profile: don't interpret NULL as current_dive in plotDive()

ProfileWidget2::plotDive() had this weird interface, where passing
in NULL as dive would mean "show current_dive". However, most callers
would already pass in current_dive. Therefore, unify and always pass
in current_dive if the caller wants to draw the current dive.

This allows us to interpret NULL as "show empty profile". Thus,
passing in current_dive when there is no current_dive simply shows
an empty profile. This makes the calling code in
MainWindow::selectionChanged() simpler.

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

desktop-widgets/mainwindow.cpp

@@ -453,13 +453,12 @@ void MainWindow::selectionChanged()
 	if (!current_dive) {
 		mainTab->clearTabs();
 		mainTab->updateDiveInfo();
-		graphics->setEmptyState();
 	} else {
-		graphics->plotDive(nullptr, false, true);
 		mainTab->updateDiveInfo();
 		configureToolbar();
 		enableDisableOtherDCsActions();
 	}
+	graphics->plotDive(current_dive, false, true);
 	MapWidget::instance()->selectionChanged();
 }
 
@@ -1112,7 +1111,7 @@ void MainWindow::on_actionPreviousDC_triggered()
 	unsigned nrdc = number_of_computers(current_dive);
 	dc_number = (dc_number + nrdc - 1) % nrdc;
 	configureToolbar();
-	graphics->plotDive(nullptr, false, true);
+	graphics->plotDive(current_dive, false, true);
 	mainTab->updateDiveInfo();
 }
 
@@ -1121,7 +1120,7 @@ void MainWindow::on_actionNextDC_triggered()
 	unsigned nrdc = number_of_computers(current_dive);
 	dc_number = (dc_number + 1) % nrdc;
 	configureToolbar();
-	graphics->plotDive(nullptr, false, true);
+	graphics->plotDive(current_dive, false, true);
 	mainTab->updateDiveInfo();
 }
 

desktop-widgets/printer.cpp

@@ -185,7 +185,7 @@ void Printer::render(int Pages = 0)
 	qPrefDisplay::set_animation_speed(animationOriginal);
 
 	//replot the dive after returning the settings
-	profile->plotDive(0, true, true);
+	profile->plotDive(current_dive, true, true);
 }
 
 //value: ranges from 0 : 100 and shows the progress of the templating engine

profile-widget/profilewidget2.cpp

@@ -381,8 +381,7 @@ void ProfileWidget2::setupItemOnScene()
 
 void ProfileWidget2::replot()
 {
-	dataModel->clear();
+	plotDive(current_dive, true, false);
-	plotDive(nullptr, true, false);
 }
 
 void ProfileWidget2::createPPGas(PartialPressureGasItem *item, int verticalColumn, color_index_t color, color_index_t colorAlert,
@@ -566,12 +565,9 @@ void ProfileWidget2::plotDive(const struct dive *d, bool force, bool doClearPict
 #endif
 	if (currentState != ADD && currentState != PLAN) {
 		if (!d) {
-			if (!current_dive) {
 			setEmptyState();
 			return;
 		}
-			d = current_dive; // display the current dive
-		}
 
 		// No need to do this again if we are already showing the same dive
 		// computer of the same dive, so we check the unique id of the dive

profile-widget/profilewidget2.h

@@ -76,7 +76,7 @@ public:
 	~ProfileWidget2();
 	void resetZoom();
 	void scale(qreal sx, qreal sy);
-	void plotDive(const struct dive *d = 0, bool force = false, bool clearPictures = false, bool instant = false);
+	void plotDive(const struct dive *d, bool force = false, bool clearPictures = false, bool instant = false);
 	void setupItem(AbstractProfilePolygonItem *item, DiveCartesianAxis *vAxis, int vData, int hData, int zValue);
 	void setPrintMode(bool mode, bool grayscale = false);
 	bool getPrintMode();