diff --git a/gtk2_ardour/audio_trigger_properties_box.cc b/gtk2_ardour/audio_trigger_properties_box.cc
index e2aab4b56e..a72e70e17a 100644
--- a/gtk2_ardour/audio_trigger_properties_box.cc
+++ b/gtk2_ardour/audio_trigger_properties_box.cc
@@ -44,35 +44,6 @@ using namespace ArdourWidgets;
 using std::max;
 using std::min;
 
-void
-TriggerPropertiesBox::set_trigger (TriggerReference tr)
-{
-	tref = tr;
-	tref.trigger()->PropertyChanged.connect (_state_connection, invalidator (*this), boost::bind (&TriggerPropertiesBox::trigger_changed, this, _1), gui_context ());
-	tref.box->TriggerSwapped.connect (trigger_swap_connection, MISSING_INVALIDATOR, boost::bind (&TriggerPropertiesBox::trigger_swap, this, _1), gui_context ());
-
-	PBD::PropertyChange changed;
-	changed.add (ARDOUR::Properties::name);
-	changed.add (ARDOUR::Properties::running);
-	trigger_changed (changed);
-}
-
-void
-TriggerPropertiesBox::trigger_swap (uint32_t n)
-{
-	if (n != tref.slot) {
-		/* some other slot in the same box got swapped. we don't care */
-		return;
-	}
-	_state_connection.disconnect ();
-	tref.trigger()->PropertyChanged.connect (_state_connection, invalidator (*this), boost::bind (&TriggerPropertiesBox::trigger_changed, this, _1), gui_context ());
-
-	PBD::PropertyChange changed;
-	changed.add (ARDOUR::Properties::name);
-	changed.add (ARDOUR::Properties::running);
-	trigger_changed (changed);
-}
-
 AudioTriggerPropertiesBox::AudioTriggerPropertiesBox ()
 	: _length_clock (X_("regionlength"), true, "", true, false, true)
 	, _start_clock (X_("regionstart"), true, "", false, false)
@@ -220,19 +191,7 @@ AudioTriggerPropertiesBox::set_session (Session* s)
 }
 
 void
-AudioTriggerPropertiesBox::set_trigger (ARDOUR::TriggerReference tr)
-{
-	boost::shared_ptr<ARDOUR::AudioTrigger> audio_trigger = boost::dynamic_pointer_cast<ARDOUR::AudioTrigger> (tr.trigger());
-
-	if (!audio_trigger) {
-		return;
-	}
-
-	TriggerPropertiesBox::set_trigger (tr);
-}
-
-void
-AudioTriggerPropertiesBox::trigger_changed (const PBD::PropertyChange& what_changed)
+AudioTriggerPropertiesBox::on_trigger_changed (const PBD::PropertyChange& what_changed)
 {
 	TriggerPtr trigger (tref.trigger());
 
diff --git a/gtk2_ardour/audio_trigger_properties_box.h b/gtk2_ardour/audio_trigger_properties_box.h
index d41aeb68a4..f218106dcc 100644
--- a/gtk2_ardour/audio_trigger_properties_box.h
+++ b/gtk2_ardour/audio_trigger_properties_box.h
@@ -31,24 +31,18 @@
 #include "widgets/ardour_button.h"
 
 #include "audio_clock.h"
+#include "trigger_ui.h"
 
-class TriggerPropertiesBox : public Gtk::VBox, public ARDOUR::SessionHandlePtr
+class TriggerPropertiesBox : public Gtk::VBox, public ARDOUR::SessionHandlePtr, public TriggerUI
 {
 public:
 	TriggerPropertiesBox () {}
 	~TriggerPropertiesBox () {}
 
-	virtual void set_trigger (ARDOUR::TriggerReference) = 0;
-
 protected:
-	ARDOUR::TriggerReference tref;
 	Gtk::Label _header_label;
 
-	virtual void trigger_changed (const PBD::PropertyChange& what_changed) = 0;
-	void trigger_swap (uint32_t);
-
 	PBD::ScopedConnection _state_connection;
-	PBD::ScopedConnection trigger_swap_connection;
 };
 
 class AudioTriggerPropertiesBox : public TriggerPropertiesBox
@@ -57,13 +51,12 @@ public:
 	AudioTriggerPropertiesBox ();
 	~AudioTriggerPropertiesBox ();
 
-	void set_trigger (ARDOUR::TriggerReference);
-
 	void set_session (ARDOUR::Session*);
 
 protected:
+	virtual void on_trigger_changed (const PBD::PropertyChange& what_changed);
+
 	void toggle_stretch ();
-	void trigger_changed (const PBD::PropertyChange& what_changed);
 
 	void start_clock_changed();
 	void length_clock_changed();
diff --git a/gtk2_ardour/midi_trigger_properties_box.cc b/gtk2_ardour/midi_trigger_properties_box.cc
index af10a098db..5643e800ab 100644
--- a/gtk2_ardour/midi_trigger_properties_box.cc
+++ b/gtk2_ardour/midi_trigger_properties_box.cc
@@ -79,19 +79,7 @@ MidiTriggerPropertiesBox::~MidiTriggerPropertiesBox ()
 }
 
 void
-MidiTriggerPropertiesBox::set_trigger (ARDOUR::TriggerReference tr)
-{
-	boost::shared_ptr<ARDOUR::MIDITrigger> midi_trigger = boost::dynamic_pointer_cast<ARDOUR::MIDITrigger> (tr.trigger());
-
-	if (!midi_trigger) {
-		return;
-	}
-
-	TriggerPropertiesBox::set_trigger (tr);
-}
-
-void
-MidiTriggerPropertiesBox::trigger_changed (const PBD::PropertyChange& what_changed)
+MidiTriggerPropertiesBox::on_trigger_changed (const PBD::PropertyChange& what_changed)
 {
 	/* CC and Pgm stuff ...? */
 }
diff --git a/gtk2_ardour/midi_trigger_properties_box.h b/gtk2_ardour/midi_trigger_properties_box.h
index caaa35bce3..62850a1452 100644
--- a/gtk2_ardour/midi_trigger_properties_box.h
+++ b/gtk2_ardour/midi_trigger_properties_box.h
@@ -33,10 +33,8 @@ public:
 	MidiTriggerPropertiesBox ();
 	~MidiTriggerPropertiesBox ();
 
-	void set_trigger (ARDOUR::TriggerReference);
-
 protected:
-	void trigger_changed (const PBD::PropertyChange& what_changed);
+	virtual void on_trigger_changed (const PBD::PropertyChange& what_changed);
 
 private:
 	ArdourWidgets::ArdourButton _patch_enable_button;