Refactor Clipboard methods (#5627)

* Moves mimeType from StringPairDrag to Clipboard

* Simplifies decodeKey and decodeValue methods

* Adds method to copy a string to clipboard

* Adds method to copy a string pair to the Clipboard

* Adds convenience methods to Clipboard.h to retrieve the QMimeData from the clipboard and checking whether a particular mime type format is present on it

* Uses only the TCOV copy/paste methods on the song editor
To keep consistency on the behavior of the TCOV copy and paste operations, we now only use the TCOV::copy() and TCOV::paste() methods for copying both individual and multiple TCOs.

* Removes obsolete TrackContentObject::cut() and merge copy() and paste() methods to single function TrackContentObject::copyStateTo()

* Adds Clipboard::getString method to get data for particular mime type

* Makes AutomatableModelView.cpp use the Clipboard class instead of calling Qt clipboard directly

include/Clipboard.h

@@ -29,25 +29,40 @@
 #include <QDomElement>
 
 
-class JournallingObject;
-
-class Clipboard
+namespace Clipboard
 {
-public:
-	typedef QMap<QString, QDomElement> Map;
-
-	static void copy( JournallingObject * _object );
-	static const QDomElement * getContent( const QString & _node_name );
-
-	static const char * mimeType()
+	enum class MimeType
 	{
-		return( "application/x-lmms-clipboard" );
+		StringPair,
+		Default
+	};
+
+	// Convenience Methods
+	const QMimeData * getMimeData();
+	bool hasFormat( MimeType mT );
+
+	// Helper methods for String data
+	void copyString( const QString & str, MimeType mT );
+	QString getString( MimeType mT );
+
+	// Helper methods for String Pair data
+	void copyStringPair( const QString & key, const QString & value );
+	QString decodeKey( const QMimeData * mimeData );
+	QString decodeValue( const QMimeData * mimeData );
+
+	inline const char * mimeType( MimeType type )
+	{
+		switch( type )
+		{
+			case MimeType::StringPair:
+				return "application/x-lmms-stringpair";
+			break;
+			case MimeType::Default:
+			default:
+				return "application/x-lmms-clipboard";
+				break;
+		}
 	}
-
-
-private:
-	static Map content;
-
 } ;
 
 #endif

include/StringPairDrag.h

@@ -45,16 +45,8 @@ public:
 
 	static bool processDragEnterEvent( QDragEnterEvent * _dee,
 						const QString & _allowed_keys );
-	static QString decodeMimeKey( const QMimeData * mimeData );
-	static QString decodeMimeValue( const QMimeData * mimeData );
 	static QString decodeKey( QDropEvent * _de );
 	static QString decodeValue( QDropEvent * _de );
-
-	static const char * mimeType()
-	{
-		return( "application/x-lmms-stringpair" );
-	}
-
 } ;
 
 

include/Track.h

@@ -155,9 +155,10 @@ public:
 	MidiTime startTimeOffset() const;
 	void setStartTimeOffset( const MidiTime &startTimeOffset );
 
+	// Will copy the state of a TCO to another TCO
+	static void copyStateTo( TrackContentObject *src, TrackContentObject *dst );
+
 public slots:
-	void copy();
-	void paste();
 	void toggleMute();
 
 
@@ -266,7 +267,6 @@ public:
 
 public slots:
 	virtual bool close();
-	void cut();
 	void remove();
 	void update() override;