Refactor Global Spacebar Play (#7926)

This PR simplifies #7762 by removing the editor-specific code from MainWindow and m_lastPlayMode from Song, and instead uses a static variable in Editor which keeps track of the last played editor.

This PR also removes the spacebar shortcut from MixerChannelView for changing the volume, as multiple users have noticed that it clashes with their intuition after getting used to the spacebar working everywhere else.

src/core/Song.cpp

@@ -499,7 +499,6 @@ void Song::playSong()
 	}
 
 	m_playMode = PlayMode::Song;
-	m_lastPlayMode = m_playMode;
 	m_playing = true;
 	m_paused = false;
 
@@ -539,7 +538,6 @@ void Song::playPattern()
 	}
 
 	m_playMode = PlayMode::Pattern;
-	m_lastPlayMode = m_playMode;
 	m_playing = true;
 	m_paused = false;
 
@@ -566,7 +564,6 @@ void Song::playMidiClip( const MidiClip* midiClipToPlay, bool loop )
 	if( m_midiClipToPlay != nullptr )
 	{
 		m_playMode = PlayMode::MidiClip;
-		m_lastPlayMode = m_playMode;
 		m_playing = true;
 		m_paused = false;
 	}

src/gui/MainWindow.cpp

@@ -1285,27 +1285,11 @@ void MainWindow::keyPressEvent( QKeyEvent * _ke )
 		case Qt::Key_Alt: m_keyMods.m_alt = true; break;
 		case Qt::Key_Space:
 		{
-			Editor* lastEditor = nullptr;
-			switch (Engine::getSong()->lastPlayMode())
+			if (Editor::lastPlayedEditor() != nullptr)
 			{
-			case Song::PlayMode::Song:
-				lastEditor = getGUI()->songEditor();
-				break;
-			case Song::PlayMode::MidiClip:
-				lastEditor = getGUI()->pianoRoll();
-				break;
-			case Song::PlayMode::Pattern:
-				lastEditor = getGUI()->patternEditor();
-				break;
-			case Song::PlayMode::AutomationClip:
-				lastEditor = getGUI()->automationEditor();
-				break;
-			default:
-				lastEditor = getGUI()->songEditor();
-				break;
+				if (m_keyMods.m_shift) { Editor::lastPlayedEditor()->togglePause(); }
+				else { Editor::lastPlayedEditor()->togglePlayStop(); }
 			}
-			if (m_keyMods.m_shift) { lastEditor->togglePause(); }
-			else { lastEditor->togglePlayStop(); }
 			break;
 		}
 		default:

src/gui/MixerChannelView.cpp

@@ -240,10 +240,6 @@ void MixerChannelView::keyPressEvent(QKeyEvent* ke)
 			renameFinished();
 		}
 	}
-	else if (ke->key() == Qt::Key_Space)
-	{
-		m_fader->adjustByDialog();
-	}
 	else
 	{
 		ke->ignore();

src/gui/editors/Editor.cpp

@@ -73,6 +73,7 @@ DropToolBar * Editor::addDropToolBar(QWidget * parent, Qt::ToolBarArea whereToAd
 
 void Editor::togglePlayStop()
 {
+	s_lastPlayedEditor = this;
 	if (Engine::getSong()->isPlaying())
 		stop();
 	else
@@ -81,6 +82,7 @@ void Editor::togglePlayStop()
 
 void Editor::togglePause()
 {
+	s_lastPlayedEditor = this;
 	Engine::getSong()->togglePause();
 }
 
@@ -118,7 +120,6 @@ Editor::Editor(bool record, bool stepRecord) :
 	connect(m_recordAccompanyAction, SIGNAL(triggered()), this, SLOT(recordAccompany()));
 	connect(m_toggleStepRecordingAction, SIGNAL(triggered()), this, SLOT(toggleStepRecording()));
 	connect(m_stopAction, SIGNAL(triggered()), this, SLOT(stop()));
-	new QShortcut(QKeySequence(combine(Qt::SHIFT, Qt::Key_Space)), this, SLOT(togglePause()));
 	new QShortcut(QKeySequence(combine(Qt::SHIFT, Qt::Key_F11)), this, SLOT(toggleMaximize()));
 
 	// Add actions to toolbar
@@ -158,7 +159,14 @@ void Editor::closeEvent(QCloseEvent * event)
  {
 	if (ke->key() == Qt::Key_Space)
 	{
-		togglePlayStop();
+		if (ke->modifiers() & Qt::ShiftModifier)
+		{
+			togglePause();
+		}
+		else
+		{
+			togglePlayStop();
+		}
 		return;
 	}
 	ke->ignore();