Dive site: explicitly init displayed_dive_site on show widget

The global object "displayed_dive_site" is used to store the
old dive site data for the edit-dive-site widget. The fields
of the widget were initialized from this object in the show
event. Therefore the object was updated in numerous parts of
the code to make sure that it was up-to-date. Instead, move
the initialization of the object to the function that also
initiatlizes the fields. Call this function explicitly before
showing the widget.

This makes the data-fow distinctly easier to understand.

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

core/divelist.c

@@ -1677,7 +1677,6 @@ void clear_dive_file_data()
 		delete_dive_site(get_dive_site(0)->uuid);
 
 	clear_dive(&displayed_dive);
-	clear_dive_site(&displayed_dive_site);
 
 	reset_min_datafile_version();
 	saved_git_id = "";

desktop-widgets/locationinformation.cpp

@@ -200,7 +200,6 @@ void LocationInformationWidget::acceptChanges()
 		LocationInformationModel::instance()->removeRow(get_divesite_idx(currentDs));
 		displayed_dive.dive_site_uuid = 0;
 	}
-	copy_dive_site(currentDs, &displayed_dive_site);
 	mark_divelist_changed(true);
 	resetState();
 }
@@ -210,9 +209,10 @@ void LocationInformationWidget::rejectChanges()
 	resetState();
 }
 
-void LocationInformationWidget::showEvent(QShowEvent *ev)
+void LocationInformationWidget::initFields(dive_site *ds)
 {
-	if (displayed_dive_site.uuid) {
+	if (ds) {
+		copy_dive_site(ds, &displayed_dive_site);
 		filter_model.set(displayed_dive_site.uuid, displayed_dive_site.latitude, displayed_dive_site.longitude);
 		updateLabels();
 		enableLocationButtons(dive_site_has_gps_location(&displayed_dive_site));
@@ -221,11 +221,11 @@ void LocationInformationWidget::showEvent(QShowEvent *ev)
 		if (m)
 			m->invalidate();
 	} else {
+		clear_dive_site(&displayed_dive_site);
 		filter_model.set(0, degrees_t{ 0 }, degrees_t{ 0 });
 		clearLabels();
 	}
 	MapWidget::instance()->prepareForGetDiveCoordinates(displayed_dive_site.uuid);
-	QGroupBox::showEvent(ev);
 }
 
 void LocationInformationWidget::markChangedWidget(QWidget *w)

desktop-widgets/locationinformation.h

@@ -14,9 +14,9 @@ Q_OBJECT
 public:
 	LocationInformationWidget(QWidget *parent = 0);
 	bool eventFilter(QObject*, QEvent*) override;
+	void initFields(dive_site *ds);
 
 protected:
-	void showEvent(QShowEvent *);
 	void enableLocationButtons(bool enable);
 
 public slots:

desktop-widgets/mainwindow.cpp

@@ -173,7 +173,7 @@ MainWindow::MainWindow() : QMainWindow(),
 	profLayout->addWidget(profileWidget);
 	profileContainer->setLayout(profLayout);
 
-	LocationInformationWidget * diveSiteEdit = new LocationInformationWidget();
+	diveSiteEdit = new LocationInformationWidget(this);
 	connect(diveSiteEdit, &LocationInformationWidget::endEditDiveSite,
 			this, &MainWindow::setDefaultState);
 	connect(diveSiteEdit, SIGNAL(endEditDiveSite()), this, SLOT(refreshDisplay()));
@@ -445,7 +445,9 @@ void MainWindow::setStateProperties(const QByteArray& state, const PropertyList&
 	stateProperties[state] = PropertiesForQuadrant(tl, tr, bl, br);
 }
 
-void MainWindow::on_actionDiveSiteEdit_triggered() {
+void MainWindow::on_actionDiveSiteEdit_triggered()
+{
+	diveSiteEdit->initFields(get_dive_site_for_dive(&displayed_dive));
 	setApplicationState("EditDiveSite");
 }
 
@@ -957,7 +959,6 @@ void MainWindow::setupForAddAndPlan(const char *model)
 {
 	// clean out the dive and give it an id and the correct dc model
 	clear_dive(&displayed_dive);
-	clear_dive_site(&displayed_dive_site);
 	displayed_dive.id = dive_getUniqID();
 	displayed_dive.when = QDateTime::currentMSecsSinceEpoch() / 1000L + gettimezoneoffset() + 3600;
 	displayed_dive.dc.model = strdup(model); // don't translate! this is stored in the XML file

desktop-widgets/mainwindow.h

@@ -214,6 +214,7 @@ private:
 	void enterState(CurrentState);
 	bool filesAsArguments;
 	UpdateManager *updateManager;
+	LocationInformationWidget *diveSiteEdit;
 
 	bool plannerStateClean();
 	void setupForAddAndPlan(const char *model);

desktop-widgets/tab-widgets/maintab.cpp

@@ -419,11 +419,9 @@ void MainTab::updateDiveInfo(bool clear)
 		if (ds) {
 			ui.location->setCurrentDiveSiteUuid(ds->uuid);
 			ui.locationTags->setText(constructLocationTags(ds, true));
-			copy_dive_site(ds, &displayed_dive_site);
 		} else {
 			ui.location->clear();
 			ui.locationTags->clear();
-			clear_dive_site(&displayed_dive_site);
 		}
 
 		// Subsurface always uses "local time" as in "whatever was the local time at the location"
@@ -657,10 +655,8 @@ MainTab::EditMode MainTab::getEditMode() const
 void MainTab::refreshDisplayedDiveSite()
 {
 	struct dive_site *ds = get_dive_site_for_dive(&displayed_dive);
-	if (ds) {
-		copy_dive_site(ds, &displayed_dive_site);
+	if (ds)
 		ui.location->setCurrentDiveSiteUuid(ds->uuid);
-	}
 }
 
 // when this is called we already have updated the current_dive and know that it exists
@@ -906,9 +902,6 @@ void MainTab::acceptChanges()
 		// so let's make sure here that our data is consistent now that we have handled the
 		// dive sites
 		displayed_dive.dive_site_uuid = current_dive->dive_site_uuid;
-		struct dive_site *ds = get_dive_site_by_uuid(displayed_dive.dive_site_uuid);
-		if (ds)
-			copy_dive_site(ds, &displayed_dive_site);
 
 		// each dive that was selected might have had the temperatures in its active divecomputer changed
 		// so re-populate the temperatures - easiest way to do this is by calling fixup_dive