Dive list: propagate current-item to frontend

The command-objects select a current item, but this selection
was not propagated to the front-end. The current item is the
base for keyboard-navigation through the dive-list and therefore
should be set correctly.

It took some experimentation to get the flags right:
 QItemSelectionModel::Current
Hopefully, these are the correct flags across all supported
Qt versions!

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

4 files changed, 33 insertions, 5 deletions

diff --git a/desktop-widgets/command_divelist.cpp b/desktop-widgets/command_divelist.cpp
index d3ecfb796..7fbda35dc 100644
--- a/desktop-widgets/command_divelist.cpp
+++ b/desktop-widgets/command_divelist.cpp
@@ -423,7 +423,12 @@ void DiveListBase::restoreSelection(const std::vector<dive *> &selection, dive *
 	});
 
 	bool currentDiveChanged = false;
-	if (current_dive != currentDive) {
+	// If currentDive is null, we have no current dive. In such a case always
+	// signal the frontend.
+	if (!currentDive) {
+		currentDiveChanged = true;
+		emit diveListNotifier.currentDiveChanged();
+	} else if (current_dive != currentDive) {
 		currentDiveChanged = true;
 
 		// We cannot simply change the currentd dive to the given dive.
diff --git a/desktop-widgets/divelistview.cpp b/desktop-widgets/divelistview.cpp
index 4bfc6ea60..eb65e9e6e 100644
--- a/desktop-widgets/divelistview.cpp
+++ b/desktop-widgets/divelistview.cpp
@@ -45,6 +45,7 @@ DiveListView::DiveListView(QWidget *parent) : QTreeView(parent), mouseClickSelec
 	setSelectionMode(ExtendedSelection);
 	header()->setContextMenuPolicy(Qt::ActionsContextMenu);
 	connect(DiveTripModel::instance(), &DiveTripModel::selectionChanged, this, &DiveListView::diveSelectionChanged);
+	connect(DiveTripModel::instance(), &DiveTripModel::newCurrentDive, this, &DiveListView::currentDiveChanged);
 
 	header()->setStretchLastSection(true);
 
@@ -207,6 +208,21 @@ void DiveListView::diveSelectionChanged(const QVector<QModelIndex> &indexes, boo
 	}
 }
 
+void DiveListView::currentDiveChanged(QModelIndex index)
+{
+	// Transform the index into a local index, since
+	// there might be sorting or filtering in effect.
+	MultiFilterSortModel *m = MultiFilterSortModel::instance();
+	QModelIndex localIndex = m->mapFromSource(index);
+
+	// Then, set the currently activated row.
+	// Note, we have to use the QItemSelectionModel::Current mode to avoid
+	// changing our selection (in contrast to Qt's documentation, which
+	// instructs to use QItemSelectionModel::NoUpdate, which results in
+	// funny side-effects).
+	selectionModel()->setCurrentIndex(localIndex, QItemSelectionModel::Current);
+}
+
 // If rows are added, check which of these rows is a trip and expand the first column
 void DiveListView::rowsInserted(const QModelIndex &parent, int start, int end)
 {
diff --git a/desktop-widgets/divelistview.h b/desktop-widgets/divelistview.h
index effde2ece..5c9ac2f25 100644
--- a/desktop-widgets/divelistview.h
+++ b/desktop-widgets/divelistview.h
@@ -59,6 +59,7 @@ slots:
 	void loadImages();
 	void loadWebImages();
 	void diveSelectionChanged(const QVector<QModelIndex> &indexes, bool select);
+	void currentDiveChanged(QModelIndex index);
 private:
 	bool mouseClickSelection;
 	QList<int> expandedRows;
diff --git a/desktop-widgets/mainwindow.cpp b/desktop-widgets/mainwindow.cpp
index 72b4e4720..625c094c1 100644
--- a/desktop-widgets/mainwindow.cpp
+++ b/desktop-widgets/mainwindow.cpp
@@ -530,10 +530,16 @@ void MainWindow::configureToolbar() {
 
 void MainWindow::selectionChanged()
 {
-	graphics()->plotDive(nullptr, false, true);
-	information()->updateDiveInfo();
-	configureToolbar();
-	MapWidget::instance()->reload();
+	if (!current_dive) {
+		information()->clearTabs();
+		information()->updateDiveInfo(true);
+		graphics()->setEmptyState();
+	} else {
+		graphics()->plotDive(nullptr, false, true);
+		information()->updateDiveInfo();
+		configureToolbar();
+		MapWidget::instance()->reload();
+	}
 }
 
 void MainWindow::on_actionNew_triggered()