From 89a7c390e617e965bdeef0cf5b637dd34560fc4f Mon Sep 17 00:00:00 2001
From: allejok96 <allejok96@gmail.com>
Date: Wed, 25 May 2022 16:38:49 +0200
Subject: [PATCH] Avoid update if nothing has changed

---
 include/Note.h                 | 2 +-
 src/core/Note.cpp              | 6 ++++--
 src/gui/clips/MidiClipView.cpp | 9 ++++++---
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/include/Note.h b/include/Note.h
index b528b89f7..c2644e197 100644
--- a/include/Note.h
+++ b/include/Note.h
@@ -250,7 +250,7 @@ class NoteVector: public QVector<Note*>
 {
 public:
 	bool getBounds(TimePos& start, TimePos& end, int& lower, int& upper) const;
-	void transpose(int semitones) const;
+	bool transpose(int semitones) const;
 };
 
 
diff --git a/src/core/Note.cpp b/src/core/Note.cpp
index b9ce91cf4..cb55c1a8b 100644
--- a/src/core/Note.cpp
+++ b/src/core/Note.cpp
@@ -278,13 +278,15 @@ bool NoteVector::getBounds(TimePos& start, TimePos& end, int& lower, int& upper)
  *  Notes will be hard-clipped to the MIDI note range. To prevent this use getBounds() prior to transposing.
  *
  *  \param semitones Semitones to transpose
+ *  \return bool True if notes were transposed
  */
-void NoteVector::transpose(int semitones) const
+bool NoteVector::transpose(int semitones) const
 {
-	if (empty() || !semitones) { return; }
+	if (empty() || !semitones) { return false; }
 
 	for (Note* note: *this)
 	{
 		note->setKey(note->key() + semitones);
 	}
+	return true;
 }
diff --git a/src/gui/clips/MidiClipView.cpp b/src/gui/clips/MidiClipView.cpp
index 9909525fe..eb26e5295 100644
--- a/src/gui/clips/MidiClipView.cpp
+++ b/src/gui/clips/MidiClipView.cpp
@@ -172,7 +172,7 @@ void MidiClipView::transposeSelection()
 	// Engine::getSong()->addJournalCheckPoint();
 
 	QSet<Track*> m_changedTracks;
-	for (ClipView* clipview: getClickedClips())
+	for (ClipView* clipview: selection)
 	{
 		if (auto mcv = dynamic_cast<MidiClipView*>(clipview))
 		{
@@ -183,10 +183,13 @@ void MidiClipView::transposeSelection()
 				m_changedTracks.insert(track);
 			}
 			auto clip = mcv->getMidiClip();
-			clip->notes().transpose(semitones);
-			emit clip->dataChanged();
+			if (clip->notes().transpose(semitones))
+			{
+				emit clip->dataChanged();
+			}
 		}
 	}
+	// At least one clip must have notes to show the transpose dialog, so something *has* changed
 	Engine::getSong()->setModified();
 }