ResourceBrowser: stop preview when drag operation starts

Make sure preview is stopped as soon as a drag operation starts. This
is done by overloading QAbstractItemView::startDrag() and emit a signal
from there which is connected to an according slot in ResourceBrowser.

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

include/ResourceBrowser.h

@@ -63,6 +63,7 @@ private slots:
 	void updateFilterStatus();
 	void startItemPreview( const QModelIndex & _idx );
 	void stopItemPreview( const QModelIndex & _idx );
+	void stopPreview();
 	void triggerDefaultAction( const QModelIndex & _idx );
 
 

include/ResourceTreeView.h

@@ -1,7 +1,7 @@
 /*
  * ResourceTreeView.h - view for ResourceTreeModel
  *
- * Copyright (c) 2008 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ * Copyright (c) 2008-2009 Tobias Doerffel <tobydox/at/users.sourceforge.net>
  *
  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
  *
@@ -41,11 +41,20 @@ public slots:
 	void setFilter( const QString & _s );
 	void updateFilter( void );
 
+
+protected:
+	virtual void startDrag( Qt::DropActions supportedActions );
+
+
 private:
 	ResourceTreeModel * m_tm;
 
 	QString m_lastFilter;
 
+
+signals:
+	void dragStarted();
+
 } ;
 
 

src/gui/ResourceBrowser.cpp

@@ -110,6 +110,11 @@ ResourceBrowser::ResourceBrowser( QWidget * _parent ) :
 	connect( m_treeView,
 			SIGNAL( clicked( const QModelIndex & ) ),
 			this, SLOT( stopItemPreview( const QModelIndex & ) ) );
+	// setup a direct connection so preview is instantly stopped when
+	// drag operation begins
+	connect( m_treeView,
+			SIGNAL( dragStarted() ),
+			this, SLOT( stopPreview() ), Qt::DirectConnection );
 	connect( m_treeView,
 			SIGNAL( doubleClicked( const QModelIndex & ) ),
 			this,
@@ -240,7 +245,15 @@ void ResourceBrowser::startItemPreview( const QModelIndex & _idx )
 
 
 
-void ResourceBrowser::stopItemPreview( const QModelIndex & _idx )
+void ResourceBrowser::stopItemPreview( const QModelIndex & )
+{
+	stopPreview();
+}
+
+
+
+
+void ResourceBrowser::stopPreview()
 {
 	m_previewer.stopPreview();
 }

src/gui/ResourceTreeView.cpp

@@ -72,4 +72,13 @@ void ResourceTreeView::updateFilter( void )
 
 
 
+void ResourceTreeView::startDrag( Qt::DropActions supportedActions )
+{
+	emit dragStarted();
+
+	QTreeView::startDrag( supportedActions );
+}
+
+
+
 #include "moc_ResourceTreeView.cxx"