From 101744b81272817fe5025570eaf1625ac263cf33 Mon Sep 17 00:00:00 2001
From: Ben Loftis <ben@harrisonconsoles.com>
Date: Sun, 3 Sep 2023 14:17:08 -0500
Subject: [PATCH] Add method to find a section location by position

---
 libs/ardour/ardour/location.h |  5 +++++
 libs/ardour/location.cc       | 42 +++++++++++++++++++++++++++++------
 2 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/libs/ardour/ardour/location.h b/libs/ardour/ardour/location.h
index acfbc2cc79..8889ca39af 100644
--- a/libs/ardour/ardour/location.h
+++ b/libs/ardour/ardour/location.h
@@ -29,6 +29,7 @@
 #include <list>
 #include <iostream>
 #include <map>
+#include <vector>
 
 #include <sys/types.h>
 
@@ -246,6 +247,7 @@ class LIBARDOUR_API Locations : public SessionHandleRef, public PBD::StatefulDes
 {
 public:
 	typedef std::list<Location *> LocationList;
+	typedef std::pair<Temporal::timepos_t, Location*> LocationPair;
 
 	Locations (Session &);
 	~Locations ();
@@ -299,6 +301,7 @@ public:
 	timepos_t first_mark_after (timepos_t const &, bool include_special_ranges = false);
 
 	Location* next_section (Location*, timepos_t&, timepos_t&) const;
+	Location* section_at (timepos_t const&, timepos_t&, timepos_t&) const;
 
 	void marks_either_side (timepos_t const &, timepos_t &, timepos_t &) const;
 
@@ -343,6 +346,8 @@ public:
 	}
 
 private:
+	void sorted_section_locations (std::vector<LocationPair>&) const;
+
 	LocationList locations;
 	Location*    current_location;
 	mutable Glib::Threads::RWLock _lock;
diff --git a/libs/ardour/location.cc b/libs/ardour/location.cc
index b2faac7e9d..3b06c9b090 100644
--- a/libs/ardour/location.cc
+++ b/libs/ardour/location.cc
@@ -1370,18 +1370,16 @@ Locations::set_state (const XMLNode& node, int version)
 }
 
 
-typedef std::pair<timepos_t,Location*> LocationPair;
-
 struct LocationStartEarlierComparison
 {
-	bool operator() (LocationPair a, LocationPair b) {
+	bool operator() (Locations::LocationPair a, Locations::LocationPair b) {
 		return a.first < b.first;
 	}
 };
 
 struct LocationStartLaterComparison
 {
-	bool operator() (LocationPair a, LocationPair b) {
+	bool operator() (Locations::LocationPair a, Locations::LocationPair b) {
 		return a.first > b.first;
 	}
 };
@@ -1568,10 +1566,9 @@ Locations::marks_either_side (timepos_t const & pos, timepos_t& before, timepos_
 	before = *i;
 }
 
-Location*
-Locations::next_section (Location* l, timepos_t& start, timepos_t& end) const
+void
+Locations::sorted_section_locations (vector<LocationPair>& locs) const
 {
-	vector<LocationPair> locs;
 	{
 		Glib::Threads::RWLock::ReaderLock lm (_lock);
 
@@ -1586,6 +1583,13 @@ Locations::next_section (Location* l, timepos_t& start, timepos_t& end) const
 
 	LocationStartEarlierComparison cmp;
 	sort (locs.begin(), locs.end(), cmp);
+}
+
+Location*
+Locations::next_section (Location* l, timepos_t& start, timepos_t& end) const
+{
+	vector<LocationPair> locs;
+	sorted_section_locations (locs);
 
 	if (locs.size () < 2) {
 		return NULL;
@@ -1619,6 +1623,30 @@ Locations::next_section (Location* l, timepos_t& start, timepos_t& end) const
 	return NULL;
 }
 
+Location*
+Locations::section_at (timepos_t const& when, timepos_t& start, timepos_t& end) const
+{
+	vector<LocationPair> locs;
+	sorted_section_locations (locs);
+
+	if (locs.size () < 2) {
+		return NULL;
+	}
+
+	Location* rv = NULL;
+	for (auto const& i: locs) {
+		if (when >= i.first) {
+			start = i.first;
+			rv    = i.second;
+		} else {
+			end = i.first;
+			return rv;
+		}
+	}
+
+	return NULL;
+}
+
 Location*
 Locations::session_range_location () const
 {