ExportProjectDialog: added option for exporting song as loop (backport)

This patch adds the option to remove the extra silence at the end,
so that the exported song can be seamlessly looped.

This is a backport of commit 8f1657164a.

Closes #3588890.

Signed-off-by: Tobias Doerffel <tobias.doerffel@gmail.com>

src/core/song.cpp

@@ -1,7 +1,7 @@
 /*
  * song.cpp - root of the model tree
  *
- * Copyright (c) 2004-2011 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ * Copyright (c) 2004-2012 Tobias Doerffel <tobydox/at/users.sourceforge.net>
  *
  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
  *
@@ -80,6 +80,7 @@ song::song() :
 	m_modified( false ),
 	m_recording( false ),
 	m_exporting( false ),
+	m_exportLoop( false ),
 	m_playing( false ),
 	m_paused( false ),
 	m_loadingProject( false ),
@@ -645,6 +646,7 @@ void song::stopExport()
 {
 	stop();
 	m_exporting = false;
+	m_exportLoop = false;
 }
 
 

src/gui/dialogs/export_project.ui

@@ -279,6 +279,13 @@
           </property>
          </widget>
         </item>
+        <item>
+         <widget class="QCheckBox" name="exportLoopCB">
+          <property name="text">
+           <string>Export as loop (remove end silence)</string>
+          </property>
+         </widget>
+        </item>
         <item>
          <widget class="QCheckBox" name="aliasFreeOscillatorsCB" >
           <property name="text" >

src/gui/export_project_dialog.cpp

@@ -243,6 +243,8 @@ ProjectRenderer* exportProjectDialog::prepRender()
 			bitrateCB->currentText().section(" ", 0, 0).toUInt(),
 			static_cast<ProjectRenderer::Depths>( depthCB->currentIndex() ) );
 
+	engine::getSong()->setExportLoop( exportLoopCB->isChecked() );
+
 	ProjectRenderer* renderer = new ProjectRenderer( qs, os, m_ft, m_fileName );
 
 	m_renderers.push_back(renderer);