Avoid update if nothing has changed

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;
 };
 
 

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;
 }

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();
 }