Fixed slider position handling

src/graphview.cpp

@@ -51,6 +51,8 @@ GraphView::GraphView(QWidget *parent)
 
 	_precision = 0;
 	_minYRange = 0.01;
+
+	_sliderPos = 0;
 }
 
 GraphView::~GraphView()
@@ -215,15 +217,12 @@ void GraphView::redraw(const QSizeF &size)
 	_scene->addItem(_xAxis);
 	_scene->addItem(_yAxis);
 
-
-	qreal sp = (_slider->pos().x() == _slider->area().left())
-		? 0 : (_slider->pos().x() - _slider->area().left())
-		  / _slider->area().width();
 	_slider->setArea(r);
-	_slider->setPos(QPointF(sp * r.width(), r.bottom()));
+	_slider->setPos((_sliderPos / _bounds.width()) * _slider->area().width(),
+	  r.bottom());
 	_scene->addItem(_slider);
 
-	_sliderInfo->setVisible(_graphs.size() == 1);
+	updateSliderInfo();
 
 	r = _scene->itemsBoundingRect();
 	_info->setPos(r.topLeft() + QPointF(r.width()/2
@@ -272,6 +271,7 @@ void GraphView::clear()
 	_palette.reset();
 
 	_bounds = QRectF();
+	_sliderPos = 0;
 
 	_scene->setSceneRect(0, 0, 0, 0);
 }
@@ -307,13 +307,9 @@ static qreal yAtX(const QPainterPath &path, qreal x)
 	return l.pointAt((x - l.p1().x()) / (l.p2().x() - l.p1().x())).y();
 }
 
-void GraphView::emitSliderPositionChanged(const QPointF &pos)
+void GraphView::updateSliderInfo()
 {
-	if (_graphs.isEmpty())
-		return;
-
-	qreal val = pos.x() / _slider->area().width();
-	emit sliderPositionChanged(val * _bounds.width());
+	_sliderInfo->setVisible(_graphs.size() == 1);
 
 	if (_graphs.size() > 1)
 		return;
@@ -324,10 +320,11 @@ void GraphView::emitSliderPositionChanged(const QPointF &pos)
 		br.adjust(0, -(_minYRange/2 - br.height()/2), 0,
 		  _minYRange/2 - br.height()/2);
 
-	qreal y = yAtX(path, val * _bounds.width());
+	qreal y = yAtX(path, _sliderPos);
 	qreal r = (y - br.bottom()) / br.height();
 
-	SliderInfoItem::Side s = (pos.x() + _sliderInfo->boundingRect().width()
+	qreal pos = (_sliderPos / _bounds.width()) * _slider->area().width();
+	SliderInfoItem::Side s = (pos + _sliderInfo->boundingRect().width()
 	  > _slider->area().right()) ? SliderInfoItem::Left : SliderInfoItem::Right;
 
 	_sliderInfo->setSide(s);
@@ -335,16 +332,21 @@ void GraphView::emitSliderPositionChanged(const QPointF &pos)
 	_sliderInfo->setText(QString::number(-y * _yScale, 'f', _precision));
 }
 
-qreal GraphView::sliderPosition() const
+void GraphView::emitSliderPositionChanged(const QPointF &pos)
 {
-	if (!_slider->isVisible())
-		return -1;
-	else
-		return (_slider->pos().x() / _slider->area().width()) * _bounds.width();
+	if (_graphs.isEmpty())
+		return;
+
+	_sliderPos = (pos.x() / _slider->area().width()) * _bounds.width();
+	emit sliderPositionChanged(_sliderPos);
+
+	updateSliderInfo();
 }
 
 void GraphView::setSliderPosition(qreal pos)
 {
+	_sliderPos = pos;
+
 	if (_graphs.isEmpty())
 		return;
 

src/graphview.h

@@ -58,7 +58,7 @@ public:
 	void setSliderPrecision(int precision) {_precision = precision;}
 	void setMinYRange(qreal range) {_minYRange = range;}
 
-	qreal sliderPosition() const;
+	qreal sliderPosition() const {return _sliderPos;}
 	void setSliderPosition(qreal pos);
 
 	void plot(QPainter *painter, const QRectF &target);
@@ -82,12 +82,14 @@ private:
 	void createXLabel();
 	void createYLabel();
 	void updateBounds(const QPointF &point);
+	void updateSliderInfo();
 
 	qreal _xScale, _yScale;
 	QString _xUnits, _yUnits;
 	QString _xLabel, _yLabel;
 	int _precision;
 	qreal _minYRange;
+	qreal _sliderPos;
 
