profile: explicitly update gas-axis

On each profile replot, the gas axis was implicitly reset
by calling "dataModel->emitDataChanged()", which would send
a signal recieved by the axis. To make the code less confusing
and, more importantly, make order of execution deterministic,
explicitly reset the axis.

Rename the function that resets the axis from "settingsChanged"
to "update" to reflect its usage.

Moreover, remove the "setModel()" function and pass the model
to the constructore. Make it a const reference to make clear
that it can't change during the life time of the axis.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

3 files changed, 16 insertions, 24 deletions

diff --git a/profile-widget/divecartesianaxis.cpp b/profile-widget/divecartesianaxis.cpp
index 8ee74e7f1..33b09b615 100644
--- a/profile-widget/divecartesianaxis.cpp
+++ b/profile-widget/divecartesianaxis.cpp
@@ -413,34 +413,27 @@ QString TemperatureAxis::textForValue(double value) const
 	return QString::number(mkelvin_to_C((int)value));
 }
 
-PartialGasPressureAxis::PartialGasPressureAxis(ProfileWidget2 *widget) :
+PartialGasPressureAxis::PartialGasPressureAxis(const DivePlotDataModel &model, ProfileWidget2 *widget) :
 	DiveCartesianAxis(widget),
-	model(NULL)
+	model(model)
 {
-	connect(&diveListNotifier, &DiveListNotifier::settingsChanged, this, &PartialGasPressureAxis::settingsChanged);
+	connect(&diveListNotifier, &DiveListNotifier::settingsChanged, this, &PartialGasPressureAxis::update);
 }
 
-void PartialGasPressureAxis::setModel(DivePlotDataModel *m)
-{
-	model = m;
-	connect(model, SIGNAL(dataChanged(QModelIndex, QModelIndex)), this, SLOT(settingsChanged()));
-	settingsChanged();
-}
-
-void PartialGasPressureAxis::settingsChanged()
+void PartialGasPressureAxis::update()
 {
 	bool showPhe = prefs.pp_graphs.phe;
 	bool showPn2 = prefs.pp_graphs.pn2;
 	bool showPo2 = prefs.pp_graphs.po2;
 	setVisible(showPhe || showPn2 || showPo2);
-	if (!model->rowCount())
+	if (!model.rowCount())
 		return;
 
-	double max = showPhe ? model->pheMax() : -1;
-	if (showPn2 && model->pn2Max() > max)
-		max = model->pn2Max();
-	if (showPo2 && model->po2Max() > max)
-		max = model->po2Max();
+	double max = showPhe ? model.pheMax() : -1;
+	if (showPn2 && model.pn2Max() > max)
+		max = model.pn2Max();
+	if (showPo2 && model.po2Max() > max)
+		max = model.po2Max();
 
 	qreal pp = floor(max * 10.0) / 10.0 + 0.2;
 	if (IS_FP_SAME(maximum(), pp))
diff --git a/profile-widget/divecartesianaxis.h b/profile-widget/divecartesianaxis.h
index 1ea623649..a4a38dd1e 100644
--- a/profile-widget/divecartesianaxis.h
+++ b/profile-widget/divecartesianaxis.h
@@ -109,13 +109,12 @@ private:
 class PartialGasPressureAxis : public DiveCartesianAxis {
 	Q_OBJECT
 public:
-	PartialGasPressureAxis(ProfileWidget2 *widget);
-	void setModel(DivePlotDataModel *model);
+	PartialGasPressureAxis(const DivePlotDataModel &model, ProfileWidget2 *widget);
 public
 slots:
-	void settingsChanged();
+	void update();
 private:
-	DivePlotDataModel *model;
+	const DivePlotDataModel &model;
 };
 
 #endif // DIVECARTESIANAXIS_H
diff --git a/profile-widget/profilewidget2.cpp b/profile-widget/profilewidget2.cpp
index 20897b674..737fdf306 100644
--- a/profile-widget/profilewidget2.cpp
+++ b/profile-widget/profilewidget2.cpp
@@ -120,7 +120,7 @@ ProfileWidget2::ProfileWidget2(QWidget *parent) : QGraphicsView(parent),
 #endif
 	isPlotZoomed(prefs.zoomed_plot),// no! bad use of prefs. 'PreferencesDialog::loadSettings' NOT CALLED yet.
 	profileYAxis(new DepthAxis(this)),
-	gasYAxis(new PartialGasPressureAxis(this)),
+	gasYAxis(new PartialGasPressureAxis(*dataModel, this)),
 	temperatureAxis(new TemperatureAxis(this)),
 	timeAxis(new TimeAxis(this)),
 	diveProfileItem(createItem<DiveProfileItem>(*profileYAxis, DivePlotDataModel::DEPTH, 0)),
@@ -288,7 +288,6 @@ void ProfileWidget2::setupItemOnScene()
 	gasYAxis->setTickInterval(1);
 	gasYAxis->setTickSize(1);
 	gasYAxis->setMinimum(0);
-	gasYAxis->setModel(dataModel);
 	gasYAxis->setFontLabelScale(0.7);
 	gasYAxis->setLineSize(96);
 
@@ -735,6 +734,7 @@ void ProfileWidget2::plotDive(const struct dive *d, bool force, bool doClearPict
 #endif
 	tankItem->setData(&plotInfo, &displayed_dive);
 
+	gasYAxis->update();
 	dataModel->emitDataChanged();
 	// The event items are a bit special since we don't know how many events are going to
 	// exist on a dive, so I cant create cache items for that. that's why they are here
@@ -837,7 +837,7 @@ void ProfileWidget2::settingsChanged()
 	else
 		needReplot = prefs.calcceiling;
 #ifndef SUBSURFACE_MOBILE
-	gasYAxis->settingsChanged();	// Initialize ticks of partial pressure graph
+	gasYAxis->update();	// Initialize ticks of partial pressure graph
 	if ((prefs.percentagegraph||prefs.hrgraph) && PP_GRAPHS_ENABLED) {
 		profileYAxis->animateChangeLine(itemPos.depth.shrinked);
 		temperatureAxis->setPos(itemPos.temperatureAll.pos.on);