From 2e595563482c0953e2212cc8ddcc65f5e7291030 Mon Sep 17 00:00:00 2001
From: regulus79 <117475203+regulus79@users.noreply.github.com>
Date: Thu, 28 Nov 2024 11:40:34 -0500
Subject: [PATCH 1/3] Add midi reversing

---
 include/PianoRoll.h           |  1 +
 src/gui/editors/PianoRoll.cpp | 30 ++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/include/PianoRoll.h b/include/PianoRoll.h
index a85e50a163b..1280bc44638 100644
--- a/include/PianoRoll.h
+++ b/include/PianoRoll.h
@@ -246,6 +246,7 @@ protected slots:
 	void clearGhostClip();
 	void glueNotes();
 	void fitNoteLengths(bool fill);
+	void reverseNotes();
 	void constrainNoteLengths(bool constrainMax);
 
 	void changeSnapMode();
diff --git a/src/gui/editors/PianoRoll.cpp b/src/gui/editors/PianoRoll.cpp
index a2d7c832aaa..b01f595431c 100644
--- a/src/gui/editors/PianoRoll.cpp
+++ b/src/gui/editors/PianoRoll.cpp
@@ -788,6 +788,31 @@ void PianoRoll::constrainNoteLengths(bool constrainMax)
 	Engine::getSong()->setModified();
 }
 
+void PianoRoll::reverseNotes()
+{
+	if (!hasValidMidiClip()) { return; }
+	m_midiClip->addJournalCheckPoint();
+
+	const NoteVector selectedNotes = getSelectedNotes();
+	const auto& notes = selectedNotes.empty() ? m_midiClip->notes() : selectedNotes;
+	const auto firstNote = notes.front();
+	const auto lastNote = notes.back();
+	const TimePos firstPos = firstNote->pos();
+	const TimePos lastPos = lastNote->endPos();
+
+	for (auto note : notes)
+	{
+		TimePos oldStart = note->pos();
+		TimePos newEnd = lastPos - (oldStart - firstPos);
+		TimePos newStart = newEnd - note->length();
+		note->setPos(newStart);
+	}
+
+	update();
+	getGUI()->songEditor()->update();
+	Engine::getSong()->setModified();
+}
+
 
 void PianoRoll::loadMarkedSemiTones(const QDomElement & de)
 {
@@ -4869,12 +4894,17 @@ PianoRollWindow::PianoRollWindow() :
 	auto maxLengthAction = new QAction(embed::getIconPixmap("max_length"), tr("Max length as last"), noteToolsButton);
 	connect(maxLengthAction, &QAction::triggered, [this](){ m_editor->constrainNoteLengths(true); });
 
+	auto reverseAction = new QAction(embed::getIconPixmap("back_to_start"), tr("Reverse Notes"), noteToolsButton);
+	connect(reverseAction, &QAction::triggered, [this](){ m_editor->reverseNotes(); });
+	reverseAction->setShortcut(combine(Qt::SHIFT, Qt::Key_R));
+
 	noteToolsButton->addAction(glueAction);
 	noteToolsButton->addAction(knifeAction);
 	noteToolsButton->addAction(fillAction);
 	noteToolsButton->addAction(cutOverlapsAction);
 	noteToolsButton->addAction(minLengthAction);
 	noteToolsButton->addAction(maxLengthAction);
+	noteToolsButton->addAction(reverseAction);
 
 	notesActionsToolBar->addWidget(noteToolsButton);
 

From 42838f6d833120c58edd51dbc45bcdc911d829ef Mon Sep 17 00:00:00 2001
From: regulus79 <117475203+regulus79@users.noreply.github.com>
Date: Thu, 28 Nov 2024 11:57:01 -0500
Subject: [PATCH 2/3] Fix bugs

---
 src/gui/editors/PianoRoll.cpp | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/gui/editors/PianoRoll.cpp b/src/gui/editors/PianoRoll.cpp
index b01f595431c..5941c9d0580 100644
--- a/src/gui/editors/PianoRoll.cpp
+++ b/src/gui/editors/PianoRoll.cpp
@@ -795,10 +795,15 @@ void PianoRoll::reverseNotes()
 
 	const NoteVector selectedNotes = getSelectedNotes();
 	const auto& notes = selectedNotes.empty() ? m_midiClip->notes() : selectedNotes;
-	const auto firstNote = notes.front();
-	const auto lastNote = notes.back();
-	const TimePos firstPos = firstNote->pos();
-	const TimePos lastPos = lastNote->endPos();
+
+	TimePos firstPos = notes.front()->pos();
+	TimePos lastPos = notes.back()->endPos();
+	// Find the actual min/max positions
+	for (auto note : notes)
+	{
+		if (note->pos() < firstPos) { firstPos = note->pos(); }
+		if (note->endPos() > lastPos) { lastPos = note->endPos(); }
+	}
 
 	for (auto note : notes)
 	{
@@ -807,6 +812,9 @@ void PianoRoll::reverseNotes()
 		TimePos newStart = newEnd - note->length();
 		note->setPos(newStart);
 	}
+	
+	m_midiClip->rearrangeAllNotes();
+	m_midiClip->dataChanged();
 
 	update();
 	getGUI()->songEditor()->update();

From 276643b5103e2d3d8596f4686d3b3640f66e0f80 Mon Sep 17 00:00:00 2001
From: regulus79 <117475203+regulus79@users.noreply.github.com>
Date: Thu, 28 Nov 2024 14:18:39 -0500
Subject: [PATCH 3/3] Put calculation of new pos on single line

Co-authored-by: szeli1 <143485814+szeli1@users.noreply.github.com>
---
 src/gui/editors/PianoRoll.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/gui/editors/PianoRoll.cpp b/src/gui/editors/PianoRoll.cpp
index 5941c9d0580..da2c8b89093 100644
--- a/src/gui/editors/PianoRoll.cpp
+++ b/src/gui/editors/PianoRoll.cpp
@@ -808,8 +808,7 @@ void PianoRoll::reverseNotes()
 	for (auto note : notes)
 	{
 		TimePos oldStart = note->pos();
-		TimePos newEnd = lastPos - (oldStart - firstPos);
-		TimePos newStart = newEnd - note->length();
+		TimePos newStart = lastPos - (oldStart - firstPos) - note->length();
 		note->setPos(newStart);
 	}