made song-length being cached and only updated upon changed length or position of TCOs

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@880 0778d3d1-df1d-0410-868b-ea421aaaa00d

src/core/song.cpp

@@ -538,15 +538,18 @@ void song::playPattern( pattern * _patternToPlay, bool _loop )
 
 
 
-tact song::lengthInTacts( void ) const
+void song::updateLength( void )
 {
-	tact len = 0;
+	m_length = 0;
 	const QList<track *> & ctl = tracks();
 	for( int i = 0; i < ctl.size(); ++i )
 	{
-		len = tMax( ctl[i]->length(), len );
+		const tact cur = ctl[i]->length();
+		if( cur > m_length )
+		{
+			m_length = cur;
+		}
 	}
-	return( len );
 }
 
 

src/gui/export_project_dialog.cpp

@@ -370,8 +370,8 @@ void exportProjectDialog::exportBtnClicked( void )
 							&& !m_deleteFile )
 	{
 		dev->processNextBuffer();
-		int pval = pp * 100 /
-			( ( engine::getSong()->lengthInTacts() + 1 ) * 64 );
+		const int pval = pp * 100 /
+				( ( engine::getSong()->length() + 1 ) * 64 );
 		m_exportProgressBar->setValue( pval );
 		if( engine::getMainWindow() )
 		{

src/gui/song_editor.cpp

@@ -378,7 +378,7 @@ songEditor::~songEditor()
 
 void songEditor::paintEvent( QPaintEvent * _pe )
 {
-	m_leftRightScroll->setMaximum( m_s->lengthInTacts() );
+	m_leftRightScroll->setMaximum( m_s->length() );
 	trackContainerView::paintEvent( _pe );
 }