From 8baaa7eb66988d7a062e6efad1905a16fe4173b1 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Tue, 17 Sep 2024 10:55:11 -0600
Subject: [PATCH] TriggerReference requires some sort of lifetime tracking

For now we use std::weak_ptr and std::enable_shared_from_this to accomplish tracking. There
may be an argument for using our own (PBD::Destructible) mechanisms instead.
---
 libs/ardour/ardour/triggerbox.h | 20 +++++++++++++-------
 libs/ardour/triggerbox.cc       |  7 +++++++
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/libs/ardour/ardour/triggerbox.h b/libs/ardour/ardour/triggerbox.h
index 5b6c4a2b74..6a5b9d0933 100644
--- a/libs/ardour/ardour/triggerbox.h
+++ b/libs/ardour/ardour/triggerbox.h
@@ -23,6 +23,7 @@
 
 #include <atomic>
 #include <map>
+#include <memory>
 #include <vector>
 #include <string>
 #include <exception>
@@ -375,6 +376,7 @@ class LIBARDOUR_API Trigger : public PBD::Stateful {
 	void* ui () const { return _ui; }
 
 	TriggerBox& box() const { return _box; }
+	std::shared_ptr<TriggerBox> boxptr() const;
 
 	double estimated_tempo() const { return _estimated_tempo; }
 
@@ -731,7 +733,7 @@ struct CueRecord {
 
 typedef PBD::RingBuffer<CueRecord> CueRecords;
 
-class LIBARDOUR_API TriggerBox : public Processor
+class LIBARDOUR_API TriggerBox : public Processor, public std::enable_shared_from_this<TriggerBox>
 {
   public:
 
@@ -979,14 +981,18 @@ class LIBARDOUR_API TriggerBox : public Processor
 
 class TriggerReference
 {
-public:
-	TriggerReference () : box (0), slot (0) {}
-	TriggerReference (ARDOUR::TriggerBox& b, uint32_t s) : box (&b), slot (s) {}
+ public:
+	TriggerReference () : _slot (0) {}
+	TriggerReference (std::shared_ptr<ARDOUR::TriggerBox> b, uint32_t s) : weak_box (b), _slot (s) {}
 
-	std::shared_ptr<ARDOUR::Trigger> trigger() const { assert (box); return box->trigger (slot); }
+	std::shared_ptr<ARDOUR::Trigger> trigger() const { std::shared_ptr<ARDOUR::TriggerBox> box (weak_box.lock()); return box ? box->trigger (_slot) : std::shared_ptr<ARDOUR::Trigger>(); }
+	void set (std::shared_ptr<ARDOUR::TriggerBox> b, uint32_t s) { weak_box = b; _slot = s; }
+	uint32_t slot() const { return _slot; }
+	std::shared_ptr<ARDOUR::TriggerBox> box() const { return weak_box.lock(); }
 
-	ARDOUR::TriggerBox* box;
-	uint32_t            slot;
+ private:
+	std::weak_ptr<ARDOUR::TriggerBox> weak_box;
+	uint32_t              _slot;
 };
 
 namespace Properties {
diff --git a/libs/ardour/triggerbox.cc b/libs/ardour/triggerbox.cc
index 4746229749..273e130699 100644
--- a/libs/ardour/triggerbox.cc
+++ b/libs/ardour/triggerbox.cc
@@ -268,6 +268,12 @@ Trigger::Trigger (uint32_t n, TriggerBox& b)
 	copy_to_ui_state ();
 }
 
+std::shared_ptr<TriggerBox>
+Trigger::boxptr() const
+{
+	return _box.shared_from_this();
+}
+
 void
 Trigger::request_trigger_delete (Trigger* t)
 {
@@ -5133,3 +5139,4 @@ TriggerBoxThread::delete_trigger (Trigger* t)
 {
 	delete t;
 }
+