Implementation of next & previous instrument buttons in InstrumentTrackWindow

include/InstrumentTrack.h

@@ -52,6 +52,7 @@ class InstrumentMidiIOView;
 class InstrumentMiscView;
 class Knob;
 class LcdSpinBox;
+class LeftRightNav;
 class midiPortMenu;
 class DataFile;
 class PluginView;
@@ -416,16 +417,19 @@ protected:
 
 protected slots:
 	void saveSettingsBtnClicked();
-
+	void viewNextInstrument();
+	void viewPrevInstrument();
 
 private:
 	virtual void modelChanged();
+	void viewInstrumentInDirection(int d);
 
 	InstrumentTrack * m_track;
 	InstrumentTrackView * m_itv;
 
 	// widgets on the top of an instrument-track-window
 	QLineEdit * m_nameLineEdit;
+	LeftRightNav * m_leftRightNav;
 	Knob * m_volumeKnob;
 	Knob * m_panningKnob;
 	Knob * m_pitchKnob;

include/LeftRightNav.h

@@ -0,0 +1,49 @@
+/*
+ * LeftRightNav.cpp - side-by-side left-facing and right-facing arrows for navigation (looks like < > )
+ *
+ * Copyright (c) 2015 Colin Wallace <wallacoloo/at/gmail.com>
+ *
+ * This file is part of LMMS - http://lmms.io
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef LEFT_RIGHT_NAV_H
+#define LEFT_RIGHT_NAV_H
+
+#include "PixmapButton.h"
+
+#include <QLayout>
+
+class LeftRightNav : public QWidget
+{
+	Q_OBJECT
+public:
+	LeftRightNav(QWidget *parent=NULL);
+	PixmapButton* getLeftBtn();
+	PixmapButton* getRightBtn();
+	void setShortcuts(const QKeySequence &leftShortcut=Qt::Key_Minus, const QKeySequence &rightShortcut=Qt::Key_Plus);
+signals:
+	void onNavLeft();
+	void onNavRight();
+private:
+	QHBoxLayout m_layout;
+	PixmapButton m_leftBtn;
+	PixmapButton m_rightBtn;
+};
+
+#endif

include/PixmapButton.h

@@ -42,6 +42,7 @@ public:
 	void setActiveGraphic( const QPixmap & _pm );
 	void setInactiveGraphic( const QPixmap & _pm, bool _update = true );
 
+	QSize sizeHint() const;
 
 signals:
 	void doubleClicked();

include/TrackContainerView.h

@@ -111,6 +111,7 @@ public:
 	void moveTrackView( TrackView * trackView, int indexTo );
 	void moveTrackViewUp( TrackView * trackView );
 	void moveTrackViewDown( TrackView * trackView );
+	void scrollToTrackView( TrackView * _tv );
 
 	// -- for usage by trackView only ---------------
 	TrackView * addTrackView( TrackView * _tv );