hpp>
 #include <boost/thread.hpp>
diff --git a/src/lib/text_content.cc b/src/lib/text_content.cc
index 79ac42f43..0c25e5696 100644
--- a/src/lib/text_content.cc
+++ b/src/lib/text_content.cc
@@ -430,7 +430,7 @@ void
 TextContent::font_changed ()
 {
 	/* XXX: too late */
-	ChangeSignaller<Content> cc (_parent, TextContentProperty::FONTS);
+	ContentChangeSignaller cc (_parent, TextContentProperty::FONTS);
 }
 
 void
diff --git a/src/lib/types.h b/src/lib/types.h
index 3cd8768e8..6fbad2188 100644
--- a/src/lib/types.h
+++ b/src/lib/types.h
@@ -131,13 +131,6 @@ enum class ReelType
 	BY_LENGTH
 };
 
-enum class ChangeType
-{
-	PENDING,
-	DONE,
-	CANCELLED
-};
-
 
 enum class VideoRange
 {
diff --git a/src/lib/video_content.cc b/src/lib/video_content.cc
index 216ad6784..fed28b5e4 100644
--- a/src/lib/video_content.cc
+++ b/src/lib/video_content.cc
@@ -284,10 +284,10 @@ VideoContent::take_from_examiner (shared_ptr<VideoExaminer> d)
 	auto const yuv = d->yuv ();
 	auto const range = d->range ();
 
-	ChangeSignaller<Content> cc1 (_parent, VideoContentProperty::SIZE);
-	ChangeSignaller<Content> cc2 (_parent, VideoContentProperty::SCALE);
-	ChangeSignaller<Content> cc3 (_parent, ContentProperty::LENGTH);
-	ChangeSignaller<Content> cc4 (_parent, VideoContentProperty::RANGE);
+	ContentChangeSignaller cc1 (_parent, VideoContentProperty::SIZE);
+	ContentChangeSignaller cc2 (_parent, VideoContentProperty::SCALE);
+	ContentChangeSignaller cc3 (_parent, ContentProperty::LENGTH);
+	ContentChangeSignaller cc4 (_parent, VideoContentProperty::RANGE);
 
 	{
 		boost::mutex::scoped_lock lm (_mutex);