 	Scene *_scene;
 

src/gui.cpp

@@ -61,12 +61,12 @@ GUI::GUI(QWidget *parent) : QMainWindow(parent)
 	createTrackGraphs();
 	createStatusBar();
 
-	connect(_elevationGraph, SIGNAL(sliderPositionChanged(qreal)), _track,
-	  SLOT(movePositionMarker(qreal)));
-	connect(_speedGraph, SIGNAL(sliderPositionChanged(qreal)), _track,
-	  SLOT(movePositionMarker(qreal)));
-	connect(_heartRateGraph, SIGNAL(sliderPositionChanged(qreal)), _track,
-	  SLOT(movePositionMarker(qreal)));
+	connect(_elevationGraph, SIGNAL(sliderPositionChanged(qreal)), this,
+	  SLOT(sliderPositionChanged(qreal)));
+	connect(_speedGraph, SIGNAL(sliderPositionChanged(qreal)), this,
+	  SLOT(sliderPositionChanged(qreal)));
+	connect(_heartRateGraph, SIGNAL(sliderPositionChanged(qreal)), this,
+	  SLOT(sliderPositionChanged(qreal)));
 
 	_browser = new FileBrowser(this);
 	_browser->setFilter(QStringList("*.gpx"));
@@ -86,8 +86,8 @@ GUI::GUI(QWidget *parent) : QMainWindow(parent)
 	_time = 0;
 	_trackCount = 0;
 
-	_lastGraph = 0;
-	_lastSliderPos = -1.0;
+	_sliderPos = 0;
+
 	updateGraphTabs();
 	updateTrackView();
 
@@ -515,6 +515,7 @@ bool GUI::loadFile(const QString &fileName)
 		_track->loadGPX(gpx);
 		if (_showPOIAction->isChecked())
 			_track->loadPOI(_poi);
+		_track->movePositionMarker(_sliderPos);
 
 		for (int i = 0; i < gpx.trackCount(); i++) {
 			_distance += gpx.track(i).distance();
@@ -680,6 +681,8 @@ void GUI::closeFiles()
 	_time = 0;
 	_trackCount = 0;
 
+	_sliderPos = 0;
+
 	_elevationGraph->clear();
 	_speedGraph->clear();
 	_heartRateGraph->clear();
@@ -783,18 +786,19 @@ void GUI::poiFileChecked(int index)
 		_track->loadPOI(_poi);
 }
 
+void GUI::sliderPositionChanged(qreal pos)
+{
+	_track->movePositionMarker(_sliderPos);
+	_sliderPos = pos;
+}
+
 void GUI::graphChanged(int index)
 {
 	if (index < 0)
 		return;
 
-	GraphView *tv = static_cast<GraphView*>(_trackGraphs->widget(index));
-	if (_lastGraph) {
-		if (_lastGraph->sliderPosition() >= 0)
-			_lastSliderPos = _lastGraph->sliderPosition();
-		tv->setSliderPosition(_lastSliderPos);
-	}
-	_lastGraph = tv;
+	GraphView *gv = static_cast<GraphView*>(_trackGraphs->widget(index));
+	gv->setSliderPosition(_sliderPos);
 }
 
 void GUI::updateNavigationActions()

src/gui.h

@@ -58,6 +58,8 @@ private slots:
 	void setMetricUnits();
 	void setImperialUnits();
 
+	void sliderPositionChanged(qreal pos);
+
 private:
 	void loadMaps();
 	void loadPOIs();
@@ -146,8 +148,7 @@ private:
 	qreal _time;
 	int _trackCount;
 
-	GraphView *_lastGraph;
-	qreal _lastSliderPos;
+	qreal _sliderPos;
 };
 
 #endif // GUI_H

src/slideritem.cpp

@@ -41,7 +41,7 @@ QVariant SliderItem::itemChange(GraphicsItemChange change, const QVariant &value
 		}
 	}
 
-	if (change == ItemPositionHasChanged)
+	if (change == ItemPositionHasChanged && scene())
 		emit positionChanged(value.toPointF());
 
 	return QGraphicsItem::itemChange(change, value);

src/trackview.cpp

@@ -420,7 +420,7 @@ void TrackView::movePositionMarker(qreal val)
 
 	for (int i = 0; i < _paths.size(); i++) {
 		qreal f = _maxPath / _paths.at(i)->path().length();
-		if (mp * f > 1.0)
+		if (mp * f < 0 || mp * f > 1.0)
 			_markers.at(i)->setVisible(false);
 		else {
 			QPointF pos = _paths.at(i)->path().pointAtPercent(mp * f);