From fecce7c33360d5e3dd0e788c587dde412bb20e3f Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Fri, 28 May 2021 12:35:30 -0600
Subject: [PATCH] libardour: initial implementation of Playlist::remove_gaps()

This is probably a little naive and may need extending to cover cross-track scenarios
---
 libs/ardour/ardour/playlist.h |  3 ++-
 libs/ardour/playlist.cc       | 46 +++++++++++++++++++++++++++++++++--
 2 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/libs/ardour/ardour/playlist.h b/libs/ardour/ardour/playlist.h
index 64b3576568..26a8a3523a 100644
--- a/libs/ardour/ardour/playlist.h
+++ b/libs/ardour/ardour/playlist.h
@@ -163,6 +163,7 @@ public:
 	void duplicate_ranges (std::list<AudioRange>&, float times);
 	void nudge_after (samplepos_t start, samplecnt_t distance, bool forwards);
 	void fade_range (std::list<AudioRange>&);
+	void remove_gaps (samplepos_t gap_threshold, samplepos_t leave_gap);
 
 	boost::shared_ptr<Region> combine (const RegionList&);
 	void                      uncombine (boost::shared_ptr<Region>);
@@ -405,7 +406,7 @@ protected:
 	void splice_unlocked (samplepos_t at, samplecnt_t distance, boost::shared_ptr<Region> exclude, ThawList& thawlist);
 
 	void ripple_locked (samplepos_t at, samplecnt_t distance, RegionList* exclude);
-	void ripple_unlocked (samplepos_t at, samplecnt_t distance, RegionList* exclude, ThawList& thawlist);
+	void ripple_unlocked (samplepos_t at, samplecnt_t distance, RegionList* exclude, ThawList& thawlist, bool notify = true);
 
 	virtual void remove_dependents (boost::shared_ptr<Region> /*region*/) {}
 	virtual void region_going_away (boost::weak_ptr<Region> /*region*/) {}
diff --git a/libs/ardour/playlist.cc b/libs/ardour/playlist.cc
index 7863b0df68..a6c5988d29 100644
--- a/libs/ardour/playlist.cc
+++ b/libs/ardour/playlist.cc
@@ -883,6 +883,45 @@ Playlist::remove_region_internal (boost::shared_ptr<Region> region, ThawList& th
 	return -1;
 }
 
+void
+Playlist::remove_gaps (samplepos_t gap_threshold, samplepos_t leave_gap)
+{
+	RegionWriteLock rlock (this);
+	RegionList::iterator i;
+	RegionList::iterator nxt (regions.end());
+	bool closed = false;
+
+	if (regions.size() < 2) {
+		return;
+	}
+
+	for (i = regions.begin(); i != regions.end(); ++i) {
+
+		nxt = i;
+		++nxt;
+
+		if (nxt == regions.end()) {
+			break;
+		}
+
+		const samplepos_t gap = (*nxt)->position() - ((*i)->position() + (*i)->length());
+
+		if (gap < gap_threshold) {
+			continue;
+		}
+
+		const samplepos_t shift = gap - leave_gap;
+
+		ripple_unlocked ((*nxt)->position(), -shift, 0, rlock.thawlist, false);
+
+		closed = true;
+	}
+
+	if (closed) {
+		notify_contents_changed ();
+	}
+}
+
 void
 Playlist::get_equivalent_regions (boost::shared_ptr<Region> other, vector<boost::shared_ptr<Region> >& results)
 {
@@ -1645,7 +1684,7 @@ Playlist::ripple_locked (samplepos_t at, samplecnt_t distance, RegionList* exclu
 }
 
 void
-Playlist::ripple_unlocked (samplepos_t at, samplecnt_t distance, RegionList* exclude, ThawList& thawlist)
+Playlist::ripple_unlocked (samplepos_t at, samplecnt_t distance, RegionList* exclude, ThawList& thawlist, bool notify)
 {
 	if (distance == 0) {
 		return;
@@ -1677,7 +1716,10 @@ Playlist::ripple_unlocked (samplepos_t at, samplecnt_t distance, RegionList* exc
 	}
 
 	_rippling = false;
-	notify_contents_changed ();
+
+	if (notify) {
+		notify_contents_changed ();
+	}
 }
 
 void