Implement 1429 -- move to next and previous pattern

src/gui/editors/PianoRoll.cpp

@@ -967,6 +967,14 @@ void PianoRoll::keyPressEvent(QKeyEvent* ke )
 				int amt = quantized ? quantization() : 1;
 				shiftPos( -amt );
 			}
+			else if( ke->modifiers() & Qt::AltModifier)
+			{
+				Pattern * p = m_pattern->previousPattern();
+				if(p != NULL)
+				{
+					setCurrentPattern(p);
+				}
+			}
 			else
 			{
 				// scroll
@@ -1001,6 +1009,13 @@ void PianoRoll::keyPressEvent(QKeyEvent* ke )
 				int amt = quantized ? quantization() : 1;
 				shiftPos( +amt );
 			}
+			else if( ke->modifiers() & Qt::AltModifier) {
+				Pattern * p = m_pattern->nextPattern();
+				if(p != NULL)
+				{
+					setCurrentPattern(p);
+				}
+			}
 			else
 			{
 				// scroll

src/tracks/Pattern.cpp

@@ -434,6 +434,32 @@ void Pattern::loadSettings( const QDomElement & _this )
 
 
 
+Pattern *  Pattern::previousPattern() const
+{
+	return adjacentPatternByOffset(-1);
+}
+
+
+
+
+Pattern *  Pattern::nextPattern() const
+{
+	return adjacentPatternByOffset(1);
+}
+
+
+
+
+Pattern * Pattern::adjacentPatternByOffset(int offset) const
+{
+	QVector<TrackContentObject *> tcos = m_instrumentTrack->getTCOs();
+	int tcoNum = m_instrumentTrack->getTCONum(this);
+	return dynamic_cast<Pattern*>(tcos.value(tcoNum + offset, NULL));
+}
+
+
+
+
 void Pattern::clear()
 {
 	addJournalCheckPoint();