delete main window on close

...and set AllPlot's parent so that it gets deleted, too.

src/AllPlot.cpp

@@ -170,7 +170,8 @@ max(double a, double b) { if (a > b) return a; else return b; }
 #define MILES_PER_KM 0.62137119
 #define FEET_PER_M 3.2808399
 
-AllPlot::AllPlot():
+AllPlot::AllPlot(QWidget *parent):
+    QwtPlot(parent),
     settings(NULL),
     unit(0),
     rideItem(NULL),

src/AllPlot.h

@@ -53,7 +53,7 @@ class AllPlot : public QwtPlot
         QVector<QwtPlotMarker*> d_mrk;
 	QList <AllPlotZoneLabel *> zoneLabels;
 
-        AllPlot();
+        AllPlot(QWidget *parent);
 
         int smoothing() const { return smooth; }
 

src/MainWindow.cpp

@@ -232,7 +232,7 @@ MainWindow::MainWindow(const QDir &home) :
                                                    smoothSlider->maximum(), 
                                                    smoothLineEdit));
     smoothLayout->addWidget(smoothSlider);
-    allPlot = new AllPlot();
+    allPlot = new AllPlot(this);
     smoothSlider->setValue(allPlot->smoothing());
     smoothLineEdit->setText(QString("%1").arg(allPlot->smoothing()));
 
@@ -618,6 +618,8 @@ MainWindow::MainWindow(const QDir &home) :
             treeWidget->setCurrentItem(allRides->child(0));
         }
     }
+
+    setAttribute(Qt::WA_DeleteOnClose);
 }
 
 void