InstrumentTrackView: added one-window-mode + global piano focus

Added a one-window-mode which allows to have only one instrument track
window open at a time. The content of this window is replaced each time
you open a different track.

Furthermore added global reception and forwarding of key events to the
piano widget of the top-most instrument track window. This for example
enables the user to play test sounds while tweaking some effects in a
different subwindow.
(cherry picked from commit 93681760d2)

include/InstrumentTrack.h

@@ -2,7 +2,7 @@
  * InstrumentTrack.h - declaration of class InstrumentTrack, a track + window
  *                     which holds an instrument-plugin
  *
- * Copyright (c) 2004-2009 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ * Copyright (c) 2004-2010 Tobias Doerffel <tobydox/at/users.sourceforge.net>
  *
  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
  *
@@ -41,6 +41,7 @@
 
 class QLineEdit;
 template<class T> class QQueue;
+template<class T> class QStack;
 class ArpeggiatorView;
 class ChordCreatorView;
 class EffectRackView;
@@ -258,6 +259,10 @@ public:
 		return castModel<InstrumentTrack>();
 	}
 
+	static InstrumentTrackWindow * topLevelInstrumentTrackWindow()
+	{
+		return s_windowStack.isEmpty() ? NULL : s_windowStack.top();
+	}
 
 	QMenu * midiMenu()
 	{
@@ -266,7 +271,7 @@ public:
 
 	void freeInstrumentTrackWindow();
 
-	static void cleanupWindowPool();
+	static void cleanupWindowCache();
 
 
 protected:
@@ -287,7 +292,8 @@ private slots:
 private:
 	InstrumentTrackWindow * m_window;
 
-	static QQueue<InstrumentTrackWindow *> s_windows;
+	static QQueue<InstrumentTrackWindow *> s_windowCache;
+	static QStack<InstrumentTrackWindow *> s_windowStack;
 
 	// widgets in track-settings-widget
 	trackLabelButton * m_tlb;
@@ -334,9 +340,11 @@ public:
 		return castModel<InstrumentTrack>();
 	}
 
-	void setInstrumentTrackView( InstrumentTrackView * _tv )
+	void setInstrumentTrackView( InstrumentTrackView * _tv );
+
+	PianoView * pianoView()
 	{
-		m_itv = _tv;
+		return m_pianoView;
 	}
 
 	static void dragEnterEventGeneric( QDragEnterEvent * _dee );

include/PianoView.h

@@ -1,7 +1,7 @@
 /*
  * PianoView.h - declaration of PianoView, an interactive piano/keyboard-widget
  *
- * Copyright (c) 2004-2009 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ * Copyright (c) 2004-2010 Tobias Doerffel <tobydox/at/users.sourceforge.net>
  *
  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
  *
@@ -43,10 +43,13 @@ public:
 	static int getKeyFromKeyEvent( QKeyEvent * _ke );
 
 
-protected:
-	virtual void modelChanged();
+public:
 	virtual void keyPressEvent( QKeyEvent * ke );
 	virtual void keyReleaseEvent( QKeyEvent * ke );
+
+
+protected:
+	virtual void modelChanged();
 	virtual void contextMenuEvent( QContextMenuEvent * _me );
 	virtual void paintEvent( QPaintEvent * );
 	virtual void mousePressEvent( QMouseEvent * me );

include/setup_dialog.h

@@ -1,7 +1,7 @@
 /*
  * setup_dialog.h - dialog for setting up LMMS
  *
- * Copyright (c) 2005-2009 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ * Copyright (c) 2005-2010 Tobias Doerffel <tobydox/at/users.sourceforge.net>
  *
  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
  *
@@ -104,6 +104,7 @@ private slots:
 
 	void toggleDisableChActInd( bool _disabled );
 	void toggleManualChPiano( bool _enabled );
+	void toggleOneInstrumentTrackWindow( bool _enabled );
 
 
 private:
@@ -148,6 +149,7 @@ private:
 
 	bool m_disableChActInd;
 	bool m_manualChPiano;
+	bool m_oneInstrumentTrackWindow;
 
 	typedef QMap<QString, AudioDevice::setupWidget *> AswMap;
 	typedef QMap<QString, MidiClient::setupWidget *> MswMap;