Improvements to SelectTemplateDialog (#109 and #142)

- Added side pane for product preview and information
- Product selection is done with a separate pushbutton, so that user gets a
  chance to preview the complete product information before committing to the
  selection
- Supports two view modes: Grid View and List View
- View mode is automatically stored in Settings, so it will default to the
  user's prefered mode
- Should address most concerns in #109 and #142

glabels/SimplePreview.cpp

@@ -18,6 +18,7 @@
  *  along with gLabels-qt.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+
 #include "SimplePreview.h"
 
 #include "RollTemplatePath.h"
@@ -61,7 +62,7 @@ namespace glabels
 	/// Constructor
 	///
 	SimplePreview::SimplePreview( QWidget *parent )
-		: QGraphicsView(parent), mTmplate(nullptr), mRotateFlag(false)
+		: QGraphicsView(parent)
 	{
 		mScene = new QGraphicsScene();
 		setScene( mScene );
@@ -84,6 +85,16 @@ namespace glabels
 	}
 
 
+	///
+	/// Show Arrow Property Setter
+	///
+	void SimplePreview::setShowArrow( bool showArrow )
+	{
+		mShowArrow = showArrow;
+		update();
+	}
+
+
 	///
 	/// Rotate Property Setter
 	///
@@ -132,7 +143,10 @@ namespace glabels
 
 			drawPaper();
 			drawLabels();
-			drawArrow();
+			if ( mShowArrow )
+			{
+				drawArrow();
+			}
 		}
 	